diff options
| author | Junio C Hamano <junio@hera.kernel.org> | 2008-07-06 05:20:31 +0000 |
|---|---|---|
| committer | Junio C Hamano <junio@hera.kernel.org> | 2008-07-06 05:20:31 +0000 |
| commit | ba4b9286c25f18c7ebbb809ee5732a7810377ab6 (patch) | |
| tree | 390507328a7564b65dc803683c34235700b97409 /git-fast-import.html | |
| parent | 05bf9c54a827e48b2b576488f5170a3490b5180e (diff) | |
| download | git-htmldocs-ba4b9286c25f18c7ebbb809ee5732a7810377ab6.tar.gz | |
Autogenerated HTML docs for v1.5.6.2-212-g08b5
Diffstat (limited to 'git-fast-import.html')
| -rw-r--r-- | git-fast-import.html | 742 |
1 files changed, 395 insertions, 347 deletions
diff --git a/git-fast-import.html b/git-fast-import.html index 3a52e701a..5b0932dbf 100644 --- a/git-fast-import.html +++ b/git-fast-import.html @@ -3,7 +3,7 @@ <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
-<meta name="generator" content="AsciiDoc 7.0.2" />
+<meta name="generator" content="AsciiDoc 8.2.5" />
<style type="text/css">
/* Debug borders */
p, li, dt, dd, div, pre, h1, h2, h3, h4, h5, h6 {
@@ -16,8 +16,13 @@ body { margin: 1em 5% 1em 5%;
}
-a { color: blue; }
-a:visited { color: fuchsia; }
+a {
+ color: blue;
+ text-decoration: underline;
+}
+a:visited {
+ color: fuchsia;
+}
em {
font-style: italic;
@@ -39,13 +44,18 @@ h1, h2, h3, h4, h5, h6 { line-height: 1.3;
}
-h1 {
+h1, h2, h3 {
border-bottom: 2px solid silver;
}
h2 {
- border-bottom: 2px solid silver;
padding-top: 0.5em;
}
+h3 {
+ float: left;
+}
+h3 + * {
+ clear: left;
+}
div.sectionbody {
font-family: serif;
@@ -70,7 +80,7 @@ span#author { color: #527bbd;
font-family: sans-serif;
font-weight: bold;
- font-size: 1.2em;
+ font-size: 1.1em;
}
span#email {
}
@@ -139,6 +149,9 @@ div.sidebarblock > div.content { padding: 0.5em;
}
+div.listingblock {
+ margin-right: 0%;
+}
div.listingblock > div.content {
border: 1px solid silver;
background: #f4f4f4;
@@ -148,9 +161,13 @@ div.listingblock > div.content { div.quoteblock > div.content {
padding-left: 2.0em;
}
-div.quoteblock .attribution {
+
+div.attribution {
text-align: right;
}
+div.verseblock + div.attribution {
+ text-align: left;
+}
div.admonitionblock .icon {
vertical-align: top;
@@ -194,13 +211,12 @@ dd > *:first-child { ul, ol {
list-style-position: outside;
}
-ol.olist2 {
+div.olist2 ol {
list-style-type: lower-alpha;
}
div.tableblock > table {
- border-color: #527bbd;
- border-width: 3px;
+ border: 3px solid #527bbd;
}
thead {
font-family: sans-serif;
@@ -214,6 +230,9 @@ div.hlist { margin-top: 0.8em;
margin-bottom: 0.8em;
}
+div.hlist td {
+ padding-bottom: 5px;
+}
td.hlist1 {
vertical-align: top;
font-style: italic;
@@ -226,7 +245,33 @@ td.hlist2 { @media print {
div#footer-badges { display: none; }
}
-include::./stylesheets/xhtml11-manpage.css[]
+
+div#toctitle {
+ color: #527bbd;
+ font-family: sans-serif;
+ font-size: 1.1em;
+ font-weight: bold;
+ margin-top: 1.0em;
+ margin-bottom: 0.1em;
+}
+
+div.toclevel1, div.toclevel2, div.toclevel3, div.toclevel4 {
+ margin-top: 0;
+ margin-bottom: 0;
+}
+div.toclevel2 {
+ margin-left: 2em;
+ font-size: 0.9em;
+}
+div.toclevel3 {
+ margin-left: 4em;
+ font-size: 0.9em;
+}
+div.toclevel4 {
+ margin-left: 6em;
+ font-size: 0.9em;
+}
+include1::./stylesheets/xhtml11-manpage.css[]
/* Workarounds for IE6's broken and incomplete CSS2. */
div.sidebar-content {
@@ -255,6 +300,9 @@ div.exampleblock-content { border-left: 2px solid silver;
padding-left: 0.5em;
}
+
+/* IE6 sets dynamically generated links as visited. */
+div#toc a:visited { color: blue; }
</style>
<title>git-fast-import(1)</title>
</head>
@@ -272,28 +320,28 @@ git-fast-import(1) Manual Page </div>
<h2>SYNOPSIS</h2>
<div class="sectionbody">
-<p>frontend | <em>git fast-import</em> [options]</p>
+<div class="para"><p>frontend | <em>git fast-import</em> [options]</p></div>
</div>
-<h2>DESCRIPTION</h2>
+<h2 id="_description">DESCRIPTION</h2>
<div class="sectionbody">
-<p>This program is usually not what the end user wants to run directly.
+<div class="para"><p>This program is usually not what the end user wants to run directly.
Most end users want to use one of the existing frontend programs,
which parses a specific type of foreign source and feeds the contents
-stored there to <tt>git-fast-import</tt>.</p>
-<p>fast-import reads a mixed command/data stream from standard input and
+stored there to <em>git-fast-import</em>.</p></div>
+<div class="para"><p>fast-import reads a mixed command/data stream from standard input and
writes one or more packfiles directly into the current repository.
When EOF is received on standard input, fast import writes out
updated branch and tag refs, fully updating the current repository
-with the newly imported data.</p>
-<p>The fast-import backend itself can import into an empty repository (one that
-has already been initialized by <tt>git-init</tt>) or incrementally
+with the newly imported data.</p></div>
+<div class="para"><p>The fast-import backend itself can import into an empty repository (one that
+has already been initialized by <em>git-init</em>) or incrementally
update an existing populated repository. Whether or not incremental
imports are supported from a particular foreign source depends on
-the frontend program in use.</p>
+the frontend program in use.</p></div>
</div>
-<h2>OPTIONS</h2>
+<h2 id="_options">OPTIONS</h2>
<div class="sectionbody">
-<dl>
+<div class="vlist"><dl>
<dt>
--date-format=<fmt>
</dt>
@@ -383,7 +431,7 @@ the frontend program in use.</p> This information may be useful after importing projects
whose total object set exceeds the 4 GiB packfile limit,
as these commits can be used as edge points during calls
- to <tt>git-pack-objects</tt>.
+ to <em>git-pack-objects</em>.
</p>
</dd>
<dt>
@@ -407,91 +455,91 @@ the frontend program in use.</p> is currently the default, but can be disabled with --quiet.
</p>
</dd>
-</dl>
+</dl></div>
</div>
-<h2>Performance</h2>
+<h2 id="_performance">Performance</h2>
<div class="sectionbody">
-<p>The design of fast-import allows it to import large projects in a minimum
+<div class="para"><p>The design of fast-import allows it to import large projects in a minimum
amount of memory usage and processing time. Assuming the frontend
is able to keep up with fast-import and feed it a constant stream of data,
import times for projects holding 10+ years of history and containing
100,000+ individual commits are generally completed in just 1-2
-hours on quite modest (~$2,000 USD) hardware.</p>
-<p>Most bottlenecks appear to be in foreign source data access (the
+hours on quite modest (~$2,000 USD) hardware.</p></div>
+<div class="para"><p>Most bottlenecks appear to be in foreign source data access (the
source just cannot extract revisions fast enough) or disk IO (fast-import
writes as fast as the disk will take the data). Imports will run
faster if the source data is stored on a different drive than the
-destination Git repository (due to less IO contention).</p>
+destination Git repository (due to less IO contention).</p></div>
</div>
-<h2>Development Cost</h2>
+<h2 id="_development_cost">Development Cost</h2>
<div class="sectionbody">
-<p>A typical frontend for fast-import tends to weigh in at approximately 200
+<div class="para"><p>A typical frontend for fast-import tends to weigh in at approximately 200
lines of Perl/Python/Ruby code. Most developers have been able to
create working importers in just a couple of hours, even though it
is their first exposure to fast-import, and sometimes even to Git. This is
an ideal situation, given that most conversion tools are throw-away
-(use once, and never look back).</p>
+(use once, and never look back).</p></div>
</div>
-<h2>Parallel Operation</h2>
+<h2 id="_parallel_operation">Parallel Operation</h2>
<div class="sectionbody">
-<p>Like <tt>git-push</tt> or <tt>git-fetch</tt>, imports handled by fast-import are safe to
+<div class="para"><p>Like <em>git-push</em> or <em>git-fetch</em>, imports handled by fast-import are safe to
run alongside parallel <tt>git repack -a -d</tt> or <tt>git gc</tt> invocations,
-or any other Git operation (including <tt>git-prune</tt>, as loose objects
-are never used by fast-import).</p>
-<p>fast-import does not lock the branch or tag refs it is actively importing.
+or any other Git operation (including <em>git-prune</em>, as loose objects
+are never used by fast-import).</p></div>
+<div class="para"><p>fast-import does not lock the branch or tag refs it is actively importing.
After the import, during its ref update phase, fast-import tests each
existing branch ref to verify the update will be a fast-forward
update (the commit stored in the ref is contained in the new
history of the commit to be written). If the update is not a
fast-forward update, fast-import will skip updating that ref and instead
prints a warning message. fast-import will always attempt to update all
-branch refs, and does not stop on the first failure.</p>
-<p>Branch updates can be forced with --force, but its recommended that
+branch refs, and does not stop on the first failure.</p></div>
+<div class="para"><p>Branch updates can be forced with --force, but its recommended that
this only be used on an otherwise quiet repository. Using --force
-is not necessary for an initial import into an empty repository.</p>
+is not necessary for an initial import into an empty repository.</p></div>
</div>
-<h2>Technical Discussion</h2>
+<h2 id="_technical_discussion">Technical Discussion</h2>
<div class="sectionbody">
-<p>fast-import tracks a set of branches in memory. Any branch can be created
+<div class="para"><p>fast-import tracks a set of branches in memory. Any branch can be created
or modified at any point during the import process by sending a
<tt>commit</tt> command on the input stream. This design allows a frontend
program to process an unlimited number of branches simultaneously,
generating commits in the order they are available from the source
-data. It also simplifies the frontend programs considerably.</p>
-<p>fast-import does not use or alter the current working directory, or any
+data. It also simplifies the frontend programs considerably.</p></div>
+<div class="para"><p>fast-import does not use or alter the current working directory, or any
file within it. (It does however update the current Git repository,
as referenced by <tt>GIT_DIR</tt>.) Therefore an import frontend may use
the working directory for its own purposes, such as extracting file
revisions from the foreign source. This ignorance of the working
directory also allows fast-import to run very quickly, as it does not
need to perform any costly file update operations when switching
-between branches.</p>
+between branches.</p></div>
</div>
-<h2>Input Format</h2>
+<h2 id="_input_format">Input Format</h2>
<div class="sectionbody">
-<p>With the exception of raw file data (which Git does not interpret)
+<div class="para"><p>With the exception of raw file data (which Git does not interpret)
the fast-import input format is text (ASCII) based. This text based
format simplifies development and debugging of frontend programs,
especially when a higher level language such as Perl, Python or
-Ruby is being used.</p>
-<p>fast-import is very strict about its input. Where we say SP below we mean
+Ruby is being used.</p></div>
+<div class="para"><p>fast-import is very strict about its input. Where we say SP below we mean
<strong>exactly</strong> one space. Likewise LF means one (and only one) linefeed.
Supplying additional whitespace characters will cause unexpected
results, such as branch names or file names with leading or trailing
spaces in their name, or early termination of fast-import when it encounters
-unexpected input.</p>
-<h3>Stream Comments</h3>
-<p>To aid in debugging frontends fast-import ignores any line that
+unexpected input.</p></div>
+<h3 id="_stream_comments">Stream Comments</h3><div style="clear:left"></div>
+<div class="para"><p>To aid in debugging frontends fast-import ignores any line that
begins with <tt>#</tt> (ASCII pound/hash) up to and including the line
ending <tt>LF</tt>. A comment line may contain any sequence of bytes
that does not contain an LF and therefore may be used to include
any detailed debugging information that might be specific to the
-frontend and useful when inspecting a fast-import data stream.</p>
-<h3>Date Formats</h3>
-<p>The following date formats are supported. A frontend should select
+frontend and useful when inspecting a fast-import data stream.</p></div>
+<h3 id="_date_formats">Date Formats</h3><div style="clear:left"></div>
+<div class="para"><p>The following date formats are supported. A frontend should select
the format it will use for this import by passing the format name
-in the --date-format=<fmt> command line option.</p>
-<dl>
+in the --date-format=<fmt> command line option.</p></div>
+<div class="vlist"><dl>
<dt>
<tt>raw</tt>
</dt>
@@ -501,21 +549,21 @@ in the --date-format=<fmt> command line option.</p> It is also fast-import's default format, if --date-format was
not specified.
</p>
-<p>The time of the event is specified by <tt><time></tt> as the number of
+<div class="para"><p>The time of the event is specified by <tt><time></tt> as the number of
seconds since the UNIX epoch (midnight, Jan 1, 1970, UTC) and is
-written as an ASCII decimal integer.</p>
-<p>The local offset is specified by <tt><offutc></tt> as a positive or negative
+written as an ASCII decimal integer.</p></div>
+<div class="para"><p>The local offset is specified by <tt><offutc></tt> as a positive or negative
offset from UTC. For example EST (which is 5 hours behind UTC)
would be expressed in <tt><tz></tt> by “-0500” while UTC is “+0000”.
The local offset does not affect <tt><time></tt>; it is used only as an
-advisement to help formatting routines display the timestamp.</p>
-<p>If the local offset is not available in the source material, use
+advisement to help formatting routines display the timestamp.</p></div>
+<div class="para"><p>If the local offset is not available in the source material, use
“+0000”, or the most common local offset. For example many
organizations have a CVS repository which has only ever been accessed
by users who are located in the same location and timezone. In this
-case a reasonable offset from UTC could be assumed.</p>
-<p>Unlike the <tt>rfc2822</tt> format, this format is very strict. Any
-variation in formatting will cause fast-import to reject the value.</p>
+case a reasonable offset from UTC could be assumed.</p></div>
+<div class="para"><p>Unlike the <tt>rfc2822</tt> format, this format is very strict. Any
+variation in formatting will cause fast-import to reject the value.</p></div>
</dd>
<dt>
<tt>rfc2822</tt>
@@ -524,27 +572,27 @@ variation in formatting will cause fast-import to reject the value.</p> <p>
This is the standard email format as described by RFC 2822.
</p>
-<p>An example value is “Tue Feb 6 11:22:18 2007 -0500”. The Git
+<div class="para"><p>An example value is “Tue Feb 6 11:22:18 2007 -0500”. The Git
parser is accurate, but a little on the lenient side. It is the
-same parser used by <tt>git-am</tt> when applying patches
-received from email.</p>
-<p>Some malformed strings may be accepted as valid dates. In some of
+same parser used by <em>git-am</em> when applying patches
+received from email.</p></div>
+<div class="para"><p>Some malformed strings may be accepted as valid dates. In some of
these cases Git will still be able to obtain the correct date from
the malformed string. There are also some types of malformed
strings which Git will parse wrong, and yet consider valid.
-Seriously malformed strings will be rejected.</p>
-<p>Unlike the <tt>raw</tt> format above, the timezone/UTC offset information
+Seriously malformed strings will be rejected.</p></div>
+<div class="para"><p>Unlike the <tt>raw</tt> format above, the timezone/UTC offset information
contained in an RFC 2822 date string is used to adjust the date
value to UTC prior to storage. Therefore it is important that
-this information be as accurate as possible.</p>
-<p>If the source material uses RFC 2822 style dates,
+this information be as accurate as possible.</p></div>
+<div class="para"><p>If the source material uses RFC 2822 style dates,
the frontend should let fast-import handle the parsing and conversion
(rather than attempting to do it itself) as the Git parser has
-been well tested in the wild.</p>
-<p>Frontends should prefer the <tt>raw</tt> format if the source material
+been well tested in the wild.</p></div>
+<div class="para"><p>Frontends should prefer the <tt>raw</tt> format if the source material
already uses UNIX-epoch format, can be coaxed to give dates in that
format, or its format is easily convertible to it, as there is no
-ambiguity in parsing.</p>
+ambiguity in parsing.</p></div>
</dd>
<dt>
<tt>now</tt>
@@ -554,27 +602,27 @@ ambiguity in parsing.</p> Always use the current time and timezone. The literal
<tt>now</tt> must always be supplied for <tt><when></tt>.
</p>
-<p>This is a toy format. The current time and timezone of this system
+<div class="para"><p>This is a toy format. The current time and timezone of this system
is always copied into the identity string at the time it is being
created by fast-import. There is no way to specify a different time or
-timezone.</p>
-<p>This particular format is supplied as its short to implement and
+timezone.</p></div>
+<div class="para"><p>This particular format is supplied as its short to implement and
may be useful to a process that wants to create a new commit
right now, without needing to use a working directory or
-<tt>git-update-index</tt>.</p>
-<p>If separate <tt>author</tt> and <tt>committer</tt> commands are used in a <tt>commit</tt>
+<em>git-update-index</em>.</p></div>
+<div class="para"><p>If separate <tt>author</tt> and <tt>committer</tt> commands are used in a <tt>commit</tt>
the timestamps may not match, as the system clock will be polled
twice (once for each command). The only way to ensure that both
author and committer identity information has the same timestamp
is to omit <tt>author</tt> (thus copying from <tt>committer</tt>) or to use a
-date format other than <tt>now</tt>.</p>
+date format other than <tt>now</tt>.</p></div>
</dd>
-</dl>
-<h3>Commands</h3>
-<p>fast-import accepts several commands to update the current repository
+</dl></div>
+<h3 id="_commands">Commands</h3><div style="clear:left"></div>
+<div class="para"><p>fast-import accepts several commands to update the current repository
and control the current import process. More detailed discussion
-(with examples) of each command follows later.</p>
-<dl>
+(with examples) of each command follows later.</p></div>
+<div class="vlist"><dl>
<dt>
<tt>commit</tt>
</dt>
@@ -637,10 +685,10 @@ and control the current import process. More detailed discussion to perform an import.
</p>
</dd>
-</dl>
-<h3><tt>commit</tt></h3>
-<p>Create or update a branch with a new commit, recording one logical
-change to the project.</p>
+</dl></div>
+<h3 id="_tt_commit_tt"><tt>commit</tt></h3><div style="clear:left"></div>
+<div class="para"><p>Create or update a branch with a new commit, recording one logical
+change to the project.</p></div>
<div class="literalblock">
<div class="content">
<pre><tt> 'commit' SP <ref> LF
@@ -653,56 +701,56 @@ change to the project.</p> (filemodify | filedelete | filecopy | filerename | filedeleteall)*
LF?</tt></pre>
</div></div>
-<p>where <tt><ref></tt> is the name of the branch to make the commit on.
+<div class="para"><p>where <tt><ref></tt> is the name of the branch to make the commit on.
Typically branch names are prefixed with <tt>refs/heads/</tt> in
Git, so importing the CVS branch symbol <tt>RELENG-1_0</tt> would use
<tt>refs/heads/RELENG-1_0</tt> for the value of <tt><ref></tt>. The value of
<tt><ref></tt> must be a valid refname in Git. As <tt>LF</tt> is not valid in
-a Git refname, no quoting or escaping syntax is supported here.</p>
-<p>A <tt>mark</tt> command may optionally appear, requesting fast-import to save a
+a Git refname, no quoting or escaping syntax is supported here.</p></div>
+<div class="para"><p>A <tt>mark</tt> command may optionally appear, requesting fast-import to save a
reference to the newly created commit for future use by the frontend
(see below for format). It is very common for frontends to mark
every commit they create, thereby allowing future branch creation
-from any imported commit.</p>
-<p>The <tt>data</tt> command following <tt>committer</tt> must supply the commit
+from any imported commit.</p></div>
+<div class="para"><p>The <tt>data</tt> command following <tt>committer</tt> must supply the commit
message (see below for <tt>data</tt> command syntax). To import an empty
commit message use a 0 length data. Commit messages are free-form
and are not interpreted by Git. Currently they must be encoded in
-UTF-8, as fast-import does not permit other encodings to be specified.</p>
-<p>Zero or more <tt>filemodify</tt>, <tt>filedelete</tt>, <tt>filecopy</tt>, <tt>filerename</tt>
+UTF-8, as fast-import does not permit other encodings to be specified.</p></div>
+<div class="para"><p>Zero or more <tt>filemodify</tt>, <tt>filedelete</tt>, <tt>filecopy</tt>, <tt>filerename</tt>
and <tt>filedeleteall</tt> commands
may be included to update the contents of the branch prior to
creating the commit. These commands may be supplied in any order.
However it is recommended that a <tt>filedeleteall</tt> command precede
all <tt>filemodify</tt>, <tt>filecopy</tt> and <tt>filerename</tt> commands in the same
commit, as <tt>filedeleteall</tt>
-wipes the branch clean (see below).</p>
-<p>The <tt>LF</tt> after the command is optional (it used to be required).</p>
-<h4><tt>author</tt></h4>
-<p>An <tt>author</tt> command may optionally appear, if the author information
+wipes the branch clean (see below).</p></div>
+<div class="para"><p>The <tt>LF</tt> after the command is optional (it used to be required).</p></div>
+<h4 id="_tt_author_tt"><tt>author</tt></h4>
+<div class="para"><p>An <tt>author</tt> command may optionally appear, if the author information
might differ from the committer information. If <tt>author</tt> is omitted
then fast-import will automatically use the committer's information for
the author portion of the commit. See below for a description of
-the fields in <tt>author</tt>, as they are identical to <tt>committer</tt>.</p>
-<h4><tt>committer</tt></h4>
-<p>The <tt>committer</tt> command indicates who made this commit, and when
-they made it.</p>
-<p>Here <tt><name></tt> is the person's display name (for example
+the fields in <tt>author</tt>, as they are identical to <tt>committer</tt>.</p></div>
+<h4 id="_tt_committer_tt"><tt>committer</tt></h4>
+<div class="para"><p>The <tt>committer</tt> command indicates who made this commit, and when
+they made it.</p></div>
+<div class="para"><p>Here <tt><name></tt> is the person's display name (for example
“Com M Itter”) and <tt><email></tt> is the person's email address
(“cm@example.com”). <tt>LT</tt> and <tt>GT</tt> are the literal less-than (\x3c)
and greater-than (\x3e) symbols. These are required to delimit
the email address from the other fields in the line. Note that
<tt><name></tt> is free-form and may contain any sequence of bytes, except
-<tt>LT</tt> and <tt>LF</tt>. It is typically UTF-8 encoded.</p>
-<p>The time of the change is specified by <tt><when></tt> using the date format
+<tt>LT</tt> and <tt>LF</tt>. It is typically UTF-8 encoded.</p></div>
+<div class="para"><p>The time of the change is specified by <tt><when></tt> using the date format
that was selected by the --date-format=<fmt> command line option.
See “Date Formats” above for the set of supported formats, and
-their syntax.</p>
-<h4><tt>from</tt></h4>
-<p>The <tt>from</tt> command is used to specify the commit to initialize
+their syntax.</p></div>
+<h4 id="_tt_from_tt"><tt>from</tt></h4>
+<div class="para"><p>The <tt>from</tt> command is used to specify the commit to initialize
this branch from. This revision will be the first ancestor of the
-new commit.</p>
-<p>Omitting the <tt>from</tt> command in the first commit of a new branch
+new commit.</p></div>
+<div class="para"><p>Omitting the <tt>from</tt> command in the first commit of a new branch
will cause fast-import to create that commit with no ancestor. This
tends to be desired only for the initial commit of a project.
If the frontend creates all files from scratch when making a new
@@ -710,11 +758,11 @@ branch, a <tt>merge</tt> command may be used instead of <tt>from</tt> to start the commit with an empty tree.
Omitting the <tt>from</tt> command on existing branches is usually desired,
as the current commit on that branch is automatically assumed to
-be the first ancestor of the new commit.</p>
-<p>As <tt>LF</tt> is not valid in a Git refname or SHA-1 expression, no
-quoting or escaping syntax is supported within <tt><committish></tt>.</p>
-<p>Here <tt><committish></tt> is any of the following:</p>
-<ul>
+be the first ancestor of the new commit.</p></div>
+<div class="para"><p>As <tt>LF</tt> is not valid in a Git refname or SHA-1 expression, no
+quoting or escaping syntax is supported within <tt><committish></tt>.</p></div>
+<div class="para"><p>Here <tt><committish></tt> is any of the following:</p></div>
+<div class="ilist"><ul>
<li>
<p>
The name of an existing branch already in fast-import's internal branch
@@ -726,12 +774,12 @@ The name of an existing branch already in fast-import's internal branch <p>
A mark reference, <tt>:<idnum></tt>, where <tt><idnum></tt> is the mark number.
</p>
-<p>The reason fast-import uses <tt>:</tt> to denote a mark reference is this character
+<div class="para"><p>The reason fast-import uses <tt>:</tt> to denote a mark reference is this character
is not legal in a Git branch name. The leading <tt>:</tt> makes it easy
to distinguish between the mark 42 (<tt>:42</tt>) and the branch 42 (<tt>42</tt>
or <tt>refs/heads/42</tt>), or an abbreviated SHA-1 which happened to
-consist only of base-10 digits.</p>
-<p>Marks must be declared (via <tt>mark</tt>) before they can be used.</p>
+consist only of base-10 digits.</p></div>
+<div class="para"><p>Marks must be declared (via <tt>mark</tt>) before they can be used.</p></div>
</li>
<li>
<p>
@@ -744,21 +792,21 @@ Any valid Git SHA-1 expression that resolves to a commit. See “SPECIFYING REVISIONS” in <a href="git-rev-parse.html">git-rev-parse(1)</a> for details.
</p>
</li>
-</ul>
-<p>The special case of restarting an incremental import from the
-current branch value should be written as:</p>
+</ul></div>
+<div class="para"><p>The special case of restarting an incremental import from the
+current branch value should be written as:</p></div>
<div class="listingblock">
<div class="content">
<pre><tt> from refs/heads/branch^0</tt></pre>
</div></div>
-<p>The <tt>^0</tt> suffix is necessary as fast-import does not permit a branch to
+<div class="para"><p>The <tt>^0</tt> suffix is necessary as fast-import does not permit a branch to
start from itself, and the branch is created in memory before the
<tt>from</tt> command is even read from the input. Adding <tt>^0</tt> will force
fast-import to resolve the commit through Git's revision parsing library,
rather than its internal branch table, thereby loading in the
-existing value of the branch.</p>
-<h4><tt>merge</tt></h4>
-<p>Includes one additional ancestor commit. If the <tt>from</tt> command is
+existing value of the branch.</p></div>
+<h4 id="_tt_merge_tt"><tt>merge</tt></h4>
+<div class="para"><p>Includes one additional ancestor commit. If the <tt>from</tt> command is
omitted when creating a new branch, the first <tt>merge</tt> commit will be
the first ancestor of the current commit, and the branch will start
out with no files. An unlimited number of <tt>merge</tt> commands per
@@ -766,14 +814,14 @@ commit are permitted by fast-import, thereby establishing an n-way merge. However Git's other tools never create commits with more than 15
additional ancestors (forming a 16-way merge). For this reason
it is suggested that frontends do not use more than 15 <tt>merge</tt>
-commands per commit; 16, if starting a new, empty branch.</p>
-<p>Here <tt><committish></tt> is any of the commit specification expressions
-also accepted by <tt>from</tt> (see above).</p>
-<h4><tt>filemodify</tt></h4>
-<p>Included in a <tt>commit</tt> command to add a new file or change the
+commands per commit; 16, if starting a new, empty branch.</p></div>
+<div class="para"><p>Here <tt><committish></tt> is any of the commit specification expressions
+also accepted by <tt>from</tt> (see above).</p></div>
+<h4 id="_tt_filemodify_tt"><tt>filemodify</tt></h4>
+<div class="para"><p>Included in a <tt>commit</tt> command to add a new file or change the
content of an existing file. This command has two different means
-of specifying the content of the file.</p>
-<dl>
+of specifying the content of the file.</p></div>
+<div class="vlist"><dl>
<dt>
External data format
</dt>
@@ -786,9 +834,9 @@ External data format <div class="content">
<pre><tt> 'M' SP <mode> SP <dataref> SP <path> LF</tt></pre>
</div></div>
-<p>Here <tt><dataref></tt> can be either a mark reference (<tt>:<idnum></tt>)
+<div class="para"><p>Here <tt><dataref></tt> can be either a mark reference (<tt>:<idnum></tt>)
set by a prior <tt>blob</tt> command, or a full 40-byte SHA-1 of an
-existing Git blob object.</p>
+existing Git blob object.</p></div>
</dd>
<dt>
Inline data format
@@ -804,12 +852,12 @@ Inline data format <pre><tt> 'M' SP <mode> SP 'inline' SP <path> LF
data</tt></pre>
</div></div>
-<p>See below for a detailed description of the <tt>data</tt> command.</p>
+<div class="para"><p>See below for a detailed description of the <tt>data</tt> command.</p></div>
</dd>
-</dl>
-<p>In both formats <tt><mode></tt> is the type of file entry, specified
-in octal. Git only supports the following modes:</p>
-<ul>
+</dl></div>
+<div class="para"><p>In both formats <tt><mode></tt> is the type of file entry, specified
+in octal. Git only supports the following modes:</p></div>
+<div class="ilist"><ul>
<li>
<p>
<tt>100644</tt> or <tt>644</tt>: A normal (not-executable) file. The majority
@@ -827,16 +875,16 @@ in octal. Git only supports the following modes:</p> <tt>120000</tt>: A symlink, the content of the file will be the link target.
</p>
</li>
-</ul>
-<p>In both formats <tt><path></tt> is the complete path of the file to be added
-(if not already existing) or modified (if already existing).</p>
-<p>A <tt><path></tt> string must use UNIX-style directory separators (forward
+</ul></div>
+<div class="para"><p>In both formats <tt><path></tt> is the complete path of the file to be added
+(if not already existing) or modified (if already existing).</p></div>
+<div class="para"><p>A <tt><path></tt> string must use UNIX-style directory separators (forward
slash <tt>/</tt>), may contain any byte other than <tt>LF</tt>, and must not
-start with double quote (<tt>"</tt>).</p>
-<p>If an <tt>LF</tt> or double quote must be encoded into <tt><path></tt> shell-style
-quoting should be used, e.g. <tt>"path/with\n and \" in it"</tt>.</p>
-<p>The value of <tt><path></tt> must be in canonical form. That is it must not:</p>
-<ul>
+start with double quote (<tt>"</tt>).</p></div>
+<div class="para"><p>If an <tt>LF</tt> or double quote must be encoded into <tt><path></tt> shell-style
+quoting should be used, e.g. <tt>"path/with\n and \" in it"</tt>.</p></div>
+<div class="para"><p>The value of <tt><path></tt> must be in canonical form. That is it must not:</p></div>
+<div class="ilist"><ul>
<li>
<p>
contain an empty directory component (e.g. <tt>foo//bar</tt> is invalid),
@@ -858,102 +906,102 @@ contain the special component <tt>.</tt> or <tt>..</tt> (e.g. <tt>foo/./bar</tt> <tt>foo/../bar</tt> are invalid).
</p>
</li>
-</ul>
-<p>It is recommended that <tt><path></tt> always be encoded using UTF-8.</p>
-<h4><tt>filedelete</tt></h4>
-<p>Included in a <tt>commit</tt> command to remove a file or recursively
+</ul></div>
+<div class="para"><p>It is recommended that <tt><path></tt> always be encoded using UTF-8.</p></div>
+<h4 id="_tt_filedelete_tt"><tt>filedelete</tt></h4>
+<div class="para"><p>Included in a <tt>commit</tt> command to remove a file or recursively
delete an entire directory from the branch. If the file or directory
removal makes its parent directory empty, the parent directory will
be automatically removed too. This cascades up the tree until the
-first non-empty directory or the root is reached.</p>
+first non-empty directory or the root is reached.</p></div>
<div class="literalblock">
<div class="content">
<pre><tt> 'D' SP <path> LF</tt></pre>
</div></div>
-<p>here <tt><path></tt> is the complete path of the file or subdirectory to
+<div class="para"><p>here <tt><path></tt> is the complete path of the file or subdirectory to
be removed from the branch.
-See <tt>filemodify</tt> above for a detailed description of <tt><path></tt>.</p>
-<h4><tt>filecopy</tt></h4>
-<p>Recursively copies an existing file or subdirectory to a different
+See <tt>filemodify</tt> above for a detailed description of <tt><path></tt>.</p></div>
+<h4 id="_tt_filecopy_tt"><tt>filecopy</tt></h4>
+<div class="para"><p>Recursively copies an existing file or subdirectory to a different
location within the branch. The existing file or directory must
exist. If the destination exists it will be completely replaced
-by the content copied from the source.</p>
+by the content copied from the source.</p></div>
<div class="literalblock">
<div class="content">
<pre><tt> 'C' SP <path> SP <path> LF</tt></pre>
</div></div>
-<p>here the first <tt><path></tt> is the source location and the second
+<div class="para"><p>here the first <tt><path></tt> is the source location and the second
<tt><path></tt> is the destination. See <tt>filemodify</tt> above for a detailed
description of what <tt><path></tt> may look like. To use a source path
-that contains SP the path must be quoted.</p>
-<p>A <tt>filecopy</tt> command takes effect immediately. Once the source
+that contains SP the path must be quoted.</p></div>
+<div class="para"><p>A <tt>filecopy</tt> command takes effect immediately. Once the source
location has been copied to the destination any future commands
applied to the source location will not impact the destination of
-the copy.</p>
-<h4><tt>filerename</tt></h4>
-<p>Renames an existing file or subdirectory to a different location
+the copy.</p></div>
+<h4 id="_tt_filerename_tt"><tt>filerename</tt></h4>
+<div class="para"><p>Renames an existing file or subdirectory to a different location
within the branch. The existing file or directory must exist. If
-the destination exists it will be replaced by the source directory.</p>
+the destination exists it will be replaced by the source directory.</p></div>
<div class="literalblock">
<div class="content">
<pre><tt> 'R' SP <path> SP <path> LF</tt></pre>
</div></div>
-<p>here the first <tt><path></tt> is the source location and the second
+<div class="para"><p>here the first <tt><path></tt> is the source location and the second
<tt><path></tt> is the destination. See <tt>filemodify</tt> above for a detailed
description of what <tt><path></tt> may look like. To use a source path
-that contains SP the path must be quoted.</p>
-<p>A <tt>filerename</tt> command takes effect immediately. Once the source
+that contains SP the path must be quoted.</p></div>
+<div class="para"><p>A <tt>filerename</tt> command takes effect immediately. Once the source
location has been renamed to the destination any future commands
applied to the source location will create new files there and not
-impact the destination of the rename.</p>
-<p>Note that a <tt>filerename</tt> is the same as a <tt>filecopy</tt> followed by a
+impact the destination of the rename.</p></div>
+<div class="para"><p>Note that a <tt>filerename</tt> is the same as a <tt>filecopy</tt> followed by a
<tt>filedelete</tt> of the source location. There is a slight performance
advantage to using <tt>filerename</tt>, but the advantage is so small
that it is never worth trying to convert a delete/add pair in
source material into a rename for fast-import. This <tt>filerename</tt>
command is provided just to simplify frontends that already have
rename information and don't want bother with decomposing it into a
-<tt>filecopy</tt> followed by a <tt>filedelete</tt>.</p>
-<h4><tt>filedeleteall</tt></h4>
-<p>Included in a <tt>commit</tt> command to remove all files (and also all
+<tt>filecopy</tt> followed by a <tt>filedelete</tt>.</p></div>
+<h4 id="_tt_filedeleteall_tt"><tt>filedeleteall</tt></h4>
+<div class="para"><p>Included in a <tt>commit</tt> command to remove all files (and also all
directories) from the branch. This command resets the internal
branch structure to have no files in it, allowing the frontend
-to subsequently add all interesting files from scratch.</p>
+to subsequently add all interesting files from scratch.</p></div>
<div class="literalblock">
<div class="content">
<pre><tt> 'deleteall' LF</tt></pre>
</div></div>
-<p>This command is extremely useful if the frontend does not know
+<div class="para"><p>This command is extremely useful if the frontend does not know
(or does not care to know) what files are currently on the branch,
and therefore cannot generate the proper <tt>filedelete</tt> commands to
-update the content.</p>
-<p>Issuing a <tt>filedeleteall</tt> followed by the needed <tt>filemodify</tt>
+update the content.</p></div>
+<div class="para"><p>Issuing a <tt>filedeleteall</tt> followed by the needed <tt>filemodify</tt>
commands to set the correct content will produce the same results
as sending only the needed <tt>filemodify</tt> and <tt>filedelete</tt> commands.
The <tt>filedeleteall</tt> approach may however require fast-import to use slightly
more memory per active branch (less than 1 MiB for even most large
projects); so frontends that can easily obtain only the affected
-paths for a commit are encouraged to do so.</p>
-<h3><tt>mark</tt></h3>
-<p>Arranges for fast-import to save a reference to the current object, allowing
+paths for a commit are encouraged to do so.</p></div>
+<h3 id="_tt_mark_tt"><tt>mark</tt></h3><div style="clear:left"></div>
+<div class="para"><p>Arranges for fast-import to save a reference to the current object, allowing
the frontend to recall this object at a future point in time, without
knowing its SHA-1. Here the current object is the object creation
command the <tt>mark</tt> command appears within. This can be <tt>commit</tt>,
-<tt>tag</tt>, and <tt>blob</tt>, but <tt>commit</tt> is the most common usage.</p>
+<tt>tag</tt>, and <tt>blob</tt>, but <tt>commit</tt> is the most common usage.</p></div>
<div class="literalblock">
<div class="content">
<pre><tt> 'mark' SP ':' <idnum> LF</tt></pre>
</div></div>
-<p>where <tt><idnum></tt> is the number assigned by the frontend to this mark.
+<div class="para"><p>where <tt><idnum></tt> is the number assigned by the frontend to this mark.
The value of <tt><idnum></tt> is expressed as an ASCII decimal integer.
The value 0 is reserved and cannot be used as
-a mark. Only values greater than or equal to 1 may be used as marks.</p>
-<p>New marks are created automatically. Existing marks can be moved
+a mark. Only values greater than or equal to 1 may be used as marks.</p></div>
+<div class="para"><p>New marks are created automatically. Existing marks can be moved
to another object simply by reusing the same <tt><idnum></tt> in another
-<tt>mark</tt> command.</p>
-<h3><tt>tag</tt></h3>
-<p>Creates an annotated tag referring to a specific commit. To create
-lightweight (non-annotated) tags see the <tt>reset</tt> command below.</p>
+<tt>mark</tt> command.</p></div>
+<h3 id="_tt_tag_tt"><tt>tag</tt></h3><div style="clear:left"></div>
+<div class="para"><p>Creates an annotated tag referring to a specific commit. To create
+lightweight (non-annotated) tags see the <tt>reset</tt> command below.</p></div>
<div class="literalblock">
<div class="content">
<pre><tt> 'tag' SP <name> LF
@@ -961,46 +1009,46 @@ lightweight (non-annotated) tags see the <tt>reset</tt> command below.</p> 'tagger' SP <name> SP LT <email> GT SP <when> LF
data</tt></pre>
</div></div>
-<p>where <tt><name></tt> is the name of the tag to create.</p>
-<p>Tag names are automatically prefixed with <tt>refs/tags/</tt> when stored
+<div class="para"><p>where <tt><name></tt> is the name of the tag to create.</p></div>
+<div class="para"><p>Tag names are automatically prefixed with <tt>refs/tags/</tt> when stored
in Git, so importing the CVS branch symbol <tt>RELENG-1_0-FINAL</tt> would
use just <tt>RELENG-1_0-FINAL</tt> for <tt><name></tt>, and fast-import will write the
-corresponding ref as <tt>refs/tags/RELENG-1_0-FINAL</tt>.</p>
-<p>The value of <tt><name></tt> must be a valid refname in Git and therefore
+corresponding ref as <tt>refs/tags/RELENG-1_0-FINAL</tt>.</p></div>
+<div class="para"><p>The value of <tt><name></tt> must be a valid refname in Git and therefore
may contain forward slashes. As <tt>LF</tt> is not valid in a Git refname,
-no quoting or escaping syntax is supported here.</p>
-<p>The <tt>from</tt> command is the same as in the <tt>commit</tt> command; see
-above for details.</p>
-<p>The <tt>tagger</tt> command uses the same format as <tt>committer</tt> within
-<tt>commit</tt>; again see above for details.</p>
-<p>The <tt>data</tt> command following <tt>tagger</tt> must supply the annotated tag
+no quoting or escaping syntax is supported here.</p></div>
+<div class="para"><p>The <tt>from</tt> command is the same as in the <tt>commit</tt> command; see
+above for details.</p></div>
+<div class="para"><p>The <tt>tagger</tt> command uses the same format as <tt>committer</tt> within
+<tt>commit</tt>; again see above for details.</p></div>
+<div class="para"><p>The <tt>data</tt> command following <tt>tagger</tt> must supply the annotated tag
message (see below for <tt>data</tt> command syntax). To import an empty
tag message use a 0 length data. Tag messages are free-form and are
not interpreted by Git. Currently they must be encoded in UTF-8,
-as fast-import does not permit other encodings to be specified.</p>
-<p>Signing annotated tags during import from within fast-import is not
+as fast-import does not permit other encodings to be specified.</p></div>
+<div class="para"><p>Signing annotated tags during import from within fast-import is not
supported. Trying to include your own PGP/GPG signature is not
recommended, as the frontend does not (easily) have access to the
complete set of bytes which normally goes into such a signature.
If signing is required, create lightweight tags from within fast-import with
<tt>reset</tt>, then create the annotated versions of those tags offline
-with the standard <tt>git-tag</tt> process.</p>
-<h3><tt>reset</tt></h3>
-<p>Creates (or recreates) the named branch, optionally starting from
+with the standard <em>git-tag</em> process.</p></div>
+<h3 id="_tt_reset_tt"><tt>reset</tt></h3><div style="clear:left"></div>
+<div class="para"><p>Creates (or recreates) the named branch, optionally starting from
a specific revision. The reset command allows a frontend to issue
a new <tt>from</tt> command for an existing branch, or to create a new
-branch from an existing commit without creating a new commit.</p>
+branch from an existing commit without creating a new commit.</p></div>
<div class="literalblock">
<div class="content">
<pre><tt> 'reset' SP <ref> LF
('from' SP <committish> LF)?
LF?</tt></pre>
</div></div>
-<p>For a detailed description of <tt><ref></tt> and <tt><committish></tt> see above
-under <tt>commit</tt> and <tt>from</tt>.</p>
-<p>The <tt>LF</tt> after the command is optional (it used to be required).</p>
-<p>The <tt>reset</tt> command can also be used to create lightweight
-(non-annotated) tags. For example:</p>
+<div class="para"><p>For a detailed description of <tt><ref></tt> and <tt><committish></tt> see above
+under <tt>commit</tt> and <tt>from</tt>.</p></div>
+<div class="para"><p>The <tt>LF</tt> after the command is optional (it used to be required).</p></div>
+<div class="para"><p>The <tt>reset</tt> command can also be used to create lightweight
+(non-annotated) tags. For example:</p></div>
<div class="exampleblock">
<div class="exampleblock-content">
<div class="literalblock">
@@ -1009,35 +1057,35 @@ under <tt>commit</tt> and <tt>from</tt>.</p> from :938</tt></pre>
</div></div>
</div></div>
-<p>would create the lightweight tag <tt>refs/tags/938</tt> referring to
-whatever commit mark <tt>:938</tt> references.</p>
-<h3><tt>blob</tt></h3>
-<p>Requests writing one file revision to the packfile. The revision
+<div class="para"><p>would create the lightweight tag <tt>refs/tags/938</tt> referring to
+whatever commit mark <tt>:938</tt> references.</p></div>
+<h3 id="_tt_blob_tt"><tt>blob</tt></h3><div style="clear:left"></div>
+<div class="para"><p>Requests writing one file revision to the packfile. The revision
is not connected to any commit; this connection must be formed in
a subsequent <tt>commit</tt> command by referencing the blob through an
-assigned mark.</p>
+assigned mark.</p></div>
<div class="literalblock">
<div class="content">
<pre><tt> 'blob' LF
mark?
data</tt></pre>
</div></div>
-<p>The mark command is optional here as some frontends have chosen
+<div class="para"><p>The mark command is optional here as some frontends have chosen
to generate the Git SHA-1 for the blob on their own, and feed that
directly to <tt>commit</tt>. This is typically more work than its worth
-however, as marks are inexpensive to store and easy to use.</p>
-<h3><tt>data</tt></h3>
-<p>Supplies raw data (for use as blob/file content, commit messages, or
+however, as marks are inexpensive to store and easy to use.</p></div>
+<h3 id="_tt_data_tt"><tt>data</tt></h3><div style="clear:left"></div>
+<div class="para"><p>Supplies raw data (for use as blob/file content, commit messages, or
annotated tag messages) to fast-import. Data can be supplied using an exact
byte count or delimited with a terminating line. Real frontends
intended for production-quality conversions should always use the
exact byte count format, as it is more robust and performs better.
-The delimited format is intended primarily for testing fast-import.</p>
-<p>Comment lines appearing within the <tt><raw></tt> part of <tt>data</tt> commands
+The delimited format is intended primarily for testing fast-import.</p></div>
+<div class="para"><p>Comment lines appearing within the <tt><raw></tt> part of <tt>data</tt> commands
are always taken to be part of the body of the data and are therefore
never ignored by fast-import. This makes it safe to import any
-file/message content whose lines might start with <tt>#</tt>.</p>
-<dl>
+file/message content whose lines might start with <tt>#</tt>.</p></div>
+<div class="vlist"><dl>
<dt>
Exact byte count format
</dt>
@@ -1050,14 +1098,14 @@ Exact byte count format <pre><tt> 'data' SP <count> LF
<raw> LF?</tt></pre>
</div></div>
-<p>where <tt><count></tt> is the exact number of bytes appearing within
+<div class="para"><p>where <tt><count></tt> is the exact number of bytes appearing within
<tt><raw></tt>. The value of <tt><count></tt> is expressed as an ASCII decimal
integer. The <tt>LF</tt> on either side of <tt><raw></tt> is not
-included in <tt><count></tt> and will not be included in the imported data.</p>
-<p>The <tt>LF</tt> after <tt><raw></tt> is optional (it used to be required) but
+included in <tt><count></tt> and will not be included in the imported data.</p></div>
+<div class="para"><p>The <tt>LF</tt> after <tt><raw></tt> is optional (it used to be required) but
recommended. Always including it makes debugging a fast-import
stream easier as the next command always starts in column 0
-of the next line, even if <tt><raw></tt> did not end with an <tt>LF</tt>.</p>
+of the next line, even if <tt><raw></tt> did not end with an <tt>LF</tt>.</p></div>
</dd>
<dt>
Delimited format
@@ -1076,51 +1124,51 @@ Delimited format <delim> LF
LF?</tt></pre>
</div></div>
-<p>where <tt><delim></tt> is the chosen delimiter string. The string <tt><delim></tt>
+<div class="para"><p>where <tt><delim></tt> is the chosen delimiter string. The string <tt><delim></tt>
must not appear on a line by itself within <tt><raw></tt>, as otherwise
fast-import will think the data ends earlier than it really does. The <tt>LF</tt>
immediately trailing <tt><raw></tt> is part of <tt><raw></tt>. This is one of
the limitations of the delimited format, it is impossible to supply
-a data chunk which does not have an LF as its last byte.</p>
-<p>The <tt>LF</tt> after <tt><delim> LF</tt> is optional (it used to be required).</p>
+a data chunk which does not have an LF as its last byte.</p></div>
+<div class="para"><p>The <tt>LF</tt> after <tt><delim> LF</tt> is optional (it used to be required).</p></div>
</dd>
-</dl>
-<h3><tt>checkpoint</tt></h3>
-<p>Forces fast-import to close the current packfile, start a new one, and to
-save out all current branch refs, tags and marks.</p>
+</dl></div>
+<h3 id="_tt_checkpoint_tt"><tt>checkpoint</tt></h3><div style="clear:left"></div>
+<div class="para"><p>Forces fast-import to close the current packfile, start a new one, and to
+save out all current branch refs, tags and marks.</p></div>
<div class="literalblock">
<div class="content">
<pre><tt> 'checkpoint' LF
LF?</tt></pre>
</div></div>
-<p>Note that fast-import automatically switches packfiles when the current
+<div class="para"><p>Note that fast-import automatically switches packfiles when the current
packfile reaches --max-pack-size, or 4 GiB, whichever limit is
smaller. During an automatic packfile switch fast-import does not update
-the branch refs, tags or marks.</p>
-<p>As a <tt>checkpoint</tt> can require a significant amount of CPU time and
+the branch refs, tags or marks.</p></div>
+<div class="para"><p>As a <tt>checkpoint</tt> can require a significant amount of CPU time and
disk IO (to compute the overall pack SHA-1 checksum, generate the
corresponding index file, and update the refs) it can easily take
-several minutes for a single <tt>checkpoint</tt> command to complete.</p>
-<p>Frontends may choose to issue checkpoints during extremely large
+several minutes for a single <tt>checkpoint</tt> command to complete.</p></div>
+<div class="para"><p>Frontends may choose to issue checkpoints during extremely large
and long running imports, or when they need to allow another Git
process access to a branch. However given that a 30 GiB Subversion
repository can be loaded into Git through fast-import in about 3 hours,
-explicit checkpointing may not be necessary.</p>
-<p>The <tt>LF</tt> after the command is optional (it used to be required).</p>
-<h3><tt>progress</tt></h3>
-<p>Causes fast-import to print the entire <tt>progress</tt> line unmodified to
+explicit checkpointing may not be necessary.</p></div>
+<div class="para"><p>The <tt>LF</tt> after the command is optional (it used to be required).</p></div>
+<h3 id="_tt_progress_tt"><tt>progress</tt></h3><div style="clear:left"></div>
+<div class="para"><p>Causes fast-import to print the entire <tt>progress</tt> line unmodified to
its standard output channel (file descriptor 1) when the command is
processed from the input stream. The command otherwise has no impact
-on the current import, or on any of fast-import's internal state.</p>
+on the current import, or on any of fast-import's internal state.</p></div>
<div class="literalblock">
<div class="content">
<pre><tt> 'progress' SP <any> LF
LF?</tt></pre>
</div></div>
-<p>The <tt><any></tt> part of the command may contain any sequence of bytes
+<div class="para"><p>The <tt><any></tt> part of the command may contain any sequence of bytes
that does not contain <tt>LF</tt>. The <tt>LF</tt> after the command is optional.
Callers may wish to process the output through a tool such as sed to
-remove the leading part of the line, for example:</p>
+remove the leading part of the line, for example:</p></div>
<div class="exampleblock">
<div class="exampleblock-content">
<div class="literalblock">
@@ -1128,31 +1176,31 @@ remove the leading part of the line, for example:</p> <pre><tt>frontend | git fast-import | sed 's/^progress //'</tt></pre>
</div></div>
</div></div>
-<p>Placing a <tt>progress</tt> command immediately after a <tt>checkpoint</tt> will
+<div class="para"><p>Placing a <tt>progress</tt> command immediately after a <tt>checkpoint</tt> will
inform the reader when the <tt>checkpoint</tt> has been completed and it
-can safely access the refs that fast-import updated.</p>
+can safely access the refs that fast-import updated.</p></div>
</div>
-<h2>Crash Reports</h2>
+<h2 id="_crash_reports">Crash Reports</h2>
<div class="sectionbody">
-<p>If fast-import is supplied invalid input it will terminate with a
+<div class="para"><p>If fast-import is supplied invalid input it will terminate with a
non-zero exit status and create a crash report in the top level of
the Git repository it was importing into. Crash reports contain
a snapshot of the internal fast-import state as well as the most
-recent commands that lead up to the crash.</p>
-<p>All recent commands (including stream comments, file changes and
+recent commands that lead up to the crash.</p></div>
+<div class="para"><p>All recent commands (including stream comments, file changes and
progress commands) are shown in the command history within the crash
report, but raw file data and commit messages are excluded from the
crash report. This exclusion saves space within the report file
and reduces the amount of buffering that fast-import must perform
-during execution.</p>
-<p>After writing a crash report fast-import will close the current
+during execution.</p></div>
+<div class="para"><p>After writing a crash report fast-import will close the current
packfile and export the marks table. This allows the frontend
developer to inspect the repository state and resume the import from
the point where it crashed. The modified branches and tags are not
updated during a crash, as the import did not complete successfully.
Branch and tag information can be found in the crash report and
-must be applied manually if the update is needed.</p>
-<p>An example crash:</p>
+must be applied manually if the update is needed.</p></div>
+<div class="para"><p>An example crash:</p></div>
<div class="exampleblock">
<div class="exampleblock-content">
<div class="literalblock">
@@ -1234,189 +1282,189 @@ END OF CRASH REPORT</tt></pre> </div></div>
</div></div>
</div>
-<h2>Tips and Tricks</h2>
+<h2 id="_tips_and_tricks">Tips and Tricks</h2>
<div class="sectionbody">
-<p>The following tips and tricks have been collected from various
-users of fast-import, and are offered here as suggestions.</p>
-<h3>Use One Mark Per Commit</h3>
-<p>When doing a repository conversion, use a unique mark per commit
+<div class="para"><p>The following tips and tricks have been collected from various
+users of fast-import, and are offered here as suggestions.</p></div>
+<h3 id="_use_one_mark_per_commit">Use One Mark Per Commit</h3><div style="clear:left"></div>
+<div class="para"><p>When doing a repository conversion, use a unique mark per commit
(<tt>mark :<n></tt>) and supply the --export-marks option on the command
line. fast-import will dump a file which lists every mark and the Git
object SHA-1 that corresponds to it. If the frontend can tie
the marks back to the source repository, it is easy to verify the
accuracy and completeness of the import by comparing each Git
-commit to the corresponding source revision.</p>
-<p>Coming from a system such as Perforce or Subversion this should be
+commit to the corresponding source revision.</p></div>
+<div class="para"><p>Coming from a system such as Perforce or Subversion this should be
quite simple, as the fast-import mark can also be the Perforce changeset
-number or the Subversion revision number.</p>
-<h3>Freely Skip Around Branches</h3>
-<p>Don't bother trying to optimize the frontend to stick to one branch
+number or the Subversion revision number.</p></div>
+<h3 id="_freely_skip_around_branches">Freely Skip Around Branches</h3><div style="clear:left"></div>
+<div class="para"><p>Don't bother trying to optimize the frontend to stick to one branch
at a time during an import. Although doing so might be slightly
faster for fast-import, it tends to increase the complexity of the frontend
-code considerably.</p>
-<p>The branch LRU builtin to fast-import tends to behave very well, and the
+code considerably.</p></div>
+<div class="para"><p>The branch LRU builtin to fast-import tends to behave very well, and the
cost of activating an inactive branch is so low that bouncing around
-between branches has virtually no impact on import performance.</p>
-<h3>Handling Renames</h3>
-<p>When importing a renamed file or directory, simply delete the old
+between branches has virtually no impact on import performance.</p></div>
+<h3 id="_handling_renames">Handling Renames</h3><div style="clear:left"></div>
+<div class="para"><p>When importing a renamed file or directory, simply delete the old
name(s) and modify the new name(s) during the corresponding commit.
Git performs rename detection after-the-fact, rather than explicitly
-during a commit.</p>
-<h3>Use Tag Fixup Branches</h3>
-<p>Some other SCM systems let the user create a tag from multiple
+during a commit.</p></div>
+<h3 id="_use_tag_fixup_branches">Use Tag Fixup Branches</h3><div style="clear:left"></div>
+<div class="para"><p>Some other SCM systems let the user create a tag from multiple
files which are not from the same commit/changeset. Or to create
-tags which are a subset of the files available in the repository.</p>
-<p>Importing these tags as-is in Git is impossible without making at
+tags which are a subset of the files available in the repository.</p></div>
+<div class="para"><p>Importing these tags as-is in Git is impossible without making at
least one commit which “fixes up” the files to match the content
of the tag. Use fast-import's <tt>reset</tt> command to reset a dummy branch
outside of your normal branch space to the base commit for the tag,
then commit one or more file fixup commits, and finally tag the
-dummy branch.</p>
-<p>For example since all normal branches are stored under <tt>refs/heads/</tt>
+dummy branch.</p></div>
+<div class="para"><p>For example since all normal branches are stored under <tt>refs/heads/</tt>
name the tag fixup branch <tt>TAG_FIXUP</tt>. This way it is impossible for
the fixup branch used by the importer to have namespace conflicts
with real branches imported from the source (the name <tt>TAG_FIXUP</tt>
-is not <tt>refs/heads/TAG_FIXUP</tt>).</p>
-<p>When committing fixups, consider using <tt>merge</tt> to connect the
+is not <tt>refs/heads/TAG_FIXUP</tt>).</p></div>
+<div class="para"><p>When committing fixups, consider using <tt>merge</tt> to connect the
commit(s) which are supplying file revisions to the fixup branch.
-Doing so will allow tools such as <tt>git-blame</tt> to track
+Doing so will allow tools such as <em>git-blame</em> to track
through the real commit history and properly annotate the source
-files.</p>
-<p>After fast-import terminates the frontend will need to do <tt>rm .git/TAG_FIXUP</tt>
-to remove the dummy branch.</p>
-<h3>Import Now, Repack Later</h3>
-<p>As soon as fast-import completes the Git repository is completely valid
+files.</p></div>
+<div class="para"><p>After fast-import terminates the frontend will need to do <tt>rm .git/TAG_FIXUP</tt>
+to remove the dummy branch.</p></div>
+<h3 id="_import_now_repack_later">Import Now, Repack Later</h3><div style="clear:left"></div>
+<div class="para"><p>As soon as fast-import completes the Git repository is completely valid
and ready for use. Typically this takes only a very short time,
-even for considerably large projects (100,000+ commits).</p>
-<p>However repacking the repository is necessary to improve data
+even for considerably large projects (100,000+ commits).</p></div>
+<div class="para"><p>However repacking the repository is necessary to improve data
locality and access performance. It can also take hours on extremely
large projects (especially if -f and a large --window parameter is
used). Since repacking is safe to run alongside readers and writers,
run the repack in the background and let it finish when it finishes.
-There is no reason to wait to explore your new Git project!</p>
-<p>If you choose to wait for the repack, don't try to run benchmarks
+There is no reason to wait to explore your new Git project!</p></div>
+<div class="para"><p>If you choose to wait for the repack, don't try to run benchmarks
or performance tests until repacking is completed. fast-import outputs
suboptimal packfiles that are simply never seen in real use
-situations.</p>
-<h3>Repacking Historical Data</h3>
-<p>If you are repacking very old imported data (e.g. older than the
+situations.</p></div>
+<h3 id="_repacking_historical_data">Repacking Historical Data</h3><div style="clear:left"></div>
+<div class="para"><p>If you are repacking very old imported data (e.g. older than the
last year), consider expending some extra CPU time and supplying
---window=50 (or higher) when you run <tt>git-repack</tt>.
+--window=50 (or higher) when you run <em>git-repack</em>.
This will take longer, but will also produce a smaller packfile.
You only need to expend the effort once, and everyone using your
-project will benefit from the smaller repository.</p>
-<h3>Include Some Progress Messages</h3>
-<p>Every once in a while have your frontend emit a <tt>progress</tt> message
+project will benefit from the smaller repository.</p></div>
+<h3 id="_include_some_progress_messages">Include Some Progress Messages</h3><div style="clear:left"></div>
+<div class="para"><p>Every once in a while have your frontend emit a <tt>progress</tt> message
to fast-import. The contents of the messages are entirely free-form,
so one suggestion would be to output the current month and year
each time the current commit date moves into the next month.
Your users will feel better knowing how much of the data stream
-has been processed.</p>
+has been processed.</p></div>
</div>
-<h2>Packfile Optimization</h2>
+<h2 id="_packfile_optimization">Packfile Optimization</h2>
<div class="sectionbody">
-<p>When packing a blob fast-import always attempts to deltify against the last
+<div class="para"><p>When packing a blob fast-import always attempts to deltify against the last
blob written. Unless specifically arranged for by the frontend,
this will probably not be a prior version of the same file, so the
generated delta will not be the smallest possible. The resulting
-packfile will be compressed, but will not be optimal.</p>
-<p>Frontends which have efficient access to all revisions of a
+packfile will be compressed, but will not be optimal.</p></div>
+<div class="para"><p>Frontends which have efficient access to all revisions of a
single file (for example reading an RCS/CVS ,v file) can choose
to supply all revisions of that file as a sequence of consecutive
<tt>blob</tt> commands. This allows fast-import to deltify the different file
revisions against each other, saving space in the final packfile.
Marks can be used to later identify individual file revisions during
-a sequence of <tt>commit</tt> commands.</p>
-<p>The packfile(s) created by fast-import do not encourage good disk access
+a sequence of <tt>commit</tt> commands.</p></div>
+<div class="para"><p>The packfile(s) created by fast-import do not encourage good disk access
patterns. This is caused by fast-import writing the data in the order
it is received on standard input, while Git typically organizes
data within packfiles to make the most recent (current tip) data
appear before historical data. Git also clusters commits together,
-speeding up revision traversal through better cache locality.</p>
-<p>For this reason it is strongly recommended that users repack the
+speeding up revision traversal through better cache locality.</p></div>
+<div class="para"><p>For this reason it is strongly recommended that users repack the
repository with <tt>git repack -a -d</tt> after fast-import completes, allowing
Git to reorganize the packfiles for faster data access. If blob
deltas are suboptimal (see above) then also adding the <tt>-f</tt> option
to force recomputation of all deltas can significantly reduce the
-final packfile size (30-50% smaller can be quite typical).</p>
+final packfile size (30-50% smaller can be quite typical).</p></div>
</div>
-<h2>Memory Utilization</h2>
+<h2 id="_memory_utilization">Memory Utilization</h2>
<div class="sectionbody">
-<p>There are a number of factors which affect how much memory fast-import
+<div class="para"><p>There are a number of factors which affect how much memory fast-import
requires to perform an import. Like critical sections of core
Git, fast-import uses its own memory allocators to amortize any overheads
associated with malloc. In practice fast-import tends to amortize any
-malloc overheads to 0, due to its use of large block allocations.</p>
-<h3>per object</h3>
-<p>fast-import maintains an in-memory structure for every object written in
+malloc overheads to 0, due to its use of large block allocations.</p></div>
+<h3 id="_per_object">per object</h3><div style="clear:left"></div>
+<div class="para"><p>fast-import maintains an in-memory structure for every object written in
this execution. On a 32 bit system the structure is 32 bytes,
on a 64 bit system the structure is 40 bytes (due to the larger
pointer sizes). Objects in the table are not deallocated until
fast-import terminates. Importing 2 million objects on a 32 bit system
-will require approximately 64 MiB of memory.</p>
-<p>The object table is actually a hashtable keyed on the object name
+will require approximately 64 MiB of memory.</p></div>
+<div class="para"><p>The object table is actually a hashtable keyed on the object name
(the unique SHA-1). This storage configuration allows fast-import to reuse
an existing or already written object and avoid writing duplicates
to the output packfile. Duplicate blobs are surprisingly common
-in an import, typically due to branch merges in the source.</p>
-<h3>per mark</h3>
-<p>Marks are stored in a sparse array, using 1 pointer (4 bytes or 8
+in an import, typically due to branch merges in the source.</p></div>
+<h3 id="_per_mark">per mark</h3><div style="clear:left"></div>
+<div class="para"><p>Marks are stored in a sparse array, using 1 pointer (4 bytes or 8
bytes, depending on pointer size) per mark. Although the array
is sparse, frontends are still strongly encouraged to use marks
between 1 and n, where n is the total number of marks required for
-this import.</p>
-<h3>per branch</h3>
-<p>Branches are classified as active and inactive. The memory usage
-of the two classes is significantly different.</p>
-<p>Inactive branches are stored in a structure which uses 96 or 120
+this import.</p></div>
+<h3 id="_per_branch">per branch</h3><div style="clear:left"></div>
+<div class="para"><p>Branches are classified as active and inactive. The memory usage
+of the two classes is significantly different.</p></div>
+<div class="para"><p>Inactive branches are stored in a structure which uses 96 or 120
bytes (32 bit or 64 bit systems, respectively), plus the length of
the branch name (typically under 200 bytes), per branch. fast-import will
easily handle as many as 10,000 inactive branches in under 2 MiB
-of memory.</p>
-<p>Active branches have the same overhead as inactive branches, but
+of memory.</p></div>
+<div class="para"><p>Active branches have the same overhead as inactive branches, but
also contain copies of every tree that has been recently modified on
that branch. If subtree <tt>include</tt> has not been modified since the
branch became active, its contents will not be loaded into memory,
but if subtree <tt>src</tt> has been modified by a commit since the branch
-became active, then its contents will be loaded in memory.</p>
-<p>As active branches store metadata about the files contained on that
+became active, then its contents will be loaded in memory.</p></div>
+<div class="para"><p>As active branches store metadata about the files contained on that
branch, their in-memory storage size can grow to a considerable size
-(see below).</p>
-<p>fast-import automatically moves active branches to inactive status based on
+(see below).</p></div>
+<div class="para"><p>fast-import automatically moves active branches to inactive status based on
a simple least-recently-used algorithm. The LRU chain is updated on
each <tt>commit</tt> command. The maximum number of active branches can be
-increased or decreased on the command line with --active-branches=.</p>
-<h3>per active tree</h3>
-<p>Trees (aka directories) use just 12 bytes of memory on top of the
+increased or decreased on the command line with --active-branches=.</p></div>
+<h3 id="_per_active_tree">per active tree</h3><div style="clear:left"></div>
+<div class="para"><p>Trees (aka directories) use just 12 bytes of memory on top of the
memory required for their entries (see “per active file” below).
The cost of a tree is virtually 0, as its overhead amortizes out
-over the individual file entries.</p>
-<h3>per active file entry</h3>
-<p>Files (and pointers to subtrees) within active trees require 52 or 64
+over the individual file entries.</p></div>
+<h3 id="_per_active_file_entry">per active file entry</h3><div style="clear:left"></div>
+<div class="para"><p>Files (and pointers to subtrees) within active trees require 52 or 64
bytes (32/64 bit platforms) per entry. To conserve space, file and
tree names are pooled in a common string table, allowing the filename
“Makefile” to use just 16 bytes (after including the string header
-overhead) no matter how many times it occurs within the project.</p>
-<p>The active branch LRU, when coupled with the filename string pool
+overhead) no matter how many times it occurs within the project.</p></div>
+<div class="para"><p>The active branch LRU, when coupled with the filename string pool
and lazy loading of subtrees, allows fast-import to efficiently import
projects with 2,000+ branches and 45,114+ files in a very limited
-memory footprint (less than 2.7 MiB per active branch).</p>
+memory footprint (less than 2.7 MiB per active branch).</p></div>
</div>
-<h2>Author</h2>
+<h2 id="_author">Author</h2>
<div class="sectionbody">
-<p>Written by Shawn O. Pearce <spearce@spearce.org>.</p>
+<div class="para"><p>Written by Shawn O. Pearce <spearce@spearce.org>.</p></div>
</div>
-<h2>Documentation</h2>
+<h2 id="_documentation">Documentation</h2>
<div class="sectionbody">
-<p>Documentation by Shawn O. Pearce <spearce@spearce.org>.</p>
+<div class="para"><p>Documentation by Shawn O. Pearce <spearce@spearce.org>.</p></div>
</div>
-<h2>GIT</h2>
+<h2 id="_git">GIT</h2>
<div class="sectionbody">
-<p>Part of the <a href="git.html">git(1)</a> suite</p>
+<div class="para"><p>Part of the <a href="git.html">git(1)</a> suite</p></div>
</div>
<div id="footer">
<div id="footer-text">
-Last updated 02-Jul-2008 03:01:43 UTC
+Last updated 2008-07-06 05:16:45 UTC
</div>
</div>
</body>
|