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#include "cache.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"
static const char index_pack_usage[] =
"git-index-pack [-v] [-o <index-file>] [{ ---keep | --keep=<msg> }] { <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;
};
union delta_base {
unsigned char sha1[20];
off_t offset;
};
/*
* 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
struct delta_entry
{
union delta_base base;
int obj_no;
};
static struct object_entry *objects;
static struct delta_entry *deltas;
static int nr_objects;
static int nr_deltas;
static int nr_resolved_deltas;
static int from_stdin;
static int verbose;
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 SHA_CTX input_ctx;
static uint32_t input_crc32;
static int input_fd, output_fd, pack_fd;
/* 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);
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("cannot fill %d bytes", 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("read error on input: %s", strerror(errno));
}
input_len += ret;
} 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 (consumed_bytes > 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 tmpfile[PATH_MAX];
snprintf(tmpfile, sizeof(tmpfile),
"%s/tmp_pack_XXXXXX", get_object_directory());
output_fd = xmkstemp(tmpfile);
pack_name = xstrdup(tmpfile);
} else
output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
if (output_fd < 0)
die("unable to create %s: %s\n", pack_name, strerror(errno));
pack_fd = output_fd;
} else {
input_fd = open(pack_name, O_RDONLY);
if (input_fd < 0)
die("cannot open packfile '%s': %s",
pack_name, strerror(errno));
output_fd = -1;
pack_fd = input_fd;
}
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 %d unsupported", ntohl(hdr->hdr_version));
nr_objects = ntohl(hdr->hdr_entries);
use(sizeof(struct pack_header));
}
static void bad_object(unsigned long offset, const char *format,
...) NORETURN __attribute__((format (printf, 2, 3)));
static 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 void *unpack_entry_data(unsigned long offset, unsigned long size)
{
z_stream stream;
void *buf = xmalloc(size);
memset(&stream, 0, sizeof(stream));
stream.next_out = buf;
stream.avail_out = size;
stream.next_in = fill(1);
stream.avail_in = input_len;
inflateInit(&stream);
for (;;) {
int ret = inflate(&stream, 0);
use(input_len - stream.avail_in);
if (stream.total_out == size && ret == Z_STREAM_END)
break;
if (ret != Z_OK)
bad_object(offset, "inflate returned %d", ret);
stream.next_in = fill(1);
stream.avail_in = input_len;
}
inflateEnd(&stream);
return buf;
}
static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_base)
{
unsigned char *p, c;
unsigned long size;
off_t base_offset;
unsigned shift;
void *data;
obj->idx.offset = consumed_bytes;
input_crc32 = crc32(0, Z_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 & 0x7fUL) << 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 >= 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->idx.crc32 = input_crc32;
return data;
}
static void *get_data_from_pack(struct object_entry *obj)
{
unsigned long from = obj[0].idx.offset + obj[0].hdr_size;
unsigned long len = obj[1].idx.offset - from;
unsigned long rdy = 0;
unsigned char *src, *data;
z_stream stream;
int st;
src = xmalloc(len);
data = src;
do {
ssize_t n = pread(pack_fd, data + rdy, len - rdy, from + rdy);
if (n <= 0)
die("cannot pread pack file: %s", strerror(errno));
rdy += n;
} while (rdy < len);
data = xmalloc(obj->size);
memset(&stream, 0, sizeof(stream));
stream.next_out = data;
stream.avail_out = obj->size;
stream.next_in = src;
stream.avail_in = len;
inflateInit(&stream);
while ((st = inflate(&stream, Z_FINISH)) == Z_OK);
inflateEnd(&stream);
if (st != Z_STREAM_END || stream.total_out != obj->size)
die("serious inflate inconsistency");
free(src);
return data;
}
static int find_delta(const union delta_base *base)
{
int first = 0, last = nr_deltas;
while (first < last) {
int next = (first + last) / 2;
struct delta_entry *delta = &deltas[next];
int cmp;
cmp = memcmp(base, &delta->base, UNION_BASE_SZ);
if (!cmp)
return next;
if (cmp < 0) {
last = next;
continue;
}
first = next+1;
}
return -first-1;
}
static int find_delta_children(const union delta_base *base,
int *first_index, int *last_index)
{
int first = find_delta(base);
int last = first;
int end = nr_deltas - 1;
if (first < 0)
return -1;
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;
return 0;
}
static void sha1_object(const void *data, unsigned long size,
enum object_type type, unsigned char *sha1)
{
hash_sha1_file(data, size, typename(type), sha1);
if (has_sha1_file(sha1)) {
void *has_data;
enum object_type has_type;
unsigned long has_size;
has_data = read_sha1_file(sha1, &has_type, &has_size);
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);
}
}
static void resolve_delta(struct object_entry *delta_obj, void *base_data,
unsigned long base_size, enum object_type type)
{
void *delta_data;
unsigned long delta_size;
void *result;
unsigned long result_size;
union delta_base delta_base;
int j, first, last;
delta_obj->real_type = type;
delta_data = get_data_from_pack(delta_obj);
delta_size = delta_obj->size;
result = patch_delta(base_data, base_size, delta_data, delta_size,
&result_size);
free(delta_data);
if (!result)
bad_object(delta_obj->idx.offset, "failed to apply delta");
sha1_object(result, result_size, type, delta_obj->idx.sha1);
nr_resolved_deltas++;
hashcpy(delta_base.sha1, delta_obj->idx.sha1);
if (!find_delta_children(&delta_base, &first, &last)) {
for (j = first; j <= last; j++) {
struct object_entry *child = objects + deltas[j].obj_no;
if (child->real_type == OBJ_REF_DELTA)
resolve_delta(child, result, result_size, type);
}
}
memset(&delta_base, 0, sizeof(delta_base));
delta_base.offset = delta_obj->idx.offset;
if (!find_delta_children(&delta_base, &first, &last)) {
for (j = first; j <= last; j++) {
struct object_entry *child = objects + deltas[j].obj_no;
if (child->real_type == OBJ_OFS_DELTA)
resolve_delta(child, result, result_size, type);
}
}
free(result);
}
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;
return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ);
}
/* Parse all objects and return the pack content SHA1 hash */
static void parse_pack_objects(unsigned char *sha1)
{
int i;
struct delta_entry *delta = deltas;
void *data;
struct stat st;
/*
* First pass:
* - find locations of all objects;
* - calculate SHA1 of all non-delta objects;
* - remember base (SHA1 or offset) for all deltas.
*/
if (verbose)
start_progress(&progress, "Indexing %u objects...", "", nr_objects);
for (i = 0; i < nr_objects; i++) {
struct object_entry *obj = &objects[i];
data = unpack_raw_entry(obj, &delta->base);
obj->real_type = obj->type;
if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
nr_deltas++;
delta->obj_no = i;
delta++;
} else
sha1_object(data, obj->size, obj->type, obj->idx.sha1);
free(data);
if (verbose)
display_progress(&progress, i+1);
}
objects[i].idx.offset = consumed_bytes;
if (verbose)
stop_progress(&progress);
/* Check pack integrity */
flush();
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("cannot fstat packfile: %s", strerror(errno));
if (S_ISREG(st.st_mode) &&
lseek(input_fd, 0, SEEK_CUR) - input_len != st.st_size)
die("pack has junk at the end");
if (!nr_deltas)
return;
/* Sort deltas by base SHA1/offset for fast searching */
qsort(deltas, nr_deltas, sizeof(struct delta_entry),
compare_delta_entry);
/*
* 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.
*/
if (verbose)
start_progress(&progress, "Resolving %u deltas...", "", nr_deltas);
for (i = 0; i < nr_objects; i++) {
struct object_entry *obj = &objects[i];
union delta_base base;
int j, ref, ref_first, ref_last, ofs, ofs_first, ofs_last;
if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
continue;
hashcpy(base.sha1, obj->idx.sha1);
ref = !find_delta_children(&base, &ref_first, &ref_last);
memset(&base, 0, sizeof(base));
base.offset = obj->idx.offset;
ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
if (!ref && !ofs)
continue;
data = get_data_from_pack(obj);
if (ref)
for (j = ref_first; j <= ref_last; j++) {
struct object_entry *child = objects + deltas[j].obj_no;
if (child->real_type == OBJ_REF_DELTA)
resolve_delta(child, data,
obj->size, obj->type);
}
if (ofs)
for (j = ofs_first; j <= ofs_last; j++) {
struct object_entry *child = objects + deltas[j].obj_no;
if (child->real_type == OBJ_OFS_DELTA)
resolve_delta(child, data,
obj->size, obj->type);
}
free(data);
if (verbose)
display_progress(&progress, nr_resolved_deltas);
}
}
static int write_compressed(int fd, void *in, unsigned int size, uint32_t *obj_crc)
{
z_stream stream;
unsigned long maxsize;
void *out;
memset(&stream, 0, sizeof(stream));
deflateInit(&stream, zlib_compression_level);
maxsize = deflateBound(&stream, size);
out = xmalloc(maxsize);
/* Compress it */
stream.next_in = in;
stream.avail_in = size;
stream.next_out = out;
stream.avail_out = maxsize;
while (deflate(&stream, Z_FINISH) == Z_OK);
deflateEnd(&stream);
size = stream.total_out;
write_or_die(fd, out, size);
*obj_crc = crc32(*obj_crc, out, size);
free(out);
return size;
}
static void append_obj_to_pack(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;
write_or_die(output_fd, header, n);
obj[0].idx.crc32 = crc32(0, Z_NULL, 0);
obj[0].idx.crc32 = crc32(obj[0].idx.crc32, header, n);
obj[1].idx.offset = obj[0].idx.offset + n;
obj[1].idx.offset += write_compressed(output_fd, buf, size, &obj[0].idx.crc32);
hashcpy(obj->idx.sha1, sha1);
}
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(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];
void *data;
unsigned long size;
enum object_type type;
int j, first, last;
if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
continue;
data = read_sha1_file(d->base.sha1, &type, &size);
if (!data)
continue;
find_delta_children(&d->base, &first, &last);
for (j = first; j <= last; j++) {
struct object_entry *child = objects + deltas[j].obj_no;
if (child->real_type == OBJ_REF_DELTA)
resolve_delta(child, data, size, type);
}
if (check_sha1_signature(d->base.sha1, data, size, typename(type)))
die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
append_obj_to_pack(d->base.sha1, data, size, type);
free(data);
if (verbose)
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 {
err = close(output_fd);
if (err)
die("error while closing pack file: %s", strerror(errno));
chmod(curr_pack_name, 0444);
}
if (keep_msg) {
int keep_fd, keep_msg_len = strlen(keep_msg);
if (!keep_name) {
snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
get_object_directory(), sha1_to_hex(sha1));
keep_name = name;
}
keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
if (keep_fd < 0) {
if (errno != EEXIST)
die("cannot write keep file");
} 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("cannot write keep file");
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");
}
chmod(curr_index_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");
}
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;
}
}
}
int main(int argc, char **argv)
{
int i, fix_thin_pack = 0;
const char *curr_pack, *pack_name = NULL;
const char *curr_index, *index_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;
unsigned char sha1[20];
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, "--keep")) {
keep_msg = "";
} else if (!prefixcmp(arg, "--keep=")) {
keep_msg = arg + 7;
} 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;
pack_idx_default_version = strtoul(arg + 16, &c, 10);
if (pack_idx_default_version > 2)
die("bad %s", arg);
if (*c == ',')
pack_idx_off32_limit = strtoul(c+1, &c, 0);
if (*c || pack_idx_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;
}
curr_pack = open_pack_file(pack_name);
parse_pack_header();
objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
parse_pack_objects(sha1);
if (nr_deltas == nr_resolved_deltas) {
if (verbose)
stop_progress(&progress);
/* Flush remaining pack final 20-byte SHA1. */
flush();
} else {
if (fix_thin_pack) {
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));
fix_unresolved_deltas(nr_unresolved);
if (verbose) {
stop_progress(&progress);
fprintf(stderr, "%d objects were added to complete this thin pack.\n",
nr_objects - nr_objects_initial);
}
fixup_pack_header_footer(output_fd, sha1,
curr_pack, nr_objects);
}
if (nr_deltas != nr_resolved_deltas)
die("pack has %d unresolved deltas",
nr_deltas - nr_resolved_deltas);
}
free(deltas);
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, sha1);
free(idx_objects);
final(pack_name, curr_pack,
index_name, curr_index,
keep_name, keep_msg,
sha1);
free(objects);
free(index_name_buf);
free(keep_name_buf);
return 0;
}
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