cat-file: teach --batch to stream blob objects

The regular "git cat-file -p" and "git cat-file blob" code
paths already learned to stream large blobs. Let's do the
same here.

Note that this means we look up the type and size before
making a decision of whether to load the object into memory
or stream (just like the "-p" code path does). That can lead
to extra work, but it should be dwarfed by the cost of
actually accessing the object itself. In my measurements,
there was a 1-2% slowdown when using "--batch" on a large
number of objects.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King 2013-07-10 07:38:24 -04:00 committed by Junio C Hamano
parent 03c893cbf9
commit 98e2092b50

View file

@ -117,12 +117,36 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
return 0; return 0;
} }
static void print_object_or_die(int fd, const unsigned char *sha1,
enum object_type type, unsigned long size)
{
if (type == OBJ_BLOB) {
if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
die("unable to stream %s to stdout", sha1_to_hex(sha1));
}
else {
enum object_type rtype;
unsigned long rsize;
void *contents;
contents = read_sha1_file(sha1, &rtype, &rsize);
if (!contents)
die("object %s disappeared", sha1_to_hex(sha1));
if (rtype != type)
die("object %s changed type!?", sha1_to_hex(sha1));
if (rsize != size)
die("object %s change size!?", sha1_to_hex(sha1));
write_or_die(fd, contents, size);
free(contents);
}
}
static int batch_one_object(const char *obj_name, int print_contents) static int batch_one_object(const char *obj_name, int print_contents)
{ {
unsigned char sha1[20]; unsigned char sha1[20];
enum object_type type = 0; enum object_type type = 0;
unsigned long size; unsigned long size;
void *contents = NULL;
if (!obj_name) if (!obj_name)
return 1; return 1;
@ -133,16 +157,10 @@ static int batch_one_object(const char *obj_name, int print_contents)
return 0; return 0;
} }
if (print_contents == BATCH)
contents = read_sha1_file(sha1, &type, &size);
else
type = sha1_object_info(sha1, &size); type = sha1_object_info(sha1, &size);
if (type <= 0) { if (type <= 0) {
printf("%s missing\n", obj_name); printf("%s missing\n", obj_name);
fflush(stdout); fflush(stdout);
if (print_contents == BATCH)
free(contents);
return 0; return 0;
} }
@ -150,12 +168,9 @@ static int batch_one_object(const char *obj_name, int print_contents)
fflush(stdout); fflush(stdout);
if (print_contents == BATCH) { if (print_contents == BATCH) {
write_or_die(1, contents, size); print_object_or_die(1, sha1, type, size);
printf("\n"); write_or_die(1, "\n", 1);
fflush(stdout);
free(contents);
} }
return 0; return 0;
} }