/*
* Copyright (C) the libgit2 contributors. All rights reserved.
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#include "common.h"
#include <zlib.h>
#include "git2/object.h"
#include "git2/sys/odb_backend.h"
#include "fileops.h"
#include "hash.h"
#include "odb.h"
#include "delta.h"
#include "filebuf.h"
#include "object.h"
#include "zstream.h"
#include "git2/odb_backend.h"
#include "git2/types.h"
/* maximum possible header length */
#define MAX_HEADER_LEN 64
typedef struct { /* object header data */
git_otype type; /* object type */
size_t size; /* object size */
} obj_hdr;
typedef struct {
git_odb_stream stream;
git_filebuf fbuf;
} loose_writestream;
typedef struct {
git_odb_stream stream;
git_map map;
char start[MAX_HEADER_LEN];
size_t start_len;
size_t start_read;
git_zstream zstream;
} loose_readstream;
typedef struct loose_backend {
git_odb_backend parent;
int object_zlib_level; /** loose object zlib compression level. */
int fsync_object_files; /** loose object file fsync flag. */
mode_t object_file_mode;
mode_t object_dir_mode;
size_t objects_dirlen;
char objects_dir[GIT_FLEX_ARRAY];
} loose_backend;
/* State structure for exploring directories,
* in order to locate objects matching a short oid.
*/
typedef struct {
size_t dir_len;
unsigned char short_oid[GIT_OID_HEXSZ]; /* hex formatted oid to match */
size_t short_oid_len;
int found; /* number of matching
* objects already found */
unsigned char res_oid[GIT_OID_HEXSZ]; /* hex formatted oid of
* the object found */
} loose_locate_object_state;
/***********************************************************
*
* MISCELLANEOUS HELPER FUNCTIONS
*
***********************************************************/
static int object_file_name(
git_buf *name, const loose_backend *be, const git_oid *id)
{
size_t alloclen;
/* expand length for object root + 40 hex sha1 chars + 2 * '/' + '\0' */
GITERR_CHECK_ALLOC_ADD(&alloclen, be->objects_dirlen, GIT_OID_HEXSZ);
GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 3);
if (git_buf_grow(name, alloclen) < 0)
return -1;
git_buf_set(name, be->objects_dir, be->objects_dirlen);
git_path_to_dir(name);
/* loose object filename: aa/aaa... (41 bytes) */
git_oid_pathfmt(name->ptr + name->size, id);
name->size += GIT_OID_HEXSZ + 1;
name->ptr[name->size] = '\0';
return 0;
}
static int object_mkdir(const git_buf *name, const loose_backend *be)
{
return git_futils_mkdir_relative(
name->ptr + be->objects_dirlen, be->objects_dir, be->object_dir_mode,
GIT_MKDIR_PATH | GIT_MKDIR_SKIP_LAST | GIT_MKDIR_VERIFY_DIR, NULL);
}
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)
goto on_error;
c = data[used++];
out->type = (c >> 4) & 7;
size = c & 15;
shift = 4;
while (c & 0x80) {
if (len <= used)
goto on_error;
if (sizeof(size_t) * 8 <= shift)
goto on_error;
c = data[used++];
size += (c & 0x7f) << shift;
shift += 7;
}
out->size = size;
if (out_len)
*out_len = used;
return 0;
on_error:
giterr_set(GITERR_OBJECT, "failed to parse loose object: invalid header");
return -1;
}
static int parse_header(
obj_hdr *out,
size_t *out_len,
const unsigned char *_data,
size_t data_len)
{
const char *data = (char *)_data;
size_t i, typename_len, size_idx, size_len;
int64_t size;
*out_len = 0;
/* find the object type name */
for (i = 0, typename_len = 0; i < data_len; i++, typename_len++) {
if (data[i] == ' ')
break;
}
if (typename_len == data_len)
goto on_error;
out->type = git_object_stringn2type(data, typename_len);
size_idx = typename_len + 1;
for (i = size_idx, size_len = 0; i < data_len; i++, size_len++) {
if (data[i] == '\0')
break;
}
if (i == data_len)
goto on_error;
if (git__strntol64(&size, &data[size_idx], size_len, NULL, 10) < 0 ||
size < 0)
goto on_error;
if ((uint64_t)size > SIZE_MAX) {
giterr_set(GITERR_OBJECT, "object is larger than available memory");
return -1;
}
out->size = size;
if (GIT_ADD_SIZET_OVERFLOW(out_len, i, 1))
goto on_error;
return 0;
on_error:
giterr_set(GITERR_OBJECT, "failed to parse loose object: invalid header");
return -1;
}
static int is_zlib_compressed_data(unsigned char *data, size_t data_len)
{
unsigned int w;
if (data_len < 2)
return 0;
w = ((unsigned int)(data[0]) << 8) + data[1];
return (data[0] & 0x8F) == 0x08 && !(w % 31);
}
/***********************************************************
*
* ODB OBJECT READING & WRITING
*
* Backend for the public API; read headers and full objects
* from the ODB. Write raw data to the ODB.
*
***********************************************************/
/*
* At one point, there was a loose object format that was intended to
* mimic the format used in pack-files. This was to allow easy copying
* of loose object data into packs. This format is no longer used, but
* we must still read it.
*/
static int read_loose_packlike(git_rawobj *out, git_buf *obj)
{
git_buf body = GIT_BUF_INIT;
const unsigned char *obj_data;
obj_hdr hdr;
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 ((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");
error = -1;
goto done;
}
obj_data += head_len;
obj_len -= head_len;
/*
* allocate a buffer and inflate the data into it
*/
if (GIT_ADD_SIZET_OVERFLOW(&alloc_size, hdr.size, 1) ||
git_buf_init(&body, alloc_size) < 0) {
error = -1;
goto done;
}
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);
done:
git_buf_free(&body);
return error;
}
static int read_loose_standard(git_rawobj *out, git_buf *obj)
{
git_zstream zstream = GIT_ZSTREAM_INIT;
unsigned char head[MAX_HEADER_LEN], *body = NULL;
size_t decompressed, head_len, body_len, alloc_size;
obj_hdr hdr;
int error;
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;
decompressed = sizeof(head);
/*
* inflate the initial part of the compressed buffer in order to
* parse the header; read the largest header possible, then push the
* remainder into the body buffer.
*/
if ((error = git_zstream_get_output(head, &decompressed, &zstream)) < 0 ||
(error = parse_header(&hdr, &head_len, head, decompressed)) < 0)
goto done;
if (!git_object_typeisloose(hdr.type)) {
giterr_set(GITERR_ODB, "failed to inflate disk object");
error = -1;
goto done;
}
/*
* allocate a buffer and inflate the object data into it
* (including the initial sequence in the head buffer).
*/
if (GIT_ADD_SIZET_OVERFLOW(&alloc_size, hdr.size, 1) ||
(body = git__malloc(alloc_size)) == NULL) {
error = -1;
goto done;
}
assert(decompressed >= head_len);
body_len = decompressed - head_len;
if (body_len)
memcpy(body, head + head_len, body_len);
decompressed = hdr.size - body_len;
if ((error = git_zstream_get_output(body + body_len, &decompressed, &zstream)) < 0)
goto done;
if (!git_zstream_done(&zstream)) {
giterr_set(GITERR_ZLIB, "failed to finish zlib inflation: stream aborted prematurely");
error = -1;
goto done;
}
body[hdr.size] = '\0';
out->data = body;
out->len = hdr.size;
out->type = hdr.type;
done:
if (error < 0)
git__free(body);
git_zstream_free(&zstream);
return error;
}
static int read_loose(git_rawobj *out, git_buf *loc)
{
int error;
git_buf obj = GIT_BUF_INIT;
assert(out && loc);
if (git_buf_oom(loc))
return -1;
out->data = NULL;
out->len = 0;
out->type = GIT_OBJ_BAD;
if ((error = git_futils_readbuffer(&obj, loc->ptr)) < 0)
goto done;
if (!is_zlib_compressed_data((unsigned char *)obj.ptr, obj.size))
error = read_loose_packlike(out, &obj);
else
error = read_loose_standard(out, &obj);
done:
git_buf_free(&obj);
return error;
}
static int read_header_loose_packlike(
git_rawobj *out, const unsigned char *data, size_t len)
{
obj_hdr hdr;
size_t header_len;
int error;
if ((error = parse_header_packlike(&hdr, &header_len, data, len)) < 0)
return error;
out->len = hdr.size;
out->type = hdr.type;
return error;
}
static int read_header_loose_standard(
git_rawobj *out, const unsigned char *data, size_t len)
{
git_zstream zs = GIT_ZSTREAM_INIT;
obj_hdr hdr;
unsigned char inflated[MAX_HEADER_LEN];
size_t header_len, inflated_len = sizeof(inflated);
int error;
if ((error = git_zstream_init(&zs, GIT_ZSTREAM_INFLATE)) < 0 ||
(error = git_zstream_set_input(&zs, data, len)) < 0 ||
(error = git_zstream_get_output_chunk(inflated, &inflated_len, &zs)) < 0 ||
(error = parse_header(&hdr, &header_len, inflated, inflated_len)) < 0)
goto done;
out->len = hdr.size;
out->type = hdr.type;
done:
git_zstream_free(&zs);
return error;
}
static int read_header_loose(git_rawobj *out, git_buf *loc)
{
unsigned char obj[1024];
int fd, obj_len, error;
assert(out && loc);
if (git_buf_oom(loc))
return -1;
out->data = NULL;
if ((error = fd = git_futils_open_ro(loc->ptr)) < 0 ||
(error = obj_len = p_read(fd, obj, sizeof(obj))) < 0)
goto done;
if (!is_zlib_compressed_data(obj, (size_t)obj_len))
error = read_header_loose_packlike(out, obj, (size_t)obj_len);
else
error = read_header_loose_standard(out, obj, (size_t)obj_len);
if (!error && !git_object_typeisloose(out->type)) {
giterr_set(GITERR_ZLIB, "failed to read loose object header");
error = -1;
goto done;
}
done:
if (fd >= 0)
p_close(fd);
return error;
}
static int locate_object(
git_buf *object_location,
loose_backend *backend,
const git_oid *oid)
{
int error = object_file_name(object_location, backend, oid);
if (!error && !git_path_exists(object_location->ptr))
return GIT_ENOTFOUND;
return error;
}
/* Explore an entry of a directory and see if it matches a short oid */
static int fn_locate_object_short_oid(void *state, git_buf *pathbuf) {
loose_locate_object_state *sstate = (loose_locate_object_state *)state;
if (git_buf_len(pathbuf) - sstate->dir_len != GIT_OID_HEXSZ - 2) {
/* Entry cannot be an object. Continue to next entry */
return 0;
}
if (git_path_isdir(pathbuf->ptr) == false) {
/* We are already in the directory matching the 2 first hex characters,
* compare the first ncmp characters of the oids */
if (!memcmp(sstate->short_oid + 2,
(unsigned char *)pathbuf->ptr + sstate->dir_len,
sstate->short_oid_len - 2)) {
if (!sstate->found) {
sstate->res_oid[0] = sstate->short_oid[0];
sstate->res_oid[1] = sstate->short_oid[1];
memcpy(sstate->res_oid+2, pathbuf->ptr+sstate->dir_len, GIT_OID_HEXSZ-2);
}
sstate->found++;
}
}
if (sstate->found > 1)
return GIT_EAMBIGUOUS;
return 0;
}
/* Locate an object matching a given short oid */
static int locate_object_short_oid(
git_buf *object_location,
git_oid *res_oid,
loose_backend *backend,
const git_oid *short_oid,
size_t len)
{
char *objects_dir = backend->objects_dir;
size_t dir_len = strlen(objects_dir), alloc_len;
loose_locate_object_state state;
int error;
/* prealloc memory for OBJ_DIR/xx/xx..38x..xx */
GITERR_CHECK_ALLOC_ADD(&alloc_len, dir_len, GIT_OID_HEXSZ);
GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 3);
if (git_buf_grow(object_location, alloc_len) < 0)
return -1;
git_buf_set(object_location, objects_dir, dir_len);
git_path_to_dir(object_location);
/* save adjusted position at end of dir so it can be restored later */
dir_len = git_buf_len(object_location);
/* Convert raw oid to hex formatted oid */
git_oid_fmt((char *)state.short_oid, short_oid);
/* Explore OBJ_DIR/xx/ where xx is the beginning of hex formatted short oid */
if (git_buf_put(object_location, (char *)state.short_oid, 3) < 0)
return -1;
object_location->ptr[object_location->size - 1] = '/';
/* Check that directory exists */
if (git_path_isdir(object_location->ptr) == false)
return git_odb__error_notfound("no matching loose object for prefix",
short_oid, len);
state.dir_len = git_buf_len(object_location);
state.short_oid_len = len;
state.found = 0;
/* Explore directory to find a unique object matching short_oid */
error = git_path_direach(
object_location, 0, fn_locate_object_short_oid, &state);
if (error < 0 && error != GIT_EAMBIGUOUS)
return error;
if (!state.found)
return git_odb__error_notfound("no matching loose object for prefix",
short_oid, len);
if (state.found > 1)
return git_odb__error_ambiguous("multiple matches in loose objects");
/* Convert obtained hex formatted oid to raw */
error = git_oid_fromstr(res_oid, (char *)state.res_oid);
if (error)
return error;
/* Update the location according to the oid obtained */
GITERR_CHECK_ALLOC_ADD(&alloc_len, dir_len, GIT_OID_HEXSZ);
GITERR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 2);
git_buf_truncate(object_location, dir_len);
if (git_buf_grow(object_location, alloc_len) < 0)
return -1;
git_oid_pathfmt(object_location->ptr + dir_len, res_oid);
object_location->size += GIT_OID_HEXSZ + 1;
object_location->ptr[object_location->size] = '\0';
return 0;
}
/***********************************************************
*
* LOOSE BACKEND PUBLIC API
*
* Implement the git_odb_backend API calls
*
***********************************************************/
static int loose_backend__read_header(size_t *len_p, git_otype *type_p, git_odb_backend *backend, const git_oid *oid)
{
git_buf object_path = GIT_BUF_INIT;
git_rawobj raw;
int error;
assert(backend && oid);
raw.len = 0;
raw.type = GIT_OBJ_BAD;
if (locate_object(&object_path, (loose_backend *)backend, oid) < 0) {
error = git_odb__error_notfound("no matching loose object",
oid, GIT_OID_HEXSZ);
} else if ((error = read_header_loose(&raw, &object_path)) == 0) {
*len_p = raw.len;
*type_p = raw.type;
}
git_buf_free(&object_path);
return error;
}
static int loose_backend__read(void **buffer_p, size_t *len_p, git_otype *type_p, git_odb_backend *backend, const git_oid *oid)
{
git_buf object_path = GIT_BUF_INIT;
git_rawobj raw;
int error = 0;
assert(backend && oid);
if (locate_object(&object_path, (loose_backend *)backend, oid) < 0) {
error = git_odb__error_notfound("no matching loose object",
oid, GIT_OID_HEXSZ);
} else if ((error = read_loose(&raw, &object_path)) == 0) {
*buffer_p = raw.data;
*len_p = raw.len;
*type_p = raw.type;
}
git_buf_free(&object_path);
return error;
}
static int loose_backend__read_prefix(
git_oid *out_oid,
void **buffer_p,
size_t *len_p,
git_otype *type_p,
git_odb_backend *backend,
const git_oid *short_oid,
size_t len)
{
int error = 0;
assert(len >= GIT_OID_MINPREFIXLEN && len <= GIT_OID_HEXSZ);
if (len == GIT_OID_HEXSZ) {
/* We can fall back to regular read method */
error = loose_backend__read(buffer_p, len_p, type_p, backend, short_oid);
if (!error)
git_oid_cpy(out_oid, short_oid);
} else {
git_buf object_path = GIT_BUF_INIT;
git_rawobj raw;
assert(backend && short_oid);
if ((error = locate_object_short_oid(&object_path, out_oid,
(loose_backend *)backend, short_oid, len)) == 0 &&
(error = read_loose(&raw, &object_path)) == 0)
{
*buffer_p = raw.data;
*len_p = raw.len;
*type_p = raw.type;
}
git_buf_free(&object_path);
}
return error;
}
static int loose_backend__exists(git_odb_backend *backend, const git_oid *oid)
{
git_buf object_path = GIT_BUF_INIT;
int error;
assert(backend && oid);
error = locate_object(&object_path, (loose_backend *)backend, oid);
git_buf_free(&object_path);
return !error;
}
static int loose_backend__exists_prefix(
git_oid *out, git_odb_backend *backend, const git_oid *short_id, size_t len)
{
git_buf object_path = GIT_BUF_INIT;
int error;
assert(backend && out && short_id && len >= GIT_OID_MINPREFIXLEN);
error = locate_object_short_oid(
&object_path, out, (loose_backend *)backend, short_id, len);
git_buf_free(&object_path);
return error;
}
struct foreach_state {
size_t dir_len;
git_odb_foreach_cb cb;
void *data;
};
GIT_INLINE(int) filename_to_oid(git_oid *oid, const char *ptr)
{
int v, i = 0;
if (strlen(ptr) != GIT_OID_HEXSZ+1)
return -1;
if (ptr[2] != '/') {
return -1;
}
v = (git__fromhex(ptr[i]) << 4) | git__fromhex(ptr[i+1]);
if (v < 0)
return -1;
oid->id[0] = (unsigned char) v;
ptr += 3;
for (i = 0; i < 38; i += 2) {
v = (git__fromhex(ptr[i]) << 4) | git__fromhex(ptr[i + 1]);
if (v < 0)
return -1;
oid->id[1 + i/2] = (unsigned char) v;
}
return 0;
}
static int foreach_object_dir_cb(void *_state, git_buf *path)
{
git_oid oid;
struct foreach_state *state = (struct foreach_state *) _state;
if (filename_to_oid(&oid, path->ptr + state->dir_len) < 0)
return 0;
return giterr_set_after_callback_function(
state->cb(&oid, state->data), "git_odb_foreach");
}
static int foreach_cb(void *_state, git_buf *path)
{
struct foreach_state *state = (struct foreach_state *) _state;
/* non-dir is some stray file, ignore it */
if (!git_path_isdir(git_buf_cstr(path)))
return 0;
return git_path_direach(path, 0, foreach_object_dir_cb, state);
}
static int loose_backend__foreach(git_odb_backend *_backend, git_odb_foreach_cb cb, void *data)
{
char *objects_dir;
int error;
git_buf buf = GIT_BUF_INIT;
struct foreach_state state;
loose_backend *backend = (loose_backend *) _backend;
assert(backend && cb);
objects_dir = backend->objects_dir;
git_buf_sets(&buf, objects_dir);
git_path_to_dir(&buf);
if (git_buf_oom(&buf))
return -1;
memset(&state, 0, sizeof(state));
state.cb = cb;
state.data = data;
state.dir_len = git_buf_len(&buf);
error = git_path_direach(&buf, 0, foreach_cb, &state);
git_buf_free(&buf);
return error;
}
static int loose_backend__writestream_finalize(git_odb_stream *_stream, const git_oid *oid)
{
loose_writestream *stream = (loose_writestream *)_stream;
loose_backend *backend = (loose_backend *)_stream->backend;
git_buf final_path = GIT_BUF_INIT;
int error = 0;
if (object_file_name(&final_path, backend, oid) < 0 ||
object_mkdir(&final_path, backend) < 0)
error = -1;
else
error = git_filebuf_commit_at(
&stream->fbuf, final_path.ptr);
git_buf_free(&final_path);
return error;
}
static int loose_backend__writestream_write(git_odb_stream *_stream, const char *data, size_t len)
{
loose_writestream *stream = (loose_writestream *)_stream;
return git_filebuf_write(&stream->fbuf, data, len);
}
static void loose_backend__writestream_free(git_odb_stream *_stream)
{
loose_writestream *stream = (loose_writestream *)_stream;
git_filebuf_cleanup(&stream->fbuf);
git__free(stream);
}
static int filebuf_flags(loose_backend *backend)
{
int flags = GIT_FILEBUF_TEMPORARY |
(backend->object_zlib_level << GIT_FILEBUF_DEFLATE_SHIFT);
if (backend->fsync_object_files || git_repository__fsync_gitdir)
flags |= GIT_FILEBUF_FSYNC;
return flags;
}
static int loose_backend__writestream(git_odb_stream **stream_out, git_odb_backend *_backend, git_off_t length, git_otype type)
{
loose_backend *backend;
loose_writestream *stream = NULL;
char hdr[MAX_HEADER_LEN];
git_buf tmp_path = GIT_BUF_INIT;
size_t hdrlen;
int error;
assert(_backend && length >= 0);
backend = (loose_backend *)_backend;
*stream_out = NULL;
if ((error = git_odb__format_object_header(&hdrlen,
hdr, sizeof(hdr), length, type)) < 0)
return error;
stream = git__calloc(1, sizeof(loose_writestream));
GITERR_CHECK_ALLOC(stream);
stream->stream.backend = _backend;
stream->stream.read = NULL; /* read only */
stream->stream.write = &loose_backend__writestream_write;
stream->stream.finalize_write = &loose_backend__writestream_finalize;
stream->stream.free = &loose_backend__writestream_free;
stream->stream.mode = GIT_STREAM_WRONLY;
if (git_buf_joinpath(&tmp_path, backend->objects_dir, "tmp_object") < 0 ||
git_filebuf_open(&stream->fbuf, tmp_path.ptr, filebuf_flags(backend),
backend->object_file_mode) < 0 ||
stream->stream.write((git_odb_stream *)stream, hdr, hdrlen) < 0)
{
git_filebuf_cleanup(&stream->fbuf);
git__free(stream);
stream = NULL;
}
git_buf_free(&tmp_path);
*stream_out = (git_odb_stream *)stream;
return !stream ? -1 : 0;
}
static int loose_backend__readstream_read(
git_odb_stream *_stream,
char *buffer,
size_t buffer_len)
{
loose_readstream *stream = (loose_readstream *)_stream;
size_t start_remain = stream->start_len - stream->start_read;
int total = 0, error;
/*
* if we read more than just the header in the initial read, play
* that back for the caller.
*/
if (start_remain && buffer_len) {
size_t chunk = min(start_remain, buffer_len);
memcpy(buffer, stream->start + stream->start_read, chunk);
buffer += chunk;
stream->start_read += chunk;
total += chunk;
buffer_len -= chunk;
}
if (buffer_len) {
size_t chunk = min(buffer_len, INT_MAX);
if ((error = git_zstream_get_output(buffer, &chunk, &stream->zstream)) < 0)
return error;
total += chunk;
}
return total;
}
static void loose_backend__readstream_free(git_odb_stream *_stream)
{
loose_readstream *stream = (loose_readstream *)_stream;
git_futils_mmap_free(&stream->map);
git_zstream_free(&stream->zstream);
git__free(stream);
}
static int loose_backend__readstream_packlike(
obj_hdr *hdr,
loose_readstream *stream)
{
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 ((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;
}
return git_zstream_set_input(&stream->zstream,
data + head_len, data_len - head_len);
}
static int loose_backend__readstream_standard(
obj_hdr *hdr,
loose_readstream *stream)
{
unsigned char head[MAX_HEADER_LEN];
size_t init, head_len;
int error;
if ((error = git_zstream_set_input(&stream->zstream,
stream->map.data, stream->map.len)) < 0)
return error;
init = sizeof(head);
/*
* inflate the initial part of the compressed buffer in order to
* parse the header; read the largest header possible, then store
* it in the `start` field of the stream object.
*/
if ((error = git_zstream_get_output(head, &init, &stream->zstream)) < 0 ||
(error = parse_header(hdr, &head_len, head, init)) < 0)
return error;
if (!git_object_typeisloose(hdr->type)) {
giterr_set(GITERR_ODB, "failed to inflate disk object");
return -1;
}
if (init > head_len) {
stream->start_len = init - head_len;
memcpy(stream->start, head + head_len, init - head_len);
}
return 0;
}
static int loose_backend__readstream(
git_odb_stream **stream_out,
size_t *len_out,
git_otype *type_out,
git_odb_backend *_backend,
const git_oid *oid)
{
loose_backend *backend;
loose_readstream *stream = NULL;
git_hash_ctx *hash_ctx = NULL;
git_buf object_path = GIT_BUF_INIT;
obj_hdr hdr;
int error = 0;
assert(stream_out && len_out && type_out && _backend && oid);
backend = (loose_backend *)_backend;
*stream_out = NULL;
*len_out = 0;
*type_out = GIT_OBJ_BAD;
if (locate_object(&object_path, backend, oid) < 0) {
error = git_odb__error_notfound("no matching loose object",
oid, GIT_OID_HEXSZ);
goto done;
}
stream = git__calloc(1, sizeof(loose_readstream));
GITERR_CHECK_ALLOC(stream);
hash_ctx = git__malloc(sizeof(git_hash_ctx));
GITERR_CHECK_ALLOC(hash_ctx);
if ((error = git_hash_ctx_init(hash_ctx)) < 0 ||
(error = git_futils_mmap_ro_file(&stream->map, object_path.ptr)) < 0 ||
(error = git_zstream_init(&stream->zstream, GIT_ZSTREAM_INFLATE)) < 0)
goto done;
/* check for a packlike loose object */
if (!is_zlib_compressed_data(stream->map.data, stream->map.len))
error = loose_backend__readstream_packlike(&hdr, stream);
else
error = loose_backend__readstream_standard(&hdr, stream);
if (error < 0)
goto done;
stream->stream.backend = _backend;
stream->stream.hash_ctx = hash_ctx;
stream->stream.read = &loose_backend__readstream_read;
stream->stream.free = &loose_backend__readstream_free;
*stream_out = (git_odb_stream *)stream;
*len_out = hdr.size;
*type_out = hdr.type;
done:
if (error < 0) {
git_futils_mmap_free(&stream->map);
git_zstream_free(&stream->zstream);
git_hash_ctx_cleanup(hash_ctx);
git__free(hash_ctx);
git__free(stream);
}
git_buf_free(&object_path);
return error;
}
static int loose_backend__write(git_odb_backend *_backend, const git_oid *oid, const void *data, size_t len, git_otype type)
{
int error = 0;
git_buf final_path = GIT_BUF_INIT;
char header[MAX_HEADER_LEN];
size_t header_len;
git_filebuf fbuf = GIT_FILEBUF_INIT;
loose_backend *backend;
backend = (loose_backend *)_backend;
/* prepare the header for the file */
if ((error = git_odb__format_object_header(&header_len,
header, sizeof(header), len, type)) < 0)
goto cleanup;
if (git_buf_joinpath(&final_path, backend->objects_dir, "tmp_object") < 0 ||
git_filebuf_open(&fbuf, final_path.ptr, filebuf_flags(backend),
backend->object_file_mode) < 0)
{
error = -1;
goto cleanup;
}
git_filebuf_write(&fbuf, header, header_len);
git_filebuf_write(&fbuf, data, len);
if (object_file_name(&final_path, backend, oid) < 0 ||
object_mkdir(&final_path, backend) < 0 ||
git_filebuf_commit_at(&fbuf, final_path.ptr) < 0)
error = -1;
cleanup:
if (error < 0)
git_filebuf_cleanup(&fbuf);
git_buf_free(&final_path);
return error;
}
static int loose_backend__freshen(
git_odb_backend *_backend,
const git_oid *oid)
{
loose_backend *backend = (loose_backend *)_backend;
git_buf path = GIT_BUF_INIT;
int error;
if (object_file_name(&path, backend, oid) < 0)
return -1;
error = git_futils_touch(path.ptr, NULL);
git_buf_free(&path);
return error;
}
static void loose_backend__free(git_odb_backend *_backend)
{
loose_backend *backend;
assert(_backend);
backend = (loose_backend *)_backend;
git__free(backend);
}
int git_odb_backend_loose(
git_odb_backend **backend_out,
const char *objects_dir,
int compression_level,
int do_fsync,
unsigned int dir_mode,
unsigned int file_mode)
{
loose_backend *backend;
size_t objects_dirlen, alloclen;
assert(backend_out && objects_dir);
objects_dirlen = strlen(objects_dir);
GITERR_CHECK_ALLOC_ADD(&alloclen, sizeof(loose_backend), objects_dirlen);
GITERR_CHECK_ALLOC_ADD(&alloclen, alloclen, 2);
backend = git__calloc(1, alloclen);
GITERR_CHECK_ALLOC(backend);
backend->parent.version = GIT_ODB_BACKEND_VERSION;
backend->objects_dirlen = objects_dirlen;
memcpy(backend->objects_dir, objects_dir, objects_dirlen);
if (backend->objects_dir[backend->objects_dirlen - 1] != '/')
backend->objects_dir[backend->objects_dirlen++] = '/';
if (compression_level < 0)
compression_level = Z_BEST_SPEED;
if (dir_mode == 0)
dir_mode = GIT_OBJECT_DIR_MODE;
if (file_mode == 0)
file_mode = GIT_OBJECT_FILE_MODE;
backend->object_zlib_level = compression_level;
backend->fsync_object_files = do_fsync;
backend->object_dir_mode = dir_mode;
backend->object_file_mode = file_mode;
backend->parent.read = &loose_backend__read;
backend->parent.write = &loose_backend__write;
backend->parent.read_prefix = &loose_backend__read_prefix;
backend->parent.read_header = &loose_backend__read_header;
backend->parent.writestream = &loose_backend__writestream;
backend->parent.readstream = &loose_backend__readstream;
backend->parent.exists = &loose_backend__exists;
backend->parent.exists_prefix = &loose_backend__exists_prefix;
backend->parent.foreach = &loose_backend__foreach;
backend->parent.freshen = &loose_backend__freshen;
backend->parent.free = &loose_backend__free;
*backend_out = (git_odb_backend *)backend;
return 0;
}