Shawn Pearce <spearce@xxxxxxxxxxx> wrote:
> Junio C Hamano <junkio@xxxxxxx> wrote:
> > Shawn Pearce <spearce@xxxxxxxxxxx> writes:
> >
> > > This is all well and good but its sort of useless without the diffcore
> > > being able to lookup what SHA1 was valid on a given branch at a given
> > > point in time. :-)
> > >
> > > I'm thinking about extending the 'extended SHA1' syntax to accept
> > > a date (or date expression) as a suffix:
> > >
> > > HEAD@'2 hours ago'
> > > HEAD@'2006-04-20'
> > > HEAD@'2006-04-20 14:12'
> > >
> > > etc... This would be merged into get_sha1 (sha1_name.c) so its
> > > usable pretty much anywhere. Does this seem reasonable? If so
> > > I'll work up a patch for it.
This is a preliminary patch for this syntax. I haven't handled the
absolute date parsing yet; I was hoping to use the same syntax
accepted by GIT_AUTHOR_DATE/GIT_COMMITTER_DATE but looking at the
code in date.c it wasn't going to be easily reused. I'll work
on it more tomorrow, right now I have to go do my day job to pay
the rent. :-)
Hmm... A quick look at date.c indicates I should be able to clean up
this parse_date_spec function quite a bit by using code from date.c.
I'll look at it more later.
-- >8 -
Support 'master@2 hours ago' syntax
Extended 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
$GIT_DIR/logs/<ref> then the value of the ref at the time indicated
by the specification is obtained from the ref's log.
---
Documentation/git-rev-parse.txt | 6 ++
refs.c | 52 ++++++++++++++
refs.h | 3 +
sha1_name.c | 145 ++++++++++++++++++++++++++++++++++-----
4 files changed, 189 insertions(+), 17 deletions(-)
1f16364fd8cadb6cdeb0b14a6f5439f02b578924
diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index ab896fc..df308c3 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt
@@ -124,6 +124,12 @@ syntax.
happen to have both heads/master and tags/master, you can
explicitly say 'heads/master' to tell git which one you mean.
+* A suffix '@' followed by a date specification such as 'yesterday'
+ (24 hours ago) or '1 month 2 weeks 3 days 1 hour 1 second ago'
+ to specify the value of the ref at a prior point in time.
+ This suffix may only be used immediately following a ref name
+ and the ref must have an existing log ($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 a50ea8f..da009ac 100644
--- a/refs.c
+++ b/refs.c
@@ -440,3 +440,55 @@ int log_ref_update(const char *ref, cons
close(logfd);
return 0;
}
+
+int read_ref_at(const char *ref, unsigned long at_time, unsigned char *sha1)
+{
+ const char *logfile, *logdata, *rec, *c;
+ char *tz_c;
+ int logfd, tz;
+ struct stat st;
+ unsigned long date;
+ unsigned char oldsha1[20];
+
+ 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 = 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++ != '>')
+ /* nada */;
+ date = strtoul(c, NULL, 10);
+ if (date <= at_time) {
+ if (get_sha1_hex(rec, oldsha1))
+ die("Log %s is corrupt.", logfile);
+ 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++ != '>')
+ /* nada */;
+ 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 de3cb92..4831cdb 100644
--- a/refs.h
+++ b/refs.h
@@ -31,4 +31,7 @@ extern int check_ref_format(const char *
/** If logging is enabled logs the change made to the ref. **/
extern int log_ref_update(const char *ref, const unsigned char *currsha1, const unsigned char *newsha1, 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);
+
#endif /* REFS_H */
diff --git a/sha1_name.c b/sha1_name.c
index dc68355..5f33aea 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)
{
@@ -234,6 +235,98 @@ static int ambiguous_path(const char *pa
return slash;
}
+static unsigned long parse_date_spec(const char *str, int len)
+{
+ long delta;
+ time_t now;
+
+ time(&now);
+ if (len == 9 && !strncasecmp("yesterday", str, 9))
+ return now - 24 * 60 * 60;
+ if (len > 4 && !strncasecmp(" ago", str + (len - 4), 4)) {
+ len -= 4;
+ while (len) {
+ if (len > 2 && !strncasecmp("a ", str, 2)) {
+ delta = 1;
+ len -= 2;
+ str += 2;
+ }
+ else if (len > 3 && !strncasecmp("an ", str, 3)) {
+ delta = 1;
+ len -= 2;
+ str += 2;
+ } else {
+ delta = 0;
+ while (len && isdigit(*str)) {
+ if (delta)
+ delta *= 10;
+ delta += *str++ - '0';
+ len--;
+ }
+ if (!delta)
+ return (time_t)-1;
+ while (len && isspace(*str)) {
+ str++;
+ len--;
+ }
+ }
+
+ if (len >= 5 && !strncasecmp("month", str, 5)) {
+ len -= 5;
+ str += 5;
+ now -= 30 * 24 * 60 * 60 * delta;
+ }
+ else if (len >= 4 && !strncasecmp("week", str, 4)) {
+ len -= 4;
+ str += 4;
+ now -= 7 * 24 * 60 * 60 * delta;
+ }
+ else if (len >= 3 && !strncasecmp("day", str, 3)) {
+ len -= 3;
+ str += 3;
+ now -= 24 * 60 * 60 * delta;
+ }
+ else if (len >= 4 && !strncasecmp("hour", str, 4)) {
+ len -= 4;
+ str += 4;
+ now -= 60 * 60 * delta;
+ }
+ else if (len >= 6 && !strncasecmp("minute", str, 6)) {
+ len -= 6;
+ str += 6;
+ now -= 60 * delta;
+ }
+ else if (len >= 3 && !strncasecmp("min", str, 3)) {
+ len -= 3;
+ str += 3;
+ now -= 60 * delta;
+ }
+ else if (len >= 6 && !strncasecmp("second", str, 6)) {
+ len -= 6;
+ str += 6;
+ now -= delta;
+ }
+ else if (len >= 3 && !strncasecmp("sec", str, 3)) {
+ len -= 3;
+ str += 3;
+ now -= delta;
+ }
+
+ if (len && *str == 's') {
+ len -= 1;
+ str += 1;
+ }
+
+ while (len && isspace(*str)) {
+ str++;
+ len--;
+ }
+ }
+ return now;
+ }
+ return (time_t)-1;
+}
+
static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
{
static const char *fmt[] = {
@@ -245,36 +338,54 @@ 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] == '@') {
+ at_time = parse_date_spec(str + at_mark + 1, len - at_mark - 1);
+ if (at_time == (unsigned long)-1)
+ die("Invalid date spec after @ in '%.*s'", len, str);
+ 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
-
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