From f932729cc7707390f4d6739be1573e93ceb9df22 Mon Sep 17 00:00:00 2001 From: Jeff King Date: Mon, 10 Aug 2015 05:38:57 -0400 Subject: memoize common git-path "constant" files One of the most common uses of git_path() is to pass a constant, like git_path("MERGE_MSG"). This has two drawbacks: 1. The return value is a static buffer, and the lifetime is dependent on other calls to git_path, etc. 2. There's no compile-time checking of the pathname. This is OK for a one-off (after all, we have to spell it correctly at least once), but many of these constant strings appear throughout the code. This patch introduces a series of functions to "memoize" these strings, which are essentially globals for the lifetime of the program. We compute the value once, take ownership of the buffer, and return the cached value for subsequent calls. cache.h provides a helper macro for defining these functions as one-liners, and defines a few common ones for global use. Using a macro is a little bit gross, but it does nicely document the purpose of the functions. If we need to touch them all later (e.g., because we learned how to change the git_dir variable at runtime, and need to invalidate all of the stored values), it will be much easier to have the complete list. Note that the shared-global functions have separate, manual declarations. We could do something clever with the macros (e.g., expand it to a declaration in some places, and a declaration _and_ a definition in path.c). But there aren't that many, and it's probably better to stay away from too-magical macros. Likewise, if we abandon the C preprocessor in favor of generating these with a script, we could get much fancier. E.g., normalizing "FOO/BAR-BAZ" into "git_path_foo_bar_baz". But the small amount of saved typing is probably not worth the resulting confusion to readers who want to grep for the function's definition. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano --- builtin/merge.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) (limited to 'builtin/merge.c') diff --git a/builtin/merge.c b/builtin/merge.c index 85c54dcd5a..a0edacab20 100644 --- a/builtin/merge.c +++ b/builtin/merge.c @@ -231,9 +231,9 @@ static struct option builtin_merge_options[] = { /* Cleans up metadata that is uninteresting after a succeeded merge. */ static void drop_save(void) { - unlink(git_path("MERGE_HEAD")); - unlink(git_path("MERGE_MSG")); - unlink(git_path("MERGE_MODE")); + unlink(git_path_merge_head()); + unlink(git_path_merge_msg()); + unlink(git_path_merge_mode()); } static int save_state(unsigned char *stash) @@ -338,7 +338,7 @@ static void squash_message(struct commit *commit, struct commit_list *remotehead struct pretty_print_context ctx = {0}; printf(_("Squash commit -- not updating HEAD\n")); - filename = git_path("SQUASH_MSG"); + filename = git_path_squash_msg(); fd = open(filename, O_WRONLY | O_CREAT, 0666); if (fd < 0) die_errno(_("Could not write to '%s'"), filename); @@ -754,7 +754,7 @@ static void add_strategies(const char *string, unsigned attr) static void write_merge_msg(struct strbuf *msg) { - const char *filename = git_path("MERGE_MSG"); + const char *filename = git_path_merge_msg(); int fd = open(filename, O_WRONLY | O_CREAT, 0666); if (fd < 0) die_errno(_("Could not open '%s' for writing"), @@ -766,7 +766,7 @@ static void write_merge_msg(struct strbuf *msg) static void read_merge_msg(struct strbuf *msg) { - const char *filename = git_path("MERGE_MSG"); + const char *filename = git_path_merge_msg(); strbuf_reset(msg); if (strbuf_read_file(msg, filename, 0) < 0) die_errno(_("Could not read from '%s'"), filename); @@ -799,10 +799,10 @@ static void prepare_to_commit(struct commit_list *remoteheads) strbuf_commented_addf(&msg, _(merge_editor_comment), comment_line_char); write_merge_msg(&msg); if (run_commit_hook(0 < option_edit, get_index_file(), "prepare-commit-msg", - git_path("MERGE_MSG"), "merge", NULL)) + git_path_merge_msg(), "merge", NULL)) abort_commit(remoteheads, NULL); if (0 < option_edit) { - if (launch_editor(git_path("MERGE_MSG"), NULL, NULL)) + if (launch_editor(git_path_merge_msg(), NULL, NULL)) abort_commit(remoteheads, NULL); } read_merge_msg(&msg); @@ -865,7 +865,7 @@ static int suggest_conflicts(void) FILE *fp; struct strbuf msgbuf = STRBUF_INIT; - filename = git_path("MERGE_MSG"); + filename = git_path_merge_msg(); fp = fopen(filename, "a"); if (!fp) die_errno(_("Could not open '%s' for writing"), filename); @@ -967,7 +967,7 @@ static void write_merge_state(struct commit_list *remoteheads) } strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1)); } - filename = git_path("MERGE_HEAD"); + filename = git_path_merge_head(); fd = open(filename, O_WRONLY | O_CREAT, 0666); if (fd < 0) die_errno(_("Could not open '%s' for writing"), filename); @@ -977,7 +977,7 @@ static void write_merge_state(struct commit_list *remoteheads) strbuf_addch(&merge_msg, '\n'); write_merge_msg(&merge_msg); - filename = git_path("MERGE_MODE"); + filename = git_path_merge_mode(); fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, 0666); if (fd < 0) die_errno(_("Could not open '%s' for writing"), filename); @@ -1070,7 +1070,7 @@ static void handle_fetch_head(struct commit_list **remotes, struct strbuf *merge if (!merge_names) merge_names = &fetch_head_file; - filename = git_path("FETCH_HEAD"); + filename = git_path_fetch_head(); fd = open(filename, O_RDONLY); if (fd < 0) die_errno(_("could not open '%s' for reading"), filename); @@ -1204,7 +1204,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix) int nargc = 2; const char *nargv[] = {"reset", "--merge", NULL}; - if (!file_exists(git_path("MERGE_HEAD"))) + if (!file_exists(git_path_merge_head())) die(_("There is no merge to abort (MERGE_HEAD missing).")); /* Invoke 'git reset --merge' */ @@ -1215,7 +1215,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix) if (read_cache_unmerged()) die_resolve_conflict("merge"); - if (file_exists(git_path("MERGE_HEAD"))) { + if (file_exists(git_path_merge_head())) { /* * There is no unmerged entry, don't advise 'git * add/rm ', just 'git commit'. @@ -1226,7 +1226,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix) else die(_("You have not concluded your merge (MERGE_HEAD exists).")); } - if (file_exists(git_path("CHERRY_PICK_HEAD"))) { + if (file_exists(git_path_cherry_pick_head())) { if (advice_resolve_conflict) die(_("You have not concluded your cherry-pick (CHERRY_PICK_HEAD exists).\n" "Please, commit your changes before you merge.")); -- cgit v1.2.3