From: Junio C Hamano <gitster@pobox.com>
To: git@vger.kernel.org
Cc: Martin Koegler <mkoegler@auto.tuwien.ac.at>,
Sergey Vlasov <vsu@altlinux.ru>
Subject: [PATCH 3/3] unpack-objects: fix --strict handling
Date: Wed, 5 Mar 2008 02:09:08 -0800 [thread overview]
Message-ID: <1204711748-10044-3-git-send-email-gitster@pobox.com> (raw)
In-Reply-To: <1204711748-10044-2-git-send-email-gitster@pobox.com>
Earlier attempt (which was reverted) called added_object() (by the way,
the function should be renamed to resolve_dependents() --- it is called
when we have a complete object data, and is responsible to resolve pending
deltified objects that use this object as their delta base object) without
updating obj_list[nr].sha1 with the correct value.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
* I still doubt that FLAG_OPEN is necessary, but at least this
seems to fix the issue for me. I am sick and tired of having
spent two nights looking at this issue, and I ran out of time
to deal with other topics I looked at on the list.
The moral of the story is _NOT_ "do not to trust Martin's
patches", but "I should ignore topics unless I have enough
time to read them line-by-line. Queuing them, hoping that
problems are caught by somebody while they are in 'next',
would NOT work".
builtin-unpack-objects.c | 73 ++++++++++++++++++++++++++++++++++++----------
t/t5300-pack-object.sh | 2 +-
2 files changed, 58 insertions(+), 17 deletions(-)
diff --git a/builtin-unpack-objects.c b/builtin-unpack-objects.c
index 9d2a854..fecf0be 100644
--- a/builtin-unpack-objects.c
+++ b/builtin-unpack-objects.c
@@ -21,6 +21,11 @@ static unsigned int offset, len;
static off_t consumed_bytes;
static SHA_CTX ctx;
+/*
+ * When running under --strict mode, objects whose reachability are
+ * suspect are kept in core without getting written in the object
+ * store.
+ */
struct obj_buffer {
char *buffer;
unsigned long size;
@@ -155,6 +160,10 @@ struct obj_info {
static struct obj_info *obj_list;
unsigned nr_objects;
+/*
+ * Called only from check_object() after it verified this object
+ * is Ok.
+ */
static void write_cached_object(struct object *obj)
{
unsigned char sha1[20];
@@ -164,6 +173,11 @@ static void write_cached_object(struct object *obj)
obj->flags |= FLAG_WRITTEN;
}
+/*
+ * At the very end of the processing, write_rest() scans the objects
+ * that have reachability requirements and calls this function.
+ * Verify its reachability and validity recursively and write it out.
+ */
static int check_object(struct object *obj, int type, void *data)
{
if (!obj)
@@ -202,19 +216,25 @@ static void write_rest(void)
static void added_object(unsigned nr, enum object_type type,
void *data, unsigned long size);
+/*
+ * Write out nr-th object from the list, now we know the contents
+ * of it. Under --strict, this buffers structured objects in-core,
+ * to be checked at the end.
+ */
static void write_object(unsigned nr, enum object_type type,
void *buf, unsigned long size)
{
- added_object(nr, type, buf, size);
if (!strict) {
if (write_sha1_file(buf, size, typename(type), obj_list[nr].sha1) < 0)
die("failed to write object");
+ added_object(nr, type, buf, size);
free(buf);
- obj_list[nr].obj = 0;
+ obj_list[nr].obj = NULL;
} else if (type == OBJ_BLOB) {
struct blob *blob;
if (write_sha1_file(buf, size, typename(type), obj_list[nr].sha1) < 0)
die("failed to write object");
+ added_object(nr, type, buf, size);
free(buf);
blob = lookup_blob(obj_list[nr].sha1);
@@ -222,15 +242,15 @@ static void write_object(unsigned nr, enum object_type type,
blob->object.flags |= FLAG_WRITTEN;
else
die("invalid blob object");
- obj_list[nr].obj = 0;
+ obj_list[nr].obj = NULL;
} else {
struct object *obj;
int eaten;
hash_sha1_file(buf, size, typename(type), obj_list[nr].sha1);
+ added_object(nr, type, buf, size);
obj = parse_object_buffer(obj_list[nr].sha1, type, size, buf, &eaten);
if (!obj)
die("invalid %s", typename(type));
- /* buf is stored via add_object_buffer and in obj, if its a tree or commit */
add_object_buffer(obj, buf, size);
obj->flags |= FLAG_OPEN;
obj_list[nr].obj = obj;
@@ -253,6 +273,10 @@ static void resolve_delta(unsigned nr, enum object_type type,
write_object(nr, type, result, result_size);
}
+/*
+ * We now know the contents of an object (which is nr-th in the pack);
+ * resolve all the deltified objects that are based on it.
+ */
static void added_object(unsigned nr, enum object_type type,
void *data, unsigned long size)
{
@@ -284,13 +308,28 @@ static void unpack_non_delta_entry(enum object_type type, unsigned long size,
free(buf);
}
+static int resolve_against_held(unsigned nr, const unsigned char *base,
+ void *delta_data, unsigned long delta_size)
+{
+ struct object *obj;
+ struct obj_buffer *obj_buffer;
+ obj = lookup_object(base);
+ if (!obj)
+ return 0;
+ obj_buffer = lookup_object_buffer(obj);
+ if (!obj_buffer)
+ return 0;
+ resolve_delta(nr, obj->type, obj_buffer->buffer,
+ obj_buffer->size, delta_data, delta_size);
+ return 1;
+}
+
static void unpack_delta_entry(enum object_type type, unsigned long delta_size,
unsigned nr)
{
void *delta_data, *base;
unsigned long base_size;
unsigned char base_sha1[20];
- struct object *obj;
if (type == OBJ_REF_DELTA) {
hashcpy(base_sha1, fill(20));
@@ -300,7 +339,13 @@ static void unpack_delta_entry(enum object_type type, unsigned long delta_size,
free(delta_data);
return;
}
- if (!has_sha1_file(base_sha1)) {
+ if (has_sha1_file(base_sha1))
+ ; /* Ok we have this one */
+ else if (resolve_against_held(nr, base_sha1,
+ delta_data, delta_size))
+ return; /* we are done */
+ else {
+ /* cannot resolve yet --- queue it */
hashcpy(obj_list[nr].sha1, null_sha1);
add_delta_to_list(nr, base_sha1, 0, delta_data, delta_size);
return;
@@ -346,22 +391,18 @@ static void unpack_delta_entry(enum object_type type, unsigned long delta_size,
}
}
if (!base_found) {
- /* The delta base object is itself a delta that
- has not been resolved yet. */
+ /*
+ * The delta base object is itself a delta that
+ * has not been resolved yet.
+ */
hashcpy(obj_list[nr].sha1, null_sha1);
add_delta_to_list(nr, null_sha1, base_offset, delta_data, delta_size);
return;
}
}
- obj = lookup_object(base_sha1);
- if (obj) {
- struct obj_buffer *obj_buf = lookup_object_buffer(obj);
- if (obj_buf) {
- resolve_delta(nr, obj->type, obj_buf->buffer, obj_buf->size, delta_data, delta_size);
- return;
- }
- }
+ if (resolve_against_held(nr, base_sha1, delta_data, delta_size))
+ return;
base = read_sha1_file(base_sha1, &type, &base_size);
if (!base) {
diff --git a/t/t5300-pack-object.sh b/t/t5300-pack-object.sh
index b297393..b7610d1 100755
--- a/t/t5300-pack-object.sh
+++ b/t/t5300-pack-object.sh
@@ -274,7 +274,7 @@ test_expect_success \
packname_4=$(git pack-objects test-4 <obj-list) &&
test 3 = $(ls test-4-*.pack | wc -l)'
-test_expect_failure 'unpacking with --strict' '
+test_expect_success 'unpacking with --strict' '
git config --unset pack.packsizelimit &&
COPYING=$(git hash-object -w ../../COPYING) &&
--
1.5.4.3.529.gb25fb
prev parent reply other threads:[~2008-03-05 10:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-05 10:09 [PATCH 1/3] unpack-objects: prevent writing of inconsistent objects Junio C Hamano
2008-03-05 10:09 ` [PATCH 2/3] t5300: add test for "unpack-objects --strict" Junio C Hamano
2008-03-05 10:09 ` Junio C Hamano [this message]
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