unpack_raw_entry() will not allocate and return decompressed blobs if
they are larger than core.bigFileThreshold.
The blob content is needed by sha1_object() in some cases. When we do
need the blob content, we put it back in core with
get_data_from_pack(). However we rarely need that in pratice.
The first case is when we find an in-repo blob with the same SHA-1. We
need to do collision test, byte-on-byte. Normally (e.g. in
fetch/pull/clone) this does not happen because git avoid to send
objects that client already has.
The other case is when --strict is specified and the object in
question is not a blob, which can't happen in reality becase we deal
with large _blobs_ here.
Note: --verify (or git-verify-pack) a pack from current repository
will trigger collision test on every object in the pack, which
effectively disables this patch. This could be easily worked around by
setting GIT_DIR to an imaginary place with no packs.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@xxxxxxxxx>
---
builtin/index-pack.c | 52 ++++++++++++++++++++++++++++++++++++++++++-------
t/t1050-large.sh | 5 ++++
2 files changed, 49 insertions(+), 8 deletions(-)
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index ccb0214..1b790df 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -392,9 +392,10 @@ static int is_delta_type(enum object_type type)
static void *unpack_entry_data(unsigned long offset, unsigned long size,
enum object_type type, unsigned char *sha1)
{
+ static char fixed_buf[8192];
int status;
git_zstream stream;
- void *buf = xmalloc(size);
+ void *buf;
git_SHA_CTX c;
char hdr[32];
int hdrlen;
@@ -406,11 +407,15 @@ static void *unpack_entry_data(unsigned long offset, unsigned long size,
git_SHA1_Update(&c, hdr, hdrlen);
} else
sha1 = NULL;
+ if (type == OBJ_BLOB && size > big_file_threshold)
+ buf = fixed_buf;
+ else
+ buf = xmalloc(size);
memset(&stream, 0, sizeof(stream));
git_inflate_init(&stream);
stream.next_out = buf;
- stream.avail_out = size;
+ stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
last_out = buf;
do {
@@ -420,6 +425,10 @@ static void *unpack_entry_data(unsigned long offset, unsigned long size,
use(input_len - stream.avail_in);
if (sha1)
git_SHA1_Update(&c, last_out, stream.next_out - last_out);
+ if (buf == fixed_buf) {
+ stream.next_out = buf;
+ stream.avail_out = sizeof(fixed_buf);
+ }
last_out = stream.next_out;
} while (status == Z_OK);
if (stream.total_out != size || status != Z_STREAM_END)
@@ -427,7 +436,7 @@ static void *unpack_entry_data(unsigned long offset, unsigned long size,
git_inflate_end(&stream);
if (sha1)
git_SHA1_Final(sha1, &c);
- return buf;
+ return buf == fixed_buf ? NULL : buf;
}
static void *unpack_raw_entry(struct object_entry *obj,
@@ -593,14 +602,21 @@ static void find_delta_children(const union delta_base *base,
*last_index = last;
}
-static void sha1_object(const void *data, unsigned long size,
- enum object_type type, const unsigned char *sha1)
+static void sha1_object(const void *data, struct object_entry *obj_entry,
+ unsigned long size, enum object_type type,
+ const unsigned char *sha1)
{
+ void *new_data = NULL;
+
+ assert(data || obj_entry);
+
read_lock();
if (has_sha1_file(sha1)) {
void *has_data;
enum object_type has_type;
unsigned long has_size;
+ if (!data)
+ data = new_data = get_data_from_pack(obj_entry);
has_data = read_sha1_file(sha1, &has_type, &has_size);
read_unlock();
if (!has_data)
@@ -625,6 +641,9 @@ static void sha1_object(const void *data, unsigned long size,
int eaten;
void *buf = (void *) data;
+ if (!buf)
+ buf = new_data = get_data_from_pack(obj_entry);
+
/*
* we do not need to free the memory here, as the
* buf is deleted by the caller.
@@ -649,6 +668,8 @@ static void sha1_object(const void *data, unsigned long size,
}
read_unlock();
}
+
+ free(new_data);
}
/*
@@ -732,7 +753,7 @@ static void resolve_delta(struct object_entry *delta_obj,
bad_object(delta_obj->idx.offset, _("failed to apply delta"));
hash_sha1_file(result->data, result->size,
typename(delta_obj->real_type), delta_obj->idx.sha1);
- sha1_object(result->data, result->size, delta_obj->real_type,
+ sha1_object(result->data, NULL, result->size, delta_obj->real_type,
delta_obj->idx.sha1);
counter_lock();
nr_resolved_deltas++;
@@ -862,7 +883,7 @@ static void *threaded_second_pass(void *data)
*/
static void parse_pack_objects(unsigned char *sha1)
{
- int i;
+ int i, nr_delays = 0;
struct delta_entry *delta = deltas;
struct stat st;
@@ -878,8 +899,12 @@ static void parse_pack_objects(unsigned char *sha1)
nr_deltas++;
delta->obj_no = i;
delta++;
+ } else if (!data) {
+ /* large blobs, check later */
+ obj->real_type = OBJ_BAD;
+ nr_delays++;
} else
- sha1_object(data, obj->size, obj->type, obj->idx.sha1);
+ sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
free(data);
display_progress(progress, i+1);
}
@@ -899,6 +924,17 @@ static void parse_pack_objects(unsigned char *sha1)
if (S_ISREG(st.st_mode) &&
lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
die(_("pack has junk at the end"));
+
+ for (i = 0; i < nr_objects; i++) {
+ struct object_entry *obj = &objects[i];
+ if (obj->real_type != OBJ_BAD)
+ continue;
+ obj->real_type = obj->type;
+ sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
+ nr_delays--;
+ }
+ if (nr_delays)
+ die(_("confusion beyond insanity in parse_pack_objects()"));
}
/*
diff --git a/t/t1050-large.sh b/t/t1050-large.sh
index 55ed955..3f80688 100755
--- a/t/t1050-large.sh
+++ b/t/t1050-large.sh
@@ -130,6 +130,11 @@ test_expect_success 'git-show a large file' '
'
+test_expect_success 'index-pack' '
+ git clone file://"`pwd`"/.git foo &&
+ GIT_DIR=non-existent git index-pack --strict --verify foo/.git/objects/pack/*.pack
+'
+
test_expect_success 'repack' '
git repack -ad
'
--
1.7.8.36.g69ee2
--
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