Shawn PearceExtended sha1 expressions may now include date specifications which indicate a point in time within the local repository's history. If the ref indicated to the left of '@' has a log in $GIT_DIR/logs/<ref> then the value of the ref at the time indicated by the specification is obtained from the ref's log.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
Documentation/git-rev-parse.txt | 6 ++++ refs.c | 53 +++++++++++++++++++++++++++++++++++ refs.h | 3 ++ sha1_name.c | 59 ++++++++++++++++++++++++++++----------- 4 files changed, 104 insertions(+), 17 deletions(-)
efffa32e4896acd7978767b6a856fc7421060040
diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt index ab896fc..df308c3 100644 --- a/Documentation/git-rev-parse.txt +++ b/Documentation/git-rev-parse.txt @@ -124,6 +124,12 @@ syntax. happen to have both heads/master and tags/master, you can explicitly say 'heads/master' to tell git which one you mean. +* A suffix '@' followed by a date specification such as 'yesterday' + (24 hours ago) or '1 month 2 weeks 3 days 1 hour 1 second ago' + to specify the value of the ref at a prior point in time. + This suffix may only be used immediately following a ref name + and the ref must have an existing log ($GIT_DIR/logs/<ref>). + * A suffix '{caret}' to a revision parameter means the first parent of that commit object. '{caret}<n>' means the <n>th parent (i.e. 'rev{caret}' diff --git a/refs.c b/refs.c index 4be75a5..4c99e37 100644 --- a/refs.c +++ b/refs.c @@ -429,3 +429,56 @@ int write_ref_sha1(struct ref_lock *lock unlock_ref(lock); return 0; } + +int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1) +{ + const char *logfile, *logdata, *logend, *rec, *c; + char *tz_c; + int logfd, tz; + struct stat st; + unsigned long date; + + logfile = git_path("logs/%s", ref); + logfd = open(logfile, O_RDONLY, 0); + if (logfd < 0) + die("Unable to read log %s: %s", logfile, strerror(errno)); + fstat(logfd, &st); + if (!st.st_size) + die("Log %s is empty.", logfile); + logdata = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, logfd, 0); + close(logfd); + + rec = logend = logdata + st.st_size; + while (logdata < rec) { + if (logdata < rec && *(rec-1) == '\n') + rec--; + while (logdata < rec && *(rec-1) != '\n') + rec--; + c = rec; + while (c < logend && *c != '>' && *c != '\n') + c++; + if (c == logend || *c == '\n') + die("Log %s is corrupt.", logfile); + date = strtoul(c, NULL, 10); + if (date <= at_time) { + if (get_sha1_hex(rec + 41, sha1)) + die("Log %s is corrupt.", logfile); + munmap((void*)logdata, st.st_size); + return 0; + } + } + + c = logdata; + while (c < logend && *c != '>' && *c != '\n') + c++; + if (c == logend || *c == '\n') + die("Log %s is corrupt.", logfile); + date = strtoul(c, &tz_c, 10); + tz = strtoul(tz_c, NULL, 10); + if (get_sha1_hex(logdata, sha1)) + die("Log %s is corrupt.", logfile); + munmap((void*)logdata, st.st_size); + fprintf(stderr, "warning: Log %s only goes back to %s.\n", + logfile, show_rfc2822_date(date, tz)); + return 0; +} diff --git a/refs.h b/refs.h index 43831e9..2c854de 100644 --- a/refs.h +++ b/refs.h @@ -34,6 +34,9 @@ extern void unlock_ref (struct ref_lock /** Writes sha1 into the ref specified by the lock. **/ extern int write_ref_sha1(struct ref_lock *lock, const unsigned char *sha1, const char *msg); +/** Reads log for the value of ref during at_time. **/ +extern int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1); + /** Returns 0 if target has the right format for a ref. **/ extern int check_ref_format(const char *target); diff --git a/sha1_name.c b/sha1_name.c index dc68355..3ac3ab4 100644 --- a/sha1_name.c +++ b/sha1_name.c @@ -4,6 +4,7 @@ #include "commit.h" #include "tree.h" #include "blob.h" #include "tree-walk.h" +#include "refs.h" static int find_short_object_filename(int len, const char *name, unsigned char *sha1) { @@ -245,36 +246,60 @@ static int get_sha1_basic(const char *st "refs/remotes/%.*s/HEAD", NULL }; - const char **p; - const char *warning = "warning: refname '%.*s' is ambiguous.\n"; - char *pathname; - int already_found = 0; + static const char *warning = "warning: refname '%.*s' is ambiguous.\n"; + const char **p, *pathname; + char *real_path = NULL; + int refs_found = 0, at_mark; + unsigned long at_time = (unsigned long)-1; unsigned char *this_result; unsigned char sha1_from_ref[20]; if (len == 40 && !get_sha1_hex(str, sha1)) return 0; + /* At a given period of time? "@2 hours ago" */ + for (at_mark = 1; at_mark < len; at_mark++) { + if (str[at_mark] == '@') { + int date_len = len - at_mark - 1; + char *date_spec = xmalloc(date_len + 1); + strncpy(date_spec, str + at_mark + 1, date_len); + date_spec[date_len] = 0; + at_time = approxidate(date_spec); + free(date_spec); + len = at_mark; + } + } + /* Accept only unambiguous ref paths. */ if (ambiguous_path(str, len)) return -1; for (p = fmt; *p; p++) { - this_result = already_found ? sha1_from_ref : sha1; - pathname = git_path(*p, len, str); - if (!read_ref(pathname, this_result)) { - if (warn_ambiguous_refs) { - if (already_found) - fprintf(stderr, warning, len, str); - already_found++; - } - else - return 0; + this_result = refs_found ? sha1_from_ref : sha1; + pathname = resolve_ref(git_path(*p, len, str), this_result, 1); + if (pathname) { + if (!refs_found++) + real_path = strdup(pathname); + if (!warn_ambiguous_refs) + break; } } - if (already_found) - return 0; - return -1; + + if (!refs_found) + return -1; + + if (warn_ambiguous_refs && refs_found > 1) + fprintf(stderr, warning, len, str); + + if (at_time != (unsigned long)-1) { + read_ref_at( + real_path + strlen(git_path(".")) - 1, + at_time, + sha1); + } + + free(real_path); + return 0; } static int get_sha1_1(const char *name, int len, unsigned char *sha1);
-- 1.3.2.g7278
