From: Adam Spiers <git@adamspiers.org>
To: git list <git@vger.kernel.org>
Subject: [PATCH v3 02/19] Improve documentation and comments regarding directory traversal API
Date: Thu, 27 Dec 2012 02:32:21 +0000 [thread overview]
Message-ID: <1356575558-2674-3-git-send-email-git@adamspiers.org> (raw)
In-Reply-To: <1356575558-2674-1-git-send-email-git@adamspiers.org>
>From the perspective of a newcomer to the codebase, the directory
traversal API has a few potentially confusing properties. These
comments clarify a few key aspects and will hopefully make it easier
to understand for other newcomers in the future.
Signed-off-by: Adam Spiers <git@adamspiers.org>
---
For some reason this patch was dropped from the v2 series when it was
applied to the 'pu' branch.
Documentation/technical/api-directory-listing.txt | 9 +++++---
dir.c | 8 ++++++-
dir.h | 26 +++++++++++++++++++++--
3 files changed, 37 insertions(+), 6 deletions(-)
diff --git a/Documentation/technical/api-directory-listing.txt b/Documentation/technical/api-directory-listing.txt
index 0356d25..944fc39 100644
--- a/Documentation/technical/api-directory-listing.txt
+++ b/Documentation/technical/api-directory-listing.txt
@@ -9,8 +9,11 @@ Data structure
--------------
`struct dir_struct` structure is used to pass directory traversal
-options to the library and to record the paths discovered. The notable
-options are:
+options to the library and to record the paths discovered. A single
+`struct dir_struct` is used regardless of whether or not the traversal
+recursively descends into subdirectories.
+
+The notable options are:
`exclude_per_dir`::
@@ -39,7 +42,7 @@ options are:
If set, recurse into a directory that looks like a git
directory. Otherwise it is shown as a directory.
-The result of the enumeration is left in these fields::
+The result of the enumeration is left in these fields:
`entries[]`::
diff --git a/dir.c b/dir.c
index ee8e711..89e27a6 100644
--- a/dir.c
+++ b/dir.c
@@ -2,6 +2,8 @@
* This handles recursive filename detection with exclude
* files, index knowledge etc..
*
+ * See Documentation/technical/api-directory-listing.txt
+ *
* Copyright (C) Linus Torvalds, 2005-2006
* Junio Hamano, 2005-2006
*/
@@ -476,6 +478,10 @@ void add_excludes_from_file(struct dir_struct *dir, const char *fname)
die("cannot use %s as an exclude file", fname);
}
+/*
+ * Loads the per-directory exclude list for the substring of base
+ * which has a char length of baselen.
+ */
static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
{
struct exclude_list *el;
@@ -486,7 +492,7 @@ static void prep_exclude(struct dir_struct *dir, const char *base, int baselen)
(baselen + strlen(dir->exclude_per_dir) >= PATH_MAX))
return; /* too long a path -- ignore */
- /* Pop the ones that are not the prefix of the path being checked. */
+ /* Pop the directories that are not the prefix of the path being checked. */
el = &dir->exclude_list[EXC_DIRS];
while ((stk = dir->exclude_stack) != NULL) {
if (stk->baselen <= baselen &&
diff --git a/dir.h b/dir.h
index f5c89e3..e0869bc 100644
--- a/dir.h
+++ b/dir.h
@@ -1,6 +1,8 @@
#ifndef DIR_H
#define DIR_H
+/* See Documentation/technical/api-directory-listing.txt */
+
#include "strbuf.h"
struct dir_entry {
@@ -13,6 +15,12 @@ struct dir_entry {
#define EXC_FLAG_MUSTBEDIR 8
#define EXC_FLAG_NEGATIVE 16
+/*
+ * Each .gitignore file will be parsed into patterns which are then
+ * appended to the relevant exclude_list (either EXC_DIRS or
+ * EXC_FILE). exclude_lists are also used to represent the list of
+ * --exclude values passed via CLI args (EXC_CMDL).
+ */
struct exclude_list {
int nr;
int alloc;
@@ -26,9 +34,15 @@ struct exclude_list {
} **excludes;
};
+/*
+ * The contents of the per-directory exclude files are lazily read on
+ * demand and then cached in memory, one per exclude_stack struct, in
+ * order to avoid opening and parsing each one every time that
+ * directory is traversed.
+ */
struct exclude_stack {
- struct exclude_stack *prev;
- char *filebuf;
+ struct exclude_stack *prev; /* the struct exclude_stack for the parent directory */
+ char *filebuf; /* remember pointer to per-directory exclude file contents so we can free() */
int baselen;
int exclude_ix;
};
@@ -59,6 +73,14 @@ struct dir_struct {
#define EXC_DIRS 1
#define EXC_FILE 2
+ /*
+ * Temporary variables which are used during loading of the
+ * per-directory exclude lists.
+ *
+ * exclude_stack points to the top of the exclude_stack, and
+ * basebuf contains the full path to the current
+ * (sub)directory in the traversal.
+ */
struct exclude_stack *exclude_stack;
char basebuf[PATH_MAX];
};
--
1.7.11.2.249.g31c7954
next prev parent reply other threads:[~2012-12-27 2:33 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-27 2:32 [PATCH v3 00/19] new git check-ignore sub-command Adam Spiers
2012-12-27 2:32 ` [PATCH v3 01/19] api-directory-listing.txt: update to match code Adam Spiers
2012-12-27 2:32 ` Adam Spiers [this message]
2013-01-01 20:52 ` [PATCH v3 02/19] Improve documentation and comments regarding directory traversal API Junio C Hamano
2013-01-02 12:54 ` Adam Spiers
2013-01-06 12:02 ` Adam Spiers
2012-12-27 2:32 ` [PATCH v3 03/19] dir.c: rename cryptic 'which' variable to more consistent name Adam Spiers
2012-12-27 2:32 ` [PATCH v3 04/19] dir.c: rename path_excluded() to is_path_excluded() Adam Spiers
2012-12-27 2:32 ` [PATCH v3 05/19] dir.c: rename excluded_from_list() to is_excluded_from_list() Adam Spiers
2012-12-27 2:32 ` [PATCH v3 06/19] dir.c: rename excluded() to is_excluded() Adam Spiers
2012-12-27 2:32 ` [PATCH v3 07/19] dir.c: refactor is_excluded_from_list() Adam Spiers
2012-12-27 2:32 ` [PATCH v3 08/19] dir.c: refactor is_excluded() Adam Spiers
2012-12-27 2:32 ` [PATCH v3 09/19] dir.c: refactor is_path_excluded() Adam Spiers
2012-12-27 2:32 ` [PATCH v3 10/19] dir.c: rename free_excludes() to clear_exclude_list() Adam Spiers
2012-12-27 2:32 ` [PATCH v3 11/19] dir.c: use a single struct exclude_list per source of excludes Adam Spiers
2013-01-04 21:03 ` Junio C Hamano
2013-01-05 7:54 ` Junio C Hamano
2013-01-06 15:27 ` Adam Spiers
2013-01-06 15:35 ` [PATCH] api-allocation-growing.txt: encourage better variable naming Adam Spiers
2013-01-06 20:29 ` Junio C Hamano
2013-01-06 20:52 ` Adam Spiers
2013-01-06 20:58 ` Junio C Hamano
2013-01-06 15:20 ` [PATCH v3 11/19] dir.c: use a single struct exclude_list per source of excludes Adam Spiers
2013-01-06 20:25 ` Junio C Hamano
2013-01-06 22:53 ` Adam Spiers
2013-01-06 23:17 ` Adam Spiers
2013-01-06 23:19 ` Junio C Hamano
2012-12-27 2:32 ` [PATCH v3 12/19] dir.c: keep track of where patterns came from Adam Spiers
2012-12-27 2:32 ` [PATCH v3 13/19] dir.c: provide clear_directory() for reclaiming dir_struct memory Adam Spiers
2012-12-27 2:32 ` [PATCH v3 14/19] add.c: refactor treat_gitlinks() Adam Spiers
2012-12-27 2:32 ` [PATCH v3 15/19] add.c: remove unused argument from validate_pathspec() Adam Spiers
2012-12-27 2:32 ` [PATCH v3 16/19] pathspec.c: move reusable code from builtin/add.c Adam Spiers
2012-12-28 20:32 ` Junio C Hamano
2012-12-28 20:45 ` Adam Spiers
2012-12-29 0:40 ` Adam Spiers
2012-12-28 20:48 ` Junio C Hamano
2012-12-28 21:15 ` Adam Spiers
2012-12-27 2:32 ` [PATCH v3 17/19] pathspec.c: extract new validate_path() for reuse Adam Spiers
2012-12-28 20:44 ` Junio C Hamano
2012-12-28 21:08 ` Adam Spiers
2012-12-27 2:32 ` [PATCH v3 18/19] setup.c: document get_pathspec() Adam Spiers
2012-12-28 20:36 ` Junio C Hamano
2012-12-28 20:40 ` Adam Spiers
2012-12-29 0:52 ` Adam Spiers
2012-12-29 1:36 ` Junio C Hamano
2012-12-27 2:32 ` [PATCH v3 19/19] Add git-check-ignore sub-command Adam Spiers
2012-12-28 21:21 ` Junio C Hamano
2012-12-29 1:23 ` Adam Spiers
2012-12-29 3:32 ` Adam Spiers
2012-12-27 5:15 ` [PATCH v3 00/19] new git check-ignore sub-command Michael Leal
2012-12-28 18:50 ` Junio C Hamano
2012-12-28 19:39 ` Adam Spiers
2012-12-28 20:15 ` Antoine Pelisse
2012-12-28 21:31 ` Junio C Hamano
2012-12-28 21:23 ` Junio C Hamano
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