604 lines
36 KiB
HTML
604 lines
36 KiB
HTML
<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="UTF-8">
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<!--[if IE]><meta http-equiv="X-UA-Compatible" content="IE=edge"><![endif]-->
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<meta name="viewport" content="width=device-width, initial-scale=1.0">
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<meta name="generator" content="Asciidoctor 1.5.8">
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<title>Multi-Pack-Index (MIDX) Design Notes</title>
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<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">
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<style>
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/* Asciidoctor default stylesheet | MIT License | http://asciidoctor.org */
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/* Uncomment @import statement below to use as custom stylesheet */
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/*@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";*/
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article,aside,details,figcaption,figure,footer,header,hgroup,main,nav,section,summary{display:block}
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audio,canvas,video{display:inline-block}
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audio:not([controls]){display:none;height:0}
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script{display:none!important}
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html{font-family:sans-serif;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%}
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a{background:transparent}
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a:focus{outline:thin dotted}
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a:active,a:hover{outline:0}
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h1{font-size:2em;margin:.67em 0}
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abbr[title]{border-bottom:1px dotted}
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b,strong{font-weight:bold}
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dfn{font-style:italic}
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hr{-moz-box-sizing:content-box;box-sizing:content-box;height:0}
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pre{white-space:pre-wrap}
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q{quotes:"\201C" "\201D" "\2018" "\2019"}
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small{font-size:80%}
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sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}
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sup{top:-.5em}
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sub{bottom:-.25em}
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img{border:0}
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svg:not(:root){overflow:hidden}
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figure{margin:0}
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fieldset{border:1px solid silver;margin:0 2px;padding:.35em .625em .75em}
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legend{border:0;padding:0}
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button,input,select,textarea{font-family:inherit;font-size:100%;margin:0}
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button,input{line-height:normal}
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button,select{text-transform:none}
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button,html input[type="button"],input[type="reset"],input[type="submit"]{-webkit-appearance:button;cursor:pointer}
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button[disabled],html input[disabled]{cursor:default}
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input[type="checkbox"],input[type="radio"]{box-sizing:border-box;padding:0}
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button::-moz-focus-inner,input::-moz-focus-inner{border:0;padding:0}
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textarea{overflow:auto;vertical-align:top}
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table{border-collapse:collapse;border-spacing:0}
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*,*::before,*::after{-moz-box-sizing:border-box;-webkit-box-sizing:border-box;box-sizing:border-box}
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html,body{font-size:100%}
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a:hover{cursor:pointer}
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img,object,embed{max-width:100%;height:auto}
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object,embed{height:100%}
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img{-ms-interpolation-mode:bicubic}
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.left{float:left!important}
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.right{float:right!important}
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.text-left{text-align:left!important}
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.text-right{text-align:right!important}
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.text-center{text-align:center!important}
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.text-justify{text-align:justify!important}
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.hide{display:none}
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img,object,svg{display:inline-block;vertical-align:middle}
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textarea{height:auto;min-height:50px}
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select{width:100%}
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.center{margin-left:auto;margin-right:auto}
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.stretch{width:100%}
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.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}
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a{color:#2156a5;text-decoration:underline;line-height:inherit}
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a:hover,a:focus{color:#1d4b8f}
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a img{border:none}
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p{font-family:inherit;font-weight:400;font-size:1em;line-height:1.6;margin-bottom:1.25em;text-rendering:optimizeLegibility}
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p aside{font-size:.875em;line-height:1.35;font-style:italic}
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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}
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h4,h5{font-size:1.125em}
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h6{font-size:1em}
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strong,b{font-weight:bold;line-height:inherit}
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small{font-size:60%;line-height:inherit}
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code{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;color:rgba(0,0,0,.9)}
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ul,ol{margin-left:1.5em}
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ul li ul,ul li ol{margin-left:1.25em;margin-bottom:0;font-size:1em}
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ul.square li ul,ul.circle li ul,ul.disc li ul{list-style:inherit}
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ul.square{list-style-type:square}
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ul.circle{list-style-type:circle}
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ul.disc{list-style-type:disc}
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ol li ul,ol li ol{margin-left:1.25em;margin-bottom:0}
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dl dt{margin-bottom:.3125em;font-weight:bold}
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dl dd{margin-bottom:1.25em}
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abbr,acronym{text-transform:uppercase;font-size:90%;color:rgba(0,0,0,.8);border-bottom:1px dotted #ddd;cursor:help}
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abbr{text-transform:none}
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blockquote{margin:0 0 1.25em;padding:.5625em 1.25em 0 1.1875em;border-left:1px solid #ddd}
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blockquote cite::before{content:"\2014 \0020"}
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blockquote cite a,blockquote cite a:visited{color:rgba(0,0,0,.6)}
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blockquote,blockquote p{line-height:1.6;color:rgba(0,0,0,.85)}
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@media screen and (min-width:768px){h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2}
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h1{font-size:2.75em}
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h2{font-size:2.3125em}
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h3,#toctitle,.sidebarblock>.content>.title{font-size:1.6875em}
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h4{font-size:1.4375em}}
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table{background:#fff;margin-bottom:1.25em;border:solid 1px #dedede}
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table thead,table tfoot{background:#f7f8f7}
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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}
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table tr th,table tr td{padding:.5625em .625em;font-size:inherit;color:rgba(0,0,0,.8)}
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table tr.even,table tr.alt,table tr:nth-of-type(even){background:#f8f8f7}
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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}
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h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2;word-spacing:-.05em}
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h1 strong,h2 strong,h3 strong,#toctitle strong,.sidebarblock>.content>.title strong,h4 strong,h5 strong,h6 strong{font-weight:400}
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.clearfix::before,.clearfix::after,.float-group::before,.float-group::after{content:" ";display:table}
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.clearfix::after,.float-group::after{clear:both}
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*: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}
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*:not(pre)>code.nobreak{word-wrap:normal}
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*:not(pre)>code.nowrap{white-space:nowrap}
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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}
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em em{font-style:normal}
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strong strong{font-weight:400}
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.keyseq{color:rgba(51,51,51,.8)}
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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}
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.keyseq kbd:first-child{margin-left:0}
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.keyseq kbd:last-child{margin-right:0}
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.menuseq,.menuref{color:#000}
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.menuseq b:not(.caret),.menuref{font-weight:inherit}
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.menuseq{word-spacing:-.02em}
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.menuseq b.caret{font-size:1.25em;line-height:.8}
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.menuseq i.caret{font-weight:bold;text-align:center;width:.45em}
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b.button::before,b.button::after{position:relative;top:-1px;font-weight:400}
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b.button::before{content:"[";padding:0 3px 0 2px}
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b.button::after{content:"]";padding:0 2px 0 3px}
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p a>code:hover{color:rgba(0,0,0,.9)}
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#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}
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#header::before,#header::after,#content::before,#content::after,#footnotes::before,#footnotes::after,#footer::before,#footer::after{content:" ";display:table}
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#header::after,#content::after,#footnotes::after,#footer::after{clear:both}
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#content{margin-top:1.25em}
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#content::before{content:none}
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#header>h1:first-child{color:rgba(0,0,0,.85);margin-top:2.25rem;margin-bottom:0}
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#header>h1:first-child+#toc{margin-top:8px;border-top:1px solid #dddddf}
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#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}
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#header .details span:first-child{margin-left:-.125em}
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#header .details span.email a{color:rgba(0,0,0,.85)}
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#header .details br{display:none}
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#header .details br+span::before{content:"\00a0\2013\00a0"}
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#header .details br+span.author::before{content:"\00a0\22c5\00a0";color:rgba(0,0,0,.85)}
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#header .details br+span#revremark::before{content:"\00a0|\00a0"}
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#header #revnumber{text-transform:capitalize}
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#header #revnumber::after{content:"\00a0"}
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#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}
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#toc{border-bottom:1px solid #e7e7e9;padding-bottom:.5em}
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#toc>ul{margin-left:.125em}
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#toc ul.sectlevel0>li>a{font-style:italic}
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#toc ul.sectlevel0 ul.sectlevel1{margin:.5em 0}
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#toc ul{font-family:"Open Sans","DejaVu Sans",sans-serif;list-style-type:none}
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#toc li{line-height:1.3334;margin-top:.3334em}
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#toc a{text-decoration:none}
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#toc a:active{text-decoration:underline}
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#toctitle{color:#7a2518;font-size:1.2em}
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@media screen and (min-width:768px){#toctitle{font-size:1.375em}
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body.toc2{padding-left:15em;padding-right:0}
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#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}
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#toc.toc2 #toctitle{margin-top:0;margin-bottom:.8rem;font-size:1.2em}
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#toc.toc2>ul{font-size:.9em;margin-bottom:0}
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#toc.toc2 ul ul{margin-left:0;padding-left:1em}
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#toc.toc2 ul.sectlevel0 ul.sectlevel1{padding-left:0;margin-top:.5em;margin-bottom:.5em}
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body.toc2.toc-right{padding-left:0;padding-right:15em}
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body.toc2.toc-right #toc.toc2{border-right-width:0;border-left:1px solid #e7e7e9;left:auto;right:0}}
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@media screen and (min-width:1280px){body.toc2{padding-left:20em;padding-right:0}
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#toc.toc2{width:20em}
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#toc.toc2 ul ul{padding-left:1.25em}
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body.toc2.toc-right{padding-left:0;padding-right:20em}}
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#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}
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#content #toc>:first-child{margin-top:0}
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#content #toc>:last-child{margin-bottom:0}
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#footer{max-width:100%;background-color:rgba(0,0,0,.8);padding:1.25em}
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#footer-text{color:rgba(255,255,255,.8);line-height:1.44}
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#content{margin-bottom:.625em}
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.sect1{padding-bottom:.625em}
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@media screen and (min-width:768px){#content{margin-bottom:1.25em}
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.sect1{padding-bottom:1.25em}}
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.sect1:last-child{padding-bottom:0}
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.sect1+.sect1{border-top:1px solid #e7e7e9}
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#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}
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#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}
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#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}
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#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}
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#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}
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.audioblock,.imageblock,.literalblock,.listingblock,.stemblock,.videoblock{margin-bottom:1.25em}
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.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}
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table.tableblock.fit-content>caption.title{white-space:nowrap;width:0}
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.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)}
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table.tableblock #preamble>.sectionbody>[class="paragraph"]:first-of-type p{font-size:inherit}
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.admonitionblock>table{border-collapse:separate;border:0;background:none;width:100%}
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.admonitionblock>table td.icon{text-align:center;width:80px}
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.admonitionblock>table td.icon img{max-width:none}
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.admonitionblock>table td.icon .title{font-weight:bold;font-family:"Open Sans","DejaVu Sans",sans-serif;text-transform:uppercase}
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.admonitionblock>table td.content{padding-left:1.125em;padding-right:1.25em;border-left:1px solid #dddddf;color:rgba(0,0,0,.6)}
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.admonitionblock>table td.content>:last-child>:last-child{margin-bottom:0}
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.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}
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.exampleblock>.content>:first-child{margin-top:0}
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.exampleblock>.content>:last-child{margin-bottom:0}
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.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}
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.sidebarblock>:first-child{margin-top:0}
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.sidebarblock>:last-child{margin-bottom:0}
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.sidebarblock>.content>.title{color:#7a2518;margin-top:0;text-align:center}
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.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}
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.literalblock pre,.listingblock pre:not(.highlight),.listingblock pre[class="highlight"],.listingblock pre[class^="highlight "],.listingblock pre.CodeRay,.listingblock pre.prettyprint{background:#f7f7f8}
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.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}
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.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}
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@media amzn-kf8{#header,#content,#footnotes,#footer{padding:0}}
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</style>
|
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</head>
|
|
<body class="article">
|
|
<div id="header">
|
|
<h1>Multi-Pack-Index (MIDX) Design Notes</h1>
|
|
</div>
|
|
<div id="content">
|
|
<div id="preamble">
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>The Git object directory contains a <em>pack</em> directory containing
|
|
packfiles (with suffix ".pack") and pack-indexes (with suffix
|
|
".idx"). The pack-indexes provide a way to lookup objects and
|
|
navigate to their offset within the pack, but these must come
|
|
in pairs with the packfiles. This pairing depends on the file
|
|
names, as the pack-index differs only in suffix with its pack-
|
|
file. While the pack-indexes provide fast lookup per packfile,
|
|
this performance degrades as the number of packfiles increases,
|
|
because abbreviations need to inspect every packfile and we are
|
|
more likely to have a miss on our most-recently-used packfile.
|
|
For some large repositories, repacking into a single packfile
|
|
is not feasible due to storage space or excessive repack times.</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>The multi-pack-index (MIDX for short) stores a list of objects
|
|
and their offsets into multiple packfiles. It contains:</p>
|
|
</div>
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>A list of packfile names.</p>
|
|
</li>
|
|
<li>
|
|
<p>A sorted list of object IDs.</p>
|
|
</li>
|
|
<li>
|
|
<p>A list of metadata for the ith object ID including:</p>
|
|
</li>
|
|
<li>
|
|
<p>A value j referring to the jth packfile.</p>
|
|
</li>
|
|
<li>
|
|
<p>An offset within the jth packfile for the object.</p>
|
|
</li>
|
|
<li>
|
|
<p>If large offsets are required, we use another list of large
|
|
offsets similar to version 2 pack-indexes.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>Thus, we can provide O(log N) lookup time for any number
|
|
of packfiles.</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_design_details">Design Details</h2>
|
|
<div class="sectionbody">
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>The MIDX is stored in a file named <em>multi-pack-index</em> in the
|
|
.git/objects/pack directory. This could be stored in the pack
|
|
directory of an alternate. It refers only to packfiles in that
|
|
same directory.</p>
|
|
</li>
|
|
<li>
|
|
<p>The pack.multiIndex config setting must be on to consume MIDX files.</p>
|
|
</li>
|
|
<li>
|
|
<p>The file format includes parameters for the object ID hash
|
|
function, so a future change of hash algorithm does not require
|
|
a change in format.</p>
|
|
</li>
|
|
<li>
|
|
<p>The MIDX keeps only one record per object ID. If an object appears
|
|
in multiple packfiles, then the MIDX selects the copy in the most-
|
|
recently modified packfile.</p>
|
|
</li>
|
|
<li>
|
|
<p>If there exist packfiles in the pack directory not registered in
|
|
the MIDX, then those packfiles are loaded into the <code>packed_git</code>
|
|
list and <code>packed_git_mru</code> cache.</p>
|
|
</li>
|
|
<li>
|
|
<p>The pack-indexes (.idx files) remain in the pack directory so we
|
|
can delete the MIDX file, set core.midx to false, or downgrade
|
|
without any loss of information.</p>
|
|
</li>
|
|
<li>
|
|
<p>The MIDX file format uses a chunk-based approach (similar to the
|
|
commit-graph file) that allows optional data to be added.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
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|
</div>
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|
</div>
|
|
<div class="sect1">
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|
<h2 id="_future_work">Future Work</h2>
|
|
<div class="sectionbody">
|
|
<div class="ulist">
|
|
<ul>
|
|
<li>
|
|
<p>Add a <em>verify</em> subcommand to the <em>git midx</em> builtin to verify the
|
|
contents of the multi-pack-index file match the offsets listed in
|
|
the corresponding pack-indexes.</p>
|
|
</li>
|
|
<li>
|
|
<p>The multi-pack-index allows many packfiles, especially in a context
|
|
where repacking is expensive (such as a very large repo), or
|
|
unexpected maintenance time is unacceptable (such as a high-demand
|
|
build machine). However, the multi-pack-index needs to be rewritten
|
|
in full every time. We can extend the format to be incremental, so
|
|
writes are fast. By storing a small "tip" multi-pack-index that
|
|
points to large "base" MIDX files, we can keep writes fast while
|
|
still reducing the number of binary searches required for object
|
|
lookups.</p>
|
|
</li>
|
|
<li>
|
|
<p>The reachability bitmap is currently paired directly with a single
|
|
packfile, using the pack-order as the object order to hopefully
|
|
compress the bitmaps well using run-length encoding. This could be
|
|
extended to pair a reachability bitmap with a multi-pack-index. If
|
|
the multi-pack-index is extended to store a "stable object order"
|
|
(a function Order(hash) = integer that is constant for a given hash,
|
|
even as the multi-pack-index is updated) then a reachability bitmap
|
|
could point to a multi-pack-index and be updated independently.</p>
|
|
</li>
|
|
<li>
|
|
<p>Packfiles can be marked as "special" using empty files that share
|
|
the initial name but replace ".pack" with ".keep" or ".promisor".
|
|
We can add an optional chunk of data to the multi-pack-index that
|
|
records flags of information about the packfiles. This allows new
|
|
states, such as <em>repacked</em> or <em>redeltified</em>, that can help with
|
|
pack maintenance in a multi-pack environment. It may also be
|
|
helpful to organize packfiles by object type (commit, tree, blob,
|
|
etc.) and use this metadata to help that maintenance.</p>
|
|
</li>
|
|
<li>
|
|
<p>The partial clone feature records special "promisor" packs that
|
|
may point to objects that are not stored locally, but available
|
|
on request to a server. The multi-pack-index does not currently
|
|
track these promisor packs.</p>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div class="sect1">
|
|
<h2 id="_related_links">Related Links</h2>
|
|
<div class="sectionbody">
|
|
<div class="paragraph">
|
|
<p>[0] <a href="https://bugs.chromium.org/p/git/issues/detail?id=6" class="bare">https://bugs.chromium.org/p/git/issues/detail?id=6</a>
|
|
Chromium work item for: Multi-Pack Index (MIDX)</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>[1] <a href="https://public-inbox.org/git/20180107181459.222909-1-dstolee@microsoft.com/" class="bare">https://public-inbox.org/git/20180107181459.222909-1-dstolee@microsoft.com/</a>
|
|
An earlier RFC for the multi-pack-index feature</p>
|
|
</div>
|
|
<div class="paragraph">
|
|
<p>[2] <a href="https://public-inbox.org/git/alpine.DEB.2.20.1803091557510.23109@alexmv-linux/" class="bare">https://public-inbox.org/git/alpine.DEB.2.20.1803091557510.23109@alexmv-linux/</a>
|
|
Git Merge 2018 Contributor’s summit notes (includes discussion of MIDX)</p>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
</div>
|
|
<div id="footer">
|
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<div id="footer-text">
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