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git/object-file.c

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/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*
* This handles basic git object files - packing, unpacking,
* creation etc.
*/
#define USE_THE_REPOSITORY_VARIABLE
#define DISABLE_SIGN_COMPARE_WARNINGS
#include "git-compat-util.h"
#include "bulk-checkin.h"
#include "convert.h"
#include "dir.h"
#include "environment.h"
#include "fsck.h"
#include "gettext.h"
#include "hex.h"
#include "loose.h"
#include "object-file-convert.h"
#include "object-file.h"
#include "object-store.h"
#include "oidtree.h"
#include "pack.h"
#include "packfile.h"
#include "path.h"
#include "setup.h"
#include "streaming.h"
/* The maximum size for an object header. */
#define MAX_HEADER_LEN 32
static int get_conv_flags(unsigned flags)
{
if (flags & INDEX_RENORMALIZE)
return CONV_EOL_RENORMALIZE;
else if (flags & INDEX_WRITE_OBJECT)
return global_conv_flags_eol | CONV_WRITE_OBJECT;
else
return 0;
}
static void fill_loose_path(struct strbuf *buf, const struct object_id *oid)
{
int i;
for (i = 0; i < the_hash_algo->rawsz; i++) {
static char hex[] = "0123456789abcdef";
unsigned int val = oid->hash[i];
strbuf_addch(buf, hex[val >> 4]);
strbuf_addch(buf, hex[val & 0xf]);
if (!i)
strbuf_addch(buf, '/');
}
}
const char *odb_loose_path(struct object_directory *odb,
struct strbuf *buf,
const struct object_id *oid)
{
strbuf_reset(buf);
strbuf_addstr(buf, odb->path);
strbuf_addch(buf, '/');
fill_loose_path(buf, oid);
return buf->buf;
}
/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
static int freshen_file(const char *fn)
{
return !utime(fn, NULL);
}
/*
* All of the check_and_freshen functions return 1 if the file exists and was
* freshened (if freshening was requested), 0 otherwise. If they return
* 0, you should not assume that it is safe to skip a write of the object (it
* either does not exist on disk, or has a stale mtime and may be subject to
* pruning).
*/
int check_and_freshen_file(const char *fn, int freshen)
{
if (access(fn, F_OK))
return 0;
if (freshen && !freshen_file(fn))
return 0;
return 1;
}
static int check_and_freshen_odb(struct object_directory *odb,
const struct object_id *oid,
int freshen)
{
static struct strbuf path = STRBUF_INIT;
odb_loose_path(odb, &path, oid);
return check_and_freshen_file(path.buf, freshen);
}
static int check_and_freshen_local(const struct object_id *oid, int freshen)
{
return check_and_freshen_odb(the_repository->objects->odb, oid, freshen);
}
static int check_and_freshen_nonlocal(const struct object_id *oid, int freshen)
{
struct object_directory *odb;
prepare_alt_odb(the_repository);
for (odb = the_repository->objects->odb->next; odb; odb = odb->next) {
if (check_and_freshen_odb(odb, oid, freshen))
return 1;
}
return 0;
}
static int check_and_freshen(const struct object_id *oid, int freshen)
{
return check_and_freshen_local(oid, freshen) ||
check_and_freshen_nonlocal(oid, freshen);
}
int has_loose_object_nonlocal(const struct object_id *oid)
{
return check_and_freshen_nonlocal(oid, 0);
}
int has_loose_object(const struct object_id *oid)
{
return check_and_freshen(oid, 0);
}
static int format_object_header_literally(char *str, size_t size,
const char *type, size_t objsize)
{
return xsnprintf(str, size, "%s %"PRIuMAX, type, (uintmax_t)objsize) + 1;
}
int format_object_header(char *str, size_t size, enum object_type type,
size_t objsize)
{
const char *name = type_name(type);
if (!name)
BUG("could not get a type name for 'enum object_type' value %d", type);
return format_object_header_literally(str, size, name, objsize);
}
int check_object_signature(struct repository *r, const struct object_id *oid,
void *buf, unsigned long size,
enum object_type type)
{
const struct git_hash_algo *algo =
oid->algo ? &hash_algos[oid->algo] : r->hash_algo;
struct object_id real_oid;
hash_object_file(algo, buf, size, type, &real_oid);
return !oideq(oid, &real_oid) ? -1 : 0;
}
int stream_object_signature(struct repository *r, const struct object_id *oid)
{
struct object_id real_oid;
unsigned long size;
enum object_type obj_type;
struct git_istream *st;
struct git_hash_ctx c;
char hdr[MAX_HEADER_LEN];
int hdrlen;
st = open_istream(r, oid, &obj_type, &size, NULL);
if (!st)
return -1;
/* Generate the header */
hdrlen = format_object_header(hdr, sizeof(hdr), obj_type, size);
/* Sha1.. */
r->hash_algo->init_fn(&c);
git_hash_update(&c, hdr, hdrlen);
for (;;) {
char buf[1024 * 16];
ssize_t readlen = read_istream(st, buf, sizeof(buf));
if (readlen < 0) {
close_istream(st);
return -1;
}
if (!readlen)
break;
git_hash_update(&c, buf, readlen);
}
git_hash_final_oid(&real_oid, &c);
close_istream(st);
return !oideq(oid, &real_oid) ? -1 : 0;
}
/*
* Find "oid" as a loose object in the local repository or in an alternate.
* Returns 0 on success, negative on failure.
*
* The "path" out-parameter will give the path of the object we found (if any).
* Note that it may point to static storage and is only valid until another
* call to stat_loose_object().
*/
static int stat_loose_object(struct repository *r, const struct object_id *oid,
struct stat *st, const char **path)
{
struct object_directory *odb;
static struct strbuf buf = STRBUF_INIT;
prepare_alt_odb(r);
for (odb = r->objects->odb; odb; odb = odb->next) {
*path = odb_loose_path(odb, &buf, oid);
if (!lstat(*path, st))
return 0;
}
return -1;
}
/*
* Like stat_loose_object(), but actually open the object and return the
* descriptor. See the caveats on the "path" parameter above.
*/
static int open_loose_object(struct repository *r,
const struct object_id *oid, const char **path)
{
int fd;
struct object_directory *odb;
int most_interesting_errno = ENOENT;
static struct strbuf buf = STRBUF_INIT;
prepare_alt_odb(r);
for (odb = r->objects->odb; odb; odb = odb->next) {
*path = odb_loose_path(odb, &buf, oid);
fd = git_open(*path);
if (fd >= 0)
return fd;
if (most_interesting_errno == ENOENT)
most_interesting_errno = errno;
}
errno = most_interesting_errno;
return -1;
}
static int quick_has_loose(struct repository *r,
const struct object_id *oid)
{
struct object_directory *odb;
prepare_alt_odb(r);
for (odb = r->objects->odb; odb; odb = odb->next) {
if (oidtree_contains(odb_loose_cache(odb, oid), oid))
return 1;
}
return 0;
}
/*
* Map and close the given loose object fd. The path argument is used for
* error reporting.
*/
static void *map_fd(int fd, const char *path, unsigned long *size)
{
void *map = NULL;
struct stat st;
if (!fstat(fd, &st)) {
*size = xsize_t(st.st_size);
if (!*size) {
/* mmap() is forbidden on empty files */
error(_("object file %s is empty"), path);
close(fd);
return NULL;
}
map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
}
close(fd);
return map;
}
void *map_loose_object(struct repository *r,
const struct object_id *oid,
unsigned long *size)
{
const char *p;
int fd = open_loose_object(r, oid, &p);
if (fd < 0)
return NULL;
return map_fd(fd, p, size);
}
enum unpack_loose_header_result unpack_loose_header(git_zstream *stream,
unsigned char *map,
unsigned long mapsize,
void *buffer,
unsigned long bufsiz,
struct strbuf *header)
{
int status;
/* Get the data stream */
memset(stream, 0, sizeof(*stream));
stream->next_in = map;
stream->avail_in = mapsize;
stream->next_out = buffer;
stream->avail_out = bufsiz;
git_inflate_init(stream);
obj_read_unlock();
status = git_inflate(stream, 0);
obj_read_lock();
if (status != Z_OK && status != Z_STREAM_END)
return ULHR_BAD;
/*
* Check if entire header is unpacked in the first iteration.
*/
if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
return ULHR_OK;
/*
* We have a header longer than MAX_HEADER_LEN. The "header"
* here is only non-NULL when we run "cat-file
* --allow-unknown-type".
*/
if (!header)
return ULHR_TOO_LONG;
/*
* buffer[0..bufsiz] was not large enough. Copy the partial
* result out to header, and then append the result of further
* reading the stream.
*/
strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
do {
stream->next_out = buffer;
stream->avail_out = bufsiz;
obj_read_unlock();
status = git_inflate(stream, 0);
obj_read_lock();
strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
return 0;
} while (status == Z_OK);
return ULHR_BAD;
}
static void *unpack_loose_rest(git_zstream *stream,
void *buffer, unsigned long size,
const struct object_id *oid)
{
int bytes = strlen(buffer) + 1;
unsigned char *buf = xmallocz(size);
unsigned long n;
int status = Z_OK;
n = stream->total_out - bytes;
if (n > size)
n = size;
memcpy(buf, (char *) buffer + bytes, n);
bytes = n;
if (bytes <= size) {
/*
* The above condition must be (bytes <= size), not
* (bytes < size). In other words, even though we
* expect no more output and set avail_out to zero,
* the input zlib stream may have bytes that express
* "this concludes the stream", and we *do* want to
* eat that input.
*
* Otherwise we would not be able to test that we
* consumed all the input to reach the expected size;
* we also want to check that zlib tells us that all
* went well with status == Z_STREAM_END at the end.
*/
stream->next_out = buf + bytes;
stream->avail_out = size - bytes;
while (status == Z_OK) {
obj_read_unlock();
status = git_inflate(stream, Z_FINISH);
obj_read_lock();
}
}
if (status != Z_STREAM_END) {
error(_("corrupt loose object '%s'"), oid_to_hex(oid));
FREE_AND_NULL(buf);
} else if (stream->avail_in) {
error(_("garbage at end of loose object '%s'"),
oid_to_hex(oid));
FREE_AND_NULL(buf);
}
return buf;
}
/*
* We used to just use "sscanf()", but that's actually way
* too permissive for what we want to check. So do an anal
* object header parse by hand.
*/
int parse_loose_header(const char *hdr, struct object_info *oi)
{
const char *type_buf = hdr;
size_t size;
int type, type_len = 0;
/*
* The type can be of any size but is followed by
* a space.
*/
for (;;) {
char c = *hdr++;
if (!c)
return -1;
if (c == ' ')
break;
type_len++;
}
type = type_from_string_gently(type_buf, type_len, 1);
if (oi->type_name)
strbuf_add(oi->type_name, type_buf, type_len);
if (oi->typep)
*oi->typep = type;
/*
* The length must follow immediately, and be in canonical
* decimal format (ie "010" is not valid).
*/
size = *hdr++ - '0';
if (size > 9)
return -1;
if (size) {
for (;;) {
unsigned long c = *hdr - '0';
if (c > 9)
break;
hdr++;
size = st_add(st_mult(size, 10), c);
}
}
if (oi->sizep)
*oi->sizep = cast_size_t_to_ulong(size);
/*
* The length must be followed by a zero byte
*/
if (*hdr)
return -1;
/*
* The format is valid, but the type may still be bogus. The
* Caller needs to check its oi->typep.
*/
return 0;
}
int loose_object_info(struct repository *r,
const struct object_id *oid,
struct object_info *oi, int flags)
{
int status = 0;
int fd;
unsigned long mapsize;
const char *path;
void *map;
git_zstream stream;
char hdr[MAX_HEADER_LEN];
struct strbuf hdrbuf = STRBUF_INIT;
unsigned long size_scratch;
enum object_type type_scratch;
int allow_unknown = flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE;
if (oi->delta_base_oid)
oidclr(oi->delta_base_oid, the_repository->hash_algo);
/*
* If we don't care about type or size, then we don't
* need to look inside the object at all. Note that we
* do not optimize out the stat call, even if the
* caller doesn't care about the disk-size, since our
* return value implicitly indicates whether the
* object even exists.
*/
if (!oi->typep && !oi->type_name && !oi->sizep && !oi->contentp) {
struct stat st;
if (!oi->disk_sizep && (flags & OBJECT_INFO_QUICK))
return quick_has_loose(r, oid) ? 0 : -1;
if (stat_loose_object(r, oid, &st, &path) < 0)
return -1;
if (oi->disk_sizep)
*oi->disk_sizep = st.st_size;
return 0;
}
fd = open_loose_object(r, oid, &path);
if (fd < 0) {
if (errno != ENOENT)
error_errno(_("unable to open loose object %s"), oid_to_hex(oid));
return -1;
}
map = map_fd(fd, path, &mapsize);
if (!map)
return -1;
if (!oi->sizep)
oi->sizep = &size_scratch;
if (!oi->typep)
oi->typep = &type_scratch;
if (oi->disk_sizep)
*oi->disk_sizep = mapsize;
switch (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr),
allow_unknown ? &hdrbuf : NULL)) {
case ULHR_OK:
if (parse_loose_header(hdrbuf.len ? hdrbuf.buf : hdr, oi) < 0)
status = error(_("unable to parse %s header"), oid_to_hex(oid));
else if (!allow_unknown && *oi->typep < 0)
die(_("invalid object type"));
if (!oi->contentp)
break;
if (hdrbuf.len)
BUG("unpacking content with unknown types not yet supported");
*oi->contentp = unpack_loose_rest(&stream, hdr, *oi->sizep, oid);
if (*oi->contentp)
goto cleanup;
status = -1;
break;
case ULHR_BAD:
status = error(_("unable to unpack %s header"),
oid_to_hex(oid));
break;
case ULHR_TOO_LONG:
status = error(_("header for %s too long, exceeds %d bytes"),
oid_to_hex(oid), MAX_HEADER_LEN);
break;
}
if (status && (flags & OBJECT_INFO_DIE_IF_CORRUPT))
die(_("loose object %s (stored in %s) is corrupt"),
oid_to_hex(oid), path);
cleanup:
git_inflate_end(&stream);
munmap(map, mapsize);
if (oi->sizep == &size_scratch)
oi->sizep = NULL;
strbuf_release(&hdrbuf);
if (oi->typep == &type_scratch)
oi->typep = NULL;
oi->whence = OI_LOOSE;
return status;
}
static void hash_object_body(const struct git_hash_algo *algo, struct git_hash_ctx *c,
const void *buf, unsigned long len,
struct object_id *oid,
char *hdr, int *hdrlen)
{
algo->init_fn(c);
git_hash_update(c, hdr, *hdrlen);
git_hash_update(c, buf, len);
git_hash_final_oid(oid, c);
}
static void write_object_file_prepare(const struct git_hash_algo *algo,
const void *buf, unsigned long len,
enum object_type type, struct object_id *oid,
char *hdr, int *hdrlen)
{
struct git_hash_ctx c;
/* Generate the header */
*hdrlen = format_object_header(hdr, *hdrlen, type, len);
/* Sha1.. */
hash_object_body(algo, &c, buf, len, oid, hdr, hdrlen);
}
static void write_object_file_prepare_literally(const struct git_hash_algo *algo,
const void *buf, unsigned long len,
const char *type, struct object_id *oid,
char *hdr, int *hdrlen)
{
struct git_hash_ctx c;
*hdrlen = format_object_header_literally(hdr, *hdrlen, type, len);
hash_object_body(algo, &c, buf, len, oid, hdr, hdrlen);
}
#define CHECK_COLLISION_DEST_VANISHED -2
static int check_collision(const char *source, const char *dest)
{
char buf_source[4096], buf_dest[4096];
int fd_source = -1, fd_dest = -1;
int ret = 0;
fd_source = open(source, O_RDONLY);
if (fd_source < 0) {
ret = error_errno(_("unable to open %s"), source);
goto out;
}
fd_dest = open(dest, O_RDONLY);
if (fd_dest < 0) {
if (errno != ENOENT)
ret = error_errno(_("unable to open %s"), dest);
else
ret = CHECK_COLLISION_DEST_VANISHED;
goto out;
}
while (1) {
ssize_t sz_a, sz_b;
sz_a = read_in_full(fd_source, buf_source, sizeof(buf_source));
if (sz_a < 0) {
ret = error_errno(_("unable to read %s"), source);
goto out;
}
sz_b = read_in_full(fd_dest, buf_dest, sizeof(buf_dest));
if (sz_b < 0) {
ret = error_errno(_("unable to read %s"), dest);
goto out;
}
if (sz_a != sz_b || memcmp(buf_source, buf_dest, sz_a)) {
ret = error(_("files '%s' and '%s' differ in contents"),
source, dest);
goto out;
}
if (sz_a < sizeof(buf_source))
break;
}
out:
if (fd_source > -1)
close(fd_source);
if (fd_dest > -1)
close(fd_dest);
return ret;
}
/*
* Move the just written object into its final resting place.
*/
int finalize_object_file(const char *tmpfile, const char *filename)
{
return finalize_object_file_flags(tmpfile, filename, 0);
}
int finalize_object_file_flags(const char *tmpfile, const char *filename,
enum finalize_object_file_flags flags)
{
unsigned retries = 0;
int ret;
retry:
ret = 0;
if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
goto try_rename;
else if (link(tmpfile, filename))
ret = errno;
else
unlink_or_warn(tmpfile);
/*
* Coda hack - coda doesn't like cross-directory links,
* so we fall back to a rename, which will mean that it
* won't be able to check collisions, but that's not a
* big deal.
*
* The same holds for FAT formatted media.
*
* When this succeeds, we just return. We have nothing
* left to unlink.
*/
if (ret && ret != EEXIST) {
struct stat st;
try_rename:
if (!stat(filename, &st))
ret = EEXIST;
else if (!rename(tmpfile, filename))
goto out;
else
ret = errno;
}
if (ret) {
if (ret != EEXIST) {
int saved_errno = errno;
unlink_or_warn(tmpfile);
errno = saved_errno;
return error_errno(_("unable to write file %s"), filename);
}
if (!(flags & FOF_SKIP_COLLISION_CHECK)) {
ret = check_collision(tmpfile, filename);
if (ret == CHECK_COLLISION_DEST_VANISHED) {
if (retries++ > 5)
return error(_("unable to write repeatedly vanishing file %s"),
filename);
goto retry;
}
else if (ret)
return -1;
}
unlink_or_warn(tmpfile);
}
out:
if (adjust_shared_perm(the_repository, filename))
return error(_("unable to set permission to '%s'"), filename);
return 0;
}
static void hash_object_file_literally(const struct git_hash_algo *algo,
const void *buf, unsigned long len,
const char *type, struct object_id *oid)
{
char hdr[MAX_HEADER_LEN];
int hdrlen = sizeof(hdr);
write_object_file_prepare_literally(algo, buf, len, type, oid, hdr, &hdrlen);
}
void hash_object_file(const struct git_hash_algo *algo, const void *buf,
unsigned long len, enum object_type type,
struct object_id *oid)
{
hash_object_file_literally(algo, buf, len, type_name(type), oid);
}
/* Finalize a file on disk, and close it. */
static void close_loose_object(int fd, const char *filename)
{
if (the_repository->objects->odb->will_destroy)
goto out;
if (batch_fsync_enabled(FSYNC_COMPONENT_LOOSE_OBJECT))
fsync_loose_object_bulk_checkin(fd, filename);
else if (fsync_object_files > 0)
fsync_or_die(fd, filename);
else
fsync_component_or_die(FSYNC_COMPONENT_LOOSE_OBJECT, fd,
filename);
out:
if (close(fd) != 0)
die_errno(_("error when closing loose object file"));
}
/* Size of directory component, including the ending '/' */
static inline int directory_size(const char *filename)
{
const char *s = strrchr(filename, '/');
if (!s)
return 0;
return s - filename + 1;
}
/*
* This creates a temporary file in the same directory as the final
* 'filename'
*
* We want to avoid cross-directory filename renames, because those
* can have problems on various filesystems (FAT, NFS, Coda).
*/
static int create_tmpfile(struct strbuf *tmp, const char *filename)
{
int fd, dirlen = directory_size(filename);
strbuf_reset(tmp);
strbuf_add(tmp, filename, dirlen);
strbuf_addstr(tmp, "tmp_obj_XXXXXX");
fd = git_mkstemp_mode(tmp->buf, 0444);
if (fd < 0 && dirlen && errno == ENOENT) {
/*
* Make sure the directory exists; note that the contents
* of the buffer are undefined after mkstemp returns an
* error, so we have to rewrite the whole buffer from
* scratch.
*/
strbuf_reset(tmp);
strbuf_add(tmp, filename, dirlen - 1);
if (mkdir(tmp->buf, 0777) && errno != EEXIST)
return -1;
if (adjust_shared_perm(the_repository, tmp->buf))
return -1;
/* Try again */
strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
fd = git_mkstemp_mode(tmp->buf, 0444);
}
return fd;
}
/**
* Common steps for loose object writers to start writing loose
* objects:
*
* - Create tmpfile for the loose object.
* - Setup zlib stream for compression.
* - Start to feed header to zlib stream.
*
* Returns a "fd", which should later be provided to
* end_loose_object_common().
*/
static int start_loose_object_common(struct strbuf *tmp_file,
const char *filename, unsigned flags,
git_zstream *stream,
unsigned char *buf, size_t buflen,
struct git_hash_ctx *c, struct git_hash_ctx *compat_c,
char *hdr, int hdrlen)
{
struct repository *repo = the_repository;
const struct git_hash_algo *algo = repo->hash_algo;
const struct git_hash_algo *compat = repo->compat_hash_algo;
int fd;
fd = create_tmpfile(tmp_file, filename);
if (fd < 0) {
if (flags & WRITE_OBJECT_FILE_SILENT)
return -1;
else if (errno == EACCES)
return error(_("insufficient permission for adding "
"an object to repository database %s"),
repo_get_object_directory(the_repository));
else
return error_errno(
_("unable to create temporary file"));
}
/* Setup zlib stream for compression */
git_deflate_init(stream, zlib_compression_level);
stream->next_out = buf;
stream->avail_out = buflen;
algo->init_fn(c);
if (compat && compat_c)
compat->init_fn(compat_c);
/* Start to feed header to zlib stream */
stream->next_in = (unsigned char *)hdr;
stream->avail_in = hdrlen;
while (git_deflate(stream, 0) == Z_OK)
; /* nothing */
git_hash_update(c, hdr, hdrlen);
if (compat && compat_c)
git_hash_update(compat_c, hdr, hdrlen);
return fd;
}
/**
* Common steps for the inner git_deflate() loop for writing loose
* objects. Returns what git_deflate() returns.
*/
static int write_loose_object_common(struct git_hash_ctx *c, struct git_hash_ctx *compat_c,
git_zstream *stream, const int flush,
unsigned char *in0, const int fd,
unsigned char *compressed,
const size_t compressed_len)
{
struct repository *repo = the_repository;
const struct git_hash_algo *compat = repo->compat_hash_algo;
int ret;
ret = git_deflate(stream, flush ? Z_FINISH : 0);
git_hash_update(c, in0, stream->next_in - in0);
if (compat && compat_c)
git_hash_update(compat_c, in0, stream->next_in - in0);
if (write_in_full(fd, compressed, stream->next_out - compressed) < 0)
die_errno(_("unable to write loose object file"));
stream->next_out = compressed;
stream->avail_out = compressed_len;
return ret;
}
/**
* Common steps for loose object writers to end writing loose objects:
*
* - End the compression of zlib stream.
* - Get the calculated oid to "oid".
*/
static int end_loose_object_common(struct git_hash_ctx *c, struct git_hash_ctx *compat_c,
git_zstream *stream, struct object_id *oid,
struct object_id *compat_oid)
{
struct repository *repo = the_repository;
const struct git_hash_algo *compat = repo->compat_hash_algo;
int ret;
ret = git_deflate_end_gently(stream);
if (ret != Z_OK)
return ret;
git_hash_final_oid(oid, c);
if (compat && compat_c)
git_hash_final_oid(compat_oid, compat_c);
return Z_OK;
}
static int write_loose_object(const struct object_id *oid, char *hdr,
int hdrlen, const void *buf, unsigned long len,
time_t mtime, unsigned flags)
{
int fd, ret;
unsigned char compressed[4096];
git_zstream stream;
struct git_hash_ctx c;
struct object_id parano_oid;
static struct strbuf tmp_file = STRBUF_INIT;
static struct strbuf filename = STRBUF_INIT;
if (batch_fsync_enabled(FSYNC_COMPONENT_LOOSE_OBJECT))
prepare_loose_object_bulk_checkin();
loose_object_path(the_repository, &filename, oid);
fd = start_loose_object_common(&tmp_file, filename.buf, flags,
&stream, compressed, sizeof(compressed),
&c, NULL, hdr, hdrlen);
if (fd < 0)
return -1;
/* Then the data itself.. */
stream.next_in = (void *)buf;
stream.avail_in = len;
do {
unsigned char *in0 = stream.next_in;
ret = write_loose_object_common(&c, NULL, &stream, 1, in0, fd,
compressed, sizeof(compressed));
} while (ret == Z_OK);
if (ret != Z_STREAM_END)
die(_("unable to deflate new object %s (%d)"), oid_to_hex(oid),
ret);
ret = end_loose_object_common(&c, NULL, &stream, &parano_oid, NULL);
if (ret != Z_OK)
die(_("deflateEnd on object %s failed (%d)"), oid_to_hex(oid),
ret);
if (!oideq(oid, &parano_oid))
die(_("confused by unstable object source data for %s"),
oid_to_hex(oid));
close_loose_object(fd, tmp_file.buf);
if (mtime) {
struct utimbuf utb;
utb.actime = mtime;
utb.modtime = mtime;
if (utime(tmp_file.buf, &utb) < 0 &&
!(flags & WRITE_OBJECT_FILE_SILENT))
warning_errno(_("failed utime() on %s"), tmp_file.buf);
}
return finalize_object_file_flags(tmp_file.buf, filename.buf,
FOF_SKIP_COLLISION_CHECK);
}
static int freshen_loose_object(const struct object_id *oid)
{
return check_and_freshen(oid, 1);
}
static int freshen_packed_object(const struct object_id *oid)
{
struct pack_entry e;
if (!find_pack_entry(the_repository, oid, &e))
return 0;
if (e.p->is_cruft)
return 0;
if (e.p->freshened)
return 1;
if (!freshen_file(e.p->pack_name))
return 0;
e.p->freshened = 1;
return 1;
}
int stream_loose_object(struct input_stream *in_stream, size_t len,
struct object_id *oid)
{
const struct git_hash_algo *compat = the_repository->compat_hash_algo;
struct object_id compat_oid;
int fd, ret, err = 0, flush = 0;
unsigned char compressed[4096];
git_zstream stream;
struct git_hash_ctx c, compat_c;
struct strbuf tmp_file = STRBUF_INIT;
struct strbuf filename = STRBUF_INIT;
int dirlen;
char hdr[MAX_HEADER_LEN];
int hdrlen;
if (batch_fsync_enabled(FSYNC_COMPONENT_LOOSE_OBJECT))
prepare_loose_object_bulk_checkin();
/* Since oid is not determined, save tmp file to odb path. */
strbuf_addf(&filename, "%s/", repo_get_object_directory(the_repository));
hdrlen = format_object_header(hdr, sizeof(hdr), OBJ_BLOB, len);
/*
* Common steps for write_loose_object and stream_loose_object to
* start writing loose objects:
*
* - Create tmpfile for the loose object.
* - Setup zlib stream for compression.
* - Start to feed header to zlib stream.
*/
fd = start_loose_object_common(&tmp_file, filename.buf, 0,
&stream, compressed, sizeof(compressed),
&c, &compat_c, hdr, hdrlen);
if (fd < 0) {
err = -1;
goto cleanup;
}
/* Then the data itself.. */
do {
unsigned char *in0 = stream.next_in;
if (!stream.avail_in && !in_stream->is_finished) {
const void *in = in_stream->read(in_stream, &stream.avail_in);
stream.next_in = (void *)in;
in0 = (unsigned char *)in;
/* All data has been read. */
if (in_stream->is_finished)
flush = 1;
}
ret = write_loose_object_common(&c, &compat_c, &stream, flush, in0, fd,
compressed, sizeof(compressed));
/*
* Unlike write_loose_object(), we do not have the entire
* buffer. If we get Z_BUF_ERROR due to too few input bytes,
* then we'll replenish them in the next input_stream->read()
* call when we loop.
*/
} while (ret == Z_OK || ret == Z_BUF_ERROR);
if (stream.total_in != len + hdrlen)
die(_("write stream object %ld != %"PRIuMAX), stream.total_in,
(uintmax_t)len + hdrlen);
/*
* Common steps for write_loose_object and stream_loose_object to
* end writing loose object:
*
* - End the compression of zlib stream.
* - Get the calculated oid.
*/
if (ret != Z_STREAM_END)
die(_("unable to stream deflate new object (%d)"), ret);
ret = end_loose_object_common(&c, &compat_c, &stream, oid, &compat_oid);
if (ret != Z_OK)
die(_("deflateEnd on stream object failed (%d)"), ret);
close_loose_object(fd, tmp_file.buf);
if (freshen_packed_object(oid) || freshen_loose_object(oid)) {
unlink_or_warn(tmp_file.buf);
goto cleanup;
}
loose_object_path(the_repository, &filename, oid);
/* We finally know the object path, and create the missing dir. */
dirlen = directory_size(filename.buf);
if (dirlen) {
struct strbuf dir = STRBUF_INIT;
strbuf_add(&dir, filename.buf, dirlen);
if (safe_create_dir_in_gitdir(the_repository, dir.buf) &&
errno != EEXIST) {
err = error_errno(_("unable to create directory %s"), dir.buf);
strbuf_release(&dir);
goto cleanup;
}
strbuf_release(&dir);
}
err = finalize_object_file_flags(tmp_file.buf, filename.buf,
FOF_SKIP_COLLISION_CHECK);
if (!err && compat)
err = repo_add_loose_object_map(the_repository, oid, &compat_oid);
cleanup:
strbuf_release(&tmp_file);
strbuf_release(&filename);
return err;
}
int write_object_file_flags(const void *buf, unsigned long len,
enum object_type type, struct object_id *oid,
struct object_id *compat_oid_in, unsigned flags)
{
struct repository *repo = the_repository;
const struct git_hash_algo *algo = repo->hash_algo;
const struct git_hash_algo *compat = repo->compat_hash_algo;
struct object_id compat_oid;
char hdr[MAX_HEADER_LEN];
int hdrlen = sizeof(hdr);
/* Generate compat_oid */
if (compat) {
if (compat_oid_in)
oidcpy(&compat_oid, compat_oid_in);
else if (type == OBJ_BLOB)
hash_object_file(compat, buf, len, type, &compat_oid);
else {
struct strbuf converted = STRBUF_INIT;
convert_object_file(the_repository, &converted, algo, compat,
buf, len, type, 0);
hash_object_file(compat, converted.buf, converted.len,
type, &compat_oid);
strbuf_release(&converted);
}
}
/* Normally if we have it in the pack then we do not bother writing
* it out into .git/objects/??/?{38} file.
*/
write_object_file_prepare(algo, buf, len, type, oid, hdr, &hdrlen);
if (freshen_packed_object(oid) || freshen_loose_object(oid))
return 0;
if (write_loose_object(oid, hdr, hdrlen, buf, len, 0, flags))
return -1;
if (compat)
return repo_add_loose_object_map(repo, oid, &compat_oid);
return 0;
}
int write_object_file_literally(const void *buf, unsigned long len,
const char *type, struct object_id *oid,
unsigned flags)
{
char *header;
struct repository *repo = the_repository;
const struct git_hash_algo *algo = repo->hash_algo;
const struct git_hash_algo *compat = repo->compat_hash_algo;
struct object_id compat_oid;
int hdrlen, status = 0;
int compat_type = -1;
if (compat) {
compat_type = type_from_string_gently(type, -1, 1);
if (compat_type == OBJ_BLOB)
hash_object_file(compat, buf, len, compat_type,
&compat_oid);
else if (compat_type != -1) {
struct strbuf converted = STRBUF_INIT;
convert_object_file(the_repository,
&converted, algo, compat,
buf, len, compat_type, 0);
hash_object_file(compat, converted.buf, converted.len,
compat_type, &compat_oid);
strbuf_release(&converted);
}
}
/* type string, SP, %lu of the length plus NUL must fit this */
hdrlen = strlen(type) + MAX_HEADER_LEN;
header = xmalloc(hdrlen);
write_object_file_prepare_literally(the_hash_algo, buf, len, type,
oid, header, &hdrlen);
if (!(flags & WRITE_OBJECT_FILE_PERSIST))
goto cleanup;
if (freshen_packed_object(oid) || freshen_loose_object(oid))
goto cleanup;
status = write_loose_object(oid, header, hdrlen, buf, len, 0, 0);
if (compat_type != -1)
return repo_add_loose_object_map(repo, oid, &compat_oid);
cleanup:
free(header);
return status;
}
int force_object_loose(const struct object_id *oid, time_t mtime)
{
struct repository *repo = the_repository;
const struct git_hash_algo *compat = repo->compat_hash_algo;
void *buf;
unsigned long len;
struct object_info oi = OBJECT_INFO_INIT;
struct object_id compat_oid;
enum object_type type;
char hdr[MAX_HEADER_LEN];
int hdrlen;
int ret;
if (has_loose_object(oid))
return 0;
oi.typep = &type;
oi.sizep = &len;
oi.contentp = &buf;
if (oid_object_info_extended(the_repository, oid, &oi, 0))
return error(_("cannot read object for %s"), oid_to_hex(oid));
if (compat) {
if (repo_oid_to_algop(repo, oid, compat, &compat_oid))
return error(_("cannot map object %s to %s"),
oid_to_hex(oid), compat->name);
}
hdrlen = format_object_header(hdr, sizeof(hdr), type, len);
ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime, 0);
if (!ret && compat)
ret = repo_add_loose_object_map(the_repository, oid, &compat_oid);
free(buf);
return ret;
}
/*
* We can't use the normal fsck_error_function() for index_mem(),
* because we don't yet have a valid oid for it to report. Instead,
* report the minimal fsck error here, and rely on the caller to
* give more context.
*/
static int hash_format_check_report(struct fsck_options *opts UNUSED,
void *fsck_report UNUSED,
enum fsck_msg_type msg_type UNUSED,
enum fsck_msg_id msg_id UNUSED,
const char *message)
{
error(_("object fails fsck: %s"), message);
return 1;
}
static int index_mem(struct index_state *istate,
struct object_id *oid,
const void *buf, size_t size,
enum object_type type,
const char *path, unsigned flags)
{
struct strbuf nbuf = STRBUF_INIT;
int ret = 0;
int write_object = flags & INDEX_WRITE_OBJECT;
if (!type)
type = OBJ_BLOB;
/*
* Convert blobs to git internal format
*/
if ((type == OBJ_BLOB) && path) {
if (convert_to_git(istate, path, buf, size, &nbuf,
get_conv_flags(flags))) {
buf = nbuf.buf;
size = nbuf.len;
}
}
if (flags & INDEX_FORMAT_CHECK) {
struct fsck_options opts = FSCK_OPTIONS_DEFAULT;
opts.strict = 1;
opts.error_func = hash_format_check_report;
if (fsck_buffer(null_oid(the_hash_algo), type, buf, size, &opts))
die(_("refusing to create malformed object"));
fsck_finish(&opts);
}
if (write_object)
ret = write_object_file(buf, size, type, oid);
else
hash_object_file(the_hash_algo, buf, size, type, oid);
strbuf_release(&nbuf);
return ret;
}
static int index_stream_convert_blob(struct index_state *istate,
struct object_id *oid,
int fd,
const char *path,
unsigned flags)
{
int ret = 0;
const int write_object = flags & INDEX_WRITE_OBJECT;
struct strbuf sbuf = STRBUF_INIT;
assert(path);
ASSERT(would_convert_to_git_filter_fd(istate, path));
convert_to_git_filter_fd(istate, path, fd, &sbuf,
get_conv_flags(flags));
if (write_object)
ret = write_object_file(sbuf.buf, sbuf.len, OBJ_BLOB,
oid);
else
hash_object_file(the_hash_algo, sbuf.buf, sbuf.len, OBJ_BLOB,
oid);
strbuf_release(&sbuf);
return ret;
}
static int index_pipe(struct index_state *istate, struct object_id *oid,
int fd, enum object_type type,
const char *path, unsigned flags)
{
struct strbuf sbuf = STRBUF_INIT;
int ret;
if (strbuf_read(&sbuf, fd, 4096) >= 0)
ret = index_mem(istate, oid, sbuf.buf, sbuf.len, type, path, flags);
else
ret = -1;
strbuf_release(&sbuf);
return ret;
}
#define SMALL_FILE_SIZE (32*1024)
static int index_core(struct index_state *istate,
struct object_id *oid, int fd, size_t size,
enum object_type type, const char *path,
unsigned flags)
{
int ret;
if (!size) {
ret = index_mem(istate, oid, "", size, type, path, flags);
} else if (size <= SMALL_FILE_SIZE) {
char *buf = xmalloc(size);
ssize_t read_result = read_in_full(fd, buf, size);
if (read_result < 0)
ret = error_errno(_("read error while indexing %s"),
path ? path : "<unknown>");
else if (read_result != size)
ret = error(_("short read while indexing %s"),
path ? path : "<unknown>");
else
ret = index_mem(istate, oid, buf, size, type, path, flags);
free(buf);
} else {
void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
ret = index_mem(istate, oid, buf, size, type, path, flags);
munmap(buf, size);
}
return ret;
}
int index_fd(struct index_state *istate, struct object_id *oid,
int fd, struct stat *st,
enum object_type type, const char *path, unsigned flags)
{
int ret;
/*
* Call xsize_t() only when needed to avoid potentially unnecessary
* die() for large files.
*/
if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(istate, path))
ret = index_stream_convert_blob(istate, oid, fd, path, flags);
else if (!S_ISREG(st->st_mode))
ret = index_pipe(istate, oid, fd, type, path, flags);
else if (st->st_size <= repo_settings_get_big_file_threshold(the_repository) ||
type != OBJ_BLOB ||
(path && would_convert_to_git(istate, path)))
ret = index_core(istate, oid, fd, xsize_t(st->st_size),
type, path, flags);
else
ret = index_blob_bulk_checkin(oid, fd, xsize_t(st->st_size), path,
flags);
close(fd);
return ret;
}
int index_path(struct index_state *istate, struct object_id *oid,
const char *path, struct stat *st, unsigned flags)
{
int fd;
struct strbuf sb = STRBUF_INIT;
int rc = 0;
switch (st->st_mode & S_IFMT) {
case S_IFREG:
fd = open(path, O_RDONLY);
if (fd < 0)
return error_errno("open(\"%s\")", path);
if (index_fd(istate, oid, fd, st, OBJ_BLOB, path, flags) < 0)
return error(_("%s: failed to insert into database"),
path);
break;
case S_IFLNK:
if (strbuf_readlink(&sb, path, st->st_size))
return error_errno("readlink(\"%s\")", path);
if (!(flags & INDEX_WRITE_OBJECT))
hash_object_file(the_hash_algo, sb.buf, sb.len,
OBJ_BLOB, oid);
else if (write_object_file(sb.buf, sb.len, OBJ_BLOB, oid))
rc = error(_("%s: failed to insert into database"), path);
strbuf_release(&sb);
break;
case S_IFDIR:
return repo_resolve_gitlink_ref(the_repository, path, "HEAD", oid);
default:
return error(_("%s: unsupported file type"), path);
}
return rc;
}
int read_pack_header(int fd, struct pack_header *header)
{
if (read_in_full(fd, header, sizeof(*header)) != sizeof(*header))
/* "eof before pack header was fully read" */
return PH_ERROR_EOF;
if (header->hdr_signature != htonl(PACK_SIGNATURE))
/* "protocol error (pack signature mismatch detected)" */
return PH_ERROR_PACK_SIGNATURE;
if (!pack_version_ok(header->hdr_version))
/* "protocol error (pack version unsupported)" */
return PH_ERROR_PROTOCOL;
return 0;
}
int for_each_file_in_obj_subdir(unsigned int subdir_nr,
struct strbuf *path,
each_loose_object_fn obj_cb,
each_loose_cruft_fn cruft_cb,
each_loose_subdir_fn subdir_cb,
void *data)
{
size_t origlen, baselen;
DIR *dir;
struct dirent *de;
int r = 0;
struct object_id oid;
if (subdir_nr > 0xff)
BUG("invalid loose object subdirectory: %x", subdir_nr);
origlen = path->len;
strbuf_complete(path, '/');
strbuf_addf(path, "%02x", subdir_nr);
dir = opendir(path->buf);
if (!dir) {
if (errno != ENOENT)
r = error_errno(_("unable to open %s"), path->buf);
strbuf_setlen(path, origlen);
return r;
}
oid.hash[0] = subdir_nr;
strbuf_addch(path, '/');
baselen = path->len;
while ((de = readdir_skip_dot_and_dotdot(dir))) {
size_t namelen;
namelen = strlen(de->d_name);
strbuf_setlen(path, baselen);
strbuf_add(path, de->d_name, namelen);
if (namelen == the_hash_algo->hexsz - 2 &&
!hex_to_bytes(oid.hash + 1, de->d_name,
the_hash_algo->rawsz - 1)) {
oid_set_algo(&oid, the_hash_algo);
memset(oid.hash + the_hash_algo->rawsz, 0,
GIT_MAX_RAWSZ - the_hash_algo->rawsz);
if (obj_cb) {
r = obj_cb(&oid, path->buf, data);
if (r)
break;
}
continue;
}
if (cruft_cb) {
r = cruft_cb(de->d_name, path->buf, data);
if (r)
break;
}
}
closedir(dir);
strbuf_setlen(path, baselen - 1);
if (!r && subdir_cb)
r = subdir_cb(subdir_nr, path->buf, data);
strbuf_setlen(path, origlen);
return r;
}
int for_each_loose_file_in_objdir_buf(struct strbuf *path,
each_loose_object_fn obj_cb,
each_loose_cruft_fn cruft_cb,
each_loose_subdir_fn subdir_cb,
void *data)
{
int r = 0;
int i;
for (i = 0; i < 256; i++) {
r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
subdir_cb, data);
if (r)
break;
}
return r;
}
int for_each_loose_file_in_objdir(const char *path,
each_loose_object_fn obj_cb,
each_loose_cruft_fn cruft_cb,
each_loose_subdir_fn subdir_cb,
void *data)
{
struct strbuf buf = STRBUF_INIT;
int r;
strbuf_addstr(&buf, path);
r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
subdir_cb, data);
strbuf_release(&buf);
return r;
}
int for_each_loose_object(each_loose_object_fn cb, void *data,
enum for_each_object_flags flags)
{
struct object_directory *odb;
prepare_alt_odb(the_repository);
for (odb = the_repository->objects->odb; odb; odb = odb->next) {
int r = for_each_loose_file_in_objdir(odb->path, cb, NULL,
NULL, data);
if (r)
return r;
if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
break;
}
return 0;
}
static int append_loose_object(const struct object_id *oid,
const char *path UNUSED,
void *data)
{
oidtree_insert(data, oid);
return 0;
}
struct oidtree *odb_loose_cache(struct object_directory *odb,
const struct object_id *oid)
{
int subdir_nr = oid->hash[0];
struct strbuf buf = STRBUF_INIT;
size_t word_bits = bitsizeof(odb->loose_objects_subdir_seen[0]);
size_t word_index = subdir_nr / word_bits;
size_t mask = (size_t)1u << (subdir_nr % word_bits);
uint32_t *bitmap;
if (subdir_nr < 0 ||
subdir_nr >= bitsizeof(odb->loose_objects_subdir_seen))
BUG("subdir_nr out of range");
bitmap = &odb->loose_objects_subdir_seen[word_index];
if (*bitmap & mask)
return odb->loose_objects_cache;
if (!odb->loose_objects_cache) {
ALLOC_ARRAY(odb->loose_objects_cache, 1);
oidtree_init(odb->loose_objects_cache);
}
strbuf_addstr(&buf, odb->path);
for_each_file_in_obj_subdir(subdir_nr, &buf,
append_loose_object,
NULL, NULL,
odb->loose_objects_cache);
*bitmap |= mask;
strbuf_release(&buf);
return odb->loose_objects_cache;
}
void odb_clear_loose_cache(struct object_directory *odb)
{
oidtree_clear(odb->loose_objects_cache);
FREE_AND_NULL(odb->loose_objects_cache);
memset(&odb->loose_objects_subdir_seen, 0,
sizeof(odb->loose_objects_subdir_seen));
}
static int check_stream_oid(git_zstream *stream,
const char *hdr,
unsigned long size,
const char *path,
const struct object_id *expected_oid)
{
struct git_hash_ctx c;
struct object_id real_oid;
unsigned char buf[4096];
unsigned long total_read;
int status = Z_OK;
the_hash_algo->init_fn(&c);
git_hash_update(&c, hdr, stream->total_out);
/*
* We already read some bytes into hdr, but the ones up to the NUL
* do not count against the object's content size.
*/
total_read = stream->total_out - strlen(hdr) - 1;
/*
* This size comparison must be "<=" to read the final zlib packets;
* see the comment in unpack_loose_rest for details.
*/
while (total_read <= size &&
(status == Z_OK ||
(status == Z_BUF_ERROR && !stream->avail_out))) {
stream->next_out = buf;
stream->avail_out = sizeof(buf);
if (size - total_read < stream->avail_out)
stream->avail_out = size - total_read;
status = git_inflate(stream, Z_FINISH);
git_hash_update(&c, buf, stream->next_out - buf);
total_read += stream->next_out - buf;
}
if (status != Z_STREAM_END) {
error(_("corrupt loose object '%s'"), oid_to_hex(expected_oid));
return -1;
}
if (stream->avail_in) {
error(_("garbage at end of loose object '%s'"),
oid_to_hex(expected_oid));
return -1;
}
git_hash_final_oid(&real_oid, &c);
if (!oideq(expected_oid, &real_oid)) {
error(_("hash mismatch for %s (expected %s)"), path,
oid_to_hex(expected_oid));
return -1;
}
return 0;
}
int read_loose_object(const char *path,
const struct object_id *expected_oid,
struct object_id *real_oid,
void **contents,
struct object_info *oi)
{
int ret = -1;
int fd;
void *map = NULL;
unsigned long mapsize;
git_zstream stream;
char hdr[MAX_HEADER_LEN];
unsigned long *size = oi->sizep;
fd = git_open(path);
if (fd >= 0)
map = map_fd(fd, path, &mapsize);
if (!map) {
error_errno(_("unable to mmap %s"), path);
goto out;
}
if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr),
NULL) != ULHR_OK) {
error(_("unable to unpack header of %s"), path);
goto out_inflate;
}
if (parse_loose_header(hdr, oi) < 0) {
error(_("unable to parse header of %s"), path);
goto out_inflate;
}
if (*oi->typep == OBJ_BLOB &&
*size > repo_settings_get_big_file_threshold(the_repository)) {
if (check_stream_oid(&stream, hdr, *size, path, expected_oid) < 0)
goto out_inflate;
} else {
*contents = unpack_loose_rest(&stream, hdr, *size, expected_oid);
if (!*contents) {
error(_("unable to unpack contents of %s"), path);
goto out_inflate;
}
hash_object_file_literally(the_repository->hash_algo,
*contents, *size,
oi->type_name->buf, real_oid);
if (!oideq(expected_oid, real_oid))
goto out_inflate;
}
ret = 0; /* everything checks out */
out_inflate:
git_inflate_end(&stream);
out:
if (map)
munmap(map, mapsize);
return ret;
}
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