git-commit-vandalism/builtin/index-pack.c
Nguyễn Thái Ngọc Duy c6807a40dc clone: open a shortcut for connectivity check
In order to make sure the cloned repository is good, we run "rev-list
--objects --not --all $new_refs" on the repository. This is expensive
on large repositories. This patch attempts to mitigate the impact in
this special case.

In the "good" clone case, we only have one pack. If all of the
following are met, we can be sure that all objects reachable from the
new refs exist, which is the intention of running "rev-list ...":

 - all refs point to an object in the pack
 - there are no dangling pointers in any object in the pack
 - no objects in the pack point to objects outside the pack

The second and third checks can be done with the help of index-pack as
a slight variation of --strict check (which introduces a new condition
for the shortcut: pack transfer must be used and the number of objects
large enough to call index-pack). The first is checked in
check_everything_connected after we get an "ok" from index-pack.

"index-pack + new checks" is still faster than the current "index-pack
+ rev-list", which is the whole point of this patch. If any of the
conditions fail, we fall back to the good old but expensive "rev-list
..". In that case it's even more expensive because we have to pay for
the new checks in index-pack. But that should only happen when the
other side is either buggy or malicious.

Cloning linux-2.6 over file://

        before         after
real    3m25.693s      2m53.050s
user    5m2.037s       4m42.396s
sys     0m13.750s      0m16.574s

A more realistic test with ssh:// over wireless

        before         after
real    11m26.629s     10m4.213s
user    5m43.196s      5m19.444s
sys     0m35.812s      0m37.630s

This shortcut is not applied to shallow clones, partly because shallow
clones should have no more objects than a usual fetch and the cost of
rev-list is acceptable, partly to avoid dealing with corner cases when
grafting is involved.

This shortcut does not apply to unpack-objects code path either
because the number of objects must be small in order to trigger that
code path.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-28 08:07:20 -07:00

1672 lines
43 KiB
C

#include "builtin.h"
#include "delta.h"
#include "pack.h"
#include "csum-file.h"
#include "blob.h"
#include "commit.h"
#include "tag.h"
#include "tree.h"
#include "progress.h"
#include "fsck.h"
#include "exec_cmd.h"
#include "streaming.h"
#include "thread-utils.h"
static const char index_pack_usage[] =
"git index-pack [-v] [-o <index-file>] [--keep | --keep=<msg>] [--verify] [--strict] (<pack-file> | --stdin [--fix-thin] [<pack-file>])";
struct object_entry {
struct pack_idx_entry idx;
unsigned long size;
unsigned int hdr_size;
enum object_type type;
enum object_type real_type;
unsigned delta_depth;
int base_object_no;
};
union delta_base {
unsigned char sha1[20];
off_t offset;
};
struct base_data {
struct base_data *base;
struct base_data *child;
struct object_entry *obj;
void *data;
unsigned long size;
int ref_first, ref_last;
int ofs_first, ofs_last;
};
#if !defined(NO_PTHREADS) && defined(NO_THREAD_SAFE_PREAD)
/* pread() emulation is not thread-safe. Disable threading. */
#define NO_PTHREADS
#endif
struct thread_local {
#ifndef NO_PTHREADS
pthread_t thread;
#endif
struct base_data *base_cache;
size_t base_cache_used;
};
/*
* Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
* to memcmp() only the first 20 bytes.
*/
#define UNION_BASE_SZ 20
#define FLAG_LINK (1u<<20)
#define FLAG_CHECKED (1u<<21)
struct delta_entry {
union delta_base base;
int obj_no;
};
static struct object_entry *objects;
static struct delta_entry *deltas;
static struct thread_local nothread_data;
static int nr_objects;
static int nr_deltas;
static int nr_resolved_deltas;
static int nr_threads;
static int from_stdin;
static int strict;
static int do_fsck_object;
static int verbose;
static int show_stat;
static int check_self_contained_and_connected;
static struct progress *progress;
/* We always read in 4kB chunks. */
static unsigned char input_buffer[4096];
static unsigned int input_offset, input_len;
static off_t consumed_bytes;
static unsigned deepest_delta;
static git_SHA_CTX input_ctx;
static uint32_t input_crc32;
static int input_fd, output_fd, pack_fd;
#ifndef NO_PTHREADS
static struct thread_local *thread_data;
static int nr_dispatched;
static int threads_active;
static pthread_mutex_t read_mutex;
#define read_lock() lock_mutex(&read_mutex)
#define read_unlock() unlock_mutex(&read_mutex)
static pthread_mutex_t counter_mutex;
#define counter_lock() lock_mutex(&counter_mutex)
#define counter_unlock() unlock_mutex(&counter_mutex)
static pthread_mutex_t work_mutex;
#define work_lock() lock_mutex(&work_mutex)
#define work_unlock() unlock_mutex(&work_mutex)
static pthread_mutex_t deepest_delta_mutex;
#define deepest_delta_lock() lock_mutex(&deepest_delta_mutex)
#define deepest_delta_unlock() unlock_mutex(&deepest_delta_mutex)
static pthread_key_t key;
static inline void lock_mutex(pthread_mutex_t *mutex)
{
if (threads_active)
pthread_mutex_lock(mutex);
}
static inline void unlock_mutex(pthread_mutex_t *mutex)
{
if (threads_active)
pthread_mutex_unlock(mutex);
}
/*
* Mutex and conditional variable can't be statically-initialized on Windows.
*/
static void init_thread(void)
{
init_recursive_mutex(&read_mutex);
pthread_mutex_init(&counter_mutex, NULL);
pthread_mutex_init(&work_mutex, NULL);
if (show_stat)
pthread_mutex_init(&deepest_delta_mutex, NULL);
pthread_key_create(&key, NULL);
thread_data = xcalloc(nr_threads, sizeof(*thread_data));
threads_active = 1;
}
static void cleanup_thread(void)
{
if (!threads_active)
return;
threads_active = 0;
pthread_mutex_destroy(&read_mutex);
pthread_mutex_destroy(&counter_mutex);
pthread_mutex_destroy(&work_mutex);
if (show_stat)
pthread_mutex_destroy(&deepest_delta_mutex);
pthread_key_delete(key);
free(thread_data);
}
#else
#define read_lock()
#define read_unlock()
#define counter_lock()
#define counter_unlock()
#define work_lock()
#define work_unlock()
#define deepest_delta_lock()
#define deepest_delta_unlock()
#endif
static int mark_link(struct object *obj, int type, void *data)
{
if (!obj)
return -1;
if (type != OBJ_ANY && obj->type != type)
die(_("object type mismatch at %s"), sha1_to_hex(obj->sha1));
obj->flags |= FLAG_LINK;
return 0;
}
/* The content of each linked object must have been checked
or it must be already present in the object database */
static unsigned check_object(struct object *obj)
{
if (!obj)
return 0;
if (!(obj->flags & FLAG_LINK))
return 0;
if (!(obj->flags & FLAG_CHECKED)) {
unsigned long size;
int type = sha1_object_info(obj->sha1, &size);
if (type != obj->type || type <= 0)
die(_("object of unexpected type"));
obj->flags |= FLAG_CHECKED;
return 1;
}
return 0;
}
static unsigned check_objects(void)
{
unsigned i, max, foreign_nr = 0;
max = get_max_object_index();
for (i = 0; i < max; i++)
foreign_nr += check_object(get_indexed_object(i));
return foreign_nr;
}
/* Discard current buffer used content. */
static void flush(void)
{
if (input_offset) {
if (output_fd >= 0)
write_or_die(output_fd, input_buffer, input_offset);
git_SHA1_Update(&input_ctx, input_buffer, input_offset);
memmove(input_buffer, input_buffer + input_offset, input_len);
input_offset = 0;
}
}
/*
* Make sure at least "min" bytes are available in the buffer, and
* return the pointer to the buffer.
*/
static void *fill(int min)
{
if (min <= input_len)
return input_buffer + input_offset;
if (min > sizeof(input_buffer))
die(Q_("cannot fill %d byte",
"cannot fill %d bytes",
min),
min);
flush();
do {
ssize_t ret = xread(input_fd, input_buffer + input_len,
sizeof(input_buffer) - input_len);
if (ret <= 0) {
if (!ret)
die(_("early EOF"));
die_errno(_("read error on input"));
}
input_len += ret;
if (from_stdin)
display_throughput(progress, consumed_bytes + input_len);
} while (input_len < min);
return input_buffer;
}
static void use(int bytes)
{
if (bytes > input_len)
die(_("used more bytes than were available"));
input_crc32 = crc32(input_crc32, input_buffer + input_offset, bytes);
input_len -= bytes;
input_offset += bytes;
/* make sure off_t is sufficiently large not to wrap */
if (signed_add_overflows(consumed_bytes, bytes))
die(_("pack too large for current definition of off_t"));
consumed_bytes += bytes;
}
static const char *open_pack_file(const char *pack_name)
{
if (from_stdin) {
input_fd = 0;
if (!pack_name) {
static char tmp_file[PATH_MAX];
output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
"pack/tmp_pack_XXXXXX");
pack_name = xstrdup(tmp_file);
} else
output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
if (output_fd < 0)
die_errno(_("unable to create '%s'"), pack_name);
pack_fd = output_fd;
} else {
input_fd = open(pack_name, O_RDONLY);
if (input_fd < 0)
die_errno(_("cannot open packfile '%s'"), pack_name);
output_fd = -1;
pack_fd = input_fd;
}
git_SHA1_Init(&input_ctx);
return pack_name;
}
static void parse_pack_header(void)
{
struct pack_header *hdr = fill(sizeof(struct pack_header));
/* Header consistency check */
if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
die(_("pack signature mismatch"));
if (!pack_version_ok(hdr->hdr_version))
die(_("pack version %"PRIu32" unsupported"),
ntohl(hdr->hdr_version));
nr_objects = ntohl(hdr->hdr_entries);
use(sizeof(struct pack_header));
}
static NORETURN void bad_object(unsigned long offset, const char *format,
...) __attribute__((format (printf, 2, 3)));
static NORETURN void bad_object(unsigned long offset, const char *format, ...)
{
va_list params;
char buf[1024];
va_start(params, format);
vsnprintf(buf, sizeof(buf), format, params);
va_end(params);
die(_("pack has bad object at offset %lu: %s"), offset, buf);
}
static inline struct thread_local *get_thread_data(void)
{
#ifndef NO_PTHREADS
if (threads_active)
return pthread_getspecific(key);
assert(!threads_active &&
"This should only be reached when all threads are gone");
#endif
return &nothread_data;
}
#ifndef NO_PTHREADS
static void set_thread_data(struct thread_local *data)
{
if (threads_active)
pthread_setspecific(key, data);
}
#endif
static struct base_data *alloc_base_data(void)
{
struct base_data *base = xmalloc(sizeof(struct base_data));
memset(base, 0, sizeof(*base));
base->ref_last = -1;
base->ofs_last = -1;
return base;
}
static void free_base_data(struct base_data *c)
{
if (c->data) {
free(c->data);
c->data = NULL;
get_thread_data()->base_cache_used -= c->size;
}
}
static void prune_base_data(struct base_data *retain)
{
struct base_data *b;
struct thread_local *data = get_thread_data();
for (b = data->base_cache;
data->base_cache_used > delta_base_cache_limit && b;
b = b->child) {
if (b->data && b != retain)
free_base_data(b);
}
}
static void link_base_data(struct base_data *base, struct base_data *c)
{
if (base)
base->child = c;
else
get_thread_data()->base_cache = c;
c->base = base;
c->child = NULL;
if (c->data)
get_thread_data()->base_cache_used += c->size;
prune_base_data(c);
}
static void unlink_base_data(struct base_data *c)
{
struct base_data *base = c->base;
if (base)
base->child = NULL;
else
get_thread_data()->base_cache = NULL;
free_base_data(c);
}
static int is_delta_type(enum object_type type)
{
return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA);
}
static void *unpack_entry_data(unsigned long offset, unsigned long size,
enum object_type type, unsigned char *sha1)
{
static char fixed_buf[8192];
int status;
git_zstream stream;
void *buf;
git_SHA_CTX c;
char hdr[32];
int hdrlen;
if (!is_delta_type(type)) {
hdrlen = sprintf(hdr, "%s %lu", typename(type), size) + 1;
git_SHA1_Init(&c);
git_SHA1_Update(&c, hdr, hdrlen);
} else
sha1 = NULL;
if (type == OBJ_BLOB && size > big_file_threshold)
buf = fixed_buf;
else
buf = xmalloc(size);
memset(&stream, 0, sizeof(stream));
git_inflate_init(&stream);
stream.next_out = buf;
stream.avail_out = buf == fixed_buf ? sizeof(fixed_buf) : size;
do {
unsigned char *last_out = stream.next_out;
stream.next_in = fill(1);
stream.avail_in = input_len;
status = git_inflate(&stream, 0);
use(input_len - stream.avail_in);
if (sha1)
git_SHA1_Update(&c, last_out, stream.next_out - last_out);
if (buf == fixed_buf) {
stream.next_out = buf;
stream.avail_out = sizeof(fixed_buf);
}
} while (status == Z_OK);
if (stream.total_out != size || status != Z_STREAM_END)
bad_object(offset, _("inflate returned %d"), status);
git_inflate_end(&stream);
if (sha1)
git_SHA1_Final(sha1, &c);
return buf == fixed_buf ? NULL : buf;
}
static void *unpack_raw_entry(struct object_entry *obj,
union delta_base *delta_base,
unsigned char *sha1)
{
unsigned char *p;
unsigned long size, c;
off_t base_offset;
unsigned shift;
void *data;
obj->idx.offset = consumed_bytes;
input_crc32 = crc32(0, NULL, 0);
p = fill(1);
c = *p;
use(1);
obj->type = (c >> 4) & 7;
size = (c & 15);
shift = 4;
while (c & 0x80) {
p = fill(1);
c = *p;
use(1);
size += (c & 0x7f) << shift;
shift += 7;
}
obj->size = size;
switch (obj->type) {
case OBJ_REF_DELTA:
hashcpy(delta_base->sha1, fill(20));
use(20);
break;
case OBJ_OFS_DELTA:
memset(delta_base, 0, sizeof(*delta_base));
p = fill(1);
c = *p;
use(1);
base_offset = c & 127;
while (c & 128) {
base_offset += 1;
if (!base_offset || MSB(base_offset, 7))
bad_object(obj->idx.offset, _("offset value overflow for delta base object"));
p = fill(1);
c = *p;
use(1);
base_offset = (base_offset << 7) + (c & 127);
}
delta_base->offset = obj->idx.offset - base_offset;
if (delta_base->offset <= 0 || delta_base->offset >= obj->idx.offset)
bad_object(obj->idx.offset, _("delta base offset is out of bound"));
break;
case OBJ_COMMIT:
case OBJ_TREE:
case OBJ_BLOB:
case OBJ_TAG:
break;
default:
bad_object(obj->idx.offset, _("unknown object type %d"), obj->type);
}
obj->hdr_size = consumed_bytes - obj->idx.offset;
data = unpack_entry_data(obj->idx.offset, obj->size, obj->type, sha1);
obj->idx.crc32 = input_crc32;
return data;
}
static void *unpack_data(struct object_entry *obj,
int (*consume)(const unsigned char *, unsigned long, void *),
void *cb_data)
{
off_t from = obj[0].idx.offset + obj[0].hdr_size;
unsigned long len = obj[1].idx.offset - from;
unsigned char *data, *inbuf;
git_zstream stream;
int status;
data = xmalloc(consume ? 64*1024 : obj->size);
inbuf = xmalloc((len < 64*1024) ? len : 64*1024);
memset(&stream, 0, sizeof(stream));
git_inflate_init(&stream);
stream.next_out = data;
stream.avail_out = consume ? 64*1024 : obj->size;
do {
ssize_t n = (len < 64*1024) ? len : 64*1024;
n = pread(pack_fd, inbuf, n, from);
if (n < 0)
die_errno(_("cannot pread pack file"));
if (!n)
die(Q_("premature end of pack file, %lu byte missing",
"premature end of pack file, %lu bytes missing",
len),
len);
from += n;
len -= n;
stream.next_in = inbuf;
stream.avail_in = n;
if (!consume)
status = git_inflate(&stream, 0);
else {
do {
status = git_inflate(&stream, 0);
if (consume(data, stream.next_out - data, cb_data)) {
free(inbuf);
free(data);
return NULL;
}
stream.next_out = data;
stream.avail_out = 64*1024;
} while (status == Z_OK && stream.avail_in);
}
} while (len && status == Z_OK && !stream.avail_in);
/* This has been inflated OK when first encountered, so... */
if (status != Z_STREAM_END || stream.total_out != obj->size)
die(_("serious inflate inconsistency"));
git_inflate_end(&stream);
free(inbuf);
if (consume) {
free(data);
data = NULL;
}
return data;
}
static void *get_data_from_pack(struct object_entry *obj)
{
return unpack_data(obj, NULL, NULL);
}
static int compare_delta_bases(const union delta_base *base1,
const union delta_base *base2,
enum object_type type1,
enum object_type type2)
{
int cmp = type1 - type2;
if (cmp)
return cmp;
return memcmp(base1, base2, UNION_BASE_SZ);
}
static int find_delta(const union delta_base *base, enum object_type type)
{
int first = 0, last = nr_deltas;
while (first < last) {
int next = (first + last) / 2;
struct delta_entry *delta = &deltas[next];
int cmp;
cmp = compare_delta_bases(base, &delta->base,
type, objects[delta->obj_no].type);
if (!cmp)
return next;
if (cmp < 0) {
last = next;
continue;
}
first = next+1;
}
return -first-1;
}
static void find_delta_children(const union delta_base *base,
int *first_index, int *last_index,
enum object_type type)
{
int first = find_delta(base, type);
int last = first;
int end = nr_deltas - 1;
if (first < 0) {
*first_index = 0;
*last_index = -1;
return;
}
while (first > 0 && !memcmp(&deltas[first - 1].base, base, UNION_BASE_SZ))
--first;
while (last < end && !memcmp(&deltas[last + 1].base, base, UNION_BASE_SZ))
++last;
*first_index = first;
*last_index = last;
}
struct compare_data {
struct object_entry *entry;
struct git_istream *st;
unsigned char *buf;
unsigned long buf_size;
};
static int compare_objects(const unsigned char *buf, unsigned long size,
void *cb_data)
{
struct compare_data *data = cb_data;
if (data->buf_size < size) {
free(data->buf);
data->buf = xmalloc(size);
data->buf_size = size;
}
while (size) {
ssize_t len = read_istream(data->st, data->buf, size);
if (len == 0)
die(_("SHA1 COLLISION FOUND WITH %s !"),
sha1_to_hex(data->entry->idx.sha1));
if (len < 0)
die(_("unable to read %s"),
sha1_to_hex(data->entry->idx.sha1));
if (memcmp(buf, data->buf, len))
die(_("SHA1 COLLISION FOUND WITH %s !"),
sha1_to_hex(data->entry->idx.sha1));
size -= len;
buf += len;
}
return 0;
}
static int check_collison(struct object_entry *entry)
{
struct compare_data data;
enum object_type type;
unsigned long size;
if (entry->size <= big_file_threshold || entry->type != OBJ_BLOB)
return -1;
memset(&data, 0, sizeof(data));
data.entry = entry;
data.st = open_istream(entry->idx.sha1, &type, &size, NULL);
if (!data.st)
return -1;
if (size != entry->size || type != entry->type)
die(_("SHA1 COLLISION FOUND WITH %s !"),
sha1_to_hex(entry->idx.sha1));
unpack_data(entry, compare_objects, &data);
close_istream(data.st);
free(data.buf);
return 0;
}
static void sha1_object(const void *data, struct object_entry *obj_entry,
unsigned long size, enum object_type type,
const unsigned char *sha1)
{
void *new_data = NULL;
int collision_test_needed;
assert(data || obj_entry);
read_lock();
collision_test_needed = has_sha1_file(sha1);
read_unlock();
if (collision_test_needed && !data) {
read_lock();
if (!check_collison(obj_entry))
collision_test_needed = 0;
read_unlock();
}
if (collision_test_needed) {
void *has_data;
enum object_type has_type;
unsigned long has_size;
read_lock();
has_type = sha1_object_info(sha1, &has_size);
if (has_type != type || has_size != size)
die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
has_data = read_sha1_file(sha1, &has_type, &has_size);
read_unlock();
if (!data)
data = new_data = get_data_from_pack(obj_entry);
if (!has_data)
die(_("cannot read existing object %s"), sha1_to_hex(sha1));
if (size != has_size || type != has_type ||
memcmp(data, has_data, size) != 0)
die(_("SHA1 COLLISION FOUND WITH %s !"), sha1_to_hex(sha1));
free(has_data);
}
if (strict) {
read_lock();
if (type == OBJ_BLOB) {
struct blob *blob = lookup_blob(sha1);
if (blob)
blob->object.flags |= FLAG_CHECKED;
else
die(_("invalid blob object %s"), sha1_to_hex(sha1));
} else {
struct object *obj;
int eaten;
void *buf = (void *) data;
assert(data && "data can only be NULL for large _blobs_");
/*
* we do not need to free the memory here, as the
* buf is deleted by the caller.
*/
obj = parse_object_buffer(sha1, type, size, buf, &eaten);
if (!obj)
die(_("invalid %s"), typename(type));
if (do_fsck_object &&
fsck_object(obj, 1, fsck_error_function))
die(_("Error in object"));
if (fsck_walk(obj, mark_link, NULL))
die(_("Not all child objects of %s are reachable"), sha1_to_hex(obj->sha1));
if (obj->type == OBJ_TREE) {
struct tree *item = (struct tree *) obj;
item->buffer = NULL;
}
if (obj->type == OBJ_COMMIT) {
struct commit *commit = (struct commit *) obj;
commit->buffer = NULL;
}
obj->flags |= FLAG_CHECKED;
}
read_unlock();
}
free(new_data);
}
/*
* This function is part of find_unresolved_deltas(). There are two
* walkers going in the opposite ways.
*
* The first one in find_unresolved_deltas() traverses down from
* parent node to children, deflating nodes along the way. However,
* memory for deflated nodes is limited by delta_base_cache_limit, so
* at some point parent node's deflated content may be freed.
*
* The second walker is this function, which goes from current node up
* to top parent if necessary to deflate the node. In normal
* situation, its parent node would be already deflated, so it just
* needs to apply delta.
*
* In the worst case scenario, parent node is no longer deflated because
* we're running out of delta_base_cache_limit; we need to re-deflate
* parents, possibly up to the top base.
*
* All deflated objects here are subject to be freed if we exceed
* delta_base_cache_limit, just like in find_unresolved_deltas(), we
* just need to make sure the last node is not freed.
*/
static void *get_base_data(struct base_data *c)
{
if (!c->data) {
struct object_entry *obj = c->obj;
struct base_data **delta = NULL;
int delta_nr = 0, delta_alloc = 0;
while (is_delta_type(c->obj->type) && !c->data) {
ALLOC_GROW(delta, delta_nr + 1, delta_alloc);
delta[delta_nr++] = c;
c = c->base;
}
if (!delta_nr) {
c->data = get_data_from_pack(obj);
c->size = obj->size;
get_thread_data()->base_cache_used += c->size;
prune_base_data(c);
}
for (; delta_nr > 0; delta_nr--) {
void *base, *raw;
c = delta[delta_nr - 1];
obj = c->obj;
base = get_base_data(c->base);
raw = get_data_from_pack(obj);
c->data = patch_delta(
base, c->base->size,
raw, obj->size,
&c->size);
free(raw);
if (!c->data)
bad_object(obj->idx.offset, _("failed to apply delta"));
get_thread_data()->base_cache_used += c->size;
prune_base_data(c);
}
free(delta);
}
return c->data;
}
static void resolve_delta(struct object_entry *delta_obj,
struct base_data *base, struct base_data *result)
{
void *base_data, *delta_data;
delta_obj->real_type = base->obj->real_type;
if (show_stat) {
delta_obj->delta_depth = base->obj->delta_depth + 1;
deepest_delta_lock();
if (deepest_delta < delta_obj->delta_depth)
deepest_delta = delta_obj->delta_depth;
deepest_delta_unlock();
}
delta_obj->base_object_no = base->obj - objects;
delta_data = get_data_from_pack(delta_obj);
base_data = get_base_data(base);
result->obj = delta_obj;
result->data = patch_delta(base_data, base->size,
delta_data, delta_obj->size, &result->size);
free(delta_data);
if (!result->data)
bad_object(delta_obj->idx.offset, _("failed to apply delta"));
hash_sha1_file(result->data, result->size,
typename(delta_obj->real_type), delta_obj->idx.sha1);
sha1_object(result->data, NULL, result->size, delta_obj->real_type,
delta_obj->idx.sha1);
counter_lock();
nr_resolved_deltas++;
counter_unlock();
}
static struct base_data *find_unresolved_deltas_1(struct base_data *base,
struct base_data *prev_base)
{
if (base->ref_last == -1 && base->ofs_last == -1) {
union delta_base base_spec;
hashcpy(base_spec.sha1, base->obj->idx.sha1);
find_delta_children(&base_spec,
&base->ref_first, &base->ref_last, OBJ_REF_DELTA);
memset(&base_spec, 0, sizeof(base_spec));
base_spec.offset = base->obj->idx.offset;
find_delta_children(&base_spec,
&base->ofs_first, &base->ofs_last, OBJ_OFS_DELTA);
if (base->ref_last == -1 && base->ofs_last == -1) {
free(base->data);
return NULL;
}
link_base_data(prev_base, base);
}
if (base->ref_first <= base->ref_last) {
struct object_entry *child = objects + deltas[base->ref_first].obj_no;
struct base_data *result = alloc_base_data();
assert(child->real_type == OBJ_REF_DELTA);
resolve_delta(child, base, result);
if (base->ref_first == base->ref_last && base->ofs_last == -1)
free_base_data(base);
base->ref_first++;
return result;
}
if (base->ofs_first <= base->ofs_last) {
struct object_entry *child = objects + deltas[base->ofs_first].obj_no;
struct base_data *result = alloc_base_data();
assert(child->real_type == OBJ_OFS_DELTA);
resolve_delta(child, base, result);
if (base->ofs_first == base->ofs_last)
free_base_data(base);
base->ofs_first++;
return result;
}
unlink_base_data(base);
return NULL;
}
static void find_unresolved_deltas(struct base_data *base)
{
struct base_data *new_base, *prev_base = NULL;
for (;;) {
new_base = find_unresolved_deltas_1(base, prev_base);
if (new_base) {
prev_base = base;
base = new_base;
} else {
free(base);
base = prev_base;
if (!base)
return;
prev_base = base->base;
}
}
}
static int compare_delta_entry(const void *a, const void *b)
{
const struct delta_entry *delta_a = a;
const struct delta_entry *delta_b = b;
/* group by type (ref vs ofs) and then by value (sha-1 or offset) */
return compare_delta_bases(&delta_a->base, &delta_b->base,
objects[delta_a->obj_no].type,
objects[delta_b->obj_no].type);
}
static void resolve_base(struct object_entry *obj)
{
struct base_data *base_obj = alloc_base_data();
base_obj->obj = obj;
base_obj->data = NULL;
find_unresolved_deltas(base_obj);
}
#ifndef NO_PTHREADS
static void *threaded_second_pass(void *data)
{
set_thread_data(data);
for (;;) {
int i;
counter_lock();
display_progress(progress, nr_resolved_deltas);
counter_unlock();
work_lock();
while (nr_dispatched < nr_objects &&
is_delta_type(objects[nr_dispatched].type))
nr_dispatched++;
if (nr_dispatched >= nr_objects) {
work_unlock();
break;
}
i = nr_dispatched++;
work_unlock();
resolve_base(&objects[i]);
}
return NULL;
}
#endif
/*
* First pass:
* - find locations of all objects;
* - calculate SHA1 of all non-delta objects;
* - remember base (SHA1 or offset) for all deltas.
*/
static void parse_pack_objects(unsigned char *sha1)
{
int i, nr_delays = 0;
struct delta_entry *delta = deltas;
struct stat st;
if (verbose)
progress = start_progress(
from_stdin ? _("Receiving objects") : _("Indexing objects"),
nr_objects);
for (i = 0; i < nr_objects; i++) {
struct object_entry *obj = &objects[i];
void *data = unpack_raw_entry(obj, &delta->base, obj->idx.sha1);
obj->real_type = obj->type;
if (is_delta_type(obj->type)) {
nr_deltas++;
delta->obj_no = i;
delta++;
} else if (!data) {
/* large blobs, check later */
obj->real_type = OBJ_BAD;
nr_delays++;
} else
sha1_object(data, NULL, obj->size, obj->type, obj->idx.sha1);
free(data);
display_progress(progress, i+1);
}
objects[i].idx.offset = consumed_bytes;
stop_progress(&progress);
/* Check pack integrity */
flush();
git_SHA1_Final(sha1, &input_ctx);
if (hashcmp(fill(20), sha1))
die(_("pack is corrupted (SHA1 mismatch)"));
use(20);
/* If input_fd is a file, we should have reached its end now. */
if (fstat(input_fd, &st))
die_errno(_("cannot fstat packfile"));
if (S_ISREG(st.st_mode) &&
lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
die(_("pack has junk at the end"));
for (i = 0; i < nr_objects; i++) {
struct object_entry *obj = &objects[i];
if (obj->real_type != OBJ_BAD)
continue;
obj->real_type = obj->type;
sha1_object(NULL, obj, obj->size, obj->type, obj->idx.sha1);
nr_delays--;
}
if (nr_delays)
die(_("confusion beyond insanity in parse_pack_objects()"));
}
/*
* Second pass:
* - for all non-delta objects, look if it is used as a base for
* deltas;
* - if used as a base, uncompress the object and apply all deltas,
* recursively checking if the resulting object is used as a base
* for some more deltas.
*/
static void resolve_deltas(void)
{
int i;
if (!nr_deltas)
return;
/* Sort deltas by base SHA1/offset for fast searching */
qsort(deltas, nr_deltas, sizeof(struct delta_entry),
compare_delta_entry);
if (verbose)
progress = start_progress(_("Resolving deltas"), nr_deltas);
#ifndef NO_PTHREADS
nr_dispatched = 0;
if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) {
init_thread();
for (i = 0; i < nr_threads; i++) {
int ret = pthread_create(&thread_data[i].thread, NULL,
threaded_second_pass, thread_data + i);
if (ret)
die(_("unable to create thread: %s"),
strerror(ret));
}
for (i = 0; i < nr_threads; i++)
pthread_join(thread_data[i].thread, NULL);
cleanup_thread();
return;
}
#endif
for (i = 0; i < nr_objects; i++) {
struct object_entry *obj = &objects[i];
if (is_delta_type(obj->type))
continue;
resolve_base(obj);
display_progress(progress, nr_resolved_deltas);
}
}
/*
* Third pass:
* - append objects to convert thin pack to full pack if required
* - write the final 20-byte SHA-1
*/
static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved);
static void conclude_pack(int fix_thin_pack, const char *curr_pack, unsigned char *pack_sha1)
{
if (nr_deltas == nr_resolved_deltas) {
stop_progress(&progress);
/* Flush remaining pack final 20-byte SHA1. */
flush();
return;
}
if (fix_thin_pack) {
struct sha1file *f;
unsigned char read_sha1[20], tail_sha1[20];
struct strbuf msg = STRBUF_INIT;
int nr_unresolved = nr_deltas - nr_resolved_deltas;
int nr_objects_initial = nr_objects;
if (nr_unresolved <= 0)
die(_("confusion beyond insanity"));
objects = xrealloc(objects,
(nr_objects + nr_unresolved + 1)
* sizeof(*objects));
memset(objects + nr_objects + 1, 0,
nr_unresolved * sizeof(*objects));
f = sha1fd(output_fd, curr_pack);
fix_unresolved_deltas(f, nr_unresolved);
strbuf_addf(&msg, _("completed with %d local objects"),
nr_objects - nr_objects_initial);
stop_progress_msg(&progress, msg.buf);
strbuf_release(&msg);
sha1close(f, tail_sha1, 0);
hashcpy(read_sha1, pack_sha1);
fixup_pack_header_footer(output_fd, pack_sha1,
curr_pack, nr_objects,
read_sha1, consumed_bytes-20);
if (hashcmp(read_sha1, tail_sha1) != 0)
die(_("Unexpected tail checksum for %s "
"(disk corruption?)"), curr_pack);
}
if (nr_deltas != nr_resolved_deltas)
die(Q_("pack has %d unresolved delta",
"pack has %d unresolved deltas",
nr_deltas - nr_resolved_deltas),
nr_deltas - nr_resolved_deltas);
}
static int write_compressed(struct sha1file *f, void *in, unsigned int size)
{
git_zstream stream;
int status;
unsigned char outbuf[4096];
memset(&stream, 0, sizeof(stream));
git_deflate_init(&stream, zlib_compression_level);
stream.next_in = in;
stream.avail_in = size;
do {
stream.next_out = outbuf;
stream.avail_out = sizeof(outbuf);
status = git_deflate(&stream, Z_FINISH);
sha1write(f, outbuf, sizeof(outbuf) - stream.avail_out);
} while (status == Z_OK);
if (status != Z_STREAM_END)
die(_("unable to deflate appended object (%d)"), status);
size = stream.total_out;
git_deflate_end(&stream);
return size;
}
static struct object_entry *append_obj_to_pack(struct sha1file *f,
const unsigned char *sha1, void *buf,
unsigned long size, enum object_type type)
{
struct object_entry *obj = &objects[nr_objects++];
unsigned char header[10];
unsigned long s = size;
int n = 0;
unsigned char c = (type << 4) | (s & 15);
s >>= 4;
while (s) {
header[n++] = c | 0x80;
c = s & 0x7f;
s >>= 7;
}
header[n++] = c;
crc32_begin(f);
sha1write(f, header, n);
obj[0].size = size;
obj[0].hdr_size = n;
obj[0].type = type;
obj[0].real_type = type;
obj[1].idx.offset = obj[0].idx.offset + n;
obj[1].idx.offset += write_compressed(f, buf, size);
obj[0].idx.crc32 = crc32_end(f);
sha1flush(f);
hashcpy(obj->idx.sha1, sha1);
return obj;
}
static int delta_pos_compare(const void *_a, const void *_b)
{
struct delta_entry *a = *(struct delta_entry **)_a;
struct delta_entry *b = *(struct delta_entry **)_b;
return a->obj_no - b->obj_no;
}
static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
{
struct delta_entry **sorted_by_pos;
int i, n = 0;
/*
* Since many unresolved deltas may well be themselves base objects
* for more unresolved deltas, we really want to include the
* smallest number of base objects that would cover as much delta
* as possible by picking the
* trunc deltas first, allowing for other deltas to resolve without
* additional base objects. Since most base objects are to be found
* before deltas depending on them, a good heuristic is to start
* resolving deltas in the same order as their position in the pack.
*/
sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
for (i = 0; i < nr_deltas; i++) {
if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
continue;
sorted_by_pos[n++] = &deltas[i];
}
qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
for (i = 0; i < n; i++) {
struct delta_entry *d = sorted_by_pos[i];
enum object_type type;
struct base_data *base_obj = alloc_base_data();
if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
continue;
base_obj->data = read_sha1_file(d->base.sha1, &type, &base_obj->size);
if (!base_obj->data)
continue;
if (check_sha1_signature(d->base.sha1, base_obj->data,
base_obj->size, typename(type)))
die(_("local object %s is corrupt"), sha1_to_hex(d->base.sha1));
base_obj->obj = append_obj_to_pack(f, d->base.sha1,
base_obj->data, base_obj->size, type);
find_unresolved_deltas(base_obj);
display_progress(progress, nr_resolved_deltas);
}
free(sorted_by_pos);
}
static void final(const char *final_pack_name, const char *curr_pack_name,
const char *final_index_name, const char *curr_index_name,
const char *keep_name, const char *keep_msg,
unsigned char *sha1)
{
const char *report = "pack";
char name[PATH_MAX];
int err;
if (!from_stdin) {
close(input_fd);
} else {
fsync_or_die(output_fd, curr_pack_name);
err = close(output_fd);
if (err)
die_errno(_("error while closing pack file"));
}
if (keep_msg) {
int keep_fd, keep_msg_len = strlen(keep_msg);
if (!keep_name)
keep_fd = odb_pack_keep(name, sizeof(name), sha1);
else
keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
if (keep_fd < 0) {
if (errno != EEXIST)
die_errno(_("cannot write keep file '%s'"),
keep_name);
} else {
if (keep_msg_len > 0) {
write_or_die(keep_fd, keep_msg, keep_msg_len);
write_or_die(keep_fd, "\n", 1);
}
if (close(keep_fd) != 0)
die_errno(_("cannot close written keep file '%s'"),
keep_name);
report = "keep";
}
}
if (final_pack_name != curr_pack_name) {
if (!final_pack_name) {
snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
get_object_directory(), sha1_to_hex(sha1));
final_pack_name = name;
}
if (move_temp_to_file(curr_pack_name, final_pack_name))
die(_("cannot store pack file"));
} else if (from_stdin)
chmod(final_pack_name, 0444);
if (final_index_name != curr_index_name) {
if (!final_index_name) {
snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
get_object_directory(), sha1_to_hex(sha1));
final_index_name = name;
}
if (move_temp_to_file(curr_index_name, final_index_name))
die(_("cannot store index file"));
} else
chmod(final_index_name, 0444);
if (!from_stdin) {
printf("%s\n", sha1_to_hex(sha1));
} else {
char buf[48];
int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
report, sha1_to_hex(sha1));
write_or_die(1, buf, len);
/*
* Let's just mimic git-unpack-objects here and write
* the last part of the input buffer to stdout.
*/
while (input_len) {
err = xwrite(1, input_buffer + input_offset, input_len);
if (err <= 0)
break;
input_len -= err;
input_offset += err;
}
}
}
static int git_index_pack_config(const char *k, const char *v, void *cb)
{
struct pack_idx_option *opts = cb;
if (!strcmp(k, "pack.indexversion")) {
opts->version = git_config_int(k, v);
if (opts->version > 2)
die(_("bad pack.indexversion=%"PRIu32), opts->version);
return 0;
}
if (!strcmp(k, "pack.threads")) {
nr_threads = git_config_int(k, v);
if (nr_threads < 0)
die(_("invalid number of threads specified (%d)"),
nr_threads);
#ifdef NO_PTHREADS
if (nr_threads != 1)
warning(_("no threads support, ignoring %s"), k);
nr_threads = 1;
#endif
return 0;
}
return git_default_config(k, v, cb);
}
static int cmp_uint32(const void *a_, const void *b_)
{
uint32_t a = *((uint32_t *)a_);
uint32_t b = *((uint32_t *)b_);
return (a < b) ? -1 : (a != b);
}
static void read_v2_anomalous_offsets(struct packed_git *p,
struct pack_idx_option *opts)
{
const uint32_t *idx1, *idx2;
uint32_t i;
/* The address of the 4-byte offset table */
idx1 = (((const uint32_t *)p->index_data)
+ 2 /* 8-byte header */
+ 256 /* fan out */
+ 5 * p->num_objects /* 20-byte SHA-1 table */
+ p->num_objects /* CRC32 table */
);
/* The address of the 8-byte offset table */
idx2 = idx1 + p->num_objects;
for (i = 0; i < p->num_objects; i++) {
uint32_t off = ntohl(idx1[i]);
if (!(off & 0x80000000))
continue;
off = off & 0x7fffffff;
if (idx2[off * 2])
continue;
/*
* The real offset is ntohl(idx2[off * 2]) in high 4
* octets, and ntohl(idx2[off * 2 + 1]) in low 4
* octets. But idx2[off * 2] is Zero!!!
*/
ALLOC_GROW(opts->anomaly, opts->anomaly_nr + 1, opts->anomaly_alloc);
opts->anomaly[opts->anomaly_nr++] = ntohl(idx2[off * 2 + 1]);
}
if (1 < opts->anomaly_nr)
qsort(opts->anomaly, opts->anomaly_nr, sizeof(uint32_t), cmp_uint32);
}
static void read_idx_option(struct pack_idx_option *opts, const char *pack_name)
{
struct packed_git *p = add_packed_git(pack_name, strlen(pack_name), 1);
if (!p)
die(_("Cannot open existing pack file '%s'"), pack_name);
if (open_pack_index(p))
die(_("Cannot open existing pack idx file for '%s'"), pack_name);
/* Read the attributes from the existing idx file */
opts->version = p->index_version;
if (opts->version == 2)
read_v2_anomalous_offsets(p, opts);
/*
* Get rid of the idx file as we do not need it anymore.
* NEEDSWORK: extract this bit from free_pack_by_name() in
* sha1_file.c, perhaps? It shouldn't matter very much as we
* know we haven't installed this pack (hence we never have
* read anything from it).
*/
close_pack_index(p);
free(p);
}
static void show_pack_info(int stat_only)
{
int i, baseobjects = nr_objects - nr_deltas;
unsigned long *chain_histogram = NULL;
if (deepest_delta)
chain_histogram = xcalloc(deepest_delta, sizeof(unsigned long));
for (i = 0; i < nr_objects; i++) {
struct object_entry *obj = &objects[i];
if (is_delta_type(obj->type))
chain_histogram[obj->delta_depth - 1]++;
if (stat_only)
continue;
printf("%s %-6s %lu %lu %"PRIuMAX,
sha1_to_hex(obj->idx.sha1),
typename(obj->real_type), obj->size,
(unsigned long)(obj[1].idx.offset - obj->idx.offset),
(uintmax_t)obj->idx.offset);
if (is_delta_type(obj->type)) {
struct object_entry *bobj = &objects[obj->base_object_no];
printf(" %u %s", obj->delta_depth, sha1_to_hex(bobj->idx.sha1));
}
putchar('\n');
}
if (baseobjects)
printf_ln(Q_("non delta: %d object",
"non delta: %d objects",
baseobjects),
baseobjects);
for (i = 0; i < deepest_delta; i++) {
if (!chain_histogram[i])
continue;
printf_ln(Q_("chain length = %d: %lu object",
"chain length = %d: %lu objects",
chain_histogram[i]),
i + 1,
chain_histogram[i]);
}
}
int cmd_index_pack(int argc, const char **argv, const char *prefix)
{
int i, fix_thin_pack = 0, verify = 0, stat_only = 0;
const char *curr_pack, *curr_index;
const char *index_name = NULL, *pack_name = NULL;
const char *keep_name = NULL, *keep_msg = NULL;
char *index_name_buf = NULL, *keep_name_buf = NULL;
struct pack_idx_entry **idx_objects;
struct pack_idx_option opts;
unsigned char pack_sha1[20];
unsigned foreign_nr = 1; /* zero is a "good" value, assume bad */
if (argc == 2 && !strcmp(argv[1], "-h"))
usage(index_pack_usage);
read_replace_refs = 0;
reset_pack_idx_option(&opts);
git_config(git_index_pack_config, &opts);
if (prefix && chdir(prefix))
die(_("Cannot come back to cwd"));
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (*arg == '-') {
if (!strcmp(arg, "--stdin")) {
from_stdin = 1;
} else if (!strcmp(arg, "--fix-thin")) {
fix_thin_pack = 1;
} else if (!strcmp(arg, "--strict")) {
strict = 1;
do_fsck_object = 1;
} else if (!strcmp(arg, "--check-self-contained-and-connected")) {
strict = 1;
check_self_contained_and_connected = 1;
} else if (!strcmp(arg, "--verify")) {
verify = 1;
} else if (!strcmp(arg, "--verify-stat")) {
verify = 1;
show_stat = 1;
} else if (!strcmp(arg, "--verify-stat-only")) {
verify = 1;
show_stat = 1;
stat_only = 1;
} else if (!strcmp(arg, "--keep")) {
keep_msg = "";
} else if (!prefixcmp(arg, "--keep=")) {
keep_msg = arg + 7;
} else if (!prefixcmp(arg, "--threads=")) {
char *end;
nr_threads = strtoul(arg+10, &end, 0);
if (!arg[10] || *end || nr_threads < 0)
usage(index_pack_usage);
#ifdef NO_PTHREADS
if (nr_threads != 1)
warning(_("no threads support, "
"ignoring %s"), arg);
nr_threads = 1;
#endif
} else if (!prefixcmp(arg, "--pack_header=")) {
struct pack_header *hdr;
char *c;
hdr = (struct pack_header *)input_buffer;
hdr->hdr_signature = htonl(PACK_SIGNATURE);
hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
if (*c != ',')
die(_("bad %s"), arg);
hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
if (*c)
die(_("bad %s"), arg);
input_len = sizeof(*hdr);
} else if (!strcmp(arg, "-v")) {
verbose = 1;
} else if (!strcmp(arg, "-o")) {
if (index_name || (i+1) >= argc)
usage(index_pack_usage);
index_name = argv[++i];
} else if (!prefixcmp(arg, "--index-version=")) {
char *c;
opts.version = strtoul(arg + 16, &c, 10);
if (opts.version > 2)
die(_("bad %s"), arg);
if (*c == ',')
opts.off32_limit = strtoul(c+1, &c, 0);
if (*c || opts.off32_limit & 0x80000000)
die(_("bad %s"), arg);
} else
usage(index_pack_usage);
continue;
}
if (pack_name)
usage(index_pack_usage);
pack_name = arg;
}
if (!pack_name && !from_stdin)
usage(index_pack_usage);
if (fix_thin_pack && !from_stdin)
die(_("--fix-thin cannot be used without --stdin"));
if (!index_name && pack_name) {
int len = strlen(pack_name);
if (!has_extension(pack_name, ".pack"))
die(_("packfile name '%s' does not end with '.pack'"),
pack_name);
index_name_buf = xmalloc(len);
memcpy(index_name_buf, pack_name, len - 5);
strcpy(index_name_buf + len - 5, ".idx");
index_name = index_name_buf;
}
if (keep_msg && !keep_name && pack_name) {
int len = strlen(pack_name);
if (!has_extension(pack_name, ".pack"))
die(_("packfile name '%s' does not end with '.pack'"),
pack_name);
keep_name_buf = xmalloc(len);
memcpy(keep_name_buf, pack_name, len - 5);
strcpy(keep_name_buf + len - 5, ".keep");
keep_name = keep_name_buf;
}
if (verify) {
if (!index_name)
die(_("--verify with no packfile name given"));
read_idx_option(&opts, index_name);
opts.flags |= WRITE_IDX_VERIFY | WRITE_IDX_STRICT;
}
if (strict)
opts.flags |= WRITE_IDX_STRICT;
#ifndef NO_PTHREADS
if (!nr_threads) {
nr_threads = online_cpus();
/* An experiment showed that more threads does not mean faster */
if (nr_threads > 3)
nr_threads = 3;
}
#endif
curr_pack = open_pack_file(pack_name);
parse_pack_header();
objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
parse_pack_objects(pack_sha1);
resolve_deltas();
conclude_pack(fix_thin_pack, curr_pack, pack_sha1);
free(deltas);
if (strict)
foreign_nr = check_objects();
if (show_stat)
show_pack_info(stat_only);
idx_objects = xmalloc((nr_objects) * sizeof(struct pack_idx_entry *));
for (i = 0; i < nr_objects; i++)
idx_objects[i] = &objects[i].idx;
curr_index = write_idx_file(index_name, idx_objects, nr_objects, &opts, pack_sha1);
free(idx_objects);
if (!verify)
final(pack_name, curr_pack,
index_name, curr_index,
keep_name, keep_msg,
pack_sha1);
else
close(input_fd);
free(objects);
free(index_name_buf);
free(keep_name_buf);
if (pack_name == NULL)
free((void *) curr_pack);
if (index_name == NULL)
free((void *) curr_index);
/*
* Let the caller know this pack is not self contained
*/
if (check_self_contained_and_connected && foreign_nr)
return 1;
return 0;
}