From: Anders Kaseorg Date: Thu, 9 Dec 2010 06:46:08 +0000 (-0500) Subject: describe: Store commit_names in a hash table by commit SHA1 X-Git-Tag: v1.7.4-rc0~35^2~1 X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=3cfa4db3226ccef8845589029090d9398b207ba3;p=git.git describe: Store commit_names in a hash table by commit SHA1 describe is currently forced to look up the commit at each tag in order to store the struct commit_name pointers in struct commit.util. For --exact-match queries, those lookups are wasteful. In preparation for removing them, put the commit_names into a hash table, indexed by commit SHA1, that can be used to quickly check for exact matches. Signed-off-by: Anders Kaseorg Signed-off-by: Junio C Hamano --- diff --git a/builtin/describe.c b/builtin/describe.c index 5b8461d87..814923305 100644 --- a/builtin/describe.c +++ b/builtin/describe.c @@ -6,6 +6,7 @@ #include "exec_cmd.h" #include "parse-options.h" #include "diff.h" +#include "hash.h" #define SEEN (1u<<0) #define MAX_TAGS (FLAG_BITS - 1) @@ -22,7 +23,7 @@ static int tags; /* Allow lightweight tags */ static int longformat; static int abbrev = DEFAULT_ABBREV; static int max_candidates = 10; -static int found_names; +static struct hash_table names; static const char *pattern; static int always; static const char *dirty; @@ -34,6 +35,8 @@ static const char *diff_index_args[] = { struct commit_name { + struct commit_name *next; + unsigned char peeled[20]; struct tag *tag; unsigned prio:2; /* annotated tag = 2, tag = 1, head = 0 */ unsigned name_checked:1; @@ -44,6 +47,21 @@ static const char *prio_names[] = { "head", "lightweight", "annotated", }; +static inline unsigned int hash_sha1(const unsigned char *sha1) +{ + unsigned int hash; + memcpy(&hash, sha1, sizeof(hash)); + return hash; +} + +static inline struct commit_name *find_commit_name(const unsigned char *peeled) +{ + struct commit_name *n = lookup_hash(hash_sha1(peeled), &names); + while (n && !!hashcmp(peeled, n->peeled)) + n = n->next; + return n; +} + static int replace_name(struct commit_name *e, int prio, const unsigned char *sha1, @@ -82,12 +100,22 @@ static void add_to_known_names(const char *path, int prio, const unsigned char *sha1) { - struct commit_name *e = commit->util; + const unsigned char *peeled = commit->object.sha1; + struct commit_name *e = find_commit_name(peeled); struct tag *tag = NULL; if (replace_name(e, prio, sha1, &tag)) { if (!e) { + void **pos; e = xmalloc(sizeof(struct commit_name)); commit->util = e; + hashcpy(e->peeled, peeled); + pos = insert_hash(hash_sha1(peeled), e, &names); + if (pos) { + e->next = *pos; + *pos = e; + } else { + e->next = NULL; + } } e->tag = tag; e->prio = prio; @@ -95,7 +123,6 @@ static void add_to_known_names(const char *path, hashcpy(e->sha1, sha1); e->path = path; } - found_names = 1; } static int get_name(const char *path, const unsigned char *sha1, int flag, void *cb_data) @@ -240,7 +267,7 @@ static void describe(const char *arg, int last_one) if (!cmit) die("%s is not a valid '%s' object", arg, commit_type); - n = cmit->util; + n = find_commit_name(cmit->object.sha1); if (n && (tags || all || n->prio == 2)) { /* * Exact match to an existing ref. @@ -418,8 +445,9 @@ int cmd_describe(int argc, const char **argv, const char *prefix) return cmd_name_rev(i + argc, args, prefix); } + init_hash(&names); for_each_rawref(get_name, NULL); - if (!found_names && !always) + if (!names.nr && !always) die("No names found, cannot describe anything."); if (argc == 0) {