git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH] refs.c: change read_ref_at to use the reflog iterators

From
Ronnie Sahlberg <sahlberg@google.com>
Date
May 30, 2014, 19:51 UTC
Message-ID
<1401479462-2329-1-git-send-email-sahlberg@google.com>

read_ref_at has its own parsing of the reflog file for no really good reason so lets change this to use the existing reflog iterators. This removes one instance where we manually unmarshall the reflog file format.

Log messages for errors are changed slightly. We no longer print the file name for the reflog, instead we refer to it as 'Log for ref <refname>'. This might be a minor useability regression, but I don't really think so, since experienced users would know where the log is anyway and inexperienced users would not know what to do about/how to repair 'Log ... has gap ...' anyway.

Adapt the t1400 test to handle the cahnge in log messages.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
---
 refs.c                | 217 ++++++++++++++++++++++++++++----------------------
 t/t1400-update-ref.sh |   4 +-
 2 files changed, 122 insertions(+), 99 deletions(-)
diff --git a/refs.c b/refs.c
index 6898263..99d4832 100644
--- a/refs.c
+++ b/refs.c
@@ -2936,109 +2936,132 @@ static char *ref_msg(const char *line, const char *endp)
 	return xmemdupz(line, ep - line);
 }
 
+struct read_ref_at_cb {
+	const char *refname;
+	unsigned long at_time;
+	int cnt;
+	int reccnt;
+	unsigned char *sha1;
+	int found_it;
+
+	char osha1[20];
+	char nsha1[20];
+	int tz;
+	unsigned long date;
+	char **msg;
+	unsigned long *cutoff_time;
+	int *cutoff_tz;
+	int *cutoff_cnt;
+};
+
+static int read_ref_at_ent(unsigned char *osha1, unsigned char *nsha1,
+		const char *email, unsigned long timestamp, int tz,
+		const char *message, void *cb_data)
+{
+	struct read_ref_at_cb *cb = cb_data;
+
+	cb->reccnt++;
+	cb->tz = tz;
+	cb->date = timestamp;
+
+	if (timestamp <= cb->at_time || cb->cnt == 0) {
+		if (cb->msg)
+			*cb->msg = xstrdup(message);
+		if (cb->cutoff_time)
+			*cb->cutoff_time = timestamp;
+		if (cb->cutoff_tz)
+			*cb->cutoff_tz = tz;
+		if (cb->cutoff_cnt)
+			*cb->cutoff_cnt = cb->reccnt - 1;
+
+		/*
+		 * we have not yet updated cb->[n|o]sha1 so they still
+		 * hold the values for the previous record.
+		 */
+		if (!is_null_sha1(cb->osha1)) {
+			hashcpy(cb->sha1, nsha1);
+			if (hashcmp(cb->osha1, nsha1))
+				warning("Log for ref %s has gap after %s.",
+					cb->refname, show_date(cb->date, cb->tz, DATE_RFC2822));
+		}
+		else if (cb->date == cb->at_time)
+			hashcpy(cb->sha1, nsha1);
+		else
+			if (hashcmp(nsha1, cb->sha1))
+				warning("Log for ref %s unexpectedly ended on %s.",
+					cb->refname, show_date(cb->date, cb->tz,
+							   DATE_RFC2822));
+
+		/* 
+		 * return 1. Not to signal an error but to break the loop
+		 * since we have found the entry we want.
+		 */
+		hashcpy(cb->osha1, osha1);
+		hashcpy(cb->nsha1, nsha1);
+		cb->found_it = 1;
+		return 1;
+	}
+
+	hashcpy(cb->osha1, osha1);
+	hashcpy(cb->nsha1, nsha1);
+	if (cb->cnt > 0)
+		cb->cnt--;
+
+	return 0;
+}
+
+static int read_ref_at_ent_oldest(unsigned char *osha1, unsigned char *nsha1,
+				  const char *email, unsigned long timestamp,
+				  int tz, const char *message, void *cb_data)
+{
+	struct read_ref_at_cb *cb = cb_data;
+
+	if (cb->msg)
+		*cb->msg = xstrdup(message);
+	if (cb->cutoff_time)
+		*cb->cutoff_time = timestamp;
+	if (cb->cutoff_tz)
+		*cb->cutoff_tz = tz;
+	if (cb->cutoff_cnt)
+		*cb->cutoff_cnt = cb->reccnt - 1;
+
+	hashcpy(cb->sha1, osha1);
+	if (is_null_sha1(cb->sha1))
+		hashcpy(cb->sha1, nsha1);
+
+	/* 
+	 * return 1. Not to signal an error but to break the loop
+	 * since we have found the entry we want.
+	 */
+	return 1;
+}
+
 int read_ref_at(const char *refname, unsigned long at_time, int cnt,
 		unsigned char *sha1, char **msg,
 		unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
 {
-	const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
-	char *tz_c;
-	int logfd, tz, reccnt = 0;
-	struct stat st;
-	unsigned long date;
-	unsigned char logged_sha1[20];
-	void *log_mapped;
-	size_t mapsz;
+	struct read_ref_at_cb cb;
 
-	logfile = git_path("logs/%s", refname);
-	logfd = open(logfile, O_RDONLY, 0);
-	if (logfd < 0)
-		die_errno("Unable to read log '%s'", logfile);
-	fstat(logfd, &st);
-	if (!st.st_size)
-		die("Log %s is empty.", logfile);
-	mapsz = xsize_t(st.st_size);
-	log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
-	logdata = log_mapped;
-	close(logfd);
+	memset(&cb, 0, sizeof(cb));
+	cb.refname = refname;
+	cb.at_time = at_time;
+	cb.cnt = cnt;
+	cb.msg = msg;
+	cb.cutoff_time = cutoff_time;
+	cb.cutoff_tz = cutoff_tz;
+	cb.cutoff_cnt = cutoff_cnt;
+	cb.sha1 = sha1;
+
+	for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
+
+	if (!cb.reccnt)
+		die("Log for %s is empty.", refname);
+
+	if (cb.found_it)
+		return 0;
+
+	for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
 
-	lastrec = NULL;
-	rec = logend = logdata + st.st_size;
-	while (logdata < rec) {
-		reccnt++;
-		if (logdata < rec && *(rec-1) == '\n')
-			rec--;
-		lastgt = NULL;
-		while (logdata < rec && *(rec-1) != '\n') {
-			rec--;
-			if (*rec == '>')
-				lastgt = rec;
-		}
-		if (!lastgt)
-			die("Log %s is corrupt.", logfile);
-		date = strtoul(lastgt + 1, &tz_c, 10);
-		if (date <= at_time || cnt == 0) {
-			tz = strtoul(tz_c, NULL, 10);
-			if (msg)
-				*msg = ref_msg(rec, logend);
-			if (cutoff_time)
-				*cutoff_time = date;
-			if (cutoff_tz)
-				*cutoff_tz = tz;
-			if (cutoff_cnt)
-				*cutoff_cnt = reccnt - 1;
-			if (lastrec) {
-				if (get_sha1_hex(lastrec, logged_sha1))
-					die("Log %s is corrupt.", logfile);
-				if (get_sha1_hex(rec + 41, sha1))
-					die("Log %s is corrupt.", logfile);
-				if (hashcmp(logged_sha1, sha1)) {
-					warning("Log %s has gap after %s.",
-						logfile, show_date(date, tz, DATE_RFC2822));
-				}
-			}
-			else if (date == at_time) {
-				if (get_sha1_hex(rec + 41, sha1))
-					die("Log %s is corrupt.", logfile);
-			}
-			else {
-				if (get_sha1_hex(rec + 41, logged_sha1))
-					die("Log %s is corrupt.", logfile);
-				if (hashcmp(logged_sha1, sha1)) {
-					warning("Log %s unexpectedly ended on %s.",
-						logfile, show_date(date, tz, DATE_RFC2822));
-				}
-			}
-			munmap(log_mapped, mapsz);
-			return 0;
-		}
-		lastrec = rec;
-		if (cnt > 0)
-			cnt--;
-	}
-
-	rec = logdata;
-	while (rec < logend && *rec != '>' && *rec != '\n')
-		rec++;
-	if (rec == logend || *rec == '\n')
-		die("Log %s is corrupt.", logfile);
-	date = strtoul(rec + 1, &tz_c, 10);
-	tz = strtoul(tz_c, NULL, 10);
-	if (get_sha1_hex(logdata, sha1))
-		die("Log %s is corrupt.", logfile);
-	if (is_null_sha1(sha1)) {
-		if (get_sha1_hex(logdata + 41, sha1))
-			die("Log %s is corrupt.", logfile);
-	}
-	if (msg)
-		*msg = ref_msg(logdata, logend);
-	munmap(log_mapped, mapsz);
-
-	if (cutoff_time)
-		*cutoff_time = date;
-	if (cutoff_tz)
-		*cutoff_tz = tz;
-	if (cutoff_cnt)
-		*cutoff_cnt = reccnt;
 	return 1;
 }
 
diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index 4e2459a..0218e96 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -235,7 +235,7 @@ test_expect_success \
 	'rm -f o e &&
 	 git rev-parse --verify "master@{2005-05-26 23:33:01}" >o 2>e &&
 	 test '"$B"' = $(cat o) &&
-	 test "warning: Log .git/logs/'"$m has gap after $gd"'." = "$(cat e)"'
+	 test "warning: Log for ref '"$m has gap after $gd"'." = "$(cat e)"'
 test_expect_success \
 	'Query "master@{2005-05-26 23:38:00}" (middle of history)' \
 	'rm -f o e &&
@@ -253,7 +253,7 @@ test_expect_success \
 	'rm -f o e &&
 	 git rev-parse --verify "master@{2005-05-28}" >o 2>e &&
 	 test '"$D"' = $(cat o) &&
-	 test "warning: Log .git/logs/'"$m unexpectedly ended on $ld"'." = "$(cat e)"'
+	 test "warning: Log for ref '"$m unexpectedly ended on $ld"'." = "$(cat e)"'
 
 
 rm -f .git/$m .git/logs/$m expect

-- 
2.0.0.527.g539d2ad
Next: Junio C Hamano
Message 1 of 5 in “refs.c: change read_ref_at to use the reflog iterators”
  1. refs.c: change read_ref_at to use the reflog iteratorsRonnie Sahlberg, May 30, 2014
  2. Junio C HamanoMay 30, 2014
  3. Ronnie SahlbergJun 2, 2014
  4. Eric SunshineMay 30, 2014
  5. Ronnie SahlbergJun 2, 2014

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.