2409 lines
105 KiB
HTML
2409 lines
105 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="en">
|
|
<head>
|
|
<meta charset="UTF-8">
|
|
<!--[if IE]><meta http-equiv="X-UA-Compatible" content="IE=edge"><![endif]-->
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
<meta name="generator" content="Asciidoctor 1.5.8">
|
|
<title>git-fast-import(1)</title>
|
|
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Open+Sans:300,300italic,400,400italic,600,600italic%7CNoto+Serif:400,400italic,700,700italic%7CDroid+Sans+Mono:400,700">
|
|
<style>
|
|
/* Asciidoctor default stylesheet | MIT License | http://asciidoctor.org */
|
|
/* Uncomment @import statement below to use as custom stylesheet */
|
|
/*@import "https://fonts.googleapis.com/css?family=Open+Sans:300,300italic,400,400italic,600,600italic%7CNoto+Serif:400,400italic,700,700italic%7CDroid+Sans+Mono:400,700";*/
|
|
article,aside,details,figcaption,figure,footer,header,hgroup,main,nav,section,summary{display:block}
|
|
audio,canvas,video{display:inline-block}
|
|
audio:not([controls]){display:none;height:0}
|
|
script{display:none!important}
|
|
html{font-family:sans-serif;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%}
|
|
a{background:transparent}
|
|
a:focus{outline:thin dotted}
|
|
a:active,a:hover{outline:0}
|
|
h1{font-size:2em;margin:.67em 0}
|
|
abbr[title]{border-bottom:1px dotted}
|
|
b,strong{font-weight:bold}
|
|
dfn{font-style:italic}
|
|
hr{-moz-box-sizing:content-box;box-sizing:content-box;height:0}
|
|
mark{background:#ff0;color:#000}
|
|
code,kbd,pre,samp{font-family:monospace;font-size:1em}
|
|
pre{white-space:pre-wrap}
|
|
q{quotes:"\201C" "\201D" "\2018" "\2019"}
|
|
small{font-size:80%}
|
|
sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}
|
|
sup{top:-.5em}
|
|
sub{bottom:-.25em}
|
|
img{border:0}
|
|
svg:not(:root){overflow:hidden}
|
|
figure{margin:0}
|
|
fieldset{border:1px solid silver;margin:0 2px;padding:.35em .625em .75em}
|
|
legend{border:0;padding:0}
|
|
button,input,select,textarea{font-family:inherit;font-size:100%;margin:0}
|
|
button,input{line-height:normal}
|
|
button,select{text-transform:none}
|
|
button,html input[type="button"],input[type="reset"],input[type="submit"]{-webkit-appearance:button;cursor:pointer}
|
|
button[disabled],html input[disabled]{cursor:default}
|
|
input[type="checkbox"],input[type="radio"]{box-sizing:border-box;padding:0}
|
|
button::-moz-focus-inner,input::-moz-focus-inner{border:0;padding:0}
|
|
textarea{overflow:auto;vertical-align:top}
|
|
table{border-collapse:collapse;border-spacing:0}
|
|
*,*::before,*::after{-moz-box-sizing:border-box;-webkit-box-sizing:border-box;box-sizing:border-box}
|
|
html,body{font-size:100%}
|
|
body{background:#fff;color:rgba(0,0,0,.8);padding:0;margin:0;font-family:"Noto Serif","DejaVu Serif",serif;font-weight:400;font-style:normal;line-height:1;position:relative;cursor:auto;tab-size:4;-moz-osx-font-smoothing:grayscale;-webkit-font-smoothing:antialiased}
|
|
a:hover{cursor:pointer}
|
|
img,object,embed{max-width:100%;height:auto}
|
|
object,embed{height:100%}
|
|
img{-ms-interpolation-mode:bicubic}
|
|
.left{float:left!important}
|
|
.right{float:right!important}
|
|
.text-left{text-align:left!important}
|
|
.text-right{text-align:right!important}
|
|
.text-center{text-align:center!important}
|
|
.text-justify{text-align:justify!important}
|
|
.hide{display:none}
|
|
img,object,svg{display:inline-block;vertical-align:middle}
|
|
textarea{height:auto;min-height:50px}
|
|
select{width:100%}
|
|
.center{margin-left:auto;margin-right:auto}
|
|
.stretch{width:100%}
|
|
.subheader,.admonitionblock td.content>.title,.audioblock>.title,.exampleblock>.title,.imageblock>.title,.listingblock>.title,.literalblock>.title,.stemblock>.title,.openblock>.title,.paragraph>.title,.quoteblock>.title,table.tableblock>.title,.verseblock>.title,.videoblock>.title,.dlist>.title,.olist>.title,.ulist>.title,.qlist>.title,.hdlist>.title{line-height:1.45;color:#7a2518;font-weight:400;margin-top:0;margin-bottom:.25em}
|
|
div,dl,dt,dd,ul,ol,li,h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6,pre,form,p,blockquote,th,td{margin:0;padding:0;direction:ltr}
|
|
a{color:#2156a5;text-decoration:underline;line-height:inherit}
|
|
a:hover,a:focus{color:#1d4b8f}
|
|
a img{border:none}
|
|
p{font-family:inherit;font-weight:400;font-size:1em;line-height:1.6;margin-bottom:1.25em;text-rendering:optimizeLegibility}
|
|
p aside{font-size:.875em;line-height:1.35;font-style:italic}
|
|
h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{font-family:"Open Sans","DejaVu Sans",sans-serif;font-weight:300;font-style:normal;color:#ba3925;text-rendering:optimizeLegibility;margin-top:1em;margin-bottom:.5em;line-height:1.0125em}
|
|
h1 small,h2 small,h3 small,#toctitle small,.sidebarblock>.content>.title small,h4 small,h5 small,h6 small{font-size:60%;color:#e99b8f;line-height:0}
|
|
h1{font-size:2.125em}
|
|
h2{font-size:1.6875em}
|
|
h3,#toctitle,.sidebarblock>.content>.title{font-size:1.375em}
|
|
h4,h5{font-size:1.125em}
|
|
h6{font-size:1em}
|
|
hr{border:solid #dddddf;border-width:1px 0 0;clear:both;margin:1.25em 0 1.1875em;height:0}
|
|
em,i{font-style:italic;line-height:inherit}
|
|
strong,b{font-weight:bold;line-height:inherit}
|
|
small{font-size:60%;line-height:inherit}
|
|
code{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;color:rgba(0,0,0,.9)}
|
|
ul,ol,dl{font-size:1em;line-height:1.6;margin-bottom:1.25em;list-style-position:outside;font-family:inherit}
|
|
ul,ol{margin-left:1.5em}
|
|
ul li ul,ul li ol{margin-left:1.25em;margin-bottom:0;font-size:1em}
|
|
ul.square li ul,ul.circle li ul,ul.disc li ul{list-style:inherit}
|
|
ul.square{list-style-type:square}
|
|
ul.circle{list-style-type:circle}
|
|
ul.disc{list-style-type:disc}
|
|
ol li ul,ol li ol{margin-left:1.25em;margin-bottom:0}
|
|
dl dt{margin-bottom:.3125em;font-weight:bold}
|
|
dl dd{margin-bottom:1.25em}
|
|
abbr,acronym{text-transform:uppercase;font-size:90%;color:rgba(0,0,0,.8);border-bottom:1px dotted #ddd;cursor:help}
|
|
abbr{text-transform:none}
|
|
blockquote{margin:0 0 1.25em;padding:.5625em 1.25em 0 1.1875em;border-left:1px solid #ddd}
|
|
blockquote cite{display:block;font-size:.9375em;color:rgba(0,0,0,.6)}
|
|
blockquote cite::before{content:"\2014 \0020"}
|
|
blockquote cite a,blockquote cite a:visited{color:rgba(0,0,0,.6)}
|
|
blockquote,blockquote p{line-height:1.6;color:rgba(0,0,0,.85)}
|
|
@media screen and (min-width:768px){h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2}
|
|
h1{font-size:2.75em}
|
|
h2{font-size:2.3125em}
|
|
h3,#toctitle,.sidebarblock>.content>.title{font-size:1.6875em}
|
|
h4{font-size:1.4375em}}
|
|
table{background:#fff;margin-bottom:1.25em;border:solid 1px #dedede}
|
|
table thead,table tfoot{background:#f7f8f7}
|
|
table thead tr th,table thead tr td,table tfoot tr th,table tfoot tr td{padding:.5em .625em .625em;font-size:inherit;color:rgba(0,0,0,.8);text-align:left}
|
|
table tr th,table tr td{padding:.5625em .625em;font-size:inherit;color:rgba(0,0,0,.8)}
|
|
table tr.even,table tr.alt,table tr:nth-of-type(even){background:#f8f8f7}
|
|
table thead tr th,table tfoot tr th,table tbody tr td,table tr td,table tfoot tr td{display:table-cell;line-height:1.6}
|
|
h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2;word-spacing:-.05em}
|
|
h1 strong,h2 strong,h3 strong,#toctitle strong,.sidebarblock>.content>.title strong,h4 strong,h5 strong,h6 strong{font-weight:400}
|
|
.clearfix::before,.clearfix::after,.float-group::before,.float-group::after{content:" ";display:table}
|
|
.clearfix::after,.float-group::after{clear:both}
|
|
*:not(pre)>code{font-size:.9375em;font-style:normal!important;letter-spacing:0;padding:.1em .5ex;word-spacing:-.15em;background-color:#f7f7f8;-webkit-border-radius:4px;border-radius:4px;line-height:1.45;text-rendering:optimizeSpeed;word-wrap:break-word}
|
|
*:not(pre)>code.nobreak{word-wrap:normal}
|
|
*:not(pre)>code.nowrap{white-space:nowrap}
|
|
pre,pre>code{line-height:1.45;color:rgba(0,0,0,.9);font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;text-rendering:optimizeSpeed}
|
|
em em{font-style:normal}
|
|
strong strong{font-weight:400}
|
|
.keyseq{color:rgba(51,51,51,.8)}
|
|
kbd{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;display:inline-block;color:rgba(0,0,0,.8);font-size:.65em;line-height:1.45;background-color:#f7f7f7;border:1px solid #ccc;-webkit-border-radius:3px;border-radius:3px;-webkit-box-shadow:0 1px 0 rgba(0,0,0,.2),0 0 0 .1em white inset;box-shadow:0 1px 0 rgba(0,0,0,.2),0 0 0 .1em #fff inset;margin:0 .15em;padding:.2em .5em;vertical-align:middle;position:relative;top:-.1em;white-space:nowrap}
|
|
.keyseq kbd:first-child{margin-left:0}
|
|
.keyseq kbd:last-child{margin-right:0}
|
|
.menuseq,.menuref{color:#000}
|
|
.menuseq b:not(.caret),.menuref{font-weight:inherit}
|
|
.menuseq{word-spacing:-.02em}
|
|
.menuseq b.caret{font-size:1.25em;line-height:.8}
|
|
.menuseq i.caret{font-weight:bold;text-align:center;width:.45em}
|
|
b.button::before,b.button::after{position:relative;top:-1px;font-weight:400}
|
|
b.button::before{content:"[";padding:0 3px 0 2px}
|
|
b.button::after{content:"]";padding:0 2px 0 3px}
|
|
p a>code:hover{color:rgba(0,0,0,.9)}
|
|
#header,#content,#footnotes,#footer{width:100%;margin-left:auto;margin-right:auto;margin-top:0;margin-bottom:0;max-width:62.5em;*zoom:1;position:relative;padding-left:.9375em;padding-right:.9375em}
|
|
#header::before,#header::after,#content::before,#content::after,#footnotes::before,#footnotes::after,#footer::before,#footer::after{content:" ";display:table}
|
|
#header::after,#content::after,#footnotes::after,#footer::after{clear:both}
|
|
#content{margin-top:1.25em}
|
|
#content::before{content:none}
|
|
#header>h1:first-child{color:rgba(0,0,0,.85);margin-top:2.25rem;margin-bottom:0}
|
|
#header>h1:first-child+#toc{margin-top:8px;border-top:1px solid #dddddf}
|
|
#header>h1:only-child,body.toc2 #header>h1:nth-last-child(2){border-bottom:1px solid #dddddf;padding-bottom:8px}
|
|
#header .details{border-bottom:1px solid #dddddf;line-height:1.45;padding-top:.25em;padding-bottom:.25em;padding-left:.25em;color:rgba(0,0,0,.6);display:-ms-flexbox;display:-webkit-flex;display:flex;-ms-flex-flow:row wrap;-webkit-flex-flow:row wrap;flex-flow:row wrap}
|
|
#header .details span:first-child{margin-left:-.125em}
|
|
#header .details span.email a{color:rgba(0,0,0,.85)}
|
|
#header .details br{display:none}
|
|
#header .details br+span::before{content:"\00a0\2013\00a0"}
|
|
#header .details br+span.author::before{content:"\00a0\22c5\00a0";color:rgba(0,0,0,.85)}
|
|
#header .details br+span#revremark::before{content:"\00a0|\00a0"}
|
|
#header #revnumber{text-transform:capitalize}
|
|
#header #revnumber::after{content:"\00a0"}
|
|
#content>h1:first-child:not([class]){color:rgba(0,0,0,.85);border-bottom:1px solid #dddddf;padding-bottom:8px;margin-top:0;padding-top:1rem;margin-bottom:1.25rem}
|
|
#toc{border-bottom:1px solid #e7e7e9;padding-bottom:.5em}
|
|
#toc>ul{margin-left:.125em}
|
|
#toc ul.sectlevel0>li>a{font-style:italic}
|
|
#toc ul.sectlevel0 ul.sectlevel1{margin:.5em 0}
|
|
#toc ul{font-family:"Open Sans","DejaVu Sans",sans-serif;list-style-type:none}
|
|
#toc li{line-height:1.3334;margin-top:.3334em}
|
|
#toc a{text-decoration:none}
|
|
#toc a:active{text-decoration:underline}
|
|
#toctitle{color:#7a2518;font-size:1.2em}
|
|
@media screen and (min-width:768px){#toctitle{font-size:1.375em}
|
|
body.toc2{padding-left:15em;padding-right:0}
|
|
#toc.toc2{margin-top:0!important;background-color:#f8f8f7;position:fixed;width:15em;left:0;top:0;border-right:1px solid #e7e7e9;border-top-width:0!important;border-bottom-width:0!important;z-index:1000;padding:1.25em 1em;height:100%;overflow:auto}
|
|
#toc.toc2 #toctitle{margin-top:0;margin-bottom:.8rem;font-size:1.2em}
|
|
#toc.toc2>ul{font-size:.9em;margin-bottom:0}
|
|
#toc.toc2 ul ul{margin-left:0;padding-left:1em}
|
|
#toc.toc2 ul.sectlevel0 ul.sectlevel1{padding-left:0;margin-top:.5em;margin-bottom:.5em}
|
|
body.toc2.toc-right{padding-left:0;padding-right:15em}
|
|
body.toc2.toc-right #toc.toc2{border-right-width:0;border-left:1px solid #e7e7e9;left:auto;right:0}}
|
|
@media screen and (min-width:1280px){body.toc2{padding-left:20em;padding-right:0}
|
|
#toc.toc2{width:20em}
|
|
#toc.toc2 #toctitle{font-size:1.375em}
|
|
#toc.toc2>ul{font-size:.95em}
|
|
#toc.toc2 ul ul{padding-left:1.25em}
|
|
body.toc2.toc-right{padding-left:0;padding-right:20em}}
|
|
#content #toc{border-style:solid;border-width:1px;border-color:#e0e0dc;margin-bottom:1.25em;padding:1.25em;background:#f8f8f7;-webkit-border-radius:4px;border-radius:4px}
|
|
#content #toc>:first-child{margin-top:0}
|
|
#content #toc>:last-child{margin-bottom:0}
|
|
#footer{max-width:100%;background-color:rgba(0,0,0,.8);padding:1.25em}
|
|
#footer-text{color:rgba(255,255,255,.8);line-height:1.44}
|
|
#content{margin-bottom:.625em}
|
|
.sect1{padding-bottom:.625em}
|
|
@media screen and (min-width:768px){#content{margin-bottom:1.25em}
|
|
.sect1{padding-bottom:1.25em}}
|
|
.sect1:last-child{padding-bottom:0}
|
|
.sect1+.sect1{border-top:1px solid #e7e7e9}
|
|
#content h1>a.anchor,h2>a.anchor,h3>a.anchor,#toctitle>a.anchor,.sidebarblock>.content>.title>a.anchor,h4>a.anchor,h5>a.anchor,h6>a.anchor{position:absolute;z-index:1001;width:1.5ex;margin-left:-1.5ex;display:block;text-decoration:none!important;visibility:hidden;text-align:center;font-weight:400}
|
|
#content h1>a.anchor::before,h2>a.anchor::before,h3>a.anchor::before,#toctitle>a.anchor::before,.sidebarblock>.content>.title>a.anchor::before,h4>a.anchor::before,h5>a.anchor::before,h6>a.anchor::before{content:"\00A7";font-size:.85em;display:block;padding-top:.1em}
|
|
#content h1:hover>a.anchor,#content h1>a.anchor:hover,h2:hover>a.anchor,h2>a.anchor:hover,h3:hover>a.anchor,#toctitle:hover>a.anchor,.sidebarblock>.content>.title:hover>a.anchor,h3>a.anchor:hover,#toctitle>a.anchor:hover,.sidebarblock>.content>.title>a.anchor:hover,h4:hover>a.anchor,h4>a.anchor:hover,h5:hover>a.anchor,h5>a.anchor:hover,h6:hover>a.anchor,h6>a.anchor:hover{visibility:visible}
|
|
#content h1>a.link,h2>a.link,h3>a.link,#toctitle>a.link,.sidebarblock>.content>.title>a.link,h4>a.link,h5>a.link,h6>a.link{color:#ba3925;text-decoration:none}
|
|
#content h1>a.link:hover,h2>a.link:hover,h3>a.link:hover,#toctitle>a.link:hover,.sidebarblock>.content>.title>a.link:hover,h4>a.link:hover,h5>a.link:hover,h6>a.link:hover{color:#a53221}
|
|
.audioblock,.imageblock,.literalblock,.listingblock,.stemblock,.videoblock{margin-bottom:1.25em}
|
|
.admonitionblock td.content>.title,.audioblock>.title,.exampleblock>.title,.imageblock>.title,.listingblock>.title,.literalblock>.title,.stemblock>.title,.openblock>.title,.paragraph>.title,.quoteblock>.title,table.tableblock>.title,.verseblock>.title,.videoblock>.title,.dlist>.title,.olist>.title,.ulist>.title,.qlist>.title,.hdlist>.title{text-rendering:optimizeLegibility;text-align:left;font-family:"Noto Serif","DejaVu Serif",serif;font-size:1rem;font-style:italic}
|
|
table.tableblock.fit-content>caption.title{white-space:nowrap;width:0}
|
|
.paragraph.lead>p,#preamble>.sectionbody>[class="paragraph"]:first-of-type p{font-size:1.21875em;line-height:1.6;color:rgba(0,0,0,.85)}
|
|
table.tableblock #preamble>.sectionbody>[class="paragraph"]:first-of-type p{font-size:inherit}
|
|
.admonitionblock>table{border-collapse:separate;border:0;background:none;width:100%}
|
|
.admonitionblock>table td.icon{text-align:center;width:80px}
|
|
.admonitionblock>table td.icon img{max-width:none}
|
|
.admonitionblock>table td.icon .title{font-weight:bold;font-family:"Open Sans","DejaVu Sans",sans-serif;text-transform:uppercase}
|
|
.admonitionblock>table td.content{padding-left:1.125em;padding-right:1.25em;border-left:1px solid #dddddf;color:rgba(0,0,0,.6)}
|
|
.admonitionblock>table td.content>:last-child>:last-child{margin-bottom:0}
|
|
.exampleblock>.content{border-style:solid;border-width:1px;border-color:#e6e6e6;margin-bottom:1.25em;padding:1.25em;background:#fff;-webkit-border-radius:4px;border-radius:4px}
|
|
.exampleblock>.content>:first-child{margin-top:0}
|
|
.exampleblock>.content>:last-child{margin-bottom:0}
|
|
.sidebarblock{border-style:solid;border-width:1px;border-color:#e0e0dc;margin-bottom:1.25em;padding:1.25em;background:#f8f8f7;-webkit-border-radius:4px;border-radius:4px}
|
|
.sidebarblock>:first-child{margin-top:0}
|
|
.sidebarblock>:last-child{margin-bottom:0}
|
|
.sidebarblock>.content>.title{color:#7a2518;margin-top:0;text-align:center}
|
|
.exampleblock>.content>:last-child>:last-child,.exampleblock>.content .olist>ol>li:last-child>:last-child,.exampleblock>.content .ulist>ul>li:last-child>:last-child,.exampleblock>.content .qlist>ol>li:last-child>:last-child,.sidebarblock>.content>:last-child>:last-child,.sidebarblock>.content .olist>ol>li:last-child>:last-child,.sidebarblock>.content .ulist>ul>li:last-child>:last-child,.sidebarblock>.content .qlist>ol>li:last-child>:last-child{margin-bottom:0}
|
|
.literalblock pre,.listingblock pre:not(.highlight),.listingblock pre[class="highlight"],.listingblock pre[class^="highlight "],.listingblock pre.CodeRay,.listingblock pre.prettyprint{background:#f7f7f8}
|
|
.sidebarblock .literalblock pre,.sidebarblock .listingblock pre:not(.highlight),.sidebarblock .listingblock pre[class="highlight"],.sidebarblock .listingblock pre[class^="highlight "],.sidebarblock .listingblock pre.CodeRay,.sidebarblock .listingblock pre.prettyprint{background:#f2f1f1}
|
|
.literalblock pre,.literalblock pre[class],.listingblock pre,.listingblock pre[class]{-webkit-border-radius:4px;border-radius:4px;word-wrap:break-word;overflow-x:auto;padding:1em;font-size:.8125em}
|
|
@media screen and (min-width:768px){.literalblock pre,.literalblock pre[class],.listingblock pre,.listingblock pre[class]{font-size:.90625em}}
|
|
@media screen and (min-width:1280px){.literalblock pre,.literalblock pre[class],.listingblock pre,.listingblock pre[class]{font-size:1em}}
|
|
.literalblock pre.nowrap,.literalblock pre.nowrap pre,.listingblock pre.nowrap,.listingblock pre.nowrap pre{white-space:pre;word-wrap:normal}
|
|
.literalblock.output pre{color:#f7f7f8;background-color:rgba(0,0,0,.9)}
|
|
.listingblock pre.highlightjs{padding:0}
|
|
.listingblock pre.highlightjs>code{padding:1em;-webkit-border-radius:4px;border-radius:4px}
|
|
.listingblock pre.prettyprint{border-width:0}
|
|
.listingblock>.content{position:relative}
|
|
.listingblock code[data-lang]::before{display:none;content:attr(data-lang);position:absolute;font-size:.75em;top:.425rem;right:.5rem;line-height:1;text-transform:uppercase;color:#999}
|
|
.listingblock:hover code[data-lang]::before{display:block}
|
|
.listingblock.terminal pre .command::before{content:attr(data-prompt);padding-right:.5em;color:#999}
|
|
.listingblock.terminal pre .command:not([data-prompt])::before{content:"$"}
|
|
table.pyhltable{border-collapse:separate;border:0;margin-bottom:0;background:none}
|
|
table.pyhltable td{vertical-align:top;padding-top:0;padding-bottom:0;line-height:1.45}
|
|
table.pyhltable td.code{padding-left:.75em;padding-right:0}
|
|
pre.pygments .lineno,table.pyhltable td:not(.code){color:#999;padding-left:0;padding-right:.5em;border-right:1px solid #dddddf}
|
|
pre.pygments .lineno{display:inline-block;margin-right:.25em}
|
|
table.pyhltable .linenodiv{background:none!important;padding-right:0!important}
|
|
.quoteblock{margin:0 1em 1.25em 1.5em;display:table}
|
|
.quoteblock>.title{margin-left:-1.5em;margin-bottom:.75em}
|
|
.quoteblock blockquote,.quoteblock p{color:rgba(0,0,0,.85);font-size:1.15rem;line-height:1.75;word-spacing:.1em;letter-spacing:0;font-style:italic;text-align:justify}
|
|
.quoteblock blockquote{margin:0;padding:0;border:0}
|
|
.quoteblock blockquote::before{content:"\201c";float:left;font-size:2.75em;font-weight:bold;line-height:.6em;margin-left:-.6em;color:#7a2518;text-shadow:0 1px 2px rgba(0,0,0,.1)}
|
|
.quoteblock blockquote>.paragraph:last-child p{margin-bottom:0}
|
|
.quoteblock .attribution{margin-top:.75em;margin-right:.5ex;text-align:right}
|
|
.verseblock{margin:0 1em 1.25em}
|
|
.verseblock pre{font-family:"Open Sans","DejaVu Sans",sans;font-size:1.15rem;color:rgba(0,0,0,.85);font-weight:300;text-rendering:optimizeLegibility}
|
|
.verseblock pre strong{font-weight:400}
|
|
.verseblock .attribution{margin-top:1.25rem;margin-left:.5ex}
|
|
.quoteblock .attribution,.verseblock .attribution{font-size:.9375em;line-height:1.45;font-style:italic}
|
|
.quoteblock .attribution br,.verseblock .attribution br{display:none}
|
|
.quoteblock .attribution cite,.verseblock .attribution cite{display:block;letter-spacing:-.025em;color:rgba(0,0,0,.6)}
|
|
.quoteblock.abstract blockquote::before,.quoteblock.excerpt blockquote::before,.quoteblock .quoteblock blockquote::before{display:none}
|
|
.quoteblock.abstract blockquote,.quoteblock.abstract p,.quoteblock.excerpt blockquote,.quoteblock.excerpt p,.quoteblock .quoteblock blockquote,.quoteblock .quoteblock p{line-height:1.6;word-spacing:0}
|
|
.quoteblock.abstract{margin:0 1em 1.25em;display:block}
|
|
.quoteblock.abstract>.title{margin:0 0 .375em;font-size:1.15em;text-align:center}
|
|
.quoteblock.excerpt,.quoteblock .quoteblock{margin:0 0 1.25em;padding:0 0 .25em 1em;border-left:.25em solid #dddddf}
|
|
.quoteblock.excerpt blockquote,.quoteblock.excerpt p,.quoteblock .quoteblock blockquote,.quoteblock .quoteblock p{color:inherit;font-size:1.0625rem}
|
|
.quoteblock.excerpt .attribution,.quoteblock .quoteblock .attribution{color:inherit;text-align:left;margin-right:0}
|
|
table.tableblock{max-width:100%;border-collapse:separate}
|
|
p.tableblock:last-child{margin-bottom:0}
|
|
td.tableblock>.content{margin-bottom:-1.25em}
|
|
table.tableblock,th.tableblock,td.tableblock{border:0 solid #dedede}
|
|
table.grid-all>thead>tr>.tableblock,table.grid-all>tbody>tr>.tableblock{border-width:0 1px 1px 0}
|
|
table.grid-all>tfoot>tr>.tableblock{border-width:1px 1px 0 0}
|
|
table.grid-cols>*>tr>.tableblock{border-width:0 1px 0 0}
|
|
table.grid-rows>thead>tr>.tableblock,table.grid-rows>tbody>tr>.tableblock{border-width:0 0 1px}
|
|
table.grid-rows>tfoot>tr>.tableblock{border-width:1px 0 0}
|
|
table.grid-all>*>tr>.tableblock:last-child,table.grid-cols>*>tr>.tableblock:last-child{border-right-width:0}
|
|
table.grid-all>tbody>tr:last-child>.tableblock,table.grid-all>thead:last-child>tr>.tableblock,table.grid-rows>tbody>tr:last-child>.tableblock,table.grid-rows>thead:last-child>tr>.tableblock{border-bottom-width:0}
|
|
table.frame-all{border-width:1px}
|
|
table.frame-sides{border-width:0 1px}
|
|
table.frame-topbot,table.frame-ends{border-width:1px 0}
|
|
table.stripes-all tr,table.stripes-odd tr:nth-of-type(odd){background:#f8f8f7}
|
|
table.stripes-none tr,table.stripes-odd tr:nth-of-type(even){background:none}
|
|
th.halign-left,td.halign-left{text-align:left}
|
|
th.halign-right,td.halign-right{text-align:right}
|
|
th.halign-center,td.halign-center{text-align:center}
|
|
th.valign-top,td.valign-top{vertical-align:top}
|
|
th.valign-bottom,td.valign-bottom{vertical-align:bottom}
|
|
th.valign-middle,td.valign-middle{vertical-align:middle}
|
|
table thead th,table tfoot th{font-weight:bold}
|
|
tbody tr th{display:table-cell;line-height:1.6;background:#f7f8f7}
|
|
tbody tr th,tbody tr th p,tfoot tr th,tfoot tr th p{color:rgba(0,0,0,.8);font-weight:bold}
|
|
p.tableblock>code:only-child{background:none;padding:0}
|
|
p.tableblock{font-size:1em}
|
|
td>div.verse{white-space:pre}
|
|
ol{margin-left:1.75em}
|
|
ul li ol{margin-left:1.5em}
|
|
dl dd{margin-left:1.125em}
|
|
dl dd:last-child,dl dd:last-child>:last-child{margin-bottom:0}
|
|
ol>li p,ul>li p,ul dd,ol dd,.olist .olist,.ulist .ulist,.ulist .olist,.olist .ulist{margin-bottom:.625em}
|
|
ul.checklist,ul.none,ol.none,ul.no-bullet,ol.no-bullet,ol.unnumbered,ul.unstyled,ol.unstyled{list-style-type:none}
|
|
ul.no-bullet,ol.no-bullet,ol.unnumbered{margin-left:.625em}
|
|
ul.unstyled,ol.unstyled{margin-left:0}
|
|
ul.checklist{margin-left:.625em}
|
|
ul.checklist li>p:first-child>.fa-square-o:first-child,ul.checklist li>p:first-child>.fa-check-square-o:first-child{width:1.25em;font-size:.8em;position:relative;bottom:.125em}
|
|
ul.checklist li>p:first-child>input[type="checkbox"]:first-child{margin-right:.25em}
|
|
ul.inline{display:-ms-flexbox;display:-webkit-box;display:flex;-ms-flex-flow:row wrap;-webkit-flex-flow:row wrap;flex-flow:row wrap;list-style:none;margin:0 0 .625em -1.25em}
|
|
ul.inline>li{margin-left:1.25em}
|
|
.unstyled dl dt{font-weight:400;font-style:normal}
|
|
ol.arabic{list-style-type:decimal}
|
|
ol.decimal{list-style-type:decimal-leading-zero}
|
|
ol.loweralpha{list-style-type:lower-alpha}
|
|
ol.upperalpha{list-style-type:upper-alpha}
|
|
ol.lowerroman{list-style-type:lower-roman}
|
|
ol.upperroman{list-style-type:upper-roman}
|
|
ol.lowergreek{list-style-type:lower-greek}
|
|
.hdlist>table,.colist>table{border:0;background:none}
|
|
.hdlist>table>tbody>tr,.colist>table>tbody>tr{background:none}
|
|
td.hdlist1,td.hdlist2{vertical-align:top;padding:0 .625em}
|
|
td.hdlist1{font-weight:bold;padding-bottom:1.25em}
|
|
.literalblock+.colist,.listingblock+.colist{margin-top:-.5em}
|
|
.colist td:not([class]):first-child{padding:.4em .75em 0;line-height:1;vertical-align:top}
|
|
.colist td:not([class]):first-child img{max-width:none}
|
|
.colist td:not([class]):last-child{padding:.25em 0}
|
|
.thumb,.th{line-height:0;display:inline-block;border:solid 4px #fff;-webkit-box-shadow:0 0 0 1px #ddd;box-shadow:0 0 0 1px #ddd}
|
|
.imageblock.left{margin:.25em .625em 1.25em 0}
|
|
.imageblock.right{margin:.25em 0 1.25em .625em}
|
|
.imageblock>.title{margin-bottom:0}
|
|
.imageblock.thumb,.imageblock.th{border-width:6px}
|
|
.imageblock.thumb>.title,.imageblock.th>.title{padding:0 .125em}
|
|
.image.left,.image.right{margin-top:.25em;margin-bottom:.25em;display:inline-block;line-height:0}
|
|
.image.left{margin-right:.625em}
|
|
.image.right{margin-left:.625em}
|
|
a.image{text-decoration:none;display:inline-block}
|
|
a.image object{pointer-events:none}
|
|
sup.footnote,sup.footnoteref{font-size:.875em;position:static;vertical-align:super}
|
|
sup.footnote a,sup.footnoteref a{text-decoration:none}
|
|
sup.footnote a:active,sup.footnoteref a:active{text-decoration:underline}
|
|
#footnotes{padding-top:.75em;padding-bottom:.75em;margin-bottom:.625em}
|
|
#footnotes hr{width:20%;min-width:6.25em;margin:-.25em 0 .75em;border-width:1px 0 0}
|
|
#footnotes .footnote{padding:0 .375em 0 .225em;line-height:1.3334;font-size:.875em;margin-left:1.2em;margin-bottom:.2em}
|
|
#footnotes .footnote a:first-of-type{font-weight:bold;text-decoration:none;margin-left:-1.05em}
|
|
#footnotes .footnote:last-of-type{margin-bottom:0}
|
|
#content #footnotes{margin-top:-.625em;margin-bottom:0;padding:.75em 0}
|
|
.gist .file-data>table{border:0;background:#fff;width:100%;margin-bottom:0}
|
|
.gist .file-data>table td.line-data{width:99%}
|
|
div.unbreakable{page-break-inside:avoid}
|
|
.big{font-size:larger}
|
|
.small{font-size:smaller}
|
|
.underline{text-decoration:underline}
|
|
.overline{text-decoration:overline}
|
|
.line-through{text-decoration:line-through}
|
|
.aqua{color:#00bfbf}
|
|
.aqua-background{background-color:#00fafa}
|
|
.black{color:#000}
|
|
.black-background{background-color:#000}
|
|
.blue{color:#0000bf}
|
|
.blue-background{background-color:#0000fa}
|
|
.fuchsia{color:#bf00bf}
|
|
.fuchsia-background{background-color:#fa00fa}
|
|
.gray{color:#606060}
|
|
.gray-background{background-color:#7d7d7d}
|
|
.green{color:#006000}
|
|
.green-background{background-color:#007d00}
|
|
.lime{color:#00bf00}
|
|
.lime-background{background-color:#00fa00}
|
|
.maroon{color:#600000}
|
|
.maroon-background{background-color:#7d0000}
|
|
.navy{color:#000060}
|
|
.navy-background{background-color:#00007d}
|
|
.olive{color:#606000}
|
|
.olive-background{background-color:#7d7d00}
|
|
.purple{color:#600060}
|
|
.purple-background{background-color:#7d007d}
|
|
.red{color:#bf0000}
|
|
.red-background{background-color:#fa0000}
|
|
.silver{color:#909090}
|
|
.silver-background{background-color:#bcbcbc}
|
|
.teal{color:#006060}
|
|
.teal-background{background-color:#007d7d}
|
|
.white{color:#bfbfbf}
|
|
.white-background{background-color:#fafafa}
|
|
.yellow{color:#bfbf00}
|
|
.yellow-background{background-color:#fafa00}
|
|
span.icon>.fa{cursor:default}
|
|
a span.icon>.fa{cursor:inherit}
|
|
.admonitionblock td.icon [class^="fa icon-"]{font-size:2.5em;text-shadow:1px 1px 2px rgba(0,0,0,.5);cursor:default}
|
|
.admonitionblock td.icon .icon-note::before{content:"\f05a";color:#19407c}
|
|
.admonitionblock td.icon .icon-tip::before{content:"\f0eb";text-shadow:1px 1px 2px rgba(155,155,0,.8);color:#111}
|
|
.admonitionblock td.icon .icon-warning::before{content:"\f071";color:#bf6900}
|
|
.admonitionblock td.icon .icon-caution::before{content:"\f06d";color:#bf3400}
|
|
.admonitionblock td.icon .icon-important::before{content:"\f06a";color:#bf0000}
|
|
.conum[data-value]{display:inline-block;color:#fff!important;background-color:rgba(0,0,0,.8);-webkit-border-radius:100px;border-radius:100px;text-align:center;font-size:.75em;width:1.67em;height:1.67em;line-height:1.67em;font-family:"Open Sans","DejaVu Sans",sans-serif;font-style:normal;font-weight:bold}
|
|
.conum[data-value] *{color:#fff!important}
|
|
.conum[data-value]+b{display:none}
|
|
.conum[data-value]::after{content:attr(data-value)}
|
|
pre .conum[data-value]{position:relative;top:-.125em}
|
|
b.conum *{color:inherit!important}
|
|
.conum:not([data-value]):empty{display:none}
|
|
dt,th.tableblock,td.content,div.footnote{text-rendering:optimizeLegibility}
|
|
h1,h2,p,td.content,span.alt{letter-spacing:-.01em}
|
|
p strong,td.content strong,div.footnote strong{letter-spacing:-.005em}
|
|
p,blockquote,dt,td.content,span.alt{font-size:1.0625rem}
|
|
p{margin-bottom:1.25rem}
|
|
.sidebarblock p,.sidebarblock dt,.sidebarblock td.content,p.tableblock{font-size:1em}
|
|
.exampleblock>.content{background-color:#fffef7;border-color:#e0e0dc;-webkit-box-shadow:0 1px 4px #e0e0dc;box-shadow:0 1px 4px #e0e0dc}
|
|
.print-only{display:none!important}
|
|
@page{margin:1.25cm .75cm}
|
|
@media print{*{-webkit-box-shadow:none!important;box-shadow:none!important;text-shadow:none!important}
|
|
html{font-size:80%}
|
|
a{color:inherit!important;text-decoration:underline!important}
|
|
a.bare,a[href^="#"],a[href^="mailto:"]{text-decoration:none!important}
|
|
a[href^="http:"]:not(.bare)::after,a[href^="https:"]:not(.bare)::after{content:"(" attr(href) ")";display:inline-block;font-size:.875em;padding-left:.25em}
|
|
abbr[title]::after{content:" (" attr(title) ")"}
|
|
pre,blockquote,tr,img,object,svg{page-break-inside:avoid}
|
|
thead{display:table-header-group}
|
|
svg{max-width:100%}
|
|
p,blockquote,dt,td.content{font-size:1em;orphans:3;widows:3}
|
|
h2,h3,#toctitle,.sidebarblock>.content>.title{page-break-after:avoid}
|
|
#toc,.sidebarblock,.exampleblock>.content{background:none!important}
|
|
#toc{border-bottom:1px solid #dddddf!important;padding-bottom:0!important}
|
|
body.book #header{text-align:center}
|
|
body.book #header>h1:first-child{border:0!important;margin:2.5em 0 1em}
|
|
body.book #header .details{border:0!important;display:block;padding:0!important}
|
|
body.book #header .details span:first-child{margin-left:0!important}
|
|
body.book #header .details br{display:block}
|
|
body.book #header .details br+span::before{content:none!important}
|
|
body.book #toc{border:0!important;text-align:left!important;padding:0!important;margin:0!important}
|
|
body.book #toc,body.book #preamble,body.book h1.sect0,body.book .sect1>h2{page-break-before:always}
|
|
.listingblock code[data-lang]::before{display:block}
|
|
#footer{padding:0 .9375em}
|
|
.hide-on-print{display:none!important}
|
|
.print-only{display:block!important}
|
|
.hide-for-print{display:none!important}
|
|
.show-for-print{display:inherit!important}}
|
|
@media print,amzn-kf8{#header>h1:first-child{margin-top:1.25rem}
|
|
.sect1{padding:0!important}
|
|
.sect1+.sect1{border:0}
|
|
#footer{background:none}
|
|
#footer-text{color:rgba(0,0,0,.6);font-size:.9em}}
|
|
@media amzn-kf8{#header,#content,#footnotes,#footer{padding:0}}
|
|
</style>
|
|
</head>
|
|
<body class="manpage">
|
|
<div id="header">
|
|
<h1>git-fast-import(1) Manual Page</h1>
|
|
<h2 id="_name">NAME</h2>
|
|
<div class="sectionbody">
|
|
<p>git-fast-import - Backend for fast Git data importers</p>
|
|
</div>
|
|
</div>
|
|
<div id="content">
|
|
<div class="sect1">
|
|
<h2 id="_synopsis">SYNOPSIS</h2>
|
|
<div class="sectionbody">
|
|
<div class="verseblock">
|
|
<pre class="content">frontend | <em>git fast-import</em> [<options>]</pre>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_description">DESCRIPTION</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>This program is usually not what the end user wants to run directly.
|
|
Most end users want to use one of the existing frontend programs,
|
|
which parses a specific type of foreign source and feeds the contents
|
|
stored there to <em>git fast-import</em>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>fast-import reads a mixed command/data stream from standard input and
|
|
writes one or more packfiles directly into the current repository.
|
|
When EOF is received on standard input, fast import writes out
|
|
updated branch and tag refs, fully updating the current repository
|
|
with the newly imported data.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The fast-import backend itself can import into an empty repository (one that
|
|
has already been initialized by <em>git init</em>) or incrementally
|
|
update an existing populated repository. Whether or not incremental
|
|
imports are supported from a particular foreign source depends on
|
|
the frontend program in use.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_options">OPTIONS</h2>
|
|
<div class="sectionbody">
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">--force</dt>
|
|
<dd>
|
|
<p>Force updating modified existing branches, even if doing
|
|
so would cause commits to be lost (as the new commit does
|
|
not contain the old commit).</p>
|
|
</dd>
|
|
<dt class="hdlist1">--quiet</dt>
|
|
<dd>
|
|
<p>Disable the output shown by --stats, making fast-import usually
|
|
be silent when it is successful. However, if the import stream
|
|
has directives intended to show user output (e.g. <code>progress</code>
|
|
directives), the corresponding messages will still be shown.</p>
|
|
</dd>
|
|
<dt class="hdlist1">--stats</dt>
|
|
<dd>
|
|
<p>Display some basic statistics about the objects fast-import has
|
|
created, the packfiles they were stored into, and the
|
|
memory used by fast-import during this run. Showing this output
|
|
is currently the default, but can be disabled with --quiet.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_options_for_frontends">Options for Frontends</h3>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">--cat-blob-fd=<fd></dt>
|
|
<dd>
|
|
<p>Write responses to <code>get-mark</code>, <code>cat-blob</code>, and <code>ls</code> queries to the
|
|
file descriptor <fd> instead of <code>stdout</code>. Allows <code>progress</code>
|
|
output intended for the end-user to be separated from other
|
|
output.</p>
|
|
</dd>
|
|
<dt class="hdlist1">--date-format=<fmt></dt>
|
|
<dd>
|
|
<p>Specify the type of dates the frontend will supply to
|
|
fast-import within <code>author</code>, <code>committer</code> and <code>tagger</code> commands.
|
|
See “Date Formats” below for details about which formats
|
|
are supported, and their syntax.</p>
|
|
</dd>
|
|
<dt class="hdlist1">--done</dt>
|
|
<dd>
|
|
<p>Terminate with error if there is no <code>done</code> command at the end of
|
|
the stream. This option might be useful for detecting errors
|
|
that cause the frontend to terminate before it has started to
|
|
write a stream.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_locations_of_marks_files">Locations of Marks Files</h3>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">--export-marks=<file></dt>
|
|
<dd>
|
|
<p>Dumps the internal marks table to <file> when complete.
|
|
Marks are written one per line as <code>:markid SHA-1</code>.
|
|
Frontends can use this file to validate imports after they
|
|
have been completed, or to save the marks table across
|
|
incremental runs. As <file> is only opened and truncated
|
|
at checkpoint (or completion) the same path can also be
|
|
safely given to --import-marks.</p>
|
|
</dd>
|
|
<dt class="hdlist1">--import-marks=<file></dt>
|
|
<dd>
|
|
<p>Before processing any input, load the marks specified in
|
|
<file>. The input file must exist, must be readable, and
|
|
must use the same format as produced by --export-marks.
|
|
Multiple options may be supplied to import more than one
|
|
set of marks. If a mark is defined to different values,
|
|
the last file wins.</p>
|
|
</dd>
|
|
<dt class="hdlist1">--import-marks-if-exists=<file></dt>
|
|
<dd>
|
|
<p>Like --import-marks but instead of erroring out, silently
|
|
skips the file if it does not exist.</p>
|
|
</dd>
|
|
<dt class="hdlist1">--[no-]relative-marks</dt>
|
|
<dd>
|
|
<p>After specifying --relative-marks the paths specified
|
|
with --import-marks= and --export-marks= are relative
|
|
to an internal directory in the current repository.
|
|
In git-fast-import this means that the paths are relative
|
|
to the .git/info/fast-import directory. However, other
|
|
importers may use a different location.</p>
|
|
<div class="paragraph">
|
|
<p>Relative and non-relative marks may be combined by interweaving
|
|
--(no-)-relative-marks with the --(import|export)-marks= options.</p>
|
|
</div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_performance_and_compression_tuning">Performance and Compression Tuning</h3>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">--active-branches=<n></dt>
|
|
<dd>
|
|
<p>Maximum number of branches to maintain active at once.
|
|
See “Memory Utilization” below for details. Default is 5.</p>
|
|
</dd>
|
|
<dt class="hdlist1">--big-file-threshold=<n></dt>
|
|
<dd>
|
|
<p>Maximum size of a blob that fast-import will attempt to
|
|
create a delta for, expressed in bytes. The default is 512m
|
|
(512 MiB). Some importers may wish to lower this on systems
|
|
with constrained memory.</p>
|
|
</dd>
|
|
<dt class="hdlist1">--depth=<n></dt>
|
|
<dd>
|
|
<p>Maximum delta depth, for blob and tree deltification.
|
|
Default is 50.</p>
|
|
</dd>
|
|
<dt class="hdlist1">--export-pack-edges=<file></dt>
|
|
<dd>
|
|
<p>After creating a packfile, print a line of data to
|
|
<file> listing the filename of the packfile and the last
|
|
commit on each branch that was written to that packfile.
|
|
This information may be useful after importing projects
|
|
whose total object set exceeds the 4 GiB packfile limit,
|
|
as these commits can be used as edge points during calls
|
|
to <em>git pack-objects</em>.</p>
|
|
</dd>
|
|
<dt class="hdlist1">--max-pack-size=<n></dt>
|
|
<dd>
|
|
<p>Maximum size of each output packfile.
|
|
The default is unlimited.</p>
|
|
</dd>
|
|
<dt class="hdlist1">fastimport.unpackLimit</dt>
|
|
<dd>
|
|
<p>See <a href="git-config.html">git-config</a>(1)</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_performance">PERFORMANCE</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>The design of fast-import allows it to import large projects in a minimum
|
|
amount of memory usage and processing time. Assuming the frontend
|
|
is able to keep up with fast-import and feed it a constant stream of data,
|
|
import times for projects holding 10+ years of history and containing
|
|
100,000+ individual commits are generally completed in just 1-2
|
|
hours on quite modest (~$2,000 USD) hardware.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Most bottlenecks appear to be in foreign source data access (the
|
|
source just cannot extract revisions fast enough) or disk IO (fast-import
|
|
writes as fast as the disk will take the data). Imports will run
|
|
faster if the source data is stored on a different drive than the
|
|
destination Git repository (due to less IO contention).</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_development_cost">DEVELOPMENT COST</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>A typical frontend for fast-import tends to weigh in at approximately 200
|
|
lines of Perl/Python/Ruby code. Most developers have been able to
|
|
create working importers in just a couple of hours, even though it
|
|
is their first exposure to fast-import, and sometimes even to Git. This is
|
|
an ideal situation, given that most conversion tools are throw-away
|
|
(use once, and never look back).</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_parallel_operation">PARALLEL OPERATION</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>Like <em>git push</em> or <em>git fetch</em>, imports handled by fast-import are safe to
|
|
run alongside parallel <code>git repack -a -d</code> or <code>git gc</code> invocations,
|
|
or any other Git operation (including <em>git prune</em>, as loose objects
|
|
are never used by fast-import).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>fast-import does not lock the branch or tag refs it is actively importing.
|
|
After the import, during its ref update phase, fast-import tests each
|
|
existing branch ref to verify the update will be a fast-forward
|
|
update (the commit stored in the ref is contained in the new
|
|
history of the commit to be written). If the update is not a
|
|
fast-forward update, fast-import will skip updating that ref and instead
|
|
prints a warning message. fast-import will always attempt to update all
|
|
branch refs, and does not stop on the first failure.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Branch updates can be forced with --force, but it’s recommended that
|
|
this only be used on an otherwise quiet repository. Using --force
|
|
is not necessary for an initial import into an empty repository.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_technical_discussion">TECHNICAL DISCUSSION</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>fast-import tracks a set of branches in memory. Any branch can be created
|
|
or modified at any point during the import process by sending a
|
|
<code>commit</code> command on the input stream. This design allows a frontend
|
|
program to process an unlimited number of branches simultaneously,
|
|
generating commits in the order they are available from the source
|
|
data. It also simplifies the frontend programs considerably.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>fast-import does not use or alter the current working directory, or any
|
|
file within it. (It does however update the current Git repository,
|
|
as referenced by <code>GIT_DIR</code>.) Therefore an import frontend may use
|
|
the working directory for its own purposes, such as extracting file
|
|
revisions from the foreign source. This ignorance of the working
|
|
directory also allows fast-import to run very quickly, as it does not
|
|
need to perform any costly file update operations when switching
|
|
between branches.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_input_format">INPUT FORMAT</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>With the exception of raw file data (which Git does not interpret)
|
|
the fast-import input format is text (ASCII) based. This text based
|
|
format simplifies development and debugging of frontend programs,
|
|
especially when a higher level language such as Perl, Python or
|
|
Ruby is being used.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>fast-import is very strict about its input. Where we say SP below we mean
|
|
<strong>exactly</strong> one space. Likewise LF means one (and only one) linefeed
|
|
and HT one (and only one) horizontal tab.
|
|
Supplying additional whitespace characters will cause unexpected
|
|
results, such as branch names or file names with leading or trailing
|
|
spaces in their name, or early termination of fast-import when it encounters
|
|
unexpected input.</p>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_stream_comments">Stream Comments</h3>
|
|
<div class="paragraph">
|
|
<p>To aid in debugging frontends fast-import ignores any line that
|
|
begins with <code>#</code> (ASCII pound/hash) up to and including the line
|
|
ending <code>LF</code>. A comment line may contain any sequence of bytes
|
|
that does not contain an LF and therefore may be used to include
|
|
any detailed debugging information that might be specific to the
|
|
frontend and useful when inspecting a fast-import data stream.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_date_formats">Date Formats</h3>
|
|
<div class="paragraph">
|
|
<p>The following date formats are supported. A frontend should select
|
|
the format it will use for this import by passing the format name
|
|
in the --date-format=<fmt> command-line option.</p>
|
|
</div>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1"><code>raw</code></dt>
|
|
<dd>
|
|
<p>This is the Git native format and is <code><time> SP <offutc></code>.
|
|
It is also fast-import’s default format, if --date-format was
|
|
not specified.</p>
|
|
<div class="paragraph">
|
|
<p>The time of the event is specified by <code><time></code> as the number of
|
|
seconds since the UNIX epoch (midnight, Jan 1, 1970, UTC) and is
|
|
written as an ASCII decimal integer.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The local offset is specified by <code><offutc></code> as a positive or negative
|
|
offset from UTC. For example EST (which is 5 hours behind UTC)
|
|
would be expressed in <code><tz></code> by “-0500” while UTC is “+0000”.
|
|
The local offset does not affect <code><time></code>; it is used only as an
|
|
advisement to help formatting routines display the timestamp.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>If the local offset is not available in the source material, use
|
|
“+0000”, or the most common local offset. For example many
|
|
organizations have a CVS repository which has only ever been accessed
|
|
by users who are located in the same location and time zone. In this
|
|
case a reasonable offset from UTC could be assumed.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Unlike the <code>rfc2822</code> format, this format is very strict. Any
|
|
variation in formatting will cause fast-import to reject the value.</p>
|
|
</div>
|
|
</dd>
|
|
<dt class="hdlist1"><code>rfc2822</code></dt>
|
|
<dd>
|
|
<p>This is the standard email format as described by RFC 2822.</p>
|
|
<div class="paragraph">
|
|
<p>An example value is “Tue Feb 6 11:22:18 2007 -0500”. The Git
|
|
parser is accurate, but a little on the lenient side. It is the
|
|
same parser used by <em>git am</em> when applying patches
|
|
received from email.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Some malformed strings may be accepted as valid dates. In some of
|
|
these cases Git will still be able to obtain the correct date from
|
|
the malformed string. There are also some types of malformed
|
|
strings which Git will parse wrong, and yet consider valid.
|
|
Seriously malformed strings will be rejected.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Unlike the <code>raw</code> format above, the time zone/UTC offset information
|
|
contained in an RFC 2822 date string is used to adjust the date
|
|
value to UTC prior to storage. Therefore it is important that
|
|
this information be as accurate as possible.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>If the source material uses RFC 2822 style dates,
|
|
the frontend should let fast-import handle the parsing and conversion
|
|
(rather than attempting to do it itself) as the Git parser has
|
|
been well tested in the wild.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Frontends should prefer the <code>raw</code> format if the source material
|
|
already uses UNIX-epoch format, can be coaxed to give dates in that
|
|
format, or its format is easily convertible to it, as there is no
|
|
ambiguity in parsing.</p>
|
|
</div>
|
|
</dd>
|
|
<dt class="hdlist1"><code>now</code></dt>
|
|
<dd>
|
|
<p>Always use the current time and time zone. The literal
|
|
<code>now</code> must always be supplied for <code><when></code>.</p>
|
|
<div class="paragraph">
|
|
<p>This is a toy format. The current time and time zone of this system
|
|
is always copied into the identity string at the time it is being
|
|
created by fast-import. There is no way to specify a different time or
|
|
time zone.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>This particular format is supplied as it’s short to implement and
|
|
may be useful to a process that wants to create a new commit
|
|
right now, without needing to use a working directory or
|
|
<em>git update-index</em>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>If separate <code>author</code> and <code>committer</code> commands are used in a <code>commit</code>
|
|
the timestamps may not match, as the system clock will be polled
|
|
twice (once for each command). The only way to ensure that both
|
|
author and committer identity information has the same timestamp
|
|
is to omit <code>author</code> (thus copying from <code>committer</code>) or to use a
|
|
date format other than <code>now</code>.</p>
|
|
</div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_commands">Commands</h3>
|
|
<div class="paragraph">
|
|
<p>fast-import accepts several commands to update the current repository
|
|
and control the current import process. More detailed discussion
|
|
(with examples) of each command follows later.</p>
|
|
</div>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1"><code>commit</code></dt>
|
|
<dd>
|
|
<p>Creates a new branch or updates an existing branch by
|
|
creating a new commit and updating the branch to point at
|
|
the newly created commit.</p>
|
|
</dd>
|
|
<dt class="hdlist1"><code>tag</code></dt>
|
|
<dd>
|
|
<p>Creates an annotated tag object from an existing commit or
|
|
branch. Lightweight tags are not supported by this command,
|
|
as they are not recommended for recording meaningful points
|
|
in time.</p>
|
|
</dd>
|
|
<dt class="hdlist1"><code>reset</code></dt>
|
|
<dd>
|
|
<p>Reset an existing branch (or a new branch) to a specific
|
|
revision. This command must be used to change a branch to
|
|
a specific revision without making a commit on it.</p>
|
|
</dd>
|
|
<dt class="hdlist1"><code>blob</code></dt>
|
|
<dd>
|
|
<p>Convert raw file data into a blob, for future use in a
|
|
<code>commit</code> command. This command is optional and is not
|
|
needed to perform an import.</p>
|
|
</dd>
|
|
<dt class="hdlist1"><code>checkpoint</code></dt>
|
|
<dd>
|
|
<p>Forces fast-import to close the current packfile, generate its
|
|
unique SHA-1 checksum and index, and start a new packfile.
|
|
This command is optional and is not needed to perform
|
|
an import.</p>
|
|
</dd>
|
|
<dt class="hdlist1"><code>progress</code></dt>
|
|
<dd>
|
|
<p>Causes fast-import to echo the entire line to its own
|
|
standard output. This command is optional and is not needed
|
|
to perform an import.</p>
|
|
</dd>
|
|
<dt class="hdlist1"><code>done</code></dt>
|
|
<dd>
|
|
<p>Marks the end of the stream. This command is optional
|
|
unless the <code>done</code> feature was requested using the
|
|
<code>--done</code> command-line option or <code>feature done</code> command.</p>
|
|
</dd>
|
|
<dt class="hdlist1"><code>get-mark</code></dt>
|
|
<dd>
|
|
<p>Causes fast-import to print the SHA-1 corresponding to a mark
|
|
to the file descriptor set with <code>--cat-blob-fd</code>, or <code>stdout</code> if
|
|
unspecified.</p>
|
|
</dd>
|
|
<dt class="hdlist1"><code>cat-blob</code></dt>
|
|
<dd>
|
|
<p>Causes fast-import to print a blob in <em>cat-file --batch</em>
|
|
format to the file descriptor set with <code>--cat-blob-fd</code> or
|
|
<code>stdout</code> if unspecified.</p>
|
|
</dd>
|
|
<dt class="hdlist1"><code>ls</code></dt>
|
|
<dd>
|
|
<p>Causes fast-import to print a line describing a directory
|
|
entry in <em>ls-tree</em> format to the file descriptor set with
|
|
<code>--cat-blob-fd</code> or <code>stdout</code> if unspecified.</p>
|
|
</dd>
|
|
<dt class="hdlist1"><code>feature</code></dt>
|
|
<dd>
|
|
<p>Enable the specified feature. This requires that fast-import
|
|
supports the specified feature, and aborts if it does not.</p>
|
|
</dd>
|
|
<dt class="hdlist1"><code>option</code></dt>
|
|
<dd>
|
|
<p>Specify any of the options listed under OPTIONS that do not
|
|
change stream semantic to suit the frontend’s needs. This
|
|
command is optional and is not needed to perform an import.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_commit"><code>commit</code></h3>
|
|
<div class="paragraph">
|
|
<p>Create or update a branch with a new commit, recording one logical
|
|
change to the project.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'commit' SP <ref> LF
|
|
mark?
|
|
original-oid?
|
|
('author' (SP <name>)? SP LT <email> GT SP <when> LF)?
|
|
'committer' (SP <name>)? SP LT <email> GT SP <when> LF
|
|
data
|
|
('from' SP <commit-ish> LF)?
|
|
('merge' SP <commit-ish> LF)?
|
|
(filemodify | filedelete | filecopy | filerename | filedeleteall | notemodify)*
|
|
LF?</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>where <code><ref></code> is the name of the branch to make the commit on.
|
|
Typically branch names are prefixed with <code>refs/heads/</code> in
|
|
Git, so importing the CVS branch symbol <code>RELENG-1_0</code> would use
|
|
<code>refs/heads/RELENG-1_0</code> for the value of <code><ref></code>. The value of
|
|
<code><ref></code> must be a valid refname in Git. As <code>LF</code> is not valid in
|
|
a Git refname, no quoting or escaping syntax is supported here.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>A <code>mark</code> command may optionally appear, requesting fast-import to save a
|
|
reference to the newly created commit for future use by the frontend
|
|
(see below for format). It is very common for frontends to mark
|
|
every commit they create, thereby allowing future branch creation
|
|
from any imported commit.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>data</code> command following <code>committer</code> must supply the commit
|
|
message (see below for <code>data</code> command syntax). To import an empty
|
|
commit message use a 0 length data. Commit messages are free-form
|
|
and are not interpreted by Git. Currently they must be encoded in
|
|
UTF-8, as fast-import does not permit other encodings to be specified.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Zero or more <code>filemodify</code>, <code>filedelete</code>, <code>filecopy</code>, <code>filerename</code>,
|
|
<code>filedeleteall</code> and <code>notemodify</code> commands
|
|
may be included to update the contents of the branch prior to
|
|
creating the commit. These commands may be supplied in any order.
|
|
However it is recommended that a <code>filedeleteall</code> command precede
|
|
all <code>filemodify</code>, <code>filecopy</code>, <code>filerename</code> and <code>notemodify</code> commands in
|
|
the same commit, as <code>filedeleteall</code> wipes the branch clean (see below).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>LF</code> after the command is optional (it used to be required).</p>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_author"><code>author</code></h4>
|
|
<div class="paragraph">
|
|
<p>An <code>author</code> command may optionally appear, if the author information
|
|
might differ from the committer information. If <code>author</code> is omitted
|
|
then fast-import will automatically use the committer’s information for
|
|
the author portion of the commit. See below for a description of
|
|
the fields in <code>author</code>, as they are identical to <code>committer</code>.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_committer"><code>committer</code></h4>
|
|
<div class="paragraph">
|
|
<p>The <code>committer</code> command indicates who made this commit, and when
|
|
they made it.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Here <code><name></code> is the person’s display name (for example
|
|
“Com M Itter”) and <code><email></code> is the person’s email address
|
|
(“cm@example.com”). <code>LT</code> and <code>GT</code> are the literal less-than (\x3c)
|
|
and greater-than (\x3e) symbols. These are required to delimit
|
|
the email address from the other fields in the line. Note that
|
|
<code><name></code> and <code><email></code> are free-form and may contain any sequence
|
|
of bytes, except <code>LT</code>, <code>GT</code> and <code>LF</code>. <code><name></code> is typically UTF-8 encoded.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The time of the change is specified by <code><when></code> using the date format
|
|
that was selected by the --date-format=<fmt> command-line option.
|
|
See “Date Formats” above for the set of supported formats, and
|
|
their syntax.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_from"><code>from</code></h4>
|
|
<div class="paragraph">
|
|
<p>The <code>from</code> command is used to specify the commit to initialize
|
|
this branch from. This revision will be the first ancestor of the
|
|
new commit. The state of the tree built at this commit will begin
|
|
with the state at the <code>from</code> commit, and be altered by the content
|
|
modifications in this commit.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Omitting the <code>from</code> command in the first commit of a new branch
|
|
will cause fast-import to create that commit with no ancestor. This
|
|
tends to be desired only for the initial commit of a project.
|
|
If the frontend creates all files from scratch when making a new
|
|
branch, a <code>merge</code> command may be used instead of <code>from</code> to start
|
|
the commit with an empty tree.
|
|
Omitting the <code>from</code> command on existing branches is usually desired,
|
|
as the current commit on that branch is automatically assumed to
|
|
be the first ancestor of the new commit.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>As <code>LF</code> is not valid in a Git refname or SHA-1 expression, no
|
|
quoting or escaping syntax is supported within <code><commit-ish></code>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Here <code><commit-ish></code> is any of the following:</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>The name of an existing branch already in fast-import’s internal branch
|
|
table. If fast-import doesn’t know the name, it’s treated as a SHA-1
|
|
expression.</p>
|
|
</li>
|
|
<li>
|
|
<p>A mark reference, <code>:<idnum></code>, where <code><idnum></code> is the mark number.</p>
|
|
<div class="paragraph">
|
|
<p>The reason fast-import uses <code>:</code> to denote a mark reference is this character
|
|
is not legal in a Git branch name. The leading <code>:</code> makes it easy
|
|
to distinguish between the mark 42 (<code>:42</code>) and the branch 42 (<code>42</code>
|
|
or <code>refs/heads/42</code>), or an abbreviated SHA-1 which happened to
|
|
consist only of base-10 digits.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Marks must be declared (via <code>mark</code>) before they can be used.</p>
|
|
</div>
|
|
</li>
|
|
<li>
|
|
<p>A complete 40 byte or abbreviated commit SHA-1 in hex.</p>
|
|
</li>
|
|
<li>
|
|
<p>Any valid Git SHA-1 expression that resolves to a commit. See
|
|
“SPECIFYING REVISIONS” in <a href="gitrevisions.html">gitrevisions</a>(7) for details.</p>
|
|
</li>
|
|
<li>
|
|
<p>The special null SHA-1 (40 zeros) specifies that the branch is to be
|
|
removed.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The special case of restarting an incremental import from the
|
|
current branch value should be written as:</p>
|
|
</div>
|
|
<div class="listingblock">
|
|
<div class="content">
|
|
<pre> from refs/heads/branch^0</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>^0</code> suffix is necessary as fast-import does not permit a branch to
|
|
start from itself, and the branch is created in memory before the
|
|
<code>from</code> command is even read from the input. Adding <code>^0</code> will force
|
|
fast-import to resolve the commit through Git’s revision parsing library,
|
|
rather than its internal branch table, thereby loading in the
|
|
existing value of the branch.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_merge"><code>merge</code></h4>
|
|
<div class="paragraph">
|
|
<p>Includes one additional ancestor commit. The additional ancestry
|
|
link does not change the way the tree state is built at this commit.
|
|
If the <code>from</code> command is
|
|
omitted when creating a new branch, the first <code>merge</code> commit will be
|
|
the first ancestor of the current commit, and the branch will start
|
|
out with no files. An unlimited number of <code>merge</code> commands per
|
|
commit are permitted by fast-import, thereby establishing an n-way merge.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Here <code><commit-ish></code> is any of the commit specification expressions
|
|
also accepted by <code>from</code> (see above).</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_filemodify"><code>filemodify</code></h4>
|
|
<div class="paragraph">
|
|
<p>Included in a <code>commit</code> command to add a new file or change the
|
|
content of an existing file. This command has two different means
|
|
of specifying the content of the file.</p>
|
|
</div>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">External data format</dt>
|
|
<dd>
|
|
<p>The data content for the file was already supplied by a prior
|
|
<code>blob</code> command. The frontend just needs to connect it.</p>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'M' SP <mode> SP <dataref> SP <path> LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Here usually <code><dataref></code> must be either a mark reference (<code>:<idnum></code>)
|
|
set by a prior <code>blob</code> command, or a full 40-byte SHA-1 of an
|
|
existing Git blob object. If <code><mode></code> is <code>040000`</code> then
|
|
<code><dataref></code> must be the full 40-byte SHA-1 of an existing
|
|
Git tree object or a mark reference set with <code>--import-marks</code>.</p>
|
|
</div>
|
|
</dd>
|
|
<dt class="hdlist1">Inline data format</dt>
|
|
<dd>
|
|
<p>The data content for the file has not been supplied yet.
|
|
The frontend wants to supply it as part of this modify
|
|
command.</p>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'M' SP <mode> SP 'inline' SP <path> LF
|
|
data</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>See below for a detailed description of the <code>data</code> command.</p>
|
|
</div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>In both formats <code><mode></code> is the type of file entry, specified
|
|
in octal. Git only supports the following modes:</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p><code>100644</code> or <code>644</code>: A normal (not-executable) file. The majority
|
|
of files in most projects use this mode. If in doubt, this is
|
|
what you want.</p>
|
|
</li>
|
|
<li>
|
|
<p><code>100755</code> or <code>755</code>: A normal, but executable, file.</p>
|
|
</li>
|
|
<li>
|
|
<p><code>120000</code>: A symlink, the content of the file will be the link target.</p>
|
|
</li>
|
|
<li>
|
|
<p><code>160000</code>: A gitlink, SHA-1 of the object refers to a commit in
|
|
another repository. Git links can only be specified by SHA or through
|
|
a commit mark. They are used to implement submodules.</p>
|
|
</li>
|
|
<li>
|
|
<p><code>040000</code>: A subdirectory. Subdirectories can only be specified by
|
|
SHA or through a tree mark set with <code>--import-marks</code>.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>In both formats <code><path></code> is the complete path of the file to be added
|
|
(if not already existing) or modified (if already existing).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>A <code><path></code> string must use UNIX-style directory separators (forward
|
|
slash <code>/</code>), may contain any byte other than <code>LF</code>, and must not
|
|
start with double quote (<code>"</code>).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>A path can use C-style string quoting; this is accepted in all cases
|
|
and mandatory if the filename starts with double quote or contains
|
|
<code>LF</code>. In C-style quoting, the complete name should be surrounded with
|
|
double quotes, and any <code>LF</code>, backslash, or double quote characters
|
|
must be escaped by preceding them with a backslash (e.g.,
|
|
<code>"path/with\n, \\ and \" in it"</code>).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The value of <code><path></code> must be in canonical form. That is it must not:</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>contain an empty directory component (e.g. <code>foo//bar</code> is invalid),</p>
|
|
</li>
|
|
<li>
|
|
<p>end with a directory separator (e.g. <code>foo/</code> is invalid),</p>
|
|
</li>
|
|
<li>
|
|
<p>start with a directory separator (e.g. <code>/foo</code> is invalid),</p>
|
|
</li>
|
|
<li>
|
|
<p>contain the special component <code>.</code> or <code>..</code> (e.g. <code>foo/./bar</code> and
|
|
<code>foo/../bar</code> are invalid).</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The root of the tree can be represented by an empty string as <code><path></code>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>It is recommended that <code><path></code> always be encoded using UTF-8.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_filedelete"><code>filedelete</code></h4>
|
|
<div class="paragraph">
|
|
<p>Included in a <code>commit</code> command to remove a file or recursively
|
|
delete an entire directory from the branch. If the file or directory
|
|
removal makes its parent directory empty, the parent directory will
|
|
be automatically removed too. This cascades up the tree until the
|
|
first non-empty directory or the root is reached.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'D' SP <path> LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>here <code><path></code> is the complete path of the file or subdirectory to
|
|
be removed from the branch.
|
|
See <code>filemodify</code> above for a detailed description of <code><path></code>.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_filecopy"><code>filecopy</code></h4>
|
|
<div class="paragraph">
|
|
<p>Recursively copies an existing file or subdirectory to a different
|
|
location within the branch. The existing file or directory must
|
|
exist. If the destination exists it will be completely replaced
|
|
by the content copied from the source.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'C' SP <path> SP <path> LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>here the first <code><path></code> is the source location and the second
|
|
<code><path></code> is the destination. See <code>filemodify</code> above for a detailed
|
|
description of what <code><path></code> may look like. To use a source path
|
|
that contains SP the path must be quoted.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>A <code>filecopy</code> command takes effect immediately. Once the source
|
|
location has been copied to the destination any future commands
|
|
applied to the source location will not impact the destination of
|
|
the copy.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_filerename"><code>filerename</code></h4>
|
|
<div class="paragraph">
|
|
<p>Renames an existing file or subdirectory to a different location
|
|
within the branch. The existing file or directory must exist. If
|
|
the destination exists it will be replaced by the source directory.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'R' SP <path> SP <path> LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>here the first <code><path></code> is the source location and the second
|
|
<code><path></code> is the destination. See <code>filemodify</code> above for a detailed
|
|
description of what <code><path></code> may look like. To use a source path
|
|
that contains SP the path must be quoted.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>A <code>filerename</code> command takes effect immediately. Once the source
|
|
location has been renamed to the destination any future commands
|
|
applied to the source location will create new files there and not
|
|
impact the destination of the rename.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Note that a <code>filerename</code> is the same as a <code>filecopy</code> followed by a
|
|
<code>filedelete</code> of the source location. There is a slight performance
|
|
advantage to using <code>filerename</code>, but the advantage is so small
|
|
that it is never worth trying to convert a delete/add pair in
|
|
source material into a rename for fast-import. This <code>filerename</code>
|
|
command is provided just to simplify frontends that already have
|
|
rename information and don’t want bother with decomposing it into a
|
|
<code>filecopy</code> followed by a <code>filedelete</code>.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_filedeleteall"><code>filedeleteall</code></h4>
|
|
<div class="paragraph">
|
|
<p>Included in a <code>commit</code> command to remove all files (and also all
|
|
directories) from the branch. This command resets the internal
|
|
branch structure to have no files in it, allowing the frontend
|
|
to subsequently add all interesting files from scratch.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'deleteall' LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>This command is extremely useful if the frontend does not know
|
|
(or does not care to know) what files are currently on the branch,
|
|
and therefore cannot generate the proper <code>filedelete</code> commands to
|
|
update the content.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Issuing a <code>filedeleteall</code> followed by the needed <code>filemodify</code>
|
|
commands to set the correct content will produce the same results
|
|
as sending only the needed <code>filemodify</code> and <code>filedelete</code> commands.
|
|
The <code>filedeleteall</code> approach may however require fast-import to use slightly
|
|
more memory per active branch (less than 1 MiB for even most large
|
|
projects); so frontends that can easily obtain only the affected
|
|
paths for a commit are encouraged to do so.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect3">
|
|
<h4 id="_notemodify"><code>notemodify</code></h4>
|
|
<div class="paragraph">
|
|
<p>Included in a <code>commit</code> <code><notes_ref></code> command to add a new note
|
|
annotating a <code><commit-ish></code> or change this annotation contents.
|
|
Internally it is similar to filemodify 100644 on <code><commit-ish></code>
|
|
path (maybe split into subdirectories). It’s not advised to
|
|
use any other commands to write to the <code><notes_ref></code> tree except
|
|
<code>filedeleteall</code> to delete all existing notes in this tree.
|
|
This command has two different means of specifying the content
|
|
of the note.</p>
|
|
</div>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">External data format</dt>
|
|
<dd>
|
|
<p>The data content for the note was already supplied by a prior
|
|
<code>blob</code> command. The frontend just needs to connect it to the
|
|
commit that is to be annotated.</p>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'N' SP <dataref> SP <commit-ish> LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Here <code><dataref></code> can be either a mark reference (<code>:<idnum></code>)
|
|
set by a prior <code>blob</code> command, or a full 40-byte SHA-1 of an
|
|
existing Git blob object.</p>
|
|
</div>
|
|
</dd>
|
|
<dt class="hdlist1">Inline data format</dt>
|
|
<dd>
|
|
<p>The data content for the note has not been supplied yet.
|
|
The frontend wants to supply it as part of this modify
|
|
command.</p>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'N' SP 'inline' SP <commit-ish> LF
|
|
data</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>See below for a detailed description of the <code>data</code> command.</p>
|
|
</div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>In both formats <code><commit-ish></code> is any of the commit specification
|
|
expressions also accepted by <code>from</code> (see above).</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_mark"><code>mark</code></h3>
|
|
<div class="paragraph">
|
|
<p>Arranges for fast-import to save a reference to the current object, allowing
|
|
the frontend to recall this object at a future point in time, without
|
|
knowing its SHA-1. Here the current object is the object creation
|
|
command the <code>mark</code> command appears within. This can be <code>commit</code>,
|
|
<code>tag</code>, and <code>blob</code>, but <code>commit</code> is the most common usage.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'mark' SP ':' <idnum> LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>where <code><idnum></code> is the number assigned by the frontend to this mark.
|
|
The value of <code><idnum></code> is expressed as an ASCII decimal integer.
|
|
The value 0 is reserved and cannot be used as
|
|
a mark. Only values greater than or equal to 1 may be used as marks.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>New marks are created automatically. Existing marks can be moved
|
|
to another object simply by reusing the same <code><idnum></code> in another
|
|
<code>mark</code> command.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_original_oid"><code>original-oid</code></h3>
|
|
<div class="paragraph">
|
|
<p>Provides the name of the object in the original source control system.
|
|
fast-import will simply ignore this directive, but filter processes
|
|
which operate on and modify the stream before feeding to fast-import
|
|
may have uses for this information</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'original-oid' SP <object-identifier> LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>where <code><object-identifer></code> is any string not containing LF.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_tag"><code>tag</code></h3>
|
|
<div class="paragraph">
|
|
<p>Creates an annotated tag referring to a specific commit. To create
|
|
lightweight (non-annotated) tags see the <code>reset</code> command below.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'tag' SP <name> LF
|
|
'from' SP <commit-ish> LF
|
|
original-oid?
|
|
'tagger' (SP <name>)? SP LT <email> GT SP <when> LF
|
|
data</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>where <code><name></code> is the name of the tag to create.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Tag names are automatically prefixed with <code>refs/tags/</code> when stored
|
|
in Git, so importing the CVS branch symbol <code>RELENG-1_0-FINAL</code> would
|
|
use just <code>RELENG-1_0-FINAL</code> for <code><name></code>, and fast-import will write the
|
|
corresponding ref as <code>refs/tags/RELENG-1_0-FINAL</code>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The value of <code><name></code> must be a valid refname in Git and therefore
|
|
may contain forward slashes. As <code>LF</code> is not valid in a Git refname,
|
|
no quoting or escaping syntax is supported here.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>from</code> command is the same as in the <code>commit</code> command; see
|
|
above for details.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>tagger</code> command uses the same format as <code>committer</code> within
|
|
<code>commit</code>; again see above for details.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>data</code> command following <code>tagger</code> must supply the annotated tag
|
|
message (see below for <code>data</code> command syntax). To import an empty
|
|
tag message use a 0 length data. Tag messages are free-form and are
|
|
not interpreted by Git. Currently they must be encoded in UTF-8,
|
|
as fast-import does not permit other encodings to be specified.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Signing annotated tags during import from within fast-import is not
|
|
supported. Trying to include your own PGP/GPG signature is not
|
|
recommended, as the frontend does not (easily) have access to the
|
|
complete set of bytes which normally goes into such a signature.
|
|
If signing is required, create lightweight tags from within fast-import with
|
|
<code>reset</code>, then create the annotated versions of those tags offline
|
|
with the standard <em>git tag</em> process.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_reset"><code>reset</code></h3>
|
|
<div class="paragraph">
|
|
<p>Creates (or recreates) the named branch, optionally starting from
|
|
a specific revision. The reset command allows a frontend to issue
|
|
a new <code>from</code> command for an existing branch, or to create a new
|
|
branch from an existing commit without creating a new commit.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'reset' SP <ref> LF
|
|
('from' SP <commit-ish> LF)?
|
|
LF?</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>For a detailed description of <code><ref></code> and <code><commit-ish></code> see above
|
|
under <code>commit</code> and <code>from</code>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>LF</code> after the command is optional (it used to be required).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>reset</code> command can also be used to create lightweight
|
|
(non-annotated) tags. For example:</p>
|
|
</div>
|
|
<div class="exampleblock">
|
|
<div class="content">
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>reset refs/tags/938
|
|
from :938</pre>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>would create the lightweight tag <code>refs/tags/938</code> referring to
|
|
whatever commit mark <code>:938</code> references.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_blob"><code>blob</code></h3>
|
|
<div class="paragraph">
|
|
<p>Requests writing one file revision to the packfile. The revision
|
|
is not connected to any commit; this connection must be formed in
|
|
a subsequent <code>commit</code> command by referencing the blob through an
|
|
assigned mark.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'blob' LF
|
|
mark?
|
|
original-oid?
|
|
data</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The mark command is optional here as some frontends have chosen
|
|
to generate the Git SHA-1 for the blob on their own, and feed that
|
|
directly to <code>commit</code>. This is typically more work than it’s worth
|
|
however, as marks are inexpensive to store and easy to use.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_data"><code>data</code></h3>
|
|
<div class="paragraph">
|
|
<p>Supplies raw data (for use as blob/file content, commit messages, or
|
|
annotated tag messages) to fast-import. Data can be supplied using an exact
|
|
byte count or delimited with a terminating line. Real frontends
|
|
intended for production-quality conversions should always use the
|
|
exact byte count format, as it is more robust and performs better.
|
|
The delimited format is intended primarily for testing fast-import.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Comment lines appearing within the <code><raw></code> part of <code>data</code> commands
|
|
are always taken to be part of the body of the data and are therefore
|
|
never ignored by fast-import. This makes it safe to import any
|
|
file/message content whose lines might start with <code>#</code>.</p>
|
|
</div>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Exact byte count format</dt>
|
|
<dd>
|
|
<p>The frontend must specify the number of bytes of data.</p>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'data' SP <count> LF
|
|
<raw> LF?</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>where <code><count></code> is the exact number of bytes appearing within
|
|
<code><raw></code>. The value of <code><count></code> is expressed as an ASCII decimal
|
|
integer. The <code>LF</code> on either side of <code><raw></code> is not
|
|
included in <code><count></code> and will not be included in the imported data.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>LF</code> after <code><raw></code> is optional (it used to be required) but
|
|
recommended. Always including it makes debugging a fast-import
|
|
stream easier as the next command always starts in column 0
|
|
of the next line, even if <code><raw></code> did not end with an <code>LF</code>.</p>
|
|
</div>
|
|
</dd>
|
|
<dt class="hdlist1">Delimited format</dt>
|
|
<dd>
|
|
<p>A delimiter string is used to mark the end of the data.
|
|
fast-import will compute the length by searching for the delimiter.
|
|
This format is primarily useful for testing and is not
|
|
recommended for real data.</p>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'data' SP '<<' <delim> LF
|
|
<raw> LF
|
|
<delim> LF
|
|
LF?</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>where <code><delim></code> is the chosen delimiter string. The string <code><delim></code>
|
|
must not appear on a line by itself within <code><raw></code>, as otherwise
|
|
fast-import will think the data ends earlier than it really does. The <code>LF</code>
|
|
immediately trailing <code><raw></code> is part of <code><raw></code>. This is one of
|
|
the limitations of the delimited format, it is impossible to supply
|
|
a data chunk which does not have an LF as its last byte.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>LF</code> after <code><delim> LF</code> is optional (it used to be required).</p>
|
|
</div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_checkpoint"><code>checkpoint</code></h3>
|
|
<div class="paragraph">
|
|
<p>Forces fast-import to close the current packfile, start a new one, and to
|
|
save out all current branch refs, tags and marks.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'checkpoint' LF
|
|
LF?</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Note that fast-import automatically switches packfiles when the current
|
|
packfile reaches --max-pack-size, or 4 GiB, whichever limit is
|
|
smaller. During an automatic packfile switch fast-import does not update
|
|
the branch refs, tags or marks.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>As a <code>checkpoint</code> can require a significant amount of CPU time and
|
|
disk IO (to compute the overall pack SHA-1 checksum, generate the
|
|
corresponding index file, and update the refs) it can easily take
|
|
several minutes for a single <code>checkpoint</code> command to complete.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Frontends may choose to issue checkpoints during extremely large
|
|
and long running imports, or when they need to allow another Git
|
|
process access to a branch. However given that a 30 GiB Subversion
|
|
repository can be loaded into Git through fast-import in about 3 hours,
|
|
explicit checkpointing may not be necessary.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>LF</code> after the command is optional (it used to be required).</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_progress"><code>progress</code></h3>
|
|
<div class="paragraph">
|
|
<p>Causes fast-import to print the entire <code>progress</code> line unmodified to
|
|
its standard output channel (file descriptor 1) when the command is
|
|
processed from the input stream. The command otherwise has no impact
|
|
on the current import, or on any of fast-import’s internal state.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'progress' SP <any> LF
|
|
LF?</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code><any></code> part of the command may contain any sequence of bytes
|
|
that does not contain <code>LF</code>. The <code>LF</code> after the command is optional.
|
|
Callers may wish to process the output through a tool such as sed to
|
|
remove the leading part of the line, for example:</p>
|
|
</div>
|
|
<div class="exampleblock">
|
|
<div class="content">
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>frontend | git fast-import | sed 's/^progress //'</pre>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Placing a <code>progress</code> command immediately after a <code>checkpoint</code> will
|
|
inform the reader when the <code>checkpoint</code> has been completed and it
|
|
can safely access the refs that fast-import updated.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_get_mark"><code>get-mark</code></h3>
|
|
<div class="paragraph">
|
|
<p>Causes fast-import to print the SHA-1 corresponding to a mark to
|
|
stdout or to the file descriptor previously arranged with the
|
|
<code>--cat-blob-fd</code> argument. The command otherwise has no impact on the
|
|
current import; its purpose is to retrieve SHA-1s that later commits
|
|
might want to refer to in their commit messages.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'get-mark' SP ':' <idnum> LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>This command can be used anywhere in the stream that comments are
|
|
accepted. In particular, the <code>get-mark</code> command can be used in the
|
|
middle of a commit but not in the middle of a <code>data</code> command.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>See “Responses To Commands” below for details about how to read
|
|
this output safely.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_cat_blob"><code>cat-blob</code></h3>
|
|
<div class="paragraph">
|
|
<p>Causes fast-import to print a blob to a file descriptor previously
|
|
arranged with the <code>--cat-blob-fd</code> argument. The command otherwise
|
|
has no impact on the current import; its main purpose is to
|
|
retrieve blobs that may be in fast-import’s memory but not
|
|
accessible from the target repository.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'cat-blob' SP <dataref> LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code><dataref></code> can be either a mark reference (<code>:<idnum></code>)
|
|
set previously or a full 40-byte SHA-1 of a Git blob, preexisting or
|
|
ready to be written.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Output uses the same format as <code>git cat-file --batch</code>:</p>
|
|
</div>
|
|
<div class="exampleblock">
|
|
<div class="content">
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre><sha1> SP 'blob' SP <size> LF
|
|
<contents> LF</pre>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>This command can be used anywhere in the stream that comments are
|
|
accepted. In particular, the <code>cat-blob</code> command can be used in the
|
|
middle of a commit but not in the middle of a <code>data</code> command.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>See “Responses To Commands” below for details about how to read
|
|
this output safely.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_ls"><code>ls</code></h3>
|
|
<div class="paragraph">
|
|
<p>Prints information about the object at a path to a file descriptor
|
|
previously arranged with the <code>--cat-blob-fd</code> argument. This allows
|
|
printing a blob from the active commit (with <code>cat-blob</code>) or copying a
|
|
blob or tree from a previous commit for use in the current one (with
|
|
<code>filemodify</code>).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code>ls</code> command can be used anywhere in the stream that comments are
|
|
accepted, including the middle of a commit.</p>
|
|
</div>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">Reading from the active commit</dt>
|
|
<dd>
|
|
<p>This form can only be used in the middle of a <code>commit</code>.
|
|
The path names a directory entry within fast-import’s
|
|
active commit. The path must be quoted in this case.</p>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'ls' SP <path> LF</pre>
|
|
</div>
|
|
</div>
|
|
</dd>
|
|
<dt class="hdlist1">Reading from a named tree</dt>
|
|
<dd>
|
|
<p>The <code><dataref></code> can be a mark reference (<code>:<idnum></code>) or the
|
|
full 40-byte SHA-1 of a Git tag, commit, or tree object,
|
|
preexisting or waiting to be written.
|
|
The path is relative to the top level of the tree
|
|
named by <code><dataref></code>.</p>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'ls' SP <dataref> SP <path> LF</pre>
|
|
</div>
|
|
</div>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>See <code>filemodify</code> above for a detailed description of <code><path></code>.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Output uses the same format as <code>git ls-tree <tree> -- <path></code>:</p>
|
|
</div>
|
|
<div class="exampleblock">
|
|
<div class="content">
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre><mode> SP ('blob' | 'tree' | 'commit') SP <dataref> HT <path> LF</pre>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <dataref> represents the blob, tree, or commit object at <path>
|
|
and can be used in later <em>get-mark</em>, <em>cat-blob</em>, <em>filemodify</em>, or
|
|
<em>ls</em> commands.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>If there is no file or subtree at that path, <em>git fast-import</em> will
|
|
instead report</p>
|
|
</div>
|
|
<div class="exampleblock">
|
|
<div class="content">
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>missing SP <path> LF</pre>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>See “Responses To Commands” below for details about how to read
|
|
this output safely.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_feature"><code>feature</code></h3>
|
|
<div class="paragraph">
|
|
<p>Require that fast-import supports the specified feature, or abort if
|
|
it does not.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'feature' SP <feature> ('=' <argument>)? LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <feature> part of the command may be any one of the following:</p>
|
|
</div>
|
|
<div class="dlist">
|
|
<dl>
|
|
<dt class="hdlist1">date-format</dt>
|
|
<dt class="hdlist1">export-marks</dt>
|
|
<dt class="hdlist1">relative-marks</dt>
|
|
<dt class="hdlist1">no-relative-marks</dt>
|
|
<dt class="hdlist1">force</dt>
|
|
<dd>
|
|
<p>Act as though the corresponding command-line option with
|
|
a leading <code>--</code> was passed on the command line
|
|
(see OPTIONS, above).</p>
|
|
</dd>
|
|
<dt class="hdlist1">import-marks</dt>
|
|
<dt class="hdlist1">import-marks-if-exists</dt>
|
|
<dd>
|
|
<p>Like --import-marks except in two respects: first, only one
|
|
"feature import-marks" or "feature import-marks-if-exists"
|
|
command is allowed per stream; second, an --import-marks=
|
|
or --import-marks-if-exists command-line option overrides
|
|
any of these "feature" commands in the stream; third,
|
|
"feature import-marks-if-exists" like a corresponding
|
|
command-line option silently skips a nonexistent file.</p>
|
|
</dd>
|
|
<dt class="hdlist1">get-mark</dt>
|
|
<dt class="hdlist1">cat-blob</dt>
|
|
<dt class="hdlist1">ls</dt>
|
|
<dd>
|
|
<p>Require that the backend support the <em>get-mark</em>, <em>cat-blob</em>,
|
|
or <em>ls</em> command respectively.
|
|
Versions of fast-import not supporting the specified command
|
|
will exit with a message indicating so.
|
|
This lets the import error out early with a clear message,
|
|
rather than wasting time on the early part of an import
|
|
before the unsupported command is detected.</p>
|
|
</dd>
|
|
<dt class="hdlist1">notes</dt>
|
|
<dd>
|
|
<p>Require that the backend support the <em>notemodify</em> (N)
|
|
subcommand to the <em>commit</em> command.
|
|
Versions of fast-import not supporting notes will exit
|
|
with a message indicating so.</p>
|
|
</dd>
|
|
<dt class="hdlist1">done</dt>
|
|
<dd>
|
|
<p>Error out if the stream ends without a <em>done</em> command.
|
|
Without this feature, errors causing the frontend to end
|
|
abruptly at a convenient point in the stream can go
|
|
undetected. This may occur, for example, if an import
|
|
front end dies in mid-operation without emitting SIGTERM
|
|
or SIGKILL at its subordinate git fast-import instance.</p>
|
|
</dd>
|
|
</dl>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_option"><code>option</code></h3>
|
|
<div class="paragraph">
|
|
<p>Processes the specified option so that git fast-import behaves in a
|
|
way that suits the frontend’s needs.
|
|
Note that options specified by the frontend are overridden by any
|
|
options the user may specify to git fast-import itself.</p>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre> 'option' SP <option> LF</pre>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The <code><option></code> part of the command may contain any of the options
|
|
listed in the OPTIONS section that do not change import semantics,
|
|
without the leading <code>--</code> and is treated in the same way.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Option commands must be the first commands on the input (not counting
|
|
feature commands), to give an option command after any non-option
|
|
command is an error.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The following command-line options change import semantics and may therefore
|
|
not be passed as option:</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>date-format</p>
|
|
</li>
|
|
<li>
|
|
<p>import-marks</p>
|
|
</li>
|
|
<li>
|
|
<p>export-marks</p>
|
|
</li>
|
|
<li>
|
|
<p>cat-blob-fd</p>
|
|
</li>
|
|
<li>
|
|
<p>force</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_done"><code>done</code></h3>
|
|
<div class="paragraph">
|
|
<p>If the <code>done</code> feature is not in use, treated as if EOF was read.
|
|
This can be used to tell fast-import to finish early.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>If the <code>--done</code> command-line option or <code>feature done</code> command is
|
|
in use, the <code>done</code> command is mandatory and marks the end of the
|
|
stream.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_responses_to_commands">RESPONSES TO COMMANDS</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>New objects written by fast-import are not available immediately.
|
|
Most fast-import commands have no visible effect until the next
|
|
checkpoint (or completion). The frontend can send commands to
|
|
fill fast-import’s input pipe without worrying about how quickly
|
|
they will take effect, which improves performance by simplifying
|
|
scheduling.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>For some frontends, though, it is useful to be able to read back
|
|
data from the current repository as it is being updated (for
|
|
example when the source material describes objects in terms of
|
|
patches to be applied to previously imported objects). This can
|
|
be accomplished by connecting the frontend and fast-import via
|
|
bidirectional pipes:</p>
|
|
</div>
|
|
<div class="exampleblock">
|
|
<div class="content">
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>mkfifo fast-import-output
|
|
frontend <fast-import-output |
|
|
git fast-import >fast-import-output</pre>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>A frontend set up this way can use <code>progress</code>, <code>get-mark</code>, <code>ls</code>, and
|
|
<code>cat-blob</code> commands to read information from the import in progress.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>To avoid deadlock, such frontends must completely consume any
|
|
pending output from <code>progress</code>, <code>ls</code>, <code>get-mark</code>, and <code>cat-blob</code> before
|
|
performing writes to fast-import that might block.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_crash_reports">CRASH REPORTS</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>If fast-import is supplied invalid input it will terminate with a
|
|
non-zero exit status and create a crash report in the top level of
|
|
the Git repository it was importing into. Crash reports contain
|
|
a snapshot of the internal fast-import state as well as the most
|
|
recent commands that lead up to the crash.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>All recent commands (including stream comments, file changes and
|
|
progress commands) are shown in the command history within the crash
|
|
report, but raw file data and commit messages are excluded from the
|
|
crash report. This exclusion saves space within the report file
|
|
and reduces the amount of buffering that fast-import must perform
|
|
during execution.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>After writing a crash report fast-import will close the current
|
|
packfile and export the marks table. This allows the frontend
|
|
developer to inspect the repository state and resume the import from
|
|
the point where it crashed. The modified branches and tags are not
|
|
updated during a crash, as the import did not complete successfully.
|
|
Branch and tag information can be found in the crash report and
|
|
must be applied manually if the update is needed.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>An example crash:</p>
|
|
</div>
|
|
<div class="exampleblock">
|
|
<div class="content">
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>$ cat >in <<END_OF_INPUT
|
|
# my very first test commit
|
|
commit refs/heads/master
|
|
committer Shawn O. Pearce <spearce> 19283 -0400
|
|
# who is that guy anyway?
|
|
data <<EOF
|
|
this is my commit
|
|
EOF
|
|
M 644 inline .gitignore
|
|
data <<EOF
|
|
.gitignore
|
|
EOF
|
|
M 777 inline bob
|
|
END_OF_INPUT</pre>
|
|
</div>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>$ git fast-import <in
|
|
fatal: Corrupt mode: M 777 inline bob
|
|
fast-import: dumping crash report to .git/fast_import_crash_8434</pre>
|
|
</div>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>$ cat .git/fast_import_crash_8434
|
|
fast-import crash report:
|
|
fast-import process: 8434
|
|
parent process : 1391
|
|
at Sat Sep 1 00:58:12 2007</pre>
|
|
</div>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>fatal: Corrupt mode: M 777 inline bob</pre>
|
|
</div>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>Most Recent Commands Before Crash
|
|
---------------------------------
|
|
# my very first test commit
|
|
commit refs/heads/master
|
|
committer Shawn O. Pearce <spearce> 19283 -0400
|
|
# who is that guy anyway?
|
|
data <<EOF
|
|
M 644 inline .gitignore
|
|
data <<EOF
|
|
* M 777 inline bob</pre>
|
|
</div>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>Active Branch LRU
|
|
-----------------
|
|
active_branches = 1 cur, 5 max</pre>
|
|
</div>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>pos clock name
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
1) 0 refs/heads/master</pre>
|
|
</div>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>Inactive Branches
|
|
-----------------
|
|
refs/heads/master:
|
|
status : active loaded dirty
|
|
tip commit : 0000000000000000000000000000000000000000
|
|
old tree : 0000000000000000000000000000000000000000
|
|
cur tree : 0000000000000000000000000000000000000000
|
|
commit clock: 0
|
|
last pack :</pre>
|
|
</div>
|
|
</div>
|
|
<div class="literalblock">
|
|
<div class="content">
|
|
<pre>-------------------
|
|
END OF CRASH REPORT</pre>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_tips_and_tricks">TIPS AND TRICKS</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>The following tips and tricks have been collected from various
|
|
users of fast-import, and are offered here as suggestions.</p>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_use_one_mark_per_commit">Use One Mark Per Commit</h3>
|
|
<div class="paragraph">
|
|
<p>When doing a repository conversion, use a unique mark per commit
|
|
(<code>mark :<n></code>) and supply the --export-marks option on the command
|
|
line. fast-import will dump a file which lists every mark and the Git
|
|
object SHA-1 that corresponds to it. If the frontend can tie
|
|
the marks back to the source repository, it is easy to verify the
|
|
accuracy and completeness of the import by comparing each Git
|
|
commit to the corresponding source revision.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Coming from a system such as Perforce or Subversion this should be
|
|
quite simple, as the fast-import mark can also be the Perforce changeset
|
|
number or the Subversion revision number.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_freely_skip_around_branches">Freely Skip Around Branches</h3>
|
|
<div class="paragraph">
|
|
<p>Don’t bother trying to optimize the frontend to stick to one branch
|
|
at a time during an import. Although doing so might be slightly
|
|
faster for fast-import, it tends to increase the complexity of the frontend
|
|
code considerably.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The branch LRU builtin to fast-import tends to behave very well, and the
|
|
cost of activating an inactive branch is so low that bouncing around
|
|
between branches has virtually no impact on import performance.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_handling_renames">Handling Renames</h3>
|
|
<div class="paragraph">
|
|
<p>When importing a renamed file or directory, simply delete the old
|
|
name(s) and modify the new name(s) during the corresponding commit.
|
|
Git performs rename detection after-the-fact, rather than explicitly
|
|
during a commit.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_use_tag_fixup_branches">Use Tag Fixup Branches</h3>
|
|
<div class="paragraph">
|
|
<p>Some other SCM systems let the user create a tag from multiple
|
|
files which are not from the same commit/changeset. Or to create
|
|
tags which are a subset of the files available in the repository.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Importing these tags as-is in Git is impossible without making at
|
|
least one commit which “fixes up” the files to match the content
|
|
of the tag. Use fast-import’s <code>reset</code> command to reset a dummy branch
|
|
outside of your normal branch space to the base commit for the tag,
|
|
then commit one or more file fixup commits, and finally tag the
|
|
dummy branch.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>For example since all normal branches are stored under <code>refs/heads/</code>
|
|
name the tag fixup branch <code>TAG_FIXUP</code>. This way it is impossible for
|
|
the fixup branch used by the importer to have namespace conflicts
|
|
with real branches imported from the source (the name <code>TAG_FIXUP</code>
|
|
is not <code>refs/heads/TAG_FIXUP</code>).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>When committing fixups, consider using <code>merge</code> to connect the
|
|
commit(s) which are supplying file revisions to the fixup branch.
|
|
Doing so will allow tools such as <em>git blame</em> to track
|
|
through the real commit history and properly annotate the source
|
|
files.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>After fast-import terminates the frontend will need to do <code>rm .git/TAG_FIXUP</code>
|
|
to remove the dummy branch.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_import_now_repack_later">Import Now, Repack Later</h3>
|
|
<div class="paragraph">
|
|
<p>As soon as fast-import completes the Git repository is completely valid
|
|
and ready for use. Typically this takes only a very short time,
|
|
even for considerably large projects (100,000+ commits).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>However repacking the repository is necessary to improve data
|
|
locality and access performance. It can also take hours on extremely
|
|
large projects (especially if -f and a large --window parameter is
|
|
used). Since repacking is safe to run alongside readers and writers,
|
|
run the repack in the background and let it finish when it finishes.
|
|
There is no reason to wait to explore your new Git project!</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>If you choose to wait for the repack, don’t try to run benchmarks
|
|
or performance tests until repacking is completed. fast-import outputs
|
|
suboptimal packfiles that are simply never seen in real use
|
|
situations.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_repacking_historical_data">Repacking Historical Data</h3>
|
|
<div class="paragraph">
|
|
<p>If you are repacking very old imported data (e.g. older than the
|
|
last year), consider expending some extra CPU time and supplying
|
|
--window=50 (or higher) when you run <em>git repack</em>.
|
|
This will take longer, but will also produce a smaller packfile.
|
|
You only need to expend the effort once, and everyone using your
|
|
project will benefit from the smaller repository.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_include_some_progress_messages">Include Some Progress Messages</h3>
|
|
<div class="paragraph">
|
|
<p>Every once in a while have your frontend emit a <code>progress</code> message
|
|
to fast-import. The contents of the messages are entirely free-form,
|
|
so one suggestion would be to output the current month and year
|
|
each time the current commit date moves into the next month.
|
|
Your users will feel better knowing how much of the data stream
|
|
has been processed.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_packfile_optimization">PACKFILE OPTIMIZATION</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>When packing a blob fast-import always attempts to deltify against the last
|
|
blob written. Unless specifically arranged for by the frontend,
|
|
this will probably not be a prior version of the same file, so the
|
|
generated delta will not be the smallest possible. The resulting
|
|
packfile will be compressed, but will not be optimal.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Frontends which have efficient access to all revisions of a
|
|
single file (for example reading an RCS/CVS ,v file) can choose
|
|
to supply all revisions of that file as a sequence of consecutive
|
|
<code>blob</code> commands. This allows fast-import to deltify the different file
|
|
revisions against each other, saving space in the final packfile.
|
|
Marks can be used to later identify individual file revisions during
|
|
a sequence of <code>commit</code> commands.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The packfile(s) created by fast-import do not encourage good disk access
|
|
patterns. This is caused by fast-import writing the data in the order
|
|
it is received on standard input, while Git typically organizes
|
|
data within packfiles to make the most recent (current tip) data
|
|
appear before historical data. Git also clusters commits together,
|
|
speeding up revision traversal through better cache locality.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>For this reason it is strongly recommended that users repack the
|
|
repository with <code>git repack -a -d</code> after fast-import completes, allowing
|
|
Git to reorganize the packfiles for faster data access. If blob
|
|
deltas are suboptimal (see above) then also adding the <code>-f</code> option
|
|
to force recomputation of all deltas can significantly reduce the
|
|
final packfile size (30-50% smaller can be quite typical).</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_memory_utilization">MEMORY UTILIZATION</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>There are a number of factors which affect how much memory fast-import
|
|
requires to perform an import. Like critical sections of core
|
|
Git, fast-import uses its own memory allocators to amortize any overheads
|
|
associated with malloc. In practice fast-import tends to amortize any
|
|
malloc overheads to 0, due to its use of large block allocations.</p>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_per_object">per object</h3>
|
|
<div class="paragraph">
|
|
<p>fast-import maintains an in-memory structure for every object written in
|
|
this execution. On a 32 bit system the structure is 32 bytes,
|
|
on a 64 bit system the structure is 40 bytes (due to the larger
|
|
pointer sizes). Objects in the table are not deallocated until
|
|
fast-import terminates. Importing 2 million objects on a 32 bit system
|
|
will require approximately 64 MiB of memory.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The object table is actually a hashtable keyed on the object name
|
|
(the unique SHA-1). This storage configuration allows fast-import to reuse
|
|
an existing or already written object and avoid writing duplicates
|
|
to the output packfile. Duplicate blobs are surprisingly common
|
|
in an import, typically due to branch merges in the source.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_per_mark">per mark</h3>
|
|
<div class="paragraph">
|
|
<p>Marks are stored in a sparse array, using 1 pointer (4 bytes or 8
|
|
bytes, depending on pointer size) per mark. Although the array
|
|
is sparse, frontends are still strongly encouraged to use marks
|
|
between 1 and n, where n is the total number of marks required for
|
|
this import.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_per_branch">per branch</h3>
|
|
<div class="paragraph">
|
|
<p>Branches are classified as active and inactive. The memory usage
|
|
of the two classes is significantly different.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Inactive branches are stored in a structure which uses 96 or 120
|
|
bytes (32 bit or 64 bit systems, respectively), plus the length of
|
|
the branch name (typically under 200 bytes), per branch. fast-import will
|
|
easily handle as many as 10,000 inactive branches in under 2 MiB
|
|
of memory.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Active branches have the same overhead as inactive branches, but
|
|
also contain copies of every tree that has been recently modified on
|
|
that branch. If subtree <code>include</code> has not been modified since the
|
|
branch became active, its contents will not be loaded into memory,
|
|
but if subtree <code>src</code> has been modified by a commit since the branch
|
|
became active, then its contents will be loaded in memory.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>As active branches store metadata about the files contained on that
|
|
branch, their in-memory storage size can grow to a considerable size
|
|
(see below).</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>fast-import automatically moves active branches to inactive status based on
|
|
a simple least-recently-used algorithm. The LRU chain is updated on
|
|
each <code>commit</code> command. The maximum number of active branches can be
|
|
increased or decreased on the command line with --active-branches=.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_per_active_tree">per active tree</h3>
|
|
<div class="paragraph">
|
|
<p>Trees (aka directories) use just 12 bytes of memory on top of the
|
|
memory required for their entries (see “per active file” below).
|
|
The cost of a tree is virtually 0, as its overhead amortizes out
|
|
over the individual file entries.</p>
|
|
</div>
|
|
</div>
|
|
<div class="sect2">
|
|
<h3 id="_per_active_file_entry">per active file entry</h3>
|
|
<div class="paragraph">
|
|
<p>Files (and pointers to subtrees) within active trees require 52 or 64
|
|
bytes (32/64 bit platforms) per entry. To conserve space, file and
|
|
tree names are pooled in a common string table, allowing the filename
|
|
“Makefile” to use just 16 bytes (after including the string header
|
|
overhead) no matter how many times it occurs within the project.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The active branch LRU, when coupled with the filename string pool
|
|
and lazy loading of subtrees, allows fast-import to efficiently import
|
|
projects with 2,000+ branches and 45,114+ files in a very limited
|
|
memory footprint (less than 2.7 MiB per active branch).</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_signals">SIGNALS</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>Sending <strong>SIGUSR1</strong> to the <em>git fast-import</em> process ends the current
|
|
packfile early, simulating a <code>checkpoint</code> command. The impatient
|
|
operator can use this facility to peek at the objects and refs from an
|
|
import in progress, at the cost of some added running time and worse
|
|
compression.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_see_also">SEE ALSO</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p><a href="git-fast-export.html">git-fast-export</a>(1)</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_git">GIT</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>Part of the <a href="git.html">git</a>(1) suite</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div id="footer">
|
|
<div id="footer-text">
|
|
Last updated 2019-02-26 19:31:11 UTC
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html> |