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Commit 80dc3946 by Edward Thomson
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odb_loose: packlike loose objects use `git_zstream` 

Refactor packlike loose object reads to use `git_zstream` for
simplification.
parent 7cb5bae7
Showing with 71 additions and 88 deletions
src/odb_loose.c
......@@ -104,32 +104,39 @@ static int object_mkdir(const git_buf *name, const loose_backend *be)
GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST | GIT_MKDIR_VERIFY_DIR, NULL);
}
static size_t get_binary_object_header(
obj_hdr *hdr, const unsigned char *data, size_t len)
static int parse_header_packlike(
obj_hdr *out, size_t *out_len, const unsigned char *data, size_t len)
{
unsigned long c;
size_t shift, size, used = 0;
if (len == 0)
return 0;
goto on_error;
c = data[used++];
hdr->type = (c >> 4) & 7;
out->type = (c >> 4) & 7;
size = c & 15;
shift = 4;
while (c & 0x80) {
if (len <= used)
return 0;
goto on_error;
if (sizeof(size_t) * 8 <= shift)
return 0;
goto on_error;
c = data[used++];
size += (c & 0x7f) << shift;
shift += 7;
}
hdr->size = size;
return used;
out->size = size;
*out_len = used;
return 0;
on_error:
giterr_set(GITERR_OBJECT, "failed to parse loose object: invalid header");
return -1;
}
static int parse_header(
......@@ -254,38 +261,15 @@ static int is_zlib_compressed_data(unsigned char *data)
return (data[0] & 0x8F) == 0x08 && !(w % 31);
}
static int inflate_buffer(void *in, size_t inlen, void *out, size_t outlen)
{
z_stream zs;
int status = Z_OK;
memset(&zs, 0x0, sizeof(zs));
zs.next_out = out;
zs.avail_out = (uInt)outlen;
zs.next_in = in;
zs.avail_in = (uInt)inlen;
if (inflateInit(&zs) < Z_OK) {
giterr_set(GITERR_ZLIB, "failed to inflate buffer");
return -1;
}
while (status == Z_OK)
status = inflate(&zs, Z_FINISH);
inflateEnd(&zs);
if (status != Z_STREAM_END /* || zs.avail_in != 0 */ ||
zs.total_out != outlen)
{
giterr_set(GITERR_ZLIB, "failed to inflate buffer; stream aborted prematurely");
return -1;
}
/***********************************************************
*
* ODB OBJECT READING & WRITING
*
* Backend for the public API; read headers and full objects
* from the ODB. Write raw data to the ODB.
*
***********************************************************/
return 0;
}
/*
* At one point, there was a loose object format that was intended to
......@@ -293,45 +277,55 @@ static int inflate_buffer(void *in, size_t inlen, void *out, size_t outlen)
* of loose object data into packs. This format is no longer used, but
* we must still read it.
*/
static int inflate_packlike_loose_disk_obj(git_rawobj *out, git_buf *obj)
static int read_loose_packlike(git_rawobj *out, git_buf *obj)
{
unsigned char *in, *buf;
git_buf body = GIT_BUF_INIT;
const unsigned char *obj_data;
obj_hdr hdr;
size_t len, used, alloclen;
size_t obj_len, head_len, alloc_size;
int error;
obj_data = (unsigned char *)obj->ptr;
obj_len = obj->size;
/*
* read the object header, which is an (uncompressed)
* binary encoding of the object type and size.
*/
if ((used = get_binary_object_header(&hdr, (unsigned char *)obj->ptr, obj->size)) == 0 ||
!git_object_typeisloose(hdr.type)) {
if ((error = parse_header_packlike(&hdr, &head_len, obj_data, obj_len)) < 0)
goto done;
if (!git_object_typeisloose(hdr.type) || head_len > obj_len) {
giterr_set(GITERR_ODB, "failed to inflate loose object");
return -1;
error = -1;
goto done;
}
obj_data += head_len;
obj_len -= head_len;
/*
* allocate a buffer and inflate the data into it
*/
GITERR_CHECK_ALLOC_ADD(&alloclen, hdr.size, 1);
buf = git__malloc(alloclen);
GITERR_CHECK_ALLOC(buf);
in = ((unsigned char *)obj->ptr) + used;
len = obj->size - used;
if (inflate_buffer(in, len, buf, hdr.size) < 0) {
git__free(buf);
return -1;
if (GIT_ADD_SIZET_OVERFLOW(&alloc_size, hdr.size, 1) ||
git_buf_init(&body, alloc_size) < 0) {
error = -1;
goto done;
}
buf[hdr.size] = '\0';
out->data = buf;
if ((error = git_zstream_inflatebuf(&body, obj_data, obj_len)) < 0)
goto done;
out->len = hdr.size;
out->type = hdr.type;
out->data = git_buf_detach(&body);
return 0;
done:
git_buf_free(&body);
return error;
}
static int inflate_disk_obj(git_rawobj *out, git_buf *obj)
static int read_loose_standard(git_rawobj *out, git_buf *obj)
{
git_zstream zstream = GIT_ZSTREAM_INIT;
unsigned char head[HEADER_LEN], *body = NULL;
......@@ -339,10 +333,6 @@ static int inflate_disk_obj(git_rawobj *out, git_buf *obj)
obj_hdr hdr;
int error;
/* check for a pack-like loose object */
if (!is_zlib_compressed_data((unsigned char *)obj->ptr))
return inflate_packlike_loose_disk_obj(out, obj);
if ((error = git_zstream_init(&zstream, GIT_ZSTREAM_INFLATE)) < 0 ||
(error = git_zstream_set_input(&zstream, git_buf_cstr(obj), git_buf_len(obj))) < 0)
goto done;
......@@ -404,20 +394,6 @@ done:
return error;
}
/***********************************************************
*
* ODB OBJECT READING & WRITING
*
* Backend for the public API; read headers and full objects
* from the ODB. Write raw data to the ODB.
*
***********************************************************/
static int read_loose(git_rawobj *out, git_buf *loc)
{
int error;
......@@ -432,11 +408,16 @@ static int read_loose(git_rawobj *out, git_buf *loc)
out->len = 0;
out->type = GIT_OBJ_BAD;
if (!(error = git_futils_readbuffer(&obj, loc->ptr)))
error = inflate_disk_obj(out, &obj);
if ((error = git_futils_readbuffer(&obj, loc->ptr)) < 0)
goto done;
git_buf_free(&obj);
if (!is_zlib_compressed_data((unsigned char *)obj.ptr))
error = read_loose_packlike(out, &obj);
else
error = read_loose_standard(out, &obj);
done:
git_buf_free(&obj);
return error;
}
......@@ -958,25 +939,27 @@ static int loose_backend__readstream_packlike(
obj_hdr *hdr,
loose_readstream *stream)
{
size_t head_len;
const unsigned char *data;
size_t data_len, head_len;
int error;
data = stream->map.data;
data_len = stream->map.len;
/*
* read the object header, which is an (uncompressed)
* binary encoding of the object type and size.
*/
if ((head_len = get_binary_object_header(hdr,
stream->map.data, stream->map.len)) == 0 ||
!git_object_typeisloose(hdr->type)) {
if ((error = parse_header_packlike(hdr, &head_len, data, data_len)) < 0)
return error;
if (!git_object_typeisloose(hdr->type)) {
giterr_set(GITERR_ODB, "failed to inflate loose object");
return -1;
}
if ((error = git_zstream_set_input(&stream->zstream,
stream->map.data + head_len, stream->map.len - head_len)) < 0)
return error;
return 0;
return git_zstream_set_input(&stream->zstream,
data + head_len, data_len - head_len);
}
static int loose_backend__readstream_standard(
......
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