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 <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/blame.c b/builtin/blame.c
index 04e4864..4db01c1 100644
--- a/builtin/blame.c
+++ b/builtin/blame.c
@@ -2227,20 +2227,19 @@
static void append_merge_parents(struct commit_list **tail)
{
int merge_head;
- const char *merge_head_file = git_path("MERGE_HEAD");
struct strbuf line = STRBUF_INIT;
- merge_head = open(merge_head_file, O_RDONLY);
+ merge_head = open(git_path_merge_head(), O_RDONLY);
if (merge_head < 0) {
if (errno == ENOENT)
return;
- die("cannot open '%s' for reading", merge_head_file);
+ die("cannot open '%s' for reading", git_path_merge_head());
}
while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) {
unsigned char sha1[20];
if (line.len < 40 || get_sha1_hex(line.buf, sha1))
- die("unknown line in '%s': %s", merge_head_file, line.buf);
+ die("unknown line in '%s': %s", git_path_merge_head(), line.buf);
tail = append_parent(tail, sha1);
}
close(merge_head);
diff --git a/builtin/commit.c b/builtin/commit.c
index 7314f33..4cbd5ff 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -166,9 +166,9 @@
static void determine_whence(struct wt_status *s)
{
- if (file_exists(git_path("MERGE_HEAD")))
+ if (file_exists(git_path_merge_head()))
whence = FROM_MERGE;
- else if (file_exists(git_path("CHERRY_PICK_HEAD"))) {
+ else if (file_exists(git_path_cherry_pick_head())) {
whence = FROM_CHERRY_PICK;
if (file_exists(git_path(SEQ_DIR)))
sequencer_in_use = 1;
@@ -725,12 +725,12 @@
format_commit_message(commit, "fixup! %s\n\n",
&sb, &ctx);
hook_arg1 = "message";
- } else if (!stat(git_path("MERGE_MSG"), &statbuf)) {
- if (strbuf_read_file(&sb, git_path("MERGE_MSG"), 0) < 0)
+ } else if (!stat(git_path_merge_msg(), &statbuf)) {
+ if (strbuf_read_file(&sb, git_path_merge_msg(), 0) < 0)
die_errno(_("could not read MERGE_MSG"));
hook_arg1 = "merge";
- } else if (!stat(git_path("SQUASH_MSG"), &statbuf)) {
- if (strbuf_read_file(&sb, git_path("SQUASH_MSG"), 0) < 0)
+ } else if (!stat(git_path_squash_msg(), &statbuf)) {
+ if (strbuf_read_file(&sb, git_path_squash_msg(), 0) < 0)
die_errno(_("could not read SQUASH_MSG"));
hook_arg1 = "squash";
} else if (template_file) {
@@ -1684,10 +1684,10 @@
if (!reflog_msg)
reflog_msg = "commit (merge)";
pptr = &commit_list_insert(current_head, pptr)->next;
- fp = fopen(git_path("MERGE_HEAD"), "r");
+ fp = fopen(git_path_merge_head(), "r");
if (fp == NULL)
die_errno(_("could not open '%s' for reading"),
- git_path("MERGE_HEAD"));
+ git_path_merge_head());
while (strbuf_getline(&m, fp, '\n') != EOF) {
struct commit *parent;
@@ -1698,8 +1698,8 @@
}
fclose(fp);
strbuf_release(&m);
- if (!stat(git_path("MERGE_MODE"), &statbuf)) {
- if (strbuf_read_file(&sb, git_path("MERGE_MODE"), 0) < 0)
+ if (!stat(git_path_merge_mode(), &statbuf)) {
+ if (strbuf_read_file(&sb, git_path_merge_mode(), 0) < 0)
die_errno(_("could not read MERGE_MODE"));
if (!strcmp(sb.buf, "no-ff"))
allow_fast_forward = 0;
@@ -1775,12 +1775,12 @@
}
ref_transaction_free(transaction);
- unlink(git_path("CHERRY_PICK_HEAD"));
- unlink(git_path("REVERT_HEAD"));
- unlink(git_path("MERGE_HEAD"));
- unlink(git_path("MERGE_MSG"));
- unlink(git_path("MERGE_MODE"));
- unlink(git_path("SQUASH_MSG"));
+ unlink(git_path_cherry_pick_head());
+ unlink(git_path_revert_head());
+ unlink(git_path_merge_head());
+ unlink(git_path_merge_msg());
+ unlink(git_path_merge_mode());
+ unlink(git_path_squash_msg());
if (commit_index_files())
die (_("Repository has been updated, but unable to write\n"
diff --git a/builtin/fetch.c b/builtin/fetch.c
index 34b6f5e..df16d0a 100644
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -591,7 +591,7 @@
const char *what, *kind;
struct ref *rm;
char *url;
- const char *filename = dry_run ? "/dev/null" : git_path("FETCH_HEAD");
+ const char *filename = dry_run ? "/dev/null" : git_path_fetch_head();
int want_status;
fp = fopen(filename, "a");
@@ -834,7 +834,7 @@
static int truncate_fetch_head(void)
{
- const char *filename = git_path("FETCH_HEAD");
+ const char *filename = git_path_fetch_head();
FILE *fp = fopen(filename, "w");
if (!fp)
diff --git a/builtin/merge.c b/builtin/merge.c
index 85c54dc..a0edaca 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -231,9 +231,9 @@
/* 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 @@
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 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 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 @@
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 @@
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 @@
}
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 @@
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 @@
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 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 @@
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 <file>', just 'git commit'.
@@ -1226,7 +1226,7 @@
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."));
diff --git a/builtin/reset.c b/builtin/reset.c
index 4c08ddc..c503e75 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -36,7 +36,7 @@
static inline int is_merge(void)
{
- return !access(git_path("MERGE_HEAD"), F_OK);
+ return !access(git_path_merge_head(), F_OK);
}
static int reset_index(const unsigned char *sha1, int reset_type, int quiet)
