From: Stefan Beller Date: Sat, 27 Jul 2013 08:50:38 GMT Subject: [PATCH] builtins: search builtin commands via binary search. Message-ID: <1374915038-6717-1-git-send-email-stefanbeller@googlemail.com> In-Reply-To: <51F38997.9010507@googlemail.com> There are currently 115 commands built into the git executable. Before this commit, it was iterated over these commands in a linear order, i.e. each command was checked. As it turns out the commands are already sorted alphabetically, it is easy to perform a binary search instead of linear searching. This results in 7 lookups in the worst case. Signed-off-by: Stefan Beller --- git.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/git.c b/git.c index 2025f77..6d4de2b 100644 --- a/git.c +++ b/git.c @@ -309,9 +309,14 @@ static int run_builtin(struct cmd_struct *p, int argc, const char **argv) return 0; } +static int compare_internal_command(const void *name, const void *cmd) { + return strcmp((const char*)name, ((const struct cmd_struct*)cmd)->cmd); +} + static void handle_internal_command(int argc, const char **argv) { const char *cmd = argv[0]; + /* commands must be sorted alphabetically for binary search */ static struct cmd_struct commands[] = { { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE }, { "annotate", cmd_annotate, RUN_SETUP }, @@ -447,12 +452,12 @@ static void handle_internal_command(int argc, const char **argv) argv[0] = cmd = "help"; } - for (i = 0; i < ARRAY_SIZE(commands); i++) { - struct cmd_struct *p = commands+i; - if (strcmp(p->cmd, cmd)) - continue; + struct cmd_struct *p = bsearch(cmd, commands, + ARRAY_SIZE(commands), sizeof(struct cmd_struct), + compare_internal_command); + + if (p) exit(run_builtin(p, argc, argv)); - } } static void execv_dashed_external(const char **argv) -- 1.8.4.rc0.1.g8f6a3e5