kernel
/
git
mirror of https://git.kernel.org/pub/scm/git/git.git
1
0
Fork 0
Code Releases Activity

git-zlib: use `struct z_stream_s` instead of typedef 

Throughout the Git codebase we're using the typedeffed version of
`z_stream`, which maps to `struct z_stream_s`. By using a typedef
instead of the struct it becomes somewhat harder to predeclare the
symbol so that headers depending on the struct can do so without having
to pull in "zlib-compat.h".

We don't yet have users that would really care about this: the only
users that declare `z_stream` as a pointer are in "reftable/block.h",
which is a header that is internal to the reftable library. But in the
next step we're going to expose the `struct reftable_block` publicly,
and that struct does contain a pointer to `z_stream`. And as the public
header shouldn't depend on "reftable/system.h", which is an internal
implementation detail, we won't have the typedef for `z_stream` readily
available.

Prepare for this change by using `struct z_stream_s` throughout our code
base. In case zlib-ng is used we use a define to map from `z_stream_s`
to `zng_stream_s`.

Drop the pre-declaration of `struct z_stream` while at it. This struct
does not exist in the first place, and the declaration wasn't needed
because "reftable/block.h" already includes "reftable/basics.h" which
transitively includes "reftable/system.h" and thus "git-zlib.h".

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
main
Patrick Steinhardt 2025-04-07 15:16:20 +02:00 committed by Junio C Hamano
parent 12a9aa8cb7
commit ce76cec964
4 changed files with 7 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
Documentation/howto/recover-corrupted-object-harder.adoc
View File

@ -125,7 +125,7 @@ static int try_zlib(unsigned char *buf, int len)
{
/* make this absurdly large so we don't have to loop */
static unsigned char out[1024*1024];
z_stream z;
struct z_stream_s z;
int ret;

memset(&z, 0, sizeof(z));
@ -278,7 +278,7 @@ int main(int argc, char **argv)
static unsigned char buf[25 * 1024 * 1024];
static unsigned char out[25 * 1024 * 1024];
int len;
z_stream z;
struct z_stream_s z;
int ret;

len = read(0, buf, sizeof(buf));

4
compat/zlib-compat.h
View File

@ -4,8 +4,8 @@
#ifdef HAVE_ZLIB_NG
# include <zlib-ng.h>

# define z_stream zng_stream
#define gz_header_s zng_gz_header_s
# define z_stream_s zng_stream_s
# define gz_header_s zng_gz_header_s

# define crc32(crc, buf, len) zng_crc32(crc, buf, len)


2
git-zlib.h
View File

@ -4,7 +4,7 @@
#include "compat/zlib-compat.h"

typedef struct git_zstream {
z_stream z;
struct z_stream_s z;
unsigned long avail_in;
unsigned long avail_out;
unsigned long total_in;

6
reftable/block.h
View File

@ -18,7 +18,7 @@
* allocation overhead.
*/
struct block_writer {
z_stream *zstream;
struct z_stream_s *zstream;
unsigned char *compressed;
size_t compressed_cap;

@ -62,8 +62,6 @@ int block_writer_finish(struct block_writer *w);
/* clears out internally allocated block_writer members. */
void block_writer_release(struct block_writer *bw);

struct z_stream;

/*
* A block part of a reftable. Contains records as well as some metadata
* describing them.
@ -78,7 +76,7 @@ struct reftable_block {
uint32_t hash_size;

/* Uncompressed data for log entries. */
z_stream *zstream;
struct z_stream_s *zstream;
unsigned char *uncompressed_data;
size_t uncompressed_cap;