Refactor resolve_ref_1 in terms of a new function read_raw_ref, which
is responsible for reading ref data from the ref storage.
Later, we will make read_raw_ref a pluggable backend function, and make
resolve_ref_unsafe common.
Testing done: Hacked in code to run both old and new version of
resolve_ref_1 and compare all outputs, failing dramatically if outputs
differed. Ran test suite.
Signed-off-by: David Turner <dturner@xxxxxxxxxxxxxxxx>
Helped-by: Duy Nguyen <pclouds@xxxxxxxxx>
Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx>
---
refs/files-backend.c | 265 ++++++++++++++++++++++++++++++---------------------
1 file changed, 159 insertions(+), 106 deletions(-)
diff --git a/refs/files-backend.c b/refs/files-backend.c
index 9676ec2..8c6a58e 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -1369,12 +1369,11 @@ static struct ref_entry *get_packed_ref(const char *refname)
/*
* A loose ref file doesn't exist; check for a packed ref. The
- * options are forwarded from resolve_safe_unsafe().
+ * options are forwarded from resolve_ref_unsafe().
*/
static int resolve_missing_loose_ref(const char *refname,
- int resolve_flags,
unsigned char *sha1,
- int *flags)
+ unsigned int *flags)
{
struct ref_entry *entry;
@@ -1390,64 +1389,48 @@ static int resolve_missing_loose_ref(const char *refname,
return 0;
}
/* The reference is not a packed reference, either. */
- if (resolve_flags & RESOLVE_REF_READING) {
- errno = ENOENT;
- return -1;
- } else {
- hashclr(sha1);
- return 0;
- }
+ errno = ENOENT;
+ return -1;
}
-/* This function needs to return a meaningful errno on failure */
-static const char *resolve_ref_1(const char *refname,
- int resolve_flags,
- unsigned char *sha1,
- int *flags,
- struct strbuf *sb_refname,
- struct strbuf *sb_path,
- struct strbuf *sb_contents)
+/*
+ * Read a raw ref from the filesystem or packed refs file.
+ *
+ * If the ref is a sha1, fill in sha1 and return 0.
+ *
+ * If the ref is symbolic, fill in *symref with the referrent
+ * (e.g. "refs/heads/master") and return 0. The caller is responsible
+ * for validating the referrent. Set REF_ISSYMREF in flags.
+ *
+ * If the ref is neither a symbolic ref nor a sha1, it is broken. Set
+ * REF_ISBROKEN in flags, set errno to EINVAL, and return -1.
+ *
+ * If the ref doesn't exist, set errno to ENOENT and return -1.
+ *
+ * If there is another error reading the ref, set errno appropriately and
+ * return -1.
+ *
+ * Backend-specific flags might be set in flags as well, regardless of
+ * outcome.
+ *
+ * sb_path is workspace: the caller should allocate and free it.
+ */
+static int read_raw_ref(const char *refname, unsigned char *sha1,
+ struct strbuf *symref, struct strbuf *sb_path,
+ unsigned int *flags)
{
- int depth = MAXDEPTH;
- int bad_name = 0;
-
- if (flags)
- *flags = 0;
+ struct strbuf sb_contents = STRBUF_INIT;
+ int ret = -1;
+ const char *path;
+ const char *buf;
- if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
- if (flags)
- *flags |= REF_BAD_NAME;
+ strbuf_reset(sb_path);
+ strbuf_git_path(sb_path, "%s", refname);
+ path = sb_path->buf;
- if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
- !refname_is_safe(refname)) {
- errno = EINVAL;
- return NULL;
- }
- /*
- * dwim_ref() uses REF_ISBROKEN to distinguish between
- * missing refs and refs that were present but invalid,
- * to complain about the latter to stderr.
- *
- * We don't know whether the ref exists, so don't set
- * REF_ISBROKEN yet.
- */
- bad_name = 1;
- }
for (;;) {
- const char *path;
struct stat st;
- char *buf;
int fd;
-
- if (--depth < 0) {
- errno = ELOOP;
- return NULL;
- }
-
- strbuf_reset(sb_path);
- strbuf_git_path(sb_path, "%s", refname);
- path = sb_path->buf;
-
/*
* We might have to loop back here to avoid a race
* condition: first we lstat() the file, then we try
@@ -1457,49 +1440,45 @@ static const char *resolve_ref_1(const char *refname,
* we don't want to report that as an error but rather
* try again starting with the lstat().
*/
- stat_ref:
+
if (lstat(path, &st) < 0) {
if (errno != ENOENT)
- return NULL;
- if (resolve_missing_loose_ref(refname, resolve_flags,
- sha1, flags))
- return NULL;
- if (bad_name) {
- hashclr(sha1);
- if (flags)
- *flags |= REF_ISBROKEN;
- }
- return refname;
+ break;
+ if (resolve_missing_loose_ref(refname, sha1, flags))
+ break;
+ ret = 0;
+ break;
}
/* Follow "normalized" - ie "refs/.." symlinks by hand */
if (S_ISLNK(st.st_mode)) {
- strbuf_reset(sb_contents);
- if (strbuf_readlink(sb_contents, path, 0) < 0) {
+ strbuf_reset(&sb_contents);
+ if (strbuf_readlink(&sb_contents, path, 0) < 0) {
if (errno == ENOENT || errno == EINVAL)
/* inconsistent with lstat; retry */
- goto stat_ref;
+ continue;
else
- return NULL;
+ break;
}
- if (starts_with(sb_contents->buf, "refs/") &&
- !check_refname_format(sb_contents->buf, 0)) {
- strbuf_swap(sb_refname, sb_contents);
- refname = sb_refname->buf;
+ if (starts_with(sb_contents.buf, "refs/") &&
+ !check_refname_format(sb_contents.buf, 0)) {
+ strbuf_swap(&sb_contents, symref);
if (flags)
*flags |= REF_ISSYMREF;
- if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
- hashclr(sha1);
- return refname;
- }
- continue;
+ ret = 0;
+ break;
+ } else {
+ /* bogus symlink ref */
+ if (flags)
+ *flags |= REF_ISBROKEN;
+ break;
}
}
/* Is it a directory? */
if (S_ISDIR(st.st_mode)) {
errno = EISDIR;
- return NULL;
+ break;
}
/*
@@ -1510,35 +1489,110 @@ static const char *resolve_ref_1(const char *refname,
if (fd < 0) {
if (errno == ENOENT)
/* inconsistent with lstat; retry */
- goto stat_ref;
+ continue;
else
- return NULL;
+ break;
}
- strbuf_reset(sb_contents);
- if (strbuf_read(sb_contents, fd, 256) < 0) {
+ strbuf_reset(&sb_contents);
+ if (strbuf_read(&sb_contents, fd, 256) < 0) {
int save_errno = errno;
close(fd);
errno = save_errno;
- return NULL;
+ break;
}
close(fd);
- strbuf_rtrim(sb_contents);
+ strbuf_rtrim(&sb_contents);
+ buf = sb_contents.buf;
+ if (starts_with(buf, "ref:")) {
+ buf += 4;
+ while (isspace(*buf))
+ buf++;
+
+ strbuf_reset(symref);
+ strbuf_addstr(symref, buf);
+ if (flags)
+ *flags |= REF_ISSYMREF;
+ ret = 0;
+ break;
+ }
/*
- * Is it a symbolic ref?
+ * Please note that FETCH_HEAD has additional
+ * data after the sha.
*/
- if (!starts_with(sb_contents->buf, "ref:")) {
- /*
- * Please note that FETCH_HEAD has a second
- * line containing other data.
- */
- if (get_sha1_hex(sb_contents->buf, sha1) ||
- (sb_contents->buf[40] != '\0' && !isspace(sb_contents->buf[40]))) {
+ if (get_sha1_hex(buf, sha1) ||
+ (buf[40] != '\0' && !isspace(buf[40]))) {
+ if (flags)
+ *flags |= REF_ISBROKEN;
+ errno = EINVAL;
+ break;
+ }
+ ret = 0;
+ break;
+ }
+
+ strbuf_release(&sb_contents);
+ return ret;
+}
+
+/* This function needs to return a meaningful errno on failure */
+static const char *resolve_ref_1(const char *refname,
+ int resolve_flags,
+ unsigned char *sha1,
+ int *flags,
+ struct strbuf *sb_refname,
+ struct strbuf *sb_path)
+{
+ int bad_name = 0;
+ int symref_count;
+
+ if (flags)
+ *flags = 0;
+
+ if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
+ if (flags)
+ *flags |= REF_BAD_NAME;
+
+ if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
+ !refname_is_safe(refname)) {
+ errno = EINVAL;
+ return NULL;
+ }
+ /*
+ * dwim_ref() uses REF_ISBROKEN to distinguish between
+ * missing refs and refs that were present but invalid,
+ * to complain about the latter to stderr.
+ *
+ * We don't know whether the ref exists, so don't set
+ * REF_ISBROKEN yet.
+ */
+ bad_name = 1;
+ }
+
+ for (symref_count = 0; symref_count < MAXDEPTH; symref_count++) {
+ unsigned int read_flags = 0;
+
+ if (read_raw_ref(refname, sha1, sb_refname, sb_path, &read_flags)) {
+ int saved_errno = errno;
+ if (flags)
+ *flags |= read_flags;
+ errno = saved_errno;
+ if (bad_name) {
+ hashclr(sha1);
if (flags)
*flags |= REF_ISBROKEN;
- errno = EINVAL;
+ }
+ if (resolve_flags & RESOLVE_REF_READING || errno != ENOENT) {
return NULL;
+ } else {
+ hashclr(sha1);
+ return refname;
}
+ }
+ if (flags)
+ *flags |= read_flags;
+
+ if (!(read_flags & REF_ISSYMREF)) {
if (bad_name) {
hashclr(sha1);
if (flags)
@@ -1546,44 +1600,43 @@ static const char *resolve_ref_1(const char *refname,
}
return refname;
}
- if (flags)
- *flags |= REF_ISSYMREF;
- buf = sb_contents->buf + 4;
- while (isspace(*buf))
- buf++;
- strbuf_reset(sb_refname);
- strbuf_addstr(sb_refname, buf);
+
refname = sb_refname->buf;
if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
hashclr(sha1);
+ if (bad_name && flags)
+ *flags |= REF_ISBROKEN;
return refname;
}
- if (check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {
+
+ if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
if (flags)
*flags |= REF_ISBROKEN;
-
if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
- !refname_is_safe(buf)) {
+ !refname_is_safe(refname)) {
errno = EINVAL;
return NULL;
}
bad_name = 1;
}
}
+
+ if (flags)
+ *flags |= REF_ISBROKEN;
+ return NULL;
}
const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
unsigned char *sha1, int *flags)
{
static struct strbuf sb_refname = STRBUF_INIT;
- struct strbuf sb_contents = STRBUF_INIT;
struct strbuf sb_path = STRBUF_INIT;
const char *ret;
ret = resolve_ref_1(refname, resolve_flags, sha1, flags,
- &sb_refname, &sb_path, &sb_contents);
+ &sb_refname, &sb_path);
+
strbuf_release(&sb_path);
- strbuf_release(&sb_contents);
return ret;
}
--
2.4.2.767.g62658d5-twtrsrc
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