Google Git
Sign in
chromium / external / gitster / git-htmldocs / 7f7e6a47a4543fc8b8335e64746e0f7e3ce80f4a / . / gitprotocol-v2.html
blob: 5a7c8306aa2b432aa3afdf108cc3514609514cc5 [file] [log] [blame]
Junio C Hamanob96f40a2024-08-01 00:57:25[diff] [blame]1<!DOCTYPE html>
2<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
3<head>
4<meta charset="UTF-8"/>
5<meta http-equiv="X-UA-Compatible" content="IE=edge"/>
6<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
7<meta name="generator" content="Asciidoctor 2.0.20"/>
8<title>gitprotocol-v2(5)</title>
9<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"/>
10<style>
11/*! Asciidoctor default stylesheet | MIT License | https://asciidoctor.org */
12/* Uncomment the following line when using as a custom stylesheet */
13/* @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"; */
14html{font-family:sans-serif;-webkit-text-size-adjust:100%}
15a{background:none}
16a:focus{outline:thin dotted}
17a:active,a:hover{outline:0}
18h1{font-size:2em;margin:.67em 0}
19b,strong{font-weight:bold}
20abbr{font-size:.9em}
21abbr[title]{cursor:help;border-bottom:1px dotted #dddddf;text-decoration:none}
22dfn{font-style:italic}
23hr{height:0}
24mark{background:#ff0;color:#000}
25code,kbd,pre,samp{font-family:monospace;font-size:1em}
26pre{white-space:pre-wrap}
27q{quotes:"\201C" "\201D" "\2018" "\2019"}
28small{font-size:80%}
29sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}
30sup{top:-.5em}
31sub{bottom:-.25em}
32img{border:0}
33svg:not(:root){overflow:hidden}
34figure{margin:0}
35audio,video{display:inline-block}
36audio:not([controls]){display:none;height:0}
37fieldset{border:1px solid silver;margin:0 2px;padding:.35em .625em .75em}
38legend{border:0;padding:0}
39button,input,select,textarea{font-family:inherit;font-size:100%;margin:0}
40button,input{line-height:normal}
41button,select{text-transform:none}
42button,html input[type=button],input[type=reset],input[type=submit]{-webkit-appearance:button;cursor:pointer}
43button[disabled],html input[disabled]{cursor:default}
44input[type=checkbox],input[type=radio]{padding:0}
45button::-moz-focus-inner,input::-moz-focus-inner{border:0;padding:0}
46textarea{overflow:auto;vertical-align:top}
47table{border-collapse:collapse;border-spacing:0}
48*,::before,::after{box-sizing:border-box}
49html,body{font-size:100%}
50body{background:#fff;color:rgba(0,0,0,.8);padding:0;margin:0;font-family:"Noto Serif","DejaVu Serif",serif;line-height:1;position:relative;cursor:auto;-moz-tab-size:4;-o-tab-size:4;tab-size:4;word-wrap:anywhere;-moz-osx-font-smoothing:grayscale;-webkit-font-smoothing:antialiased}
51a:hover{cursor:pointer}
52img,object,embed{max-width:100%;height:auto}
53object,embed{height:100%}
54img{-ms-interpolation-mode:bicubic}
55.left{float:left!important}
56.right{float:right!important}
57.text-left{text-align:left!important}
58.text-right{text-align:right!important}
59.text-center{text-align:center!important}
60.text-justify{text-align:justify!important}
61.hide{display:none}
62img,object,svg{display:inline-block;vertical-align:middle}
63textarea{height:auto;min-height:50px}
64select{width:100%}
65.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}
66div,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}
67a{color:#2156a5;text-decoration:underline;line-height:inherit}
68a:hover,a:focus{color:#1d4b8f}
69a img{border:0}
70p{line-height:1.6;margin-bottom:1.25em;text-rendering:optimizeLegibility}
71p aside{font-size:.875em;line-height:1.35;font-style:italic}
72h1,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}
73h1 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}
74h1{font-size:2.125em}
75h2{font-size:1.6875em}
76h3,#toctitle,.sidebarblock>.content>.title{font-size:1.375em}
77h4,h5{font-size:1.125em}
78h6{font-size:1em}
79hr{border:solid #dddddf;border-width:1px 0 0;clear:both;margin:1.25em 0 1.1875em}
80em,i{font-style:italic;line-height:inherit}
81strong,b{font-weight:bold;line-height:inherit}
82small{font-size:60%;line-height:inherit}
83code{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;color:rgba(0,0,0,.9)}
84ul,ol,dl{line-height:1.6;margin-bottom:1.25em;list-style-position:outside;font-family:inherit}
85ul,ol{margin-left:1.5em}
86ul li ul,ul li ol{margin-left:1.25em;margin-bottom:0}
87ul.circle{list-style-type:circle}
88ul.disc{list-style-type:disc}
89ul.square{list-style-type:square}
90ul.circle ul:not([class]),ul.disc ul:not([class]),ul.square ul:not([class]){list-style:inherit}
91ol li ul,ol li ol{margin-left:1.25em;margin-bottom:0}
92dl dt{margin-bottom:.3125em;font-weight:bold}
93dl dd{margin-bottom:1.25em}
94blockquote{margin:0 0 1.25em;padding:.5625em 1.25em 0 1.1875em;border-left:1px solid #ddd}
95blockquote,blockquote p{line-height:1.6;color:rgba(0,0,0,.85)}
96@media screen and (min-width:768px){h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2}
97h1{font-size:2.75em}
98h2{font-size:2.3125em}
99h3,#toctitle,.sidebarblock>.content>.title{font-size:1.6875em}
100h4{font-size:1.4375em}}
101table{background:#fff;margin-bottom:1.25em;border:1px solid #dedede;word-wrap:normal}
102table thead,table tfoot{background:#f7f8f7}
103table 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}
104table tr th,table tr td{padding:.5625em .625em;font-size:inherit;color:rgba(0,0,0,.8)}
105table tr.even,table tr.alt{background:#f8f8f7}
106table thead tr th,table tfoot tr th,table tbody tr td,table tr td,table tfoot tr td{line-height:1.6}
107h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2;word-spacing:-.05em}
108h1 strong,h2 strong,h3 strong,#toctitle strong,.sidebarblock>.content>.title strong,h4 strong,h5 strong,h6 strong{font-weight:400}
109.center{margin-left:auto;margin-right:auto}
110.stretch{width:100%}
111.clearfix::before,.clearfix::after,.float-group::before,.float-group::after{content:" ";display:table}
112.clearfix::after,.float-group::after{clear:both}
113:not(pre).nobreak{word-wrap:normal}
114:not(pre).nowrap{white-space:nowrap}
115:not(pre).pre-wrap{white-space:pre-wrap}
116:not(pre):not([class^=L])>code{font-size:.9375em;font-style:normal!important;letter-spacing:0;padding:.1em .5ex;word-spacing:-.15em;background:#f7f7f8;border-radius:4px;line-height:1.45;text-rendering:optimizeSpeed}
117pre{color:rgba(0,0,0,.9);font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;line-height:1.45;text-rendering:optimizeSpeed}
118pre code,pre pre{color:inherit;font-size:inherit;line-height:inherit}
119pre>code{display:block}
120pre.nowrap,pre.nowrap pre{white-space:pre;word-wrap:normal}
121em em{font-style:normal}
122strong strong{font-weight:400}
123.keyseq{color:rgba(51,51,51,.8)}
124kbd{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:#f7f7f7;border:1px solid #ccc;border-radius:3px;box-shadow:0 1px 0 rgba(0,0,0,.2),inset 0 0 0 .1em #fff;margin:0 .15em;padding:.2em .5em;vertical-align:middle;position:relative;top:-.1em;white-space:nowrap}
125.keyseq kbd:first-child{margin-left:0}
126.keyseq kbd:last-child{margin-right:0}
127.menuseq,.menuref{color:#000}
128.menuseq b:not(.caret),.menuref{font-weight:inherit}
129.menuseq{word-spacing:-.02em}
130.menuseq b.caret{font-size:1.25em;line-height:.8}
131.menuseq i.caret{font-weight:bold;text-align:center;width:.45em}
132b.button::before,b.button::after{position:relative;top:-1px;font-weight:400}
133b.button::before{content:"[";padding:0 3px 0 2px}
134b.button::after{content:"]";padding:0 2px 0 3px}
135p a>code:hover{color:rgba(0,0,0,.9)}
136#header,#content,#footnotes,#footer{width:100%;margin:0 auto;max-width:62.5em;*zoom:1;position:relative;padding-left:.9375em;padding-right:.9375em}
137#header::before,#header::after,#content::before,#content::after,#footnotes::before,#footnotes::after,#footer::before,#footer::after{content:" ";display:table}
138#header::after,#content::after,#footnotes::after,#footer::after{clear:both}
139#content{margin-top:1.25em}
140#content::before{content:none}
141#header>h1:first-child{color:rgba(0,0,0,.85);margin-top:2.25rem;margin-bottom:0}
142#header>h1:first-child+#toc{margin-top:8px;border-top:1px solid #dddddf}
143#header>h1:only-child,body.toc2 #header>h1:nth-last-child(2){border-bottom:1px solid #dddddf;padding-bottom:8px}
144#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:flex;flex-flow:row wrap}
145#header .details span:first-child{margin-left:-.125em}
146#header .details span.email a{color:rgba(0,0,0,.85)}
147#header .details br{display:none}
148#header .details br+span::before{content:"\00a0\2013\00a0"}
149#header .details br+span.author::before{content:"\00a0\22c5\00a0";color:rgba(0,0,0,.85)}
150#header .details br+span#revremark::before{content:"\00a0|\00a0"}
151#header #revnumber{text-transform:capitalize}
152#header #revnumber::after{content:"\00a0"}
153#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}
154#toc{border-bottom:1px solid #e7e7e9;padding-bottom:.5em}
155#toc>ul{margin-left:.125em}
156#toc ul.sectlevel0>li>a{font-style:italic}
157#toc ul.sectlevel0 ul.sectlevel1{margin:.5em 0}
158#toc ul{font-family:"Open Sans","DejaVu Sans",sans-serif;list-style-type:none}
159#toc li{line-height:1.3334;margin-top:.3334em}
160#toc a{text-decoration:none}
161#toc a:active{text-decoration:underline}
162#toctitle{color:#7a2518;font-size:1.2em}
163@media screen and (min-width:768px){#toctitle{font-size:1.375em}
164body.toc2{padding-left:15em;padding-right:0}
165#toc.toc2{margin-top:0!important;background:#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}
166#toc.toc2 #toctitle{margin-top:0;margin-bottom:.8rem;font-size:1.2em}
167#toc.toc2>ul{font-size:.9em;margin-bottom:0}
168#toc.toc2 ul ul{margin-left:0;padding-left:1em}
169#toc.toc2 ul.sectlevel0 ul.sectlevel1{padding-left:0;margin-top:.5em;margin-bottom:.5em}
170body.toc2.toc-right{padding-left:0;padding-right:15em}
171body.toc2.toc-right #toc.toc2{border-right-width:0;border-left:1px solid #e7e7e9;left:auto;right:0}}
172@media screen and (min-width:1280px){body.toc2{padding-left:20em;padding-right:0}
173#toc.toc2{width:20em}
174#toc.toc2 #toctitle{font-size:1.375em}
175#toc.toc2>ul{font-size:.95em}
176#toc.toc2 ul ul{padding-left:1.25em}
177body.toc2.toc-right{padding-left:0;padding-right:20em}}
178#content #toc{border:1px solid #e0e0dc;margin-bottom:1.25em;padding:1.25em;background:#f8f8f7;border-radius:4px}
179#content #toc>:first-child{margin-top:0}
180#content #toc>:last-child{margin-bottom:0}
181#footer{max-width:none;background:rgba(0,0,0,.8);padding:1.25em}
182#footer-text{color:hsla(0,0%,100%,.8);line-height:1.44}
183#content{margin-bottom:.625em}
184.sect1{padding-bottom:.625em}
185@media screen and (min-width:768px){#content{margin-bottom:1.25em}
186.sect1{padding-bottom:1.25em}}
187.sect1:last-child{padding-bottom:0}
188.sect1+.sect1{border-top:1px solid #e7e7e9}
189#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}
190#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}
191#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}
192#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}
193#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}
194details,.audioblock,.imageblock,.literalblock,.listingblock,.stemblock,.videoblock{margin-bottom:1.25em}
195details{margin-left:1.25rem}
196details>summary{cursor:pointer;display:block;position:relative;line-height:1.6;margin-bottom:.625rem;outline:none;-webkit-tap-highlight-color:transparent}
197details>summary::-webkit-details-marker{display:none}
198details>summary::before{content:"";border:solid transparent;border-left:solid;border-width:.3em 0 .3em .5em;position:absolute;top:.5em;left:-1.25rem;transform:translateX(15%)}
199details[open]>summary::before{border:solid transparent;border-top:solid;border-width:.5em .3em 0;transform:translateY(15%)}
200details>summary::after{content:"";width:1.25rem;height:1em;position:absolute;top:.3em;left:-1.25rem}
201.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}
202table.tableblock.fit-content>caption.title{white-space:nowrap;width:0}
203.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)}
204.admonitionblock>table{border-collapse:separate;border:0;background:none;width:100%}
205.admonitionblock>table td.icon{text-align:center;width:80px}
206.admonitionblock>table td.icon img{max-width:none}
207.admonitionblock>table td.icon .title{font-weight:bold;font-family:"Open Sans","DejaVu Sans",sans-serif;text-transform:uppercase}
208.admonitionblock>table td.content{padding-left:1.125em;padding-right:1.25em;border-left:1px solid #dddddf;color:rgba(0,0,0,.6);word-wrap:anywhere}
209.admonitionblock>table td.content>:last-child>:last-child{margin-bottom:0}
210.exampleblock>.content{border:1px solid #e6e6e6;margin-bottom:1.25em;padding:1.25em;background:#fff;border-radius:4px}
211.sidebarblock{border:1px solid #dbdbd6;margin-bottom:1.25em;padding:1.25em;background:#f3f3f2;border-radius:4px}
212.sidebarblock>.content>.title{color:#7a2518;margin-top:0;text-align:center}
213.exampleblock>.content>:first-child,.sidebarblock>.content>:first-child{margin-top:0}
214.exampleblock>.content>:last-child,.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,.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}
215.literalblock pre,.listingblock>.content>pre{border-radius:4px;overflow-x:auto;padding:1em;font-size:.8125em}
216@media screen and (min-width:768px){.literalblock pre,.listingblock>.content>pre{font-size:.90625em}}
217@media screen and (min-width:1280px){.literalblock pre,.listingblock>.content>pre{font-size:1em}}
218.literalblock pre,.listingblock>.content>pre:not(.highlight),.listingblock>.content>pre[class=highlight],.listingblock>.content>pre[class^="highlight "]{background:#f7f7f8}
219.literalblock.output pre{color:#f7f7f8;background:rgba(0,0,0,.9)}
220.listingblock>.content{position:relative}
221.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:inherit;opacity:.5}
222.listingblock:hover code[data-lang]::before{display:block}
223.listingblock.terminal pre .command::before{content:attr(data-prompt);padding-right:.5em;color:inherit;opacity:.5}
224.listingblock.terminal pre .command:not([data-prompt])::before{content:"$"}
225.listingblock pre.highlightjs{padding:0}
226.listingblock pre.highlightjs>code{padding:1em;border-radius:4px}
227.listingblock pre.prettyprint{border-width:0}
228.prettyprint{background:#f7f7f8}
229pre.prettyprint .linenums{line-height:1.45;margin-left:2em}
230pre.prettyprint li{background:none;list-style-type:inherit;padding-left:0}
231pre.prettyprint li code[data-lang]::before{opacity:1}
232pre.prettyprint li:not(:first-child) code[data-lang]::before{display:none}
233table.linenotable{border-collapse:separate;border:0;margin-bottom:0;background:none}
234table.linenotable td[class]{color:inherit;vertical-align:top;padding:0;line-height:inherit;white-space:normal}
235table.linenotable td.code{padding-left:.75em}
236table.linenotable td.linenos,pre.pygments .linenos{border-right:1px solid;opacity:.35;padding-right:.5em;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;user-select:none}
237pre.pygments span.linenos{display:inline-block;margin-right:.75em}
238.quoteblock{margin:0 1em 1.25em 1.5em;display:table}
239.quoteblock:not(.excerpt)>.title{margin-left:-1.5em;margin-bottom:.75em}
240.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}
241.quoteblock blockquote{margin:0;padding:0;border:0}
242.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)}
243.quoteblock blockquote>.paragraph:last-child p{margin-bottom:0}
244.quoteblock .attribution{margin-top:.75em;margin-right:.5ex;text-align:right}
245.verseblock{margin:0 1em 1.25em}
246.verseblock pre{font-family:"Open Sans","DejaVu Sans",sans-serif;font-size:1.15rem;color:rgba(0,0,0,.85);font-weight:300;text-rendering:optimizeLegibility}
247.verseblock pre strong{font-weight:400}
248.verseblock .attribution{margin-top:1.25rem;margin-left:.5ex}
249.quoteblock .attribution,.verseblock .attribution{font-size:.9375em;line-height:1.45;font-style:italic}
250.quoteblock .attribution br,.verseblock .attribution br{display:none}
251.quoteblock .attribution cite,.verseblock .attribution cite{display:block;letter-spacing:-.025em;color:rgba(0,0,0,.6)}
252.quoteblock.abstract blockquote::before,.quoteblock.excerpt blockquote::before,.quoteblock .quoteblock blockquote::before{display:none}
253.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}
254.quoteblock.abstract{margin:0 1em 1.25em;display:block}
255.quoteblock.abstract>.title{margin:0 0 .375em;font-size:1.15em;text-align:center}
256.quoteblock.excerpt>blockquote,.quoteblock .quoteblock{padding:0 0 .25em 1em;border-left:.25em solid #dddddf}
257.quoteblock.excerpt,.quoteblock .quoteblock{margin-left:0}
258.quoteblock.excerpt blockquote,.quoteblock.excerpt p,.quoteblock .quoteblock blockquote,.quoteblock .quoteblock p{color:inherit;font-size:1.0625rem}
259.quoteblock.excerpt .attribution,.quoteblock .quoteblock .attribution{color:inherit;font-size:.85rem;text-align:left;margin-right:0}
260p.tableblock:last-child{margin-bottom:0}
261td.tableblock>.content{margin-bottom:1.25em;word-wrap:anywhere}
262td.tableblock>.content>:last-child{margin-bottom:-1.25em}
263table.tableblock,th.tableblock,td.tableblock{border:0 solid #dedede}
264table.grid-all>*>tr>*{border-width:1px}
265table.grid-cols>*>tr>*{border-width:0 1px}
266table.grid-rows>*>tr>*{border-width:1px 0}
267table.frame-all{border-width:1px}
268table.frame-ends{border-width:1px 0}
269table.frame-sides{border-width:0 1px}
270table.frame-none>colgroup+*>:first-child>*,table.frame-sides>colgroup+*>:first-child>*{border-top-width:0}
271table.frame-none>:last-child>:last-child>*,table.frame-sides>:last-child>:last-child>*{border-bottom-width:0}
272table.frame-none>*>tr>:first-child,table.frame-ends>*>tr>:first-child{border-left-width:0}
273table.frame-none>*>tr>:last-child,table.frame-ends>*>tr>:last-child{border-right-width:0}
274table.stripes-all>*>tr,table.stripes-odd>*>tr:nth-of-type(odd),table.stripes-even>*>tr:nth-of-type(even),table.stripes-hover>*>tr:hover{background:#f8f8f7}
275th.halign-left,td.halign-left{text-align:left}
276th.halign-right,td.halign-right{text-align:right}
277th.halign-center,td.halign-center{text-align:center}
278th.valign-top,td.valign-top{vertical-align:top}
279th.valign-bottom,td.valign-bottom{vertical-align:bottom}
280th.valign-middle,td.valign-middle{vertical-align:middle}
281table thead th,table tfoot th{font-weight:bold}
282tbody tr th{background:#f7f8f7}
283tbody tr th,tbody tr th p,tfoot tr th,tfoot tr th p{color:rgba(0,0,0,.8);font-weight:bold}
284p.tableblock>code:only-child{background:none;padding:0}
285p.tableblock{font-size:1em}
286ol{margin-left:1.75em}
287ul li ol{margin-left:1.5em}
288dl dd{margin-left:1.125em}
289dl dd:last-child,dl dd:last-child>:last-child{margin-bottom:0}
290li p,ul dd,ol dd,.olist .olist,.ulist .ulist,.ulist .olist,.olist .ulist{margin-bottom:.625em}
291ul.checklist,ul.none,ol.none,ul.no-bullet,ol.no-bullet,ol.unnumbered,ul.unstyled,ol.unstyled{list-style-type:none}
292ul.no-bullet,ol.no-bullet,ol.unnumbered{margin-left:.625em}
293ul.unstyled,ol.unstyled{margin-left:0}
294li>p:empty:only-child::before{content:"";display:inline-block}
295ul.checklist>li>p:first-child{margin-left:-1em}
296ul.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}
297ul.checklist>li>p:first-child>input[type=checkbox]:first-child{margin-right:.25em}
298ul.inline{display:flex;flex-flow:row wrap;list-style:none;margin:0 0 .625em -1.25em}
299ul.inline>li{margin-left:1.25em}
300.unstyled dl dt{font-weight:400;font-style:normal}
301ol.arabic{list-style-type:decimal}
302ol.decimal{list-style-type:decimal-leading-zero}
303ol.loweralpha{list-style-type:lower-alpha}
304ol.upperalpha{list-style-type:upper-alpha}
305ol.lowerroman{list-style-type:lower-roman}
306ol.upperroman{list-style-type:upper-roman}
307ol.lowergreek{list-style-type:lower-greek}
308.hdlist>table,.colist>table{border:0;background:none}
309.hdlist>table>tbody>tr,.colist>table>tbody>tr{background:none}
310td.hdlist1,td.hdlist2{vertical-align:top;padding:0 .625em}
311td.hdlist1{font-weight:bold;padding-bottom:1.25em}
312td.hdlist2{word-wrap:anywhere}
313.literalblock+.colist,.listingblock+.colist{margin-top:-.5em}
314.colist td:not([class]):first-child{padding:.4em .75em 0;line-height:1;vertical-align:top}
315.colist td:not([class]):first-child img{max-width:none}
316.colist td:not([class]):last-child{padding:.25em 0}
317.thumb,.th{line-height:0;display:inline-block;border:4px solid #fff;box-shadow:0 0 0 1px #ddd}
318.imageblock.left{margin:.25em .625em 1.25em 0}
319.imageblock.right{margin:.25em 0 1.25em .625em}
320.imageblock>.title{margin-bottom:0}
321.imageblock.thumb,.imageblock.th{border-width:6px}
322.imageblock.thumb>.title,.imageblock.th>.title{padding:0 .125em}
323.image.left,.image.right{margin-top:.25em;margin-bottom:.25em;display:inline-block;line-height:0}
324.image.left{margin-right:.625em}
325.image.right{margin-left:.625em}
326a.image{text-decoration:none;display:inline-block}
327a.image object{pointer-events:none}
328sup.footnote,sup.footnoteref{font-size:.875em;position:static;vertical-align:super}
329sup.footnote a,sup.footnoteref a{text-decoration:none}
330sup.footnote a:active,sup.footnoteref a:active{text-decoration:underline}
331#footnotes{padding-top:.75em;padding-bottom:.75em;margin-bottom:.625em}
332#footnotes hr{width:20%;min-width:6.25em;margin:-.25em 0 .75em;border-width:1px 0 0}
333#footnotes .footnote{padding:0 .375em 0 .225em;line-height:1.3334;font-size:.875em;margin-left:1.2em;margin-bottom:.2em}
334#footnotes .footnote a:first-of-type{font-weight:bold;text-decoration:none;margin-left:-1.05em}
335#footnotes .footnote:last-of-type{margin-bottom:0}
336#content #footnotes{margin-top:-.625em;margin-bottom:0;padding:.75em 0}
337div.unbreakable{page-break-inside:avoid}
338.big{font-size:larger}
339.small{font-size:smaller}
340.underline{text-decoration:underline}
341.overline{text-decoration:overline}
342.line-through{text-decoration:line-through}
343.aqua{color:#00bfbf}
344.aqua-background{background:#00fafa}
345.black{color:#000}
346.black-background{background:#000}
347.blue{color:#0000bf}
348.blue-background{background:#0000fa}
349.fuchsia{color:#bf00bf}
350.fuchsia-background{background:#fa00fa}
351.gray{color:#606060}
352.gray-background{background:#7d7d7d}
353.green{color:#006000}
354.green-background{background:#007d00}
355.lime{color:#00bf00}
356.lime-background{background:#00fa00}
357.maroon{color:#600000}
358.maroon-background{background:#7d0000}
359.navy{color:#000060}
360.navy-background{background:#00007d}
361.olive{color:#606000}
362.olive-background{background:#7d7d00}
363.purple{color:#600060}
364.purple-background{background:#7d007d}
365.red{color:#bf0000}
366.red-background{background:#fa0000}
367.silver{color:#909090}
368.silver-background{background:#bcbcbc}
369.teal{color:#006060}
370.teal-background{background:#007d7d}
371.white{color:#bfbfbf}
372.white-background{background:#fafafa}
373.yellow{color:#bfbf00}
374.yellow-background{background:#fafa00}
375span.icon>.fa{cursor:default}
376a span.icon>.fa{cursor:inherit}
377.admonitionblock td.icon [class^="fa icon-"]{font-size:2.5em;text-shadow:1px 1px 2px rgba(0,0,0,.5);cursor:default}
378.admonitionblock td.icon .icon-note::before{content:"\f05a";color:#19407c}
379.admonitionblock td.icon .icon-tip::before{content:"\f0eb";text-shadow:1px 1px 2px rgba(155,155,0,.8);color:#111}
380.admonitionblock td.icon .icon-warning::before{content:"\f071";color:#bf6900}
381.admonitionblock td.icon .icon-caution::before{content:"\f06d";color:#bf3400}
382.admonitionblock td.icon .icon-important::before{content:"\f06a";color:#bf0000}
383.conum[data-value]{display:inline-block;color:#fff!important;background:rgba(0,0,0,.8);border-radius:50%;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}
384.conum[data-value] *{color:#fff!important}
385.conum[data-value]+b{display:none}
386.conum[data-value]::after{content:attr(data-value)}
387pre .conum[data-value]{position:relative;top:-.125em}
388b.conum *{color:inherit!important}
389.conum:not([data-value]):empty{display:none}
390dt,th.tableblock,td.content,div.footnote{text-rendering:optimizeLegibility}
391h1,h2,p,td.content,span.alt,summary{letter-spacing:-.01em}
392p strong,td.content strong,div.footnote strong{letter-spacing:-.005em}
393p,blockquote,dt,td.content,td.hdlist1,span.alt,summary{font-size:1.0625rem}
394p{margin-bottom:1.25rem}
395.sidebarblock p,.sidebarblock dt,.sidebarblock td.content,p.tableblock{font-size:1em}
396.exampleblock>.content{background:#fffef7;border-color:#e0e0dc;box-shadow:0 1px 4px #e0e0dc}
397.print-only{display:none!important}
398@page{margin:1.25cm .75cm}
399@media print{*{box-shadow:none!important;text-shadow:none!important}
400html{font-size:80%}
401a{color:inherit!important;text-decoration:underline!important}
402a.bare,a[href^="#"],a[href^="mailto:"]{text-decoration:none!important}
403a[href^="http:"]:not(.bare)::after,a[href^="https:"]:not(.bare)::after{content:"(" attr(href) ")";display:inline-block;font-size:.875em;padding-left:.25em}
404abbr[title]{border-bottom:1px dotted}
405abbr[title]::after{content:" (" attr(title) ")"}
406pre,blockquote,tr,img,object,svg{page-break-inside:avoid}
407thead{display:table-header-group}
408svg{max-width:100%}
409p,blockquote,dt,td.content{font-size:1em;orphans:3;widows:3}
410h2,h3,#toctitle,.sidebarblock>.content>.title{page-break-after:avoid}
411#header,#content,#footnotes,#footer{max-width:none}
412#toc,.sidebarblock,.exampleblock>.content{background:none!important}
413#toc{border-bottom:1px solid #dddddf!important;padding-bottom:0!important}
414body.book #header{text-align:center}
415body.book #header>h1:first-child{border:0!important;margin:2.5em 0 1em}
416body.book #header .details{border:0!important;display:block;padding:0!important}
417body.book #header .details span:first-child{margin-left:0!important}
418body.book #header .details br{display:block}
419body.book #header .details br+span::before{content:none!important}
420body.book #toc{border:0!important;text-align:left!important;padding:0!important;margin:0!important}
421body.book #toc,body.book #preamble,body.book h1.sect0,body.book .sect1>h2{page-break-before:always}
422.listingblock code[data-lang]::before{display:block}
423#footer{padding:0 .9375em}
424.hide-on-print{display:none!important}
425.print-only{display:block!important}
426.hide-for-print{display:none!important}
427.show-for-print{display:inherit!important}}
428@media amzn-kf8,print{#header>h1:first-child{margin-top:1.25rem}
429.sect1{padding:0!important}
430.sect1+.sect1{border:0}
431#footer{background:none}
432#footer-text{color:rgba(0,0,0,.6);font-size:.9em}}
433@media amzn-kf8{#header,#content,#footnotes,#footer{padding:0}}
434</style>
435<style>
436pre>code {
437 display: inline;
438}
439</style>
440</head>
441<body class="manpage">
442<div id="header">
443<h1>gitprotocol-v2(5) Manual Page</h1>
444<h2 id="_name">NAME</h2>
445<div class="sectionbody">
446<p>gitprotocol-v2 - Git Wire Protocol, Version 2</p>
447</div>
448</div>
449<div id="content">
450<div class="sect1">
451<h2 id="_synopsis">SYNOPSIS</h2>
452<div class="sectionbody">
453<div class="verseblock">
454<pre class="content">&lt;over-the-wire-protocol&gt;</pre>
455</div>
456</div>
457</div>
458<div class="sect1">
459<h2 id="_description">DESCRIPTION</h2>
460<div class="sectionbody">
461<div class="paragraph">
462<p>This document presents a specification for a version 2 of Git&#8217;s wire
463protocol. Protocol v2 will improve upon v1 in the following ways:</p>
464</div>
465<div class="ulist">
466<ul>
467<li>
468<p>Instead of multiple service names, multiple commands will be
469supported by a single service</p>
470</li>
471<li>
472<p>Easily extendable as capabilities are moved into their own section
473of the protocol, no longer being hidden behind a NUL byte and
474limited by the size of a pkt-line</p>
475</li>
476<li>
477<p>Separate out other information hidden behind NUL bytes (e.g. agent
478string as a capability and symrefs can be requested using <em>ls-refs</em>)</p>
479</li>
480<li>
481<p>Reference advertisement will be omitted unless explicitly requested</p>
482</li>
483<li>
484<p>ls-refs command to explicitly request some refs</p>
485</li>
486<li>
487<p>Designed with http and stateless-rpc in mind. With clear flush
488semantics the http remote helper can simply act as a proxy</p>
489</li>
490</ul>
491</div>
492<div class="paragraph">
493<p>In protocol v2 communication is command oriented. When first contacting a
494server a list of capabilities will be advertised. Some of these capabilities
495will be commands which a client can request be executed. Once a command
496has completed, a client can reuse the connection and request that other
497commands be executed.</p>
498</div>
499</div>
500</div>
501<div class="sect1">
502<h2 id="_packet_line_framing">Packet-Line Framing</h2>
503<div class="sectionbody">
504<div class="paragraph">
505<p>All communication is done using packet-line framing, just as in v1. See
506<a href="gitprotocol-pack.html">gitprotocol-pack(5)</a> and <a href="gitprotocol-common.html">gitprotocol-common(5)</a> for more information.</p>
507</div>
508<div class="paragraph">
509<p>In protocol v2 these special packets will have the following semantics:</p>
510</div>
511<div class="ulist">
512<ul>
513<li>
514<p><em>0000</em> Flush Packet (flush-pkt) - indicates the end of a message</p>
515</li>
516<li>
517<p><em>0001</em> Delimiter Packet (delim-pkt) - separates sections of a message</p>
518</li>
519<li>
520<p><em>0002</em> Response End Packet (response-end-pkt) - indicates the end of a
521response for stateless connections</p>
522</li>
523</ul>
524</div>
525</div>
526</div>
527<div class="sect1">
528<h2 id="_initial_client_request">Initial Client Request</h2>
529<div class="sectionbody">
530<div class="paragraph">
531<p>In general a client can request to speak protocol v2 by sending
532<code>version=2</code> through the respective side-channel for the transport being
533used which inevitably sets <code>GIT_PROTOCOL</code>. More information can be
534found in <a href="gitprotocol-pack.html">gitprotocol-pack(5)</a> and <a href="gitprotocol-http.html">gitprotocol-http(5)</a>, as well as the
535<code>GIT_PROTOCOL</code> definition in <code>git.txt</code>. In all cases the
536response from the server is the capability advertisement.</p>
537</div>
538<div class="sect2">
539<h3 id="_git_transport">Git Transport</h3>
540<div class="paragraph">
541<p>When using the git:// transport, you can request to use protocol v2 by
542sending "version=2" as an extra parameter:</p>
543</div>
544<div class="literalblock">
545<div class="content">
546<pre>003egit-upload-pack /project.git\0host=myserver.com\0\0version=2\0</pre>
547</div>
548</div>
549</div>
550<div class="sect2">
551<h3 id="_ssh_and_file_transport">SSH and File Transport</h3>
552<div class="paragraph">
553<p>When using either the ssh:// or file:// transport, the GIT_PROTOCOL
554environment variable must be set explicitly to include "version=2".
555The server may need to be configured to allow this environment variable
556to pass.</p>
557</div>
558</div>
559<div class="sect2">
560<h3 id="_http_transport">HTTP Transport</h3>
561<div class="paragraph">
562<p>When using the http:// or https:// transport a client makes a "smart"
563info/refs request as described in <a href="gitprotocol-http.html">gitprotocol-http(5)</a> and requests that
564v2 be used by supplying "version=2" in the <code>Git-Protocol</code> header.</p>
565</div>
566<div class="literalblock">
567<div class="content">
568<pre>C: GET $GIT_URL/info/refs?service=git-upload-pack HTTP/1.0
569C: Git-Protocol: version=2</pre>
570</div>
571</div>
572<div class="paragraph">
573<p>A v2 server would reply:</p>
574</div>
575<div class="literalblock">
576<div class="content">
577<pre>S: 200 OK
578S: &lt;Some headers&gt;
579S: ...
580S:
581S: 000eversion 2\n
582S: &lt;capability-advertisement&gt;</pre>
583</div>
584</div>
585<div class="paragraph">
586<p>Subsequent requests are then made directly to the service
587<code>$GIT_URL/git-upload-pack</code>. (This works the same for git-receive-pack).</p>
588</div>
589<div class="paragraph">
590<p>Uses the <code>--http-backend-info-refs</code> option to
591<a href="git-upload-pack.html">git-upload-pack(1)</a>.</p>
592</div>
593<div class="paragraph">
594<p>The server may need to be configured to pass this header&#8217;s contents via
595the <code>GIT_PROTOCOL</code> variable. See the discussion in <code>git-http-backend.txt</code>.</p>
596</div>
597</div>
598</div>
599</div>
600<div class="sect1">
601<h2 id="_capability_advertisement">Capability Advertisement</h2>
602<div class="sectionbody">
603<div class="paragraph">
604<p>A server which decides to communicate (based on a request from a client)
605using protocol version 2, notifies the client by sending a version string
606in its initial response followed by an advertisement of its capabilities.
607Each capability is a key with an optional value. Clients must ignore all
608unknown keys. Semantics of unknown values are left to the definition of
609each key. Some capabilities will describe commands which can be requested
610to be executed by the client.</p>
611</div>
612<div class="literalblock">
613<div class="content">
614<pre>capability-advertisement = protocol-version
615 capability-list
616 flush-pkt</pre>
617</div>
618</div>
619<div class="literalblock">
620<div class="content">
621<pre>protocol-version = PKT-LINE("version 2" LF)
622capability-list = *capability
623capability = PKT-LINE(key[=value] LF)</pre>
624</div>
625</div>
626<div class="literalblock">
627<div class="content">
628<pre>key = 1*(ALPHA | DIGIT | "-_")
629value = 1*(ALPHA | DIGIT | " -_.,?\/{}[]()&lt;&gt;!@#$%^&amp;*+=:;")</pre>
630</div>
631</div>
632</div>
633</div>
634<div class="sect1">
635<h2 id="_command_request">Command Request</h2>
636<div class="sectionbody">
637<div class="paragraph">
638<p>After receiving the capability advertisement, a client can then issue a
639request to select the command it wants with any particular capabilities
640or arguments. There is then an optional section where the client can
641provide any command specific parameters or queries. Only a single
642command can be requested at a time.</p>
643</div>
644<div class="literalblock">
645<div class="content">
646<pre>request = empty-request | command-request
647empty-request = flush-pkt
648command-request = command
649 capability-list
650 delim-pkt
651 command-args
652 flush-pkt
653command = PKT-LINE("command=" key LF)
654command-args = *command-specific-arg</pre>
655</div>
656</div>
657<div class="literalblock">
658<div class="content">
659<pre>command-specific-args are packet line framed arguments defined by
660each individual command.</pre>
661</div>
662</div>
663<div class="paragraph">
664<p>The server will then check to ensure that the client&#8217;s request is
665comprised of a valid command as well as valid capabilities which were
666advertised. If the request is valid the server will then execute the
667command. A server MUST wait till it has received the client&#8217;s entire
668request before issuing a response. The format of the response is
669determined by the command being executed, but in all cases a flush-pkt
670indicates the end of the response.</p>
671</div>
672<div class="paragraph">
673<p>When a command has finished, and the client has received the entire
674response from the server, a client can either request that another
675command be executed or can terminate the connection. A client may
676optionally send an empty request consisting of just a flush-pkt to
677indicate that no more requests will be made.</p>
678</div>
679</div>
680</div>
681<div class="sect1">
682<h2 id="_capabilities">Capabilities</h2>
683<div class="sectionbody">
684<div class="paragraph">
685<p>There are two different types of capabilities: normal capabilities,
686which can be used to convey information or alter the behavior of a
687request, and commands, which are the core actions that a client wants to
688perform (fetch, push, etc).</p>
689</div>
690<div class="paragraph">
691<p>Protocol version 2 is stateless by default. This means that all commands
692must only last a single round and be stateless from the perspective of the
693server side, unless the client has requested a capability indicating that
694state should be maintained by the server. Clients MUST NOT require state
695management on the server side in order to function correctly. This
696permits simple round-robin load-balancing on the server side, without
697needing to worry about state management.</p>
698</div>
699<div class="sect2">
700<h3 id="_agent">agent</h3>
701<div class="paragraph">
702<p>The server can advertise the <code>agent</code> capability with a value <code>X</code> (in the
703form <code>agent=X</code>) to notify the client that the server is running version
704<code>X</code>. The client may optionally send its own agent string by including
705the <code>agent</code> capability with a value <code>Y</code> (in the form <code>agent=Y</code>) in its
706request to the server (but it MUST NOT do so if the server did not
707advertise the agent capability). The <code>X</code> and <code>Y</code> strings may contain any
708printable ASCII characters except space (i.e., the byte range 32 &lt; x &lt;
709127), and are typically of the form "package/version" (e.g.,
710"git/1.8.3.1"). The agent strings are purely informative for statistics
711and debugging purposes, and MUST NOT be used to programmatically assume
712the presence or absence of particular features.</p>
713</div>
714</div>
715<div class="sect2">
716<h3 id="_ls_refs">ls-refs</h3>
717<div class="paragraph">
718<p><code>ls-refs</code> is the command used to request a reference advertisement in v2.
719Unlike the current reference advertisement, ls-refs takes in arguments
720which can be used to limit the refs sent from the server.</p>
721</div>
722<div class="paragraph">
723<p>Additional features not supported in the base command will be advertised
724as the value of the command in the capability advertisement in the form
725of a space separated list of features: "&lt;command&gt;=&lt;feature-1&gt; &lt;feature-2&gt;"</p>
726</div>
727<div class="paragraph">
728<p>ls-refs takes in the following arguments:</p>
729</div>
730<div class="literalblock">
731<div class="content">
732<pre> symrefs
733In addition to the object pointed by it, show the underlying ref
734pointed by it when showing a symbolic ref.
735 peel
736Show peeled tags.
737 ref-prefix &lt;prefix&gt;
738When specified, only references having a prefix matching one of
739the provided prefixes are displayed. Multiple instances may be
740given, in which case references matching any prefix will be
741shown. Note that this is purely for optimization; a server MAY
742show refs not matching the prefix if it chooses, and clients
743should filter the result themselves.</pre>
744</div>
745</div>
746<div class="paragraph">
747<p>If the <em>unborn</em> feature is advertised the following argument can be
748included in the client&#8217;s request.</p>
749</div>
750<div class="literalblock">
751<div class="content">
752<pre> unborn
753The server will send information about HEAD even if it is a symref
754pointing to an unborn branch in the form "unborn HEAD
755symref-target:&lt;target&gt;".</pre>
756</div>
757</div>
758<div class="paragraph">
759<p>The output of ls-refs is as follows:</p>
760</div>
761<div class="literalblock">
762<div class="content">
763<pre>output = *ref
764 flush-pkt
765obj-id-or-unborn = (obj-id | "unborn")
766ref = PKT-LINE(obj-id-or-unborn SP refname *(SP ref-attribute) LF)
767ref-attribute = (symref | peeled)
768symref = "symref-target:" symref-target
769peeled = "peeled:" obj-id</pre>
770</div>
771</div>
772</div>
773<div class="sect2">
774<h3 id="_fetch">fetch</h3>
775<div class="paragraph">
776<p><code>fetch</code> is the command used to fetch a packfile in v2. It can be looked
777at as a modified version of the v1 fetch where the ref-advertisement is
778stripped out (since the <code>ls-refs</code> command fills that role) and the
779message format is tweaked to eliminate redundancies and permit easy
780addition of future extensions.</p>
781</div>
782<div class="paragraph">
783<p>Additional features not supported in the base command will be advertised
784as the value of the command in the capability advertisement in the form
785of a space separated list of features: "&lt;command&gt;=&lt;feature-1&gt; &lt;feature-2&gt;"</p>
786</div>
787<div class="paragraph">
788<p>A <code>fetch</code> request can take the following arguments:</p>
789</div>
790<div class="literalblock">
791<div class="content">
792<pre> want &lt;oid&gt;
793Indicates to the server an object which the client wants to
794retrieve. Wants can be anything and are not limited to
795advertised objects.</pre>
796</div>
797</div>
798<div class="literalblock">
799<div class="content">
800<pre> have &lt;oid&gt;
801Indicates to the server an object which the client has locally.
802This allows the server to make a packfile which only contains
803the objects that the client needs. Multiple 'have' lines can be
804supplied.</pre>
805</div>
806</div>
807<div class="literalblock">
808<div class="content">
809<pre> done
810Indicates to the server that negotiation should terminate (or
811not even begin if performing a clone) and that the server should
812use the information supplied in the request to construct the
813packfile.</pre>
814</div>
815</div>
816<div class="literalblock">
817<div class="content">
818<pre> thin-pack
819Request that a thin pack be sent, which is a pack with deltas
820which reference base objects not contained within the pack (but
821are known to exist at the receiving end). This can reduce the
822network traffic significantly, but it requires the receiving end
823to know how to "thicken" these packs by adding the missing bases
824to the pack.</pre>
825</div>
826</div>
827<div class="literalblock">
828<div class="content">
829<pre> no-progress
830Request that progress information that would normally be sent on
831side-band channel 2, during the packfile transfer, should not be
832sent. However, the side-band channel 3 is still used for error
833responses.</pre>
834</div>
835</div>
836<div class="literalblock">
837<div class="content">
838<pre> include-tag
839Request that annotated tags should be sent if the objects they
840point to are being sent.</pre>
841</div>
842</div>
843<div class="literalblock">
844<div class="content">
845<pre> ofs-delta
846Indicate that the client understands PACKv2 with delta referring
847to its base by position in pack rather than by an oid. That is,
848they can read OBJ_OFS_DELTA (aka type 6) in a packfile.</pre>
849</div>
850</div>
851<div class="paragraph">
852<p>If the <em>shallow</em> feature is advertised the following arguments can be
853included in the clients request as well as the potential addition of the
854<em>shallow-info</em> section in the server&#8217;s response as explained below.</p>
855</div>
856<div class="literalblock">
857<div class="content">
858<pre> shallow &lt;oid&gt;
859A client must notify the server of all commits for which it only
860has shallow copies (meaning that it doesn't have the parents of
861a commit) by supplying a 'shallow &lt;oid&gt;' line for each such
862object so that the server is aware of the limitations of the
863client's history. This is so that the server is aware that the
864client may not have all objects reachable from such commits.</pre>
865</div>
866</div>
867<div class="literalblock">
868<div class="content">
869<pre> deepen &lt;depth&gt;
870Requests that the fetch/clone should be shallow having a commit
871depth of &lt;depth&gt; relative to the remote side.</pre>
872</div>
873</div>
874<div class="literalblock">
875<div class="content">
876<pre> deepen-relative
877Requests that the semantics of the "deepen" command be changed
878to indicate that the depth requested is relative to the client's
879current shallow boundary, instead of relative to the requested
880commits.</pre>
881</div>
882</div>
883<div class="literalblock">
884<div class="content">
885<pre> deepen-since &lt;timestamp&gt;
886Requests that the shallow clone/fetch should be cut at a
887specific time, instead of depth. Internally it's equivalent to
888doing "git rev-list --max-age=&lt;timestamp&gt;". Cannot be used with
889"deepen".</pre>
890</div>
891</div>
892<div class="literalblock">
893<div class="content">
894<pre> deepen-not &lt;rev&gt;
895Requests that the shallow clone/fetch should be cut at a
896specific revision specified by '&lt;rev&gt;', instead of a depth.
897Internally it's equivalent of doing "git rev-list --not &lt;rev&gt;".
898Cannot be used with "deepen", but can be used with
899"deepen-since".</pre>
900</div>
901</div>
902<div class="paragraph">
903<p>If the <em>filter</em> feature is advertised, the following argument can be
904included in the client&#8217;s request:</p>
905</div>
906<div class="literalblock">
907<div class="content">
908<pre> filter &lt;filter-spec&gt;
909Request that various objects from the packfile be omitted
910using one of several filtering techniques. These are intended
911for use with partial clone and partial fetch operations. See
912`rev-list` for possible "filter-spec" values. When communicating
913with other processes, senders SHOULD translate scaled integers
914(e.g. "1k") into a fully-expanded form (e.g. "1024") to aid
915interoperability with older receivers that may not understand
916newly-invented scaling suffixes. However, receivers SHOULD
917accept the following suffixes: 'k', 'm', and 'g' for 1024,
9181048576, and 1073741824, respectively.</pre>
919</div>
920</div>
921<div class="paragraph">
922<p>If the <em>ref-in-want</em> feature is advertised, the following argument can
923be included in the client&#8217;s request as well as the potential addition of
924the <em>wanted-refs</em> section in the server&#8217;s response as explained below.</p>
925</div>
926<div class="literalblock">
927<div class="content">
928<pre> want-ref &lt;ref&gt;
929Indicates to the server that the client wants to retrieve a
930particular ref, where &lt;ref&gt; is the full name of a ref on the
931server. It is a protocol error to send want-ref for the
932same ref more than once.</pre>
933</div>
934</div>
935<div class="paragraph">
936<p>If the <em>sideband-all</em> feature is advertised, the following argument can be
937included in the client&#8217;s request:</p>
938</div>
939<div class="literalblock">
940<div class="content">
941<pre> sideband-all
942Instruct the server to send the whole response multiplexed, not just
943the packfile section. All non-flush and non-delim PKT-LINE in the
944response (not only in the packfile section) will then start with a byte
945indicating its sideband (1, 2, or 3), and the server may send "0005\2"
946(a PKT-LINE of sideband 2 with no payload) as a keepalive packet.</pre>
947</div>
948</div>
949<div class="paragraph">
950<p>If the <em>packfile-uris</em> feature is advertised, the following argument
951can be included in the client&#8217;s request as well as the potential
952addition of the <em>packfile-uris</em> section in the server&#8217;s response as
953explained below. Note that at most one <code>packfile-uris</code> line can be sent
954to the server.</p>
955</div>
956<div class="literalblock">
957<div class="content">
958<pre> packfile-uris &lt;comma-separated-list-of-protocols&gt;
959Indicates to the server that the client is willing to receive
960URIs of any of the given protocols in place of objects in the
961sent packfile. Before performing the connectivity check, the
962client should download from all given URIs. Currently, the
963protocols supported are "http" and "https".</pre>
964</div>
965</div>
966<div class="paragraph">
967<p>If the <em>wait-for-done</em> feature is advertised, the following argument
968can be included in the client&#8217;s request.</p>
969</div>
970<div class="literalblock">
971<div class="content">
972<pre> wait-for-done
973Indicates to the server that it should never send "ready", but
974should wait for the client to say "done" before sending the
975packfile.</pre>
976</div>
977</div>
978<div class="paragraph">
979<p>The response of <code>fetch</code> is broken into a number of sections separated by
980delimiter packets (0001), with each section beginning with its section
981header. Most sections are sent only when the packfile is sent.</p>
982</div>
983<div class="literalblock">
984<div class="content">
985<pre>output = acknowledgements flush-pkt |
986 [acknowledgments delim-pkt] [shallow-info delim-pkt]
987 [wanted-refs delim-pkt] [packfile-uris delim-pkt]
988 packfile flush-pkt</pre>
989</div>
990</div>
991<div class="literalblock">
992<div class="content">
993<pre>acknowledgments = PKT-LINE("acknowledgments" LF)
994 (nak | *ack)
995 (ready)
996ready = PKT-LINE("ready" LF)
997nak = PKT-LINE("NAK" LF)
998ack = PKT-LINE("ACK" SP obj-id LF)</pre>
999</div>
1000</div>
1001<div class="literalblock">
1002<div class="content">
1003<pre>shallow-info = PKT-LINE("shallow-info" LF)
1004 *PKT-LINE((shallow | unshallow) LF)
1005shallow = "shallow" SP obj-id
1006unshallow = "unshallow" SP obj-id</pre>
1007</div>
1008</div>
1009<div class="literalblock">
1010<div class="content">
1011<pre>wanted-refs = PKT-LINE("wanted-refs" LF)
1012*PKT-LINE(wanted-ref LF)
1013wanted-ref = obj-id SP refname</pre>
1014</div>
1015</div>
1016<div class="literalblock">
1017<div class="content">
1018<pre>packfile-uris = PKT-LINE("packfile-uris" LF) *packfile-uri
1019packfile-uri = PKT-LINE(40*(HEXDIGIT) SP *%x20-ff LF)</pre>
1020</div>
1021</div>
1022<div class="literalblock">
1023<div class="content">
1024<pre>packfile = PKT-LINE("packfile" LF)
1025 *PKT-LINE(%x01-03 *%x00-ff)</pre>
1026</div>
1027</div>
1028<div class="literalblock">
1029<div class="content">
1030<pre> acknowledgments section
1031* If the client determines that it is finished with negotiations by
1032 sending a "done" line (thus requiring the server to send a packfile),
1033 the acknowledgments sections MUST be omitted from the server's
1034 response.</pre>
1035</div>
1036</div>
1037<div class="ulist">
1038<ul>
1039<li>
1040<p>Always begins with the section header "acknowledgments"</p>
1041</li>
1042<li>
1043<p>The server will respond with "NAK" if none of the object ids sent
1044as have lines were common.</p>
1045</li>
1046<li>
1047<p>The server will respond with "ACK obj-id" for all of the
1048object ids sent as have lines which are common.</p>
1049</li>
1050<li>
1051<p>A response cannot have both "ACK" lines as well as a "NAK"
1052line.</p>
1053</li>
1054<li>
1055<p>The server will respond with a "ready" line indicating that
1056the server has found an acceptable common base and is ready to
1057make and send a packfile (which will be found in the packfile
1058section of the same response)</p>
1059</li>
1060<li>
1061<p>If the server has found a suitable cut point and has decided
1062to send a "ready" line, then the server can decide to (as an
1063optimization) omit any "ACK" lines it would have sent during
1064its response. This is because the server will have already
1065determined the objects it plans to send to the client and no
1066further negotiation is needed.</p>
1067<div class="literalblock">
1068<div class="content">
1069<pre> shallow-info section
1070* If the client has requested a shallow fetch/clone, a shallow
1071 client requests a fetch or the server is shallow then the
1072 server's response may include a shallow-info section. The
1073 shallow-info section will be included if (due to one of the
1074 above conditions) the server needs to inform the client of any
1075 shallow boundaries or adjustments to the clients already
1076 existing shallow boundaries.</pre>
1077</div>
1078</div>
1079</li>
1080<li>
1081<p>Always begins with the section header "shallow-info"</p>
1082</li>
1083<li>
1084<p>If a positive depth is requested, the server will compute the
1085set of commits which are no deeper than the desired depth.</p>
1086</li>
1087<li>
1088<p>The server sends a "shallow obj-id" line for each commit whose
1089parents will not be sent in the following packfile.</p>
1090</li>
1091<li>
1092<p>The server sends an "unshallow obj-id" line for each commit
1093which the client has indicated is shallow, but is no longer
1094shallow as a result of the fetch (due to its parents being
1095sent in the following packfile).</p>
1096</li>
1097<li>
1098<p>The server MUST NOT send any "unshallow" lines for anything
1099which the client has not indicated was shallow as a part of
1100its request.</p>
1101<div class="literalblock">
1102<div class="content">
1103<pre> wanted-refs section
1104* This section is only included if the client has requested a
1105 ref using a 'want-ref' line and if a packfile section is also
1106 included in the response.</pre>
1107</div>
1108</div>
1109</li>
1110<li>
1111<p>Always begins with the section header "wanted-refs".</p>
1112</li>
1113<li>
1114<p>The server will send a ref listing ("&lt;oid&gt; &lt;refname&gt;") for
1115each reference requested using <em>want-ref</em> lines.</p>
1116</li>
1117<li>
1118<p>The server MUST NOT send any refs which were not requested
1119using <em>want-ref</em> lines.</p>
1120<div class="literalblock">
1121<div class="content">
1122<pre> packfile-uris section
1123* This section is only included if the client sent
1124 'packfile-uris' and the server has at least one such URI to
1125 send.</pre>
1126</div>
1127</div>
1128</li>
1129<li>
1130<p>Always begins with the section header "packfile-uris".</p>
1131</li>
1132<li>
1133<p>For each URI the server sends, it sends a hash of the pack&#8217;s
1134contents (as output by git index-pack) followed by the URI.</p>
1135</li>
1136<li>
1137<p>The hashes are 40 hex characters long. When Git upgrades to a new
1138hash algorithm, this might need to be updated. (It should match
1139whatever index-pack outputs after "pack\t" or "keep\t".</p>
1140<div class="literalblock">
1141<div class="content">
1142<pre> packfile section
1143* This section is only included if the client has sent 'want'
1144 lines in its request and either requested that no more
1145 negotiation be done by sending 'done' or if the server has
1146 decided it has found a sufficient cut point to produce a
1147 packfile.</pre>
1148</div>
1149</div>
1150</li>
1151<li>
1152<p>Always begins with the section header "packfile"</p>
1153</li>
1154<li>
1155<p>The transmission of the packfile begins immediately after the
1156section header</p>
1157</li>
1158<li>
1159<p>The data transfer of the packfile is always multiplexed, using
1160the same semantics of the <em>side-band-64k</em> capability from
1161protocol version 1. This means that each packet, during the
1162packfile data stream, is made up of a leading 4-byte pkt-line
1163length (typical of the pkt-line format), followed by a 1-byte
1164stream code, followed by the actual data.</p>
1165<div class="literalblock">
1166<div class="content">
1167<pre> The stream code can be one of:
11681 - pack data
11692 - progress messages
11703 - fatal error message just before stream aborts</pre>
1171</div>
1172</div>
1173</li>
1174</ul>
1175</div>
1176</div>
1177<div class="sect2">
1178<h3 id="_server_option">server-option</h3>
1179<div class="paragraph">
1180<p>If advertised, indicates that any number of server specific options can be
1181included in a request. This is done by sending each option as a
1182"server-option=&lt;option&gt;" capability line in the capability-list section of
1183a request.</p>
1184</div>
1185<div class="paragraph">
1186<p>The provided options must not contain a NUL or LF character.</p>
1187</div>
1188</div>
1189<div class="sect2">
Junio C Hamanof4e4f532024-11-02 05:48:11[diff] [blame]1190<h3 id="_object_format">object-format</h3>
Junio C Hamanob96f40a2024-08-01 00:57:25[diff] [blame]1191<div class="paragraph">
1192<p>The server can advertise the <code>object-format</code> capability with a value <code>X</code> (in the
1193form <code>object-format=X</code>) to notify the client that the server is able to deal
1194with objects using hash algorithm X. If not specified, the server is assumed to
1195only handle SHA-1. If the client would like to use a hash algorithm other than
1196SHA-1, it should specify its object-format string.</p>
1197</div>
1198</div>
1199<div class="sect2">
1200<h3 id="_session_idsession_id">session-id=&lt;session-id&gt;</h3>
1201<div class="paragraph">
1202<p>The server may advertise a session ID that can be used to identify this process
1203across multiple requests. The client may advertise its own session ID back to
1204the server as well.</p>
1205</div>
1206<div class="paragraph">
1207<p>Session IDs should be unique to a given process. They must fit within a
1208packet-line, and must not contain non-printable or whitespace characters. The
1209current implementation uses trace2 session IDs (see
1210<a href="technical/api-trace2.html">api-trace2</a> for details), but this may change
1211and users of the session ID should not rely on this fact.</p>
1212</div>
1213</div>
1214<div class="sect2">
1215<h3 id="_object_info">object-info</h3>
1216<div class="paragraph">
1217<p><code>object-info</code> is the command to retrieve information about one or more objects.
1218Its main purpose is to allow a client to make decisions based on this
1219information without having to fully fetch objects. Object size is the only
1220information that is currently supported.</p>
1221</div>
1222<div class="paragraph">
1223<p>An <code>object-info</code> request takes the following arguments:</p>
1224</div>
1225<div class="literalblock">
1226<div class="content">
1227<pre>size
1228Requests size information to be returned for each listed object id.</pre>
1229</div>
1230</div>
1231<div class="literalblock">
1232<div class="content">
1233<pre>oid &lt;oid&gt;
1234Indicates to the server an object which the client wants to obtain
1235information for.</pre>
1236</div>
1237</div>
1238<div class="paragraph">
1239<p>The response of <code>object-info</code> is a list of the requested object ids
1240and associated requested information, each separated by a single space.</p>
1241</div>
1242<div class="literalblock">
1243<div class="content">
1244<pre>output = info flush-pkt</pre>
1245</div>
1246</div>
1247<div class="literalblock">
1248<div class="content">
1249<pre>info = PKT-LINE(attrs) LF)
1250*PKT-LINE(obj-info LF)</pre>
1251</div>
1252</div>
1253<div class="literalblock">
1254<div class="content">
1255<pre>attrs = attr | attrs SP attrs</pre>
1256</div>
1257</div>
1258<div class="literalblock">
1259<div class="content">
1260<pre>attr = "size"</pre>
1261</div>
1262</div>
1263<div class="literalblock">
1264<div class="content">
1265<pre>obj-info = obj-id SP obj-size</pre>
1266</div>
1267</div>
1268</div>
1269<div class="sect2">
1270<h3 id="_bundle_uri">bundle-uri</h3>
1271<div class="paragraph">
1272<p>If the <em>bundle-uri</em> capability is advertised, the server supports the
1273&#8216;bundle-uri&#8217; command.</p>
1274</div>
1275<div class="paragraph">
1276<p>The capability is currently advertised with no value (i.e. not
1277"bundle-uri=somevalue"), a value may be added in the future for
1278supporting command-wide extensions. Clients MUST ignore any unknown
1279capability values and proceed with the 'bundle-uri` dialog they
1280support.</p>
1281</div>
1282<div class="paragraph">
1283<p>The <em>bundle-uri</em> command is intended to be issued before <code>fetch</code> to
1284get URIs to bundle files (see <a href="git-bundle.html">git-bundle(1)</a>) to "seed" and
1285inform the subsequent <code>fetch</code> command.</p>
1286</div>
1287<div class="paragraph">
1288<p>The client CAN issue <code>bundle-uri</code> before or after any other valid
1289command. To be useful to clients it&#8217;s expected that it&#8217;ll be issued
1290after an <code>ls-refs</code> and before <code>fetch</code>, but CAN be issued at any time
1291in the dialog.</p>
1292</div>
1293<div class="sect3">
1294<h4 id="_discussion_of_bundle_uri">DISCUSSION of bundle-uri</h4>
1295<div class="paragraph">
1296<p>The intent of the feature is optimize for server resource consumption
1297in the common case by changing the common case of fetching a very
1298large PACK during <a href="git-clone.html">git-clone(1)</a> into a smaller incremental
1299fetch.</p>
1300</div>
1301<div class="paragraph">
1302<p>It also allows servers to achieve better caching in combination with
1303an <code>uploadpack.packObjectsHook</code> (see <a href="git-config.html">git-config(1)</a>).</p>
1304</div>
1305<div class="paragraph">
1306<p>By having new clones or fetches be a more predictable and common
1307negotiation against the tips of recently produces *.bundle file(s).
1308Servers might even pre-generate the results of such negotiations for
1309the <code>uploadpack.packObjectsHook</code> as new pushes come in.</p>
1310</div>
1311<div class="paragraph">
1312<p>One way that servers could take advantage of these bundles is that the
1313server would anticipate that fresh clones will download a known bundle,
1314followed by catching up to the current state of the repository using ref
1315tips found in that bundle (or bundles).</p>
1316</div>
1317</div>
1318<div class="sect3">
1319<h4 id="_protocol_for_bundle_uri">PROTOCOL for bundle-uri</h4>
1320<div class="paragraph">
1321<p>A <code>bundle-uri</code> request takes no arguments, and as noted above does not
1322currently advertise a capability value. Both may be added in the
1323future.</p>
1324</div>
1325<div class="paragraph">
1326<p>When the client issues a <code>command=bundle-uri</code> request, the response is a
1327list of key-value pairs provided as packet lines with value
Junio C Hamanodc392382024-10-11 18:57:29[diff] [blame]1328<em>&lt;key&gt;</em><code>=</code><em>&lt;value&gt;</em>. Each <em>&lt;key&gt;</em> should be interpreted as a config key from
1329the <code>bundle.</code>* namespace to construct a list of bundles. These keys are
1330grouped by a <code>bundle.</code><em>&lt;id&gt;</em>. subsection, where each key corresponding to a
1331given <em>&lt;id&gt;</em> contributes attributes to the bundle defined by that <em>&lt;id&gt;</em>.
Junio C Hamanob96f40a2024-08-01 00:57:25[diff] [blame]1332See <a href="git-config.html">git-config(1)</a> for the specific details of these keys and how
1333the Git client will interpret their values.</p>
1334</div>
1335<div class="paragraph">
1336<p>Clients MUST parse the line according to the above format, lines that do
1337not conform to the format SHOULD be discarded. The user MAY be warned in
1338such a case.</p>
1339</div>
1340</div>
1341<div class="sect3">
1342<h4 id="_bundle_uri_client_and_server_expectations">bundle-uri CLIENT AND SERVER EXPECTATIONS</h4>
1343<div class="dlist">
1344<dl>
1345<dt class="hdlist1">URI CONTENTS</dt>
1346<dd>
1347<p>The content at the advertised URIs MUST be one of two types.</p>
1348<div class="paragraph">
Junio C Hamanodc392382024-10-11 18:57:29[diff] [blame]1349<p>The advertised URI may contain a bundle file that <code>git</code> <code>bundle</code> <code>verify</code>
Junio C Hamanob96f40a2024-08-01 00:57:25[diff] [blame]1350would accept. I.e. they MUST contain one or more reference tips for
1351use by the client, MUST indicate prerequisites (in any) with standard
1352"-" prefixes, and MUST indicate their "object-format", if
1353applicable.</p>
1354</div>
1355<div class="paragraph">
Junio C Hamanodc392382024-10-11 18:57:29[diff] [blame]1356<p>The advertised URI may alternatively contain a plaintext file that <code>git</code>
1357<code>config</code> <code>--list</code> would accept (with the <code>--file</code> option). The key-value
1358pairs in this list are in the <code>bundle.</code>* namespace (see
Junio C Hamanob96f40a2024-08-01 00:57:25[diff] [blame]1359<a href="git-config.html">git-config(1)</a>).</p>
1360</div>
1361</dd>
1362<dt class="hdlist1">bundle-uri CLIENT ERROR RECOVERY</dt>
1363<dd>
1364<p>A client MUST above all gracefully degrade on errors, whether that
1365error is because of bad missing/data in the bundle URI(s), because
1366that client is too dumb to e.g. understand and fully parse out bundle
1367headers and their prerequisite relationships, or something else.</p>
1368<div class="paragraph">
1369<p>Server operators should feel confident in turning on "bundle-uri" and
1370not worry if e.g. their CDN goes down that clones or fetches will run
1371into hard failures. Even if the server bundle(s) are
1372incomplete, or bad in some way the client should still end up with a
1373functioning repository, just as if it had chosen not to use this
1374protocol extension.</p>
1375</div>
1376<div class="paragraph">
1377<p>All subsequent discussion on client and server interaction MUST keep
1378this in mind.</p>
1379</div>
1380</dd>
1381<dt class="hdlist1">bundle-uri SERVER TO CLIENT</dt>
1382<dd>
1383<p>The ordering of the returned bundle uris is not significant. Clients
1384MUST parse their headers to discover their contained OIDS and
1385prerequisites. A client MUST consider the content of the bundle(s)
1386themselves and their header as the ultimate source of truth.</p>
1387<div class="paragraph">
1388<p>A server MAY even return bundle(s) that don&#8217;t have any direct
1389relationship to the repository being cloned (either through accident,
1390or intentional "clever" configuration), and expect a client to sort
1391out what data they&#8217;d like from the bundle(s), if any.</p>
1392</div>
1393</dd>
1394<dt class="hdlist1">bundle-uri CLIENT TO SERVER</dt>
1395<dd>
1396<p>The client SHOULD provide reference tips found in the bundle header(s)
1397as <em>have</em> lines in any subsequent <code>fetch</code> request. A client MAY also
1398ignore the bundle(s) entirely if doing so is deemed worse for some
1399reason, e.g. if the bundles can&#8217;t be downloaded, it doesn&#8217;t like the
1400tips it finds etc.</p>
1401</dd>
1402<dt class="hdlist1">WHEN ADVERTISED BUNDLE(S) REQUIRE NO FURTHER NEGOTIATION</dt>
1403<dd>
1404<p>If after issuing <code>bundle-uri</code> and <code>ls-refs</code>, and getting the header(s)
1405of the bundle(s) the client finds that the ref tips it wants can be
1406retrieved entirely from advertised bundle(s), the client MAY disconnect
1407from the Git server. The results of such a <em>clone</em> or <em>fetch</em> should be
1408indistinguishable from the state attained without using bundle-uri.</p>
1409</dd>
1410<dt class="hdlist1">EARLY CLIENT DISCONNECTIONS AND ERROR RECOVERY</dt>
1411<dd>
1412<p>A client MAY perform an early disconnect while still downloading the
1413bundle(s) (having streamed and parsed their headers). In such a case
1414the client MUST gracefully recover from any errors related to
1415finishing the download and validation of the bundle(s).</p>
1416<div class="paragraph">
1417<p>I.e. a client might need to re-connect and issue a <em>fetch</em> command,
1418and possibly fall back to not making use of <em>bundle-uri</em> at all.</p>
1419</div>
1420<div class="paragraph">
1421<p>This "MAY" behavior is specified as such (and not a "SHOULD") on the
1422assumption that a server advertising bundle uris is more likely than
1423not to be serving up a relatively large repository, and to be pointing
1424to URIs that have a good chance of being in working order. A client
1425MAY e.g. look at the payload size of the bundles as a heuristic to see
1426if an early disconnect is worth it, should falling back on a full
1427"fetch" dialog be necessary.</p>
1428</div>
1429</dd>
1430<dt class="hdlist1">WHEN ADVERTISED BUNDLE(S) REQUIRE FURTHER NEGOTIATION</dt>
1431<dd>
1432<p>A client SHOULD commence a negotiation of a PACK from the server via
1433the "fetch" command using the OID tips found in advertised bundles,
1434even if&#8217;s still in the process of downloading those bundle(s).</p>
1435<div class="paragraph">
1436<p>This allows for aggressive early disconnects from any interactive
1437server dialog. The client blindly trusts that the advertised OID tips
1438are relevant, and issues them as <em>have</em> lines, it then requests any
1439tips it would like (usually from the "ls-refs" advertisement) via
1440<em>want</em> lines. The server will then compute a (hopefully small) PACK
1441with the expected difference between the tips from the bundle(s) and
1442the data requested.</p>
1443</div>
1444<div class="paragraph">
1445<p>The only connection the client then needs to keep active is to the
1446concurrently downloading static bundle(s), when those and the
1447incremental PACK are retrieved they should be inflated and
1448validated. Any errors at this point should be gracefully recovered
1449from, see above.</p>
1450</div>
1451</dd>
1452</dl>
1453</div>
1454</div>
1455<div class="sect3">
1456<h4 id="_bundle_uri_protocol_features">bundle-uri PROTOCOL FEATURES</h4>
1457<div class="paragraph">
Junio C Hamanodc392382024-10-11 18:57:29[diff] [blame]1458<p>The client constructs a bundle list from the <em>&lt;key&gt;</em><code>=</code><em>&lt;value&gt;</em> pairs
1459provided by the server. These pairs are part of the <code>bundle.</code>* namespace
Junio C Hamanob96f40a2024-08-01 00:57:25[diff] [blame]1460as documented in <a href="git-config.html">git-config(1)</a>. In this section, we discuss some
1461of these keys and describe the actions the client will do in response to
1462this information.</p>
1463</div>
1464<div class="paragraph">
1465<p>In particular, the <code>bundle.version</code> key specifies an integer value. The
1466only accepted value at the moment is <code>1</code>, but if the client sees an
1467unexpected value here then the client MUST ignore the bundle list.</p>
1468</div>
1469<div class="paragraph">
1470<p>As long as <code>bundle.version</code> is understood, all other unknown keys MAY be
1471ignored by the client. The server will guarantee compatibility with older
1472clients, though newer clients may be better able to use the extra keys to
1473minimize downloads.</p>
1474</div>
1475<div class="paragraph">
1476<p>Any backwards-incompatible addition of pre-URI key-value will be
1477guarded by a new <code>bundle.version</code> value or values in <em>bundle-uri</em>
1478capability advertisement itself, and/or by new future <code>bundle-uri</code>
1479request arguments.</p>
1480</div>
1481<div class="paragraph">
1482<p>Some example key-value pairs that are not currently implemented but could
1483be implemented in the future include:</p>
1484</div>
1485<div class="ulist">
1486<ul>
1487<li>
1488<p>Add a "hash=&lt;val&gt;" or "size=&lt;bytes&gt;" advertise the expected hash or
1489size of the bundle file.</p>
1490</li>
1491<li>
1492<p>Advertise that one or more bundle files are the same (to e.g. have
1493clients round-robin or otherwise choose one of N possible files).</p>
1494</li>
1495<li>
1496<p>A "oid=&lt;OID&gt;" shortcut and "prerequisite=&lt;OID&gt;" shortcut. For
1497expressing the common case of a bundle with one tip and no
1498prerequisites, or one tip and one prerequisite.</p>
1499<div class="paragraph">
1500<p>This would allow for optimizing the common case of servers who&#8217;d like
1501to provide one "big bundle" containing only their "main" branch,
1502and/or incremental updates thereof.</p>
1503</div>
1504<div class="paragraph">
Junio C Hamanof4e4f532024-11-02 05:48:11[diff] [blame]1505<p>A client receiving such a response MAY assume that they can skip
Junio C Hamanob96f40a2024-08-01 00:57:25[diff] [blame]1506retrieving the header from a bundle at the indicated URI, and thus
1507save themselves and the server(s) the request(s) needed to inspect the
1508headers of that bundle or bundles.</p>
1509</div>
1510</li>
1511</ul>
1512</div>
1513</div>
1514</div>
1515</div>
1516</div>
1517<div class="sect1">
1518<h2 id="_git">GIT</h2>
1519<div class="sectionbody">
1520<div class="paragraph">
1521<p>Part of the <a href="git.html">git(1)</a> suite</p>
1522</div>
1523</div>
1524</div>
1525</div>
1526<div id="footer">
1527<div id="footer-text">
Junio C Hamanof4e4f532024-11-02 05:48:11[diff] [blame]1528Last updated 2024-11-01 22:46:55 -0700
Junio C Hamanob96f40a2024-08-01 00:57:25[diff] [blame]1529</div>
1530</div>
1531</body>
1532</html>