diff options
Diffstat (limited to 'MyFirstObjectWalk.html')
| -rw-r--r-- | MyFirstObjectWalk.html | 41 |
1 files changed, 23 insertions, 18 deletions
diff --git a/MyFirstObjectWalk.html b/MyFirstObjectWalk.html index 0709da55b..c0272f526 100644 --- a/MyFirstObjectWalk.html +++ b/MyFirstObjectWalk.html @@ -735,7 +735,7 @@ asciidoc.install(); <body class="article">
<div id="header">
<h1>My First Object Walk</h1>
-<span id="revdate">2024-04-05</span>
+<span id="revdate">2024-04-09</span>
</div>
<div id="content">
<div class="sect1">
@@ -989,13 +989,14 @@ We’ll also need to include the <code>config.h</code> header:</p></div> ...
-static int git_walken_config(const char *var, const char *value, void *cb)
+static int git_walken_config(const char *var, const char *value,
+ const struct config_context *ctx, void *cb)
{
/*
* For now, we don't have any custom configuration, so fall back to
* the default config.
*/
- return git_default_config(var, value, cb);
+ return git_default_config(var, value, ctx, cb);
}</code></pre>
</div></div>
<div class="paragraph"><p>Make sure to invoke <code>git_config()</code> with it in your <code>cmd_walken()</code>:</p></div>
@@ -1180,10 +1181,11 @@ modifying <code>rev_info.grep_filter</code>, which is a <code>struct grep_opt</c <div class="paragraph"><p>First some setup. Add <code>grep_config()</code> to <code>git_walken_config()</code>:</p></div>
<div class="listingblock">
<div class="content">
-<pre><code>static int git_walken_config(const char *var, const char *value, void *cb)
+<pre><code>static int git_walken_config(const char *var, const char *value,
+ const struct config_context *ctx, void *cb)
{
- grep_config(var, value, cb);
- return git_default_config(var, value, cb);
+ grep_config(var, value, ctx, cb);
+ return git_default_config(var, value, ctx, cb);
}</code></pre>
</div></div>
<div class="paragraph"><p>Next, we can modify the <code>grep_filter</code>. This is done with convenience functions
@@ -1317,7 +1319,7 @@ that! Let’s see if we can walk <em>all</em> objects, and find out some inf about each one.</p></div>
<div class="paragraph"><p>We can base our work on an example. <code>git pack-objects</code> prepares all kinds of
objects for packing into a bitmap or packfile. The work we are interested in
-resides in <code>builtins/pack-objects.c:get_object_list()</code>; examination of that
+resides in <code>builtin/pack-objects.c:get_object_list()</code>; examination of that
function shows that the all-object walk is being performed by
<code>traverse_commit_list()</code> or <code>traverse_commit_list_filtered()</code>. Those two
functions reside in <code>list-objects.c</code>; examining the source shows that, despite
@@ -1549,8 +1551,8 @@ walk we’ve just performed:</p></div> } else {
trace_printf(
_("Filtered object walk with filterspec 'tree:1'.\n"));
- CALLOC_ARRAY(rev->filter, 1);
- parse_list_objects_filter(rev->filter, "tree:1");
+
+ parse_list_objects_filter(&rev->filter, "tree:1");
}
traverse_commit_list(rev, walken_show_commit,
walken_show_object, NULL);</code></pre>
@@ -1567,10 +1569,12 @@ points to the same tree object as its grandparent.)</p></div> <div class="sect2">
<h3 id="_counting_omitted_objects">Counting Omitted Objects</h3>
<div class="paragraph"><p>We also have the capability to enumerate all objects which were omitted by a
-filter, like with <code>git log --filter=<spec> --filter-print-omitted</code>. Asking
-<code>traverse_commit_list_filtered()</code> to populate the <code>omitted</code> list means that our
-object walk does not perform any better than an unfiltered object walk; all
-reachable objects are walked in order to populate the list.</p></div>
+filter, like with <code>git log --filter=<spec> --filter-print-omitted</code>. To do this,
+change <code>traverse_commit_list()</code> to <code>traverse_commit_list_filtered()</code>, which is
+able to populate an <code>omitted</code> list. Asking for this list of filtered objects
+may cause performance degradations, however, because in this case, despite
+filtering objects, the possibly much larger set of all reachable objects must
+be processed in order to populate that list.</p></div>
<div class="paragraph"><p>First, add the <code>struct oidset</code> and related items we will use to iterate it:</p></div>
<div class="listingblock">
<div class="content">
@@ -1589,8 +1593,9 @@ static void walken_object_walk( ...</code></pre>
</div></div>
-<div class="paragraph"><p>Modify the call to <code>traverse_commit_list_filtered()</code> to include your <code>omitted</code>
-object:</p></div>
+<div class="paragraph"><p>Replace the call to <code>traverse_commit_list()</code> with
+<code>traverse_commit_list_filtered()</code> and pass a pointer to the <code>omitted</code> oidset
+defined and initialized above:</p></div>
<div class="listingblock">
<div class="content">
<pre><code> ...
@@ -1658,7 +1663,7 @@ those lines without having to recompile.</td> <div class="paragraph"><p>With only that change, run again (but save yourself some scrollback):</p></div>
<div class="listingblock">
<div class="content">
-<pre><code>$ GIT_TRACE=1 ./bin-wrappers/git walken | head -n 10</code></pre>
+<pre><code>$ GIT_TRACE=1 ./bin-wrappers/git walken 2>&1 | head -n 10</code></pre>
</div></div>
<div class="paragraph"><p>Take a look at the top commit with <code>git show</code> and the object ID you printed; it
should be the same as the output of <code>git show HEAD</code>.</p></div>
@@ -1683,7 +1688,7 @@ of the first handful:</p></div> <div class="listingblock">
<div class="content">
<pre><code>$ make
-$ GIT_TRACE=1 ./bin-wrappers git walken | tail -n 10</code></pre>
+$ GIT_TRACE=1 ./bin-wrappers/git walken 2>&1 | tail -n 10</code></pre>
</div></div>
<div class="paragraph"><p>The last commit object given should have the same OID as the one we saw at the
top before, and running <code>git show <oid></code> with that OID should give you again
@@ -1737,7 +1742,7 @@ Changed the display order of the filtered object walk <div id="footer">
<div id="footer-text">
Last updated
- 2023-07-17 11:51:48 PDT
+ 2024-04-09 14:45:01 PDT
</div>
</div>
</body>
|