[PATCH v2 1/4] name-hash: refactor polymorphic index_name_exists()
- From
Eric Sunshine <sunshine@sunshineco.com>
- Date
- Sep 17, 2013, 07:06 UTC
- Message-ID
- <1379401577-36799-2-git-send-email-sunshine@sunshineco.com>
- In-Reply-To
- <1379401577-36799-1-git-send-email-sunshine@sunshineco.com>
Depending upon the absence or presence of a trailing '/' on the incoming pathname, index_name_exists() checks either if a file is present in the index or if a directory is represented within the index. Each caller explicitly chooses the mode of operation by adding or removing a trailing '/' before invoking index_name_exists().
Since these two modes of operations are disjoint and have no code in common (one searches index_state.name_hash; the other dir_hash), they can be represented more naturally as distinct functions: one to search for a file, and one for a directory.
Splitting index searching into two functions relieves callers of the artificial burden of having to add or remove a slash to select the mode of operation; instead they just call the desired function. A subsequent patch will take advantage of this benefit in order to eliminate the requirement that the incoming pathname for a directory search must have a trailing slash.
(In order to avoid disturbing in-flight topics, index_name_exists() is retained as a thin wrapper dispatching either to index_dir_exists() or index_file_exists().)
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> --- cache.h | 4 ++++ name-hash.c | 54 ++++++++++++++++++++++++++++++------------------------ 2 files changed, 34 insertions(+), 24 deletions(-)
diff --git a/cache.h b/cache.h index a47b9c0..038afe1 100644 --- a/cache.h +++ b/cache.h @@ -314,6 +314,8 @@ extern void free_name_hash(struct index_state *istate); #define refresh_cache(flags) refresh_index(&the_index, (flags), NULL, NULL, NULL) #define ce_match_stat(ce, st, options) ie_match_stat(&the_index, (ce), (st), (options)) #define ce_modified(ce, st, options) ie_modified(&the_index, (ce), (st), (options)) +#define cache_dir_exists(name, namelen) index_dir_exists(&the_index, (name), (namelen)) +#define cache_file_exists(name, namelen, igncase) index_file_exists(&the_index, (name), (namelen), (igncase)) #define cache_name_exists(name, namelen, igncase) index_name_exists(&the_index, (name), (namelen), (igncase)) #define cache_name_is_other(name, namelen) index_name_is_other(&the_index, (name), (namelen)) #define resolve_undo_clear() resolve_undo_clear_index(&the_index) @@ -463,6 +465,8 @@ extern int write_index(struct index_state *, int newfd); extern int discard_index(struct index_state *); extern int unmerged_index(const struct index_state *); extern int verify_path(const char *path); +extern struct cache_entry *index_dir_exists(struct index_state *istate, const char *name, int namelen); +extern struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int igncase); extern struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen, int igncase); extern int index_name_pos(const struct index_state *, const char *name, int namelen); #define ADD_CACHE_OK_TO_ADD 1 /* Ok to add */ diff --git a/name-hash.c b/name-hash.c index 617c86c..f06b049 100644 --- a/name-hash.c +++ b/name-hash.c @@ -222,7 +222,29 @@ static int same_name(const struct cache_entry *ce, const char *name, int namelen return slow_same_name(name, namelen, ce->name, len); } -struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen, int icase) +struct cache_entry *index_dir_exists(struct index_state *istate, const char *name, int namelen) +{ + struct cache_entry *ce; + struct dir_entry *dir; + + lazy_init_name_hash(istate); + dir = find_dir_entry(istate, name, namelen); + if (dir && dir->nr) + return dir->ce; + + /* + * It might be a submodule. Unlike plain directories, which are stored + * in the dir-hash, submodules are stored in the name-hash, so check + * there, as well. + */ + ce = index_file_exists(istate, name, namelen - 1, 1); + if (ce && S_ISGITLINK(ce->ce_mode)) + return ce; + + return NULL; +} + +struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int icase) { unsigned int hash = hash_name(name, namelen); struct cache_entry *ce; @@ -237,32 +259,16 @@ struct cache_entry *index_name_exists(struct index_state *istate, const char *na } ce = ce->next; } - - /* - * When looking for a directory (trailing '/'), it might be a - * submodule or a directory. Despite submodules being directories, - * they are stored in the name hash without a closing slash. - * When ignore_case is 1, directories are stored in a separate hash - * table *with* their closing slash. - * - * The side effect of this storage technique is we have need to - * lookup the directory in a separate hash table, and if not found - * remove the slash from name and perform the lookup again without - * the slash. If a match is made, S_ISGITLINK(ce->mode) will be - * true. - */ - if (icase && name[namelen - 1] == '/') { - struct dir_entry *dir = find_dir_entry(istate, name, namelen); - if (dir && dir->nr) - return dir->ce; - - ce = index_name_exists(istate, name, namelen - 1, icase); - if (ce && S_ISGITLINK(ce->ce_mode)) - return ce; - } return NULL; } +struct cache_entry *index_name_exists(struct index_state *istate, const char *name, int namelen, int icase) +{ + if (namelen > 0 && name[namelen - 1] == '/') + return index_dir_exists(istate, name, namelen); + return index_file_exists(istate, name, namelen, icase); +} + static int free_dir_entry(void *entry, void *unused) { struct dir_entry *dir = entry;
-- 1.8.4.535.g7b94f8e