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From: Junio C Hamano <gitster@pobox.com>
To: git@vger.kernel.org
Subject: [PATCH v2 03/13] rerere: lift PATH_MAX limitation
Date: Tue, 30 Jun 2015 23:04:49 -0700	[thread overview]
Message-ID: <1435730699-9124-4-git-send-email-gitster@pobox.com> (raw)
In-Reply-To: <1435730699-9124-1-git-send-email-gitster@pobox.com>

The MERGE_RR file records a collection of NUL-terminated entries,
each of which consists of

 - a hash that identifies the conflict
 - a HT
 - the pathname

We used to read this piece-by-piece, and worse yet, read the
pathname part a byte at a time into a fixed buffer of size PATH_MAX.

Instead, read a whole entry using strbuf_getwholeline() and parse
out the fields.  This way, we issue fewer read(2) calls and more
importantly we do not have to limit the pathname to PATH_MAX.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 rerere.c | 35 +++++++++++++++--------------------
 1 file changed, 15 insertions(+), 20 deletions(-)

diff --git a/rerere.c b/rerere.c
index 3b9104d..e854985 100644
--- a/rerere.c
+++ b/rerere.c
@@ -35,32 +35,27 @@ static int has_rerere_resolution(const char *hex)
 
 static void read_rr(struct string_list *rr)
 {
-	unsigned char sha1[20];
-	char buf[PATH_MAX];
+	struct strbuf buf = STRBUF_INIT;
 	FILE *in = fopen(merge_rr_path, "r");
+
 	if (!in)
 		return;
-	while (fread(buf, 40, 1, in) == 1) {
-		int i;
-		char *name;
-		if (get_sha1_hex(buf, sha1))
+	while (!strbuf_getwholeline(&buf, in, '\0')) {
+		char *path;
+		unsigned char sha1[20];
+
+		/* There has to be the hash, tab, path and then NUL */
+		if (buf.len < 42 || get_sha1_hex(buf.buf, sha1))
 			die("corrupt MERGE_RR");
-		buf[40] = '\0';
-		name = xstrdup(buf);
-		if (fgetc(in) != '\t')
+
+		if (buf.buf[40] != '\t')
 			die("corrupt MERGE_RR");
-		for (i = 0; i < sizeof(buf); i++) {
-			int c = fgetc(in);
-			if (c < 0)
-				die("corrupt MERGE_RR");
-			buf[i] = c;
-			if (c == 0)
-				 break;
-		}
-		if (i == sizeof(buf))
-			die("filename too long");
-		string_list_insert(rr, buf)->util = name;
+		buf.buf[40] = '\0';
+		path = buf.buf + 41;
+
+		string_list_insert(rr, path)->util = xstrdup(buf.buf);
 	}
+	strbuf_release(&buf);
 	fclose(in);
 }
 
-- 
2.5.0-rc0-209-g5e1f148

  parent reply	other threads:[~2015-07-01  6:05 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-01  6:04 [PATCH v2 00/13] "rerere" minor clean-up Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 01/13] rerere: fix an off-by-one non-bug Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 02/13] rerere: plug conflict ID leaks Junio C Hamano
2015-07-01  6:04 ` Junio C Hamano [this message]
2015-07-01  6:04 ` [PATCH v2 04/13] rerere: write out each record of MERGE_RR in one go Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 05/13] rerere: report autoupdated paths only after actually updating them Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 06/13] rerere: drop want_sp parameter from is_cmarker() Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 07/13] rerere: stop looping unnecessarily Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 08/13] rerere: explain the rerere I/O abstraction Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 09/13] rerere: explain MERGE_RR management helpers Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 10/13] rerere: explain the primary codepath Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 11/13] rerere: explain "rerere forget" codepath Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 12/13] rerere: explain the remainder Junio C Hamano
2015-07-01  6:04 ` [PATCH v2 13/13] rerere: refactor "replay" part of do_plain_rerere() Junio C Hamano
2015-07-17 22:24 ` [PATCH v3 00/18] "rerere" preparatory clean-up Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 01/18] rerere: fix an off-by-one non-bug Junio C Hamano
2015-07-24 19:46     ` Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 02/18] rerere: plug conflict ID leaks Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 03/18] rerere: lift PATH_MAX limitation Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 04/18] rerere: write out each record of MERGE_RR in one go Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 05/18] rerere: report autoupdated paths only after actually updating them Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 06/18] rerere: drop want_sp parameter from is_cmarker() Junio C Hamano
2015-07-18  8:24     ` Philip Oakley
2015-07-18  8:47       ` Eric Sunshine
2015-07-17 22:24   ` [PATCH v3 07/18] rerere: stop looping unnecessarily Junio C Hamano
2015-07-24 20:06     ` Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 08/18] rerere: explain the rerere I/O abstraction Junio C Hamano
2015-07-24 20:42     ` Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 09/18] rerere: explain MERGE_RR management helpers Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 10/18] rerere: explain the primary codepath Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 11/18] rerere: explain "rerere forget" codepath Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 12/18] rerere: explain the remainder Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 13/18] rerere: refactor "replay" part of do_plain_rerere() Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 14/18] rerere: further de-dent do_plain_rerere() Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 15/18] rerere: further clarify do_rerere_one_path() Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 16/18] rerere: call conflict-ids IDs Junio C Hamano
2015-07-17 22:24   ` [PATCH v3 17/18] rerere: use "struct rerere_id" instead of "char *" for conflict ID Junio C Hamano
2015-07-18  8:47     ` Eric Sunshine
2015-07-17 22:24   ` [PATCH v3 18/18] rerere: un-nest merge() further Junio C Hamano

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