git/builtin-pack-objects.c
Linus Torvalds 48fb7deb5b Fix big left-shifts of unsigned char
Shifting 'unsigned char' or 'unsigned short' left can result in sign
extension errors, since the C integer promotion rules means that the
unsigned char/short will get implicitly promoted to a signed 'int' due to
the shift (or due to other operations).

This normally doesn't matter, but if you shift things up sufficiently, it
will now set the sign bit in 'int', and a subsequent cast to a bigger type
(eg 'long' or 'unsigned long') will now sign-extend the value despite the
original expression being unsigned.

One example of this would be something like

	unsigned long size;
	unsigned char c;

	size += c << 24;

where despite all the variables being unsigned, 'c << 24' ends up being a
signed entity, and will get sign-extended when then doing the addition in
an 'unsigned long' type.

Since git uses 'unsigned char' pointers extensively, we actually have this
bug in a couple of places.

I may have missed some, but this is the result of looking at

	git grep '[^0-9 	][ 	]*<<[ 	][a-z]' -- '*.c' '*.h'
	git grep '<<[   ]*24'

which catches at least the common byte cases (shifting variables by a
variable amount, and shifting by 24 bits).

I also grepped for just 'unsigned char' variables in general, and
converted the ones that most obviously ended up getting implicitly cast
immediately anyway (eg hash_name(), encode_85()).

In addition to just avoiding 'unsigned char', this patch also tries to use
a common idiom for the delta header size thing. We had three different
variations on it: "& 0x7fUL" in one place (getting the sign extension
right), and "& ~0x80" and "& 0x7f" in two other places (not getting it
right). Apart from making them all just avoid using "unsigned char" at
all, I also unified them to then use a simple "& 0x7f".

I considered making a sparse extension which warns about doing implicit
casts from unsigned types to signed types, but it gets rather complex very
quickly, so this is just a hack.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-18 09:22:46 -07:00

2326 lines
58 KiB
C

#include "builtin.h"
#include "cache.h"
#include "attr.h"
#include "object.h"
#include "blob.h"
#include "commit.h"
#include "tag.h"
#include "tree.h"
#include "delta.h"
#include "pack.h"
#include "pack-revindex.h"
#include "csum-file.h"
#include "tree-walk.h"
#include "diff.h"
#include "revision.h"
#include "list-objects.h"
#include "progress.h"
#include "refs.h"
#ifdef THREADED_DELTA_SEARCH
#include "thread-utils.h"
#include <pthread.h>
#endif
static const char pack_usage[] = "\
git pack-objects [{ -q | --progress | --all-progress }] \n\
[--max-pack-size=N] [--local] [--incremental] \n\
[--window=N] [--window-memory=N] [--depth=N] \n\
[--no-reuse-delta] [--no-reuse-object] [--delta-base-offset] \n\
[--threads=N] [--non-empty] [--revs [--unpacked | --all]*] [--reflog] \n\
[--stdout | base-name] [--include-tag] \n\
[--keep-unreachable | --unpack-unreachable] \n\
[<ref-list | <object-list]";
struct object_entry {
struct pack_idx_entry idx;
unsigned long size; /* uncompressed size */
struct packed_git *in_pack; /* already in pack */
off_t in_pack_offset;
struct object_entry *delta; /* delta base object */
struct object_entry *delta_child; /* deltified objects who bases me */
struct object_entry *delta_sibling; /* other deltified objects who
* uses the same base as me
*/
void *delta_data; /* cached delta (uncompressed) */
unsigned long delta_size; /* delta data size (uncompressed) */
unsigned long z_delta_size; /* delta data size (compressed) */
unsigned int hash; /* name hint hash */
enum object_type type;
enum object_type in_pack_type; /* could be delta */
unsigned char in_pack_header_size;
unsigned char preferred_base; /* we do not pack this, but is available
* to be used as the base object to delta
* objects against.
*/
unsigned char no_try_delta;
};
/*
* Objects we are going to pack are collected in objects array (dynamically
* expanded). nr_objects & nr_alloc controls this array. They are stored
* in the order we see -- typically rev-list --objects order that gives us
* nice "minimum seek" order.
*/
static struct object_entry *objects;
static struct pack_idx_entry **written_list;
static uint32_t nr_objects, nr_alloc, nr_result, nr_written;
static int non_empty;
static int reuse_delta = 1, reuse_object = 1;
static int keep_unreachable, unpack_unreachable, include_tag;
static int local;
static int incremental;
static int ignore_packed_keep;
static int allow_ofs_delta;
static const char *base_name;
static int progress = 1;
static int window = 10;
static uint32_t pack_size_limit, pack_size_limit_cfg;
static int depth = 50;
static int delta_search_threads;
static int pack_to_stdout;
static int num_preferred_base;
static struct progress *progress_state;
static int pack_compression_level = Z_DEFAULT_COMPRESSION;
static int pack_compression_seen;
static unsigned long delta_cache_size = 0;
static unsigned long max_delta_cache_size = 0;
static unsigned long cache_max_small_delta_size = 1000;
static unsigned long window_memory_limit = 0;
/*
* The object names in objects array are hashed with this hashtable,
* to help looking up the entry by object name.
* This hashtable is built after all the objects are seen.
*/
static int *object_ix;
static int object_ix_hashsz;
/*
* stats
*/
static uint32_t written, written_delta;
static uint32_t reused, reused_delta;
static void *get_delta(struct object_entry *entry)
{
unsigned long size, base_size, delta_size;
void *buf, *base_buf, *delta_buf;
enum object_type type;
buf = read_sha1_file(entry->idx.sha1, &type, &size);
if (!buf)
die("unable to read %s", sha1_to_hex(entry->idx.sha1));
base_buf = read_sha1_file(entry->delta->idx.sha1, &type, &base_size);
if (!base_buf)
die("unable to read %s", sha1_to_hex(entry->delta->idx.sha1));
delta_buf = diff_delta(base_buf, base_size,
buf, size, &delta_size, 0);
if (!delta_buf || delta_size != entry->delta_size)
die("delta size changed");
free(buf);
free(base_buf);
return delta_buf;
}
static unsigned long do_compress(void **pptr, unsigned long size)
{
z_stream stream;
void *in, *out;
unsigned long maxsize;
memset(&stream, 0, sizeof(stream));
deflateInit(&stream, pack_compression_level);
maxsize = deflateBound(&stream, size);
in = *pptr;
out = xmalloc(maxsize);
*pptr = out;
stream.next_in = in;
stream.avail_in = size;
stream.next_out = out;
stream.avail_out = maxsize;
while (deflate(&stream, Z_FINISH) == Z_OK)
; /* nothing */
deflateEnd(&stream);
free(in);
return stream.total_out;
}
/*
* The per-object header is a pretty dense thing, which is
* - first byte: low four bits are "size", then three bits of "type",
* and the high bit is "size continues".
* - each byte afterwards: low seven bits are size continuation,
* with the high bit being "size continues"
*/
static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
{
int n = 1;
unsigned char c;
if (type < OBJ_COMMIT || type > OBJ_REF_DELTA)
die("bad type %d", type);
c = (type << 4) | (size & 15);
size >>= 4;
while (size) {
*hdr++ = c | 0x80;
c = size & 0x7f;
size >>= 7;
n++;
}
*hdr = c;
return n;
}
/*
* we are going to reuse the existing object data as is. make
* sure it is not corrupt.
*/
static int check_pack_inflate(struct packed_git *p,
struct pack_window **w_curs,
off_t offset,
off_t len,
unsigned long expect)
{
z_stream stream;
unsigned char fakebuf[4096], *in;
int st;
memset(&stream, 0, sizeof(stream));
git_inflate_init(&stream);
do {
in = use_pack(p, w_curs, offset, &stream.avail_in);
stream.next_in = in;
stream.next_out = fakebuf;
stream.avail_out = sizeof(fakebuf);
st = git_inflate(&stream, Z_FINISH);
offset += stream.next_in - in;
} while (st == Z_OK || st == Z_BUF_ERROR);
git_inflate_end(&stream);
return (st == Z_STREAM_END &&
stream.total_out == expect &&
stream.total_in == len) ? 0 : -1;
}
static void copy_pack_data(struct sha1file *f,
struct packed_git *p,
struct pack_window **w_curs,
off_t offset,
off_t len)
{
unsigned char *in;
unsigned int avail;
while (len) {
in = use_pack(p, w_curs, offset, &avail);
if (avail > len)
avail = (unsigned int)len;
sha1write(f, in, avail);
offset += avail;
len -= avail;
}
}
static unsigned long write_object(struct sha1file *f,
struct object_entry *entry,
off_t write_offset)
{
unsigned long size, limit, datalen;
void *buf;
unsigned char header[10], dheader[10];
unsigned hdrlen;
enum object_type type;
int usable_delta, to_reuse;
if (!pack_to_stdout)
crc32_begin(f);
type = entry->type;
/* write limit if limited packsize and not first object */
if (!pack_size_limit || !nr_written)
limit = 0;
else if (pack_size_limit <= write_offset)
/*
* the earlier object did not fit the limit; avoid
* mistaking this with unlimited (i.e. limit = 0).
*/
limit = 1;
else
limit = pack_size_limit - write_offset;
if (!entry->delta)
usable_delta = 0; /* no delta */
else if (!pack_size_limit)
usable_delta = 1; /* unlimited packfile */
else if (entry->delta->idx.offset == (off_t)-1)
usable_delta = 0; /* base was written to another pack */
else if (entry->delta->idx.offset)
usable_delta = 1; /* base already exists in this pack */
else
usable_delta = 0; /* base could end up in another pack */
if (!reuse_object)
to_reuse = 0; /* explicit */
else if (!entry->in_pack)
to_reuse = 0; /* can't reuse what we don't have */
else if (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA)
/* check_object() decided it for us ... */
to_reuse = usable_delta;
/* ... but pack split may override that */
else if (type != entry->in_pack_type)
to_reuse = 0; /* pack has delta which is unusable */
else if (entry->delta)
to_reuse = 0; /* we want to pack afresh */
else
to_reuse = 1; /* we have it in-pack undeltified,
* and we do not need to deltify it.
*/
if (!to_reuse) {
no_reuse:
if (!usable_delta) {
buf = read_sha1_file(entry->idx.sha1, &type, &size);
if (!buf)
die("unable to read %s", sha1_to_hex(entry->idx.sha1));
/*
* make sure no cached delta data remains from a
* previous attempt before a pack split occurred.
*/
free(entry->delta_data);
entry->delta_data = NULL;
entry->z_delta_size = 0;
} else if (entry->delta_data) {
size = entry->delta_size;
buf = entry->delta_data;
entry->delta_data = NULL;
type = (allow_ofs_delta && entry->delta->idx.offset) ?
OBJ_OFS_DELTA : OBJ_REF_DELTA;
} else {
buf = get_delta(entry);
size = entry->delta_size;
type = (allow_ofs_delta && entry->delta->idx.offset) ?
OBJ_OFS_DELTA : OBJ_REF_DELTA;
}
if (entry->z_delta_size)
datalen = entry->z_delta_size;
else
datalen = do_compress(&buf, size);
/*
* The object header is a byte of 'type' followed by zero or
* more bytes of length.
*/
hdrlen = encode_header(type, size, header);
if (type == OBJ_OFS_DELTA) {
/*
* Deltas with relative base contain an additional
* encoding of the relative offset for the delta
* base from this object's position in the pack.
*/
off_t ofs = entry->idx.offset - entry->delta->idx.offset;
unsigned pos = sizeof(dheader) - 1;
dheader[pos] = ofs & 127;
while (ofs >>= 7)
dheader[--pos] = 128 | (--ofs & 127);
if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
free(buf);
return 0;
}
sha1write(f, header, hdrlen);
sha1write(f, dheader + pos, sizeof(dheader) - pos);
hdrlen += sizeof(dheader) - pos;
} else if (type == OBJ_REF_DELTA) {
/*
* Deltas with a base reference contain
* an additional 20 bytes for the base sha1.
*/
if (limit && hdrlen + 20 + datalen + 20 >= limit) {
free(buf);
return 0;
}
sha1write(f, header, hdrlen);
sha1write(f, entry->delta->idx.sha1, 20);
hdrlen += 20;
} else {
if (limit && hdrlen + datalen + 20 >= limit) {
free(buf);
return 0;
}
sha1write(f, header, hdrlen);
}
sha1write(f, buf, datalen);
free(buf);
}
else {
struct packed_git *p = entry->in_pack;
struct pack_window *w_curs = NULL;
struct revindex_entry *revidx;
off_t offset;
if (entry->delta)
type = (allow_ofs_delta && entry->delta->idx.offset) ?
OBJ_OFS_DELTA : OBJ_REF_DELTA;
hdrlen = encode_header(type, entry->size, header);
offset = entry->in_pack_offset;
revidx = find_pack_revindex(p, offset);
datalen = revidx[1].offset - offset;
if (!pack_to_stdout && p->index_version > 1 &&
check_pack_crc(p, &w_curs, offset, datalen, revidx->nr)) {
error("bad packed object CRC for %s", sha1_to_hex(entry->idx.sha1));
unuse_pack(&w_curs);
goto no_reuse;
}
offset += entry->in_pack_header_size;
datalen -= entry->in_pack_header_size;
if (!pack_to_stdout && p->index_version == 1 &&
check_pack_inflate(p, &w_curs, offset, datalen, entry->size)) {
error("corrupt packed object for %s", sha1_to_hex(entry->idx.sha1));
unuse_pack(&w_curs);
goto no_reuse;
}
if (type == OBJ_OFS_DELTA) {
off_t ofs = entry->idx.offset - entry->delta->idx.offset;
unsigned pos = sizeof(dheader) - 1;
dheader[pos] = ofs & 127;
while (ofs >>= 7)
dheader[--pos] = 128 | (--ofs & 127);
if (limit && hdrlen + sizeof(dheader) - pos + datalen + 20 >= limit) {
unuse_pack(&w_curs);
return 0;
}
sha1write(f, header, hdrlen);
sha1write(f, dheader + pos, sizeof(dheader) - pos);
hdrlen += sizeof(dheader) - pos;
reused_delta++;
} else if (type == OBJ_REF_DELTA) {
if (limit && hdrlen + 20 + datalen + 20 >= limit) {
unuse_pack(&w_curs);
return 0;
}
sha1write(f, header, hdrlen);
sha1write(f, entry->delta->idx.sha1, 20);
hdrlen += 20;
reused_delta++;
} else {
if (limit && hdrlen + datalen + 20 >= limit) {
unuse_pack(&w_curs);
return 0;
}
sha1write(f, header, hdrlen);
}
copy_pack_data(f, p, &w_curs, offset, datalen);
unuse_pack(&w_curs);
reused++;
}
if (usable_delta)
written_delta++;
written++;
if (!pack_to_stdout)
entry->idx.crc32 = crc32_end(f);
return hdrlen + datalen;
}
static int write_one(struct sha1file *f,
struct object_entry *e,
off_t *offset)
{
unsigned long size;
/* offset is non zero if object is written already. */
if (e->idx.offset || e->preferred_base)
return 1;
/* if we are deltified, write out base object first. */
if (e->delta && !write_one(f, e->delta, offset))
return 0;
e->idx.offset = *offset;
size = write_object(f, e, *offset);
if (!size) {
e->idx.offset = 0;
return 0;
}
written_list[nr_written++] = &e->idx;
/* make sure off_t is sufficiently large not to wrap */
if (*offset > *offset + size)
die("pack too large for current definition of off_t");
*offset += size;
return 1;
}
/* forward declaration for write_pack_file */
static int adjust_perm(const char *path, mode_t mode);
static void write_pack_file(void)
{
uint32_t i = 0, j;
struct sha1file *f;
off_t offset;
struct pack_header hdr;
uint32_t nr_remaining = nr_result;
time_t last_mtime = 0;
if (progress > pack_to_stdout)
progress_state = start_progress("Writing objects", nr_result);
written_list = xmalloc(nr_objects * sizeof(*written_list));
do {
unsigned char sha1[20];
char *pack_tmp_name = NULL;
if (pack_to_stdout) {
f = sha1fd_throughput(1, "<stdout>", progress_state);
} else {
char tmpname[PATH_MAX];
int fd;
fd = odb_mkstemp(tmpname, sizeof(tmpname),
"pack/tmp_pack_XXXXXX");
pack_tmp_name = xstrdup(tmpname);
f = sha1fd(fd, pack_tmp_name);
}
hdr.hdr_signature = htonl(PACK_SIGNATURE);
hdr.hdr_version = htonl(PACK_VERSION);
hdr.hdr_entries = htonl(nr_remaining);
sha1write(f, &hdr, sizeof(hdr));
offset = sizeof(hdr);
nr_written = 0;
for (; i < nr_objects; i++) {
if (!write_one(f, objects + i, &offset))
break;
display_progress(progress_state, written);
}
/*
* Did we write the wrong # entries in the header?
* If so, rewrite it like in fast-import
*/
if (pack_to_stdout) {
sha1close(f, sha1, CSUM_CLOSE);
} else if (nr_written == nr_remaining) {
sha1close(f, sha1, CSUM_FSYNC);
} else {
int fd = sha1close(f, sha1, 0);
fixup_pack_header_footer(fd, sha1, pack_tmp_name,
nr_written, sha1, offset);
close(fd);
}
if (!pack_to_stdout) {
mode_t mode = umask(0);
struct stat st;
char *idx_tmp_name, tmpname[PATH_MAX];
umask(mode);
mode = 0444 & ~mode;
idx_tmp_name = write_idx_file(NULL, written_list,
nr_written, sha1);
snprintf(tmpname, sizeof(tmpname), "%s-%s.pack",
base_name, sha1_to_hex(sha1));
free_pack_by_name(tmpname);
if (adjust_perm(pack_tmp_name, mode))
die("unable to make temporary pack file readable: %s",
strerror(errno));
if (rename(pack_tmp_name, tmpname))
die("unable to rename temporary pack file: %s",
strerror(errno));
/*
* Packs are runtime accessed in their mtime
* order since newer packs are more likely to contain
* younger objects. So if we are creating multiple
* packs then we should modify the mtime of later ones
* to preserve this property.
*/
if (stat(tmpname, &st) < 0) {
warning("failed to stat %s: %s",
tmpname, strerror(errno));
} else if (!last_mtime) {
last_mtime = st.st_mtime;
} else {
struct utimbuf utb;
utb.actime = st.st_atime;
utb.modtime = --last_mtime;
if (utime(tmpname, &utb) < 0)
warning("failed utime() on %s: %s",
tmpname, strerror(errno));
}
snprintf(tmpname, sizeof(tmpname), "%s-%s.idx",
base_name, sha1_to_hex(sha1));
if (adjust_perm(idx_tmp_name, mode))
die("unable to make temporary index file readable: %s",
strerror(errno));
if (rename(idx_tmp_name, tmpname))
die("unable to rename temporary index file: %s",
strerror(errno));
free(idx_tmp_name);
free(pack_tmp_name);
puts(sha1_to_hex(sha1));
}
/* mark written objects as written to previous pack */
for (j = 0; j < nr_written; j++) {
written_list[j]->offset = (off_t)-1;
}
nr_remaining -= nr_written;
} while (nr_remaining && i < nr_objects);
free(written_list);
stop_progress(&progress_state);
if (written != nr_result)
die("wrote %"PRIu32" objects while expecting %"PRIu32,
written, nr_result);
/*
* We have scanned through [0 ... i). Since we have written
* the correct number of objects, the remaining [i ... nr_objects)
* items must be either already written (due to out-of-order delta base)
* or a preferred base. Count those which are neither and complain if any.
*/
for (j = 0; i < nr_objects; i++) {
struct object_entry *e = objects + i;
j += !e->idx.offset && !e->preferred_base;
}
if (j)
die("wrote %"PRIu32" objects as expected but %"PRIu32
" unwritten", written, j);
}
static int locate_object_entry_hash(const unsigned char *sha1)
{
int i;
unsigned int ui;
memcpy(&ui, sha1, sizeof(unsigned int));
i = ui % object_ix_hashsz;
while (0 < object_ix[i]) {
if (!hashcmp(sha1, objects[object_ix[i] - 1].idx.sha1))
return i;
if (++i == object_ix_hashsz)
i = 0;
}
return -1 - i;
}
static struct object_entry *locate_object_entry(const unsigned char *sha1)
{
int i;
if (!object_ix_hashsz)
return NULL;
i = locate_object_entry_hash(sha1);
if (0 <= i)
return &objects[object_ix[i]-1];
return NULL;
}
static void rehash_objects(void)
{
uint32_t i;
struct object_entry *oe;
object_ix_hashsz = nr_objects * 3;
if (object_ix_hashsz < 1024)
object_ix_hashsz = 1024;
object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
int ix = locate_object_entry_hash(oe->idx.sha1);
if (0 <= ix)
continue;
ix = -1 - ix;
object_ix[ix] = i + 1;
}
}
static unsigned name_hash(const char *name)
{
unsigned c, hash = 0;
if (!name)
return 0;
/*
* This effectively just creates a sortable number from the
* last sixteen non-whitespace characters. Last characters
* count "most", so things that end in ".c" sort together.
*/
while ((c = *name++) != 0) {
if (isspace(c))
continue;
hash = (hash >> 2) + (c << 24);
}
return hash;
}
static void setup_delta_attr_check(struct git_attr_check *check)
{
static struct git_attr *attr_delta;
if (!attr_delta)
attr_delta = git_attr("delta", 5);
check[0].attr = attr_delta;
}
static int no_try_delta(const char *path)
{
struct git_attr_check check[1];
setup_delta_attr_check(check);
if (git_checkattr(path, ARRAY_SIZE(check), check))
return 0;
if (ATTR_FALSE(check->value))
return 1;
return 0;
}
static int add_object_entry(const unsigned char *sha1, enum object_type type,
const char *name, int exclude)
{
struct object_entry *entry;
struct packed_git *p, *found_pack = NULL;
off_t found_offset = 0;
int ix;
unsigned hash = name_hash(name);
ix = nr_objects ? locate_object_entry_hash(sha1) : -1;
if (ix >= 0) {
if (exclude) {
entry = objects + object_ix[ix] - 1;
if (!entry->preferred_base)
nr_result--;
entry->preferred_base = 1;
}
return 0;
}
if (!exclude && local && has_loose_object_nonlocal(sha1))
return 0;
for (p = packed_git; p; p = p->next) {
off_t offset = find_pack_entry_one(sha1, p);
if (offset) {
if (!found_pack) {
found_offset = offset;
found_pack = p;
}
if (exclude)
break;
if (incremental)
return 0;
if (local && !p->pack_local)
return 0;
if (ignore_packed_keep && p->pack_local && p->pack_keep)
return 0;
}
}
if (nr_objects >= nr_alloc) {
nr_alloc = (nr_alloc + 1024) * 3 / 2;
objects = xrealloc(objects, nr_alloc * sizeof(*entry));
}
entry = objects + nr_objects++;
memset(entry, 0, sizeof(*entry));
hashcpy(entry->idx.sha1, sha1);
entry->hash = hash;
if (type)
entry->type = type;
if (exclude)
entry->preferred_base = 1;
else
nr_result++;
if (found_pack) {
entry->in_pack = found_pack;
entry->in_pack_offset = found_offset;
}
if (object_ix_hashsz * 3 <= nr_objects * 4)
rehash_objects();
else
object_ix[-1 - ix] = nr_objects;
display_progress(progress_state, nr_objects);
if (name && no_try_delta(name))
entry->no_try_delta = 1;
return 1;
}
struct pbase_tree_cache {
unsigned char sha1[20];
int ref;
int temporary;
void *tree_data;
unsigned long tree_size;
};
static struct pbase_tree_cache *(pbase_tree_cache[256]);
static int pbase_tree_cache_ix(const unsigned char *sha1)
{
return sha1[0] % ARRAY_SIZE(pbase_tree_cache);
}
static int pbase_tree_cache_ix_incr(int ix)
{
return (ix+1) % ARRAY_SIZE(pbase_tree_cache);
}
static struct pbase_tree {
struct pbase_tree *next;
/* This is a phony "cache" entry; we are not
* going to evict it nor find it through _get()
* mechanism -- this is for the toplevel node that
* would almost always change with any commit.
*/
struct pbase_tree_cache pcache;
} *pbase_tree;
static struct pbase_tree_cache *pbase_tree_get(const unsigned char *sha1)
{
struct pbase_tree_cache *ent, *nent;
void *data;
unsigned long size;
enum object_type type;
int neigh;
int my_ix = pbase_tree_cache_ix(sha1);
int available_ix = -1;
/* pbase-tree-cache acts as a limited hashtable.
* your object will be found at your index or within a few
* slots after that slot if it is cached.
*/
for (neigh = 0; neigh < 8; neigh++) {
ent = pbase_tree_cache[my_ix];
if (ent && !hashcmp(ent->sha1, sha1)) {
ent->ref++;
return ent;
}
else if (((available_ix < 0) && (!ent || !ent->ref)) ||
((0 <= available_ix) &&
(!ent && pbase_tree_cache[available_ix])))
available_ix = my_ix;
if (!ent)
break;
my_ix = pbase_tree_cache_ix_incr(my_ix);
}
/* Did not find one. Either we got a bogus request or
* we need to read and perhaps cache.
*/
data = read_sha1_file(sha1, &type, &size);
if (!data)
return NULL;
if (type != OBJ_TREE) {
free(data);
return NULL;
}
/* We need to either cache or return a throwaway copy */
if (available_ix < 0)
ent = NULL;
else {
ent = pbase_tree_cache[available_ix];
my_ix = available_ix;
}
if (!ent) {
nent = xmalloc(sizeof(*nent));
nent->temporary = (available_ix < 0);
}
else {
/* evict and reuse */
free(ent->tree_data);
nent = ent;
}
hashcpy(nent->sha1, sha1);
nent->tree_data = data;
nent->tree_size = size;
nent->ref = 1;
if (!nent->temporary)
pbase_tree_cache[my_ix] = nent;
return nent;
}
static void pbase_tree_put(struct pbase_tree_cache *cache)
{
if (!cache->temporary) {
cache->ref--;
return;
}
free(cache->tree_data);
free(cache);
}
static int name_cmp_len(const char *name)
{
int i;
for (i = 0; name[i] && name[i] != '\n' && name[i] != '/'; i++)
;
return i;
}
static void add_pbase_object(struct tree_desc *tree,
const char *name,
int cmplen,
const char *fullname)
{
struct name_entry entry;
int cmp;
while (tree_entry(tree,&entry)) {
if (S_ISGITLINK(entry.mode))
continue;
cmp = tree_entry_len(entry.path, entry.sha1) != cmplen ? 1 :
memcmp(name, entry.path, cmplen);
if (cmp > 0)
continue;
if (cmp < 0)
return;
if (name[cmplen] != '/') {
add_object_entry(entry.sha1,
object_type(entry.mode),
fullname, 1);
return;
}
if (S_ISDIR(entry.mode)) {
struct tree_desc sub;
struct pbase_tree_cache *tree;
const char *down = name+cmplen+1;
int downlen = name_cmp_len(down);
tree = pbase_tree_get(entry.sha1);
if (!tree)
return;
init_tree_desc(&sub, tree->tree_data, tree->tree_size);
add_pbase_object(&sub, down, downlen, fullname);
pbase_tree_put(tree);
}
}
}
static unsigned *done_pbase_paths;
static int done_pbase_paths_num;
static int done_pbase_paths_alloc;
static int done_pbase_path_pos(unsigned hash)
{
int lo = 0;
int hi = done_pbase_paths_num;
while (lo < hi) {
int mi = (hi + lo) / 2;
if (done_pbase_paths[mi] == hash)
return mi;
if (done_pbase_paths[mi] < hash)
hi = mi;
else
lo = mi + 1;
}
return -lo-1;
}
static int check_pbase_path(unsigned hash)
{
int pos = (!done_pbase_paths) ? -1 : done_pbase_path_pos(hash);
if (0 <= pos)
return 1;
pos = -pos - 1;
if (done_pbase_paths_alloc <= done_pbase_paths_num) {
done_pbase_paths_alloc = alloc_nr(done_pbase_paths_alloc);
done_pbase_paths = xrealloc(done_pbase_paths,
done_pbase_paths_alloc *
sizeof(unsigned));
}
done_pbase_paths_num++;
if (pos < done_pbase_paths_num)
memmove(done_pbase_paths + pos + 1,
done_pbase_paths + pos,
(done_pbase_paths_num - pos - 1) * sizeof(unsigned));
done_pbase_paths[pos] = hash;
return 0;
}
static void add_preferred_base_object(const char *name)
{
struct pbase_tree *it;
int cmplen;
unsigned hash = name_hash(name);
if (!num_preferred_base || check_pbase_path(hash))
return;
cmplen = name_cmp_len(name);
for (it = pbase_tree; it; it = it->next) {
if (cmplen == 0) {
add_object_entry(it->pcache.sha1, OBJ_TREE, NULL, 1);
}
else {
struct tree_desc tree;
init_tree_desc(&tree, it->pcache.tree_data, it->pcache.tree_size);
add_pbase_object(&tree, name, cmplen, name);
}
}
}
static void add_preferred_base(unsigned char *sha1)
{
struct pbase_tree *it;
void *data;
unsigned long size;
unsigned char tree_sha1[20];
if (window <= num_preferred_base++)
return;
data = read_object_with_reference(sha1, tree_type, &size, tree_sha1);
if (!data)
return;
for (it = pbase_tree; it; it = it->next) {
if (!hashcmp(it->pcache.sha1, tree_sha1)) {
free(data);
return;
}
}
it = xcalloc(1, sizeof(*it));
it->next = pbase_tree;
pbase_tree = it;
hashcpy(it->pcache.sha1, tree_sha1);
it->pcache.tree_data = data;
it->pcache.tree_size = size;
}
static void check_object(struct object_entry *entry)
{
if (entry->in_pack) {
struct packed_git *p = entry->in_pack;
struct pack_window *w_curs = NULL;
const unsigned char *base_ref = NULL;
struct object_entry *base_entry;
unsigned long used, used_0;
unsigned int avail;
off_t ofs;
unsigned char *buf, c;
buf = use_pack(p, &w_curs, entry->in_pack_offset, &avail);
/*
* We want in_pack_type even if we do not reuse delta
* since non-delta representations could still be reused.
*/
used = unpack_object_header_buffer(buf, avail,
&entry->in_pack_type,
&entry->size);
if (used == 0)
goto give_up;
/*
* Determine if this is a delta and if so whether we can
* reuse it or not. Otherwise let's find out as cheaply as
* possible what the actual type and size for this object is.
*/
switch (entry->in_pack_type) {
default:
/* Not a delta hence we've already got all we need. */
entry->type = entry->in_pack_type;
entry->in_pack_header_size = used;
if (entry->type < OBJ_COMMIT || entry->type > OBJ_BLOB)
goto give_up;
unuse_pack(&w_curs);
return;
case OBJ_REF_DELTA:
if (reuse_delta && !entry->preferred_base)
base_ref = use_pack(p, &w_curs,
entry->in_pack_offset + used, NULL);
entry->in_pack_header_size = used + 20;
break;
case OBJ_OFS_DELTA:
buf = use_pack(p, &w_curs,
entry->in_pack_offset + used, NULL);
used_0 = 0;
c = buf[used_0++];
ofs = c & 127;
while (c & 128) {
ofs += 1;
if (!ofs || MSB(ofs, 7)) {
error("delta base offset overflow in pack for %s",
sha1_to_hex(entry->idx.sha1));
goto give_up;
}
c = buf[used_0++];
ofs = (ofs << 7) + (c & 127);
}
ofs = entry->in_pack_offset - ofs;
if (ofs <= 0 || ofs >= entry->in_pack_offset) {
error("delta base offset out of bound for %s",
sha1_to_hex(entry->idx.sha1));
goto give_up;
}
if (reuse_delta && !entry->preferred_base) {
struct revindex_entry *revidx;
revidx = find_pack_revindex(p, ofs);
if (!revidx)
goto give_up;
base_ref = nth_packed_object_sha1(p, revidx->nr);
}
entry->in_pack_header_size = used + used_0;
break;
}
if (base_ref && (base_entry = locate_object_entry(base_ref))) {
/*
* If base_ref was set above that means we wish to
* reuse delta data, and we even found that base
* in the list of objects we want to pack. Goodie!
*
* Depth value does not matter - find_deltas() will
* never consider reused delta as the base object to
* deltify other objects against, in order to avoid
* circular deltas.
*/
entry->type = entry->in_pack_type;
entry->delta = base_entry;
entry->delta_size = entry->size;
entry->delta_sibling = base_entry->delta_child;
base_entry->delta_child = entry;
unuse_pack(&w_curs);
return;
}
if (entry->type) {
/*
* This must be a delta and we already know what the
* final object type is. Let's extract the actual
* object size from the delta header.
*/
entry->size = get_size_from_delta(p, &w_curs,
entry->in_pack_offset + entry->in_pack_header_size);
if (entry->size == 0)
goto give_up;
unuse_pack(&w_curs);
return;
}
/*
* No choice but to fall back to the recursive delta walk
* with sha1_object_info() to find about the object type
* at this point...
*/
give_up:
unuse_pack(&w_curs);
}
entry->type = sha1_object_info(entry->idx.sha1, &entry->size);
/*
* The error condition is checked in prepare_pack(). This is
* to permit a missing preferred base object to be ignored
* as a preferred base. Doing so can result in a larger
* pack file, but the transfer will still take place.
*/
}
static int pack_offset_sort(const void *_a, const void *_b)
{
const struct object_entry *a = *(struct object_entry **)_a;
const struct object_entry *b = *(struct object_entry **)_b;
/* avoid filesystem trashing with loose objects */
if (!a->in_pack && !b->in_pack)
return hashcmp(a->idx.sha1, b->idx.sha1);
if (a->in_pack < b->in_pack)
return -1;
if (a->in_pack > b->in_pack)
return 1;
return a->in_pack_offset < b->in_pack_offset ? -1 :
(a->in_pack_offset > b->in_pack_offset);
}
static void get_object_details(void)
{
uint32_t i;
struct object_entry **sorted_by_offset;
sorted_by_offset = xcalloc(nr_objects, sizeof(struct object_entry *));
for (i = 0; i < nr_objects; i++)
sorted_by_offset[i] = objects + i;
qsort(sorted_by_offset, nr_objects, sizeof(*sorted_by_offset), pack_offset_sort);
for (i = 0; i < nr_objects; i++)
check_object(sorted_by_offset[i]);
free(sorted_by_offset);
}
/*
* We search for deltas in a list sorted by type, by filename hash, and then
* by size, so that we see progressively smaller and smaller files.
* That's because we prefer deltas to be from the bigger file
* to the smaller -- deletes are potentially cheaper, but perhaps
* more importantly, the bigger file is likely the more recent
* one. The deepest deltas are therefore the oldest objects which are
* less susceptible to be accessed often.
*/
static int type_size_sort(const void *_a, const void *_b)
{
const struct object_entry *a = *(struct object_entry **)_a;
const struct object_entry *b = *(struct object_entry **)_b;
if (a->type > b->type)
return -1;
if (a->type < b->type)
return 1;
if (a->hash > b->hash)
return -1;
if (a->hash < b->hash)
return 1;
if (a->preferred_base > b->preferred_base)
return -1;
if (a->preferred_base < b->preferred_base)
return 1;
if (a->size > b->size)
return -1;
if (a->size < b->size)
return 1;
return a < b ? -1 : (a > b); /* newest first */
}
struct unpacked {
struct object_entry *entry;
void *data;
struct delta_index *index;
unsigned depth;
};
static int delta_cacheable(unsigned long src_size, unsigned long trg_size,
unsigned long delta_size)
{
if (max_delta_cache_size && delta_cache_size + delta_size > max_delta_cache_size)
return 0;
if (delta_size < cache_max_small_delta_size)
return 1;
/* cache delta, if objects are large enough compared to delta size */
if ((src_size >> 20) + (trg_size >> 21) > (delta_size >> 10))
return 1;
return 0;
}
#ifdef THREADED_DELTA_SEARCH
static pthread_mutex_t read_mutex = PTHREAD_MUTEX_INITIALIZER;
#define read_lock() pthread_mutex_lock(&read_mutex)
#define read_unlock() pthread_mutex_unlock(&read_mutex)
static pthread_mutex_t cache_mutex = PTHREAD_MUTEX_INITIALIZER;
#define cache_lock() pthread_mutex_lock(&cache_mutex)
#define cache_unlock() pthread_mutex_unlock(&cache_mutex)
static pthread_mutex_t progress_mutex = PTHREAD_MUTEX_INITIALIZER;
#define progress_lock() pthread_mutex_lock(&progress_mutex)
#define progress_unlock() pthread_mutex_unlock(&progress_mutex)
#else
#define read_lock() (void)0
#define read_unlock() (void)0
#define cache_lock() (void)0
#define cache_unlock() (void)0
#define progress_lock() (void)0
#define progress_unlock() (void)0
#endif
static int try_delta(struct unpacked *trg, struct unpacked *src,
unsigned max_depth, unsigned long *mem_usage)
{
struct object_entry *trg_entry = trg->entry;
struct object_entry *src_entry = src->entry;
unsigned long trg_size, src_size, delta_size, sizediff, max_size, sz;
unsigned ref_depth;
enum object_type type;
void *delta_buf;
/* Don't bother doing diffs between different types */
if (trg_entry->type != src_entry->type)
return -1;
/*
* We do not bother to try a delta that we discarded
* on an earlier try, but only when reusing delta data.
*/
if (reuse_delta && trg_entry->in_pack &&
trg_entry->in_pack == src_entry->in_pack &&
trg_entry->in_pack_type != OBJ_REF_DELTA &&
trg_entry->in_pack_type != OBJ_OFS_DELTA)
return 0;
/* Let's not bust the allowed depth. */
if (src->depth >= max_depth)
return 0;
/* Now some size filtering heuristics. */
trg_size = trg_entry->size;
if (!trg_entry->delta) {
max_size = trg_size/2 - 20;
ref_depth = 1;
} else {
max_size = trg_entry->delta_size;
ref_depth = trg->depth;
}
max_size = (uint64_t)max_size * (max_depth - src->depth) /
(max_depth - ref_depth + 1);
if (max_size == 0)
return 0;
src_size = src_entry->size;
sizediff = src_size < trg_size ? trg_size - src_size : 0;
if (sizediff >= max_size)
return 0;
if (trg_size < src_size / 32)
return 0;
/* Load data if not already done */
if (!trg->data) {
read_lock();
trg->data = read_sha1_file(trg_entry->idx.sha1, &type, &sz);
read_unlock();
if (!trg->data)
die("object %s cannot be read",
sha1_to_hex(trg_entry->idx.sha1));
if (sz != trg_size)
die("object %s inconsistent object length (%lu vs %lu)",
sha1_to_hex(trg_entry->idx.sha1), sz, trg_size);
*mem_usage += sz;
}
if (!src->data) {
read_lock();
src->data = read_sha1_file(src_entry->idx.sha1, &type, &sz);
read_unlock();
if (!src->data)
die("object %s cannot be read",
sha1_to_hex(src_entry->idx.sha1));
if (sz != src_size)
die("object %s inconsistent object length (%lu vs %lu)",
sha1_to_hex(src_entry->idx.sha1), sz, src_size);
*mem_usage += sz;
}
if (!src->index) {
src->index = create_delta_index(src->data, src_size);
if (!src->index) {
static int warned = 0;
if (!warned++)
warning("suboptimal pack - out of memory");
return 0;
}
*mem_usage += sizeof_delta_index(src->index);
}
delta_buf = create_delta(src->index, trg->data, trg_size, &delta_size, max_size);
if (!delta_buf)
return 0;
if (trg_entry->delta) {
/* Prefer only shallower same-sized deltas. */
if (delta_size == trg_entry->delta_size &&
src->depth + 1 >= trg->depth) {
free(delta_buf);
return 0;
}
}
/*
* Handle memory allocation outside of the cache
* accounting lock. Compiler will optimize the strangeness
* away when THREADED_DELTA_SEARCH is not defined.
*/
free(trg_entry->delta_data);
cache_lock();
if (trg_entry->delta_data) {
delta_cache_size -= trg_entry->delta_size;
trg_entry->delta_data = NULL;
}
if (delta_cacheable(src_size, trg_size, delta_size)) {
delta_cache_size += delta_size;
cache_unlock();
trg_entry->delta_data = xrealloc(delta_buf, delta_size);
} else {
cache_unlock();
free(delta_buf);
}
trg_entry->delta = src_entry;
trg_entry->delta_size = delta_size;
trg->depth = src->depth + 1;
return 1;
}
static unsigned int check_delta_limit(struct object_entry *me, unsigned int n)
{
struct object_entry *child = me->delta_child;
unsigned int m = n;
while (child) {
unsigned int c = check_delta_limit(child, n + 1);
if (m < c)
m = c;
child = child->delta_sibling;
}
return m;
}
static unsigned long free_unpacked(struct unpacked *n)
{
unsigned long freed_mem = sizeof_delta_index(n->index);
free_delta_index(n->index);
n->index = NULL;
if (n->data) {
freed_mem += n->entry->size;
free(n->data);
n->data = NULL;
}
n->entry = NULL;
n->depth = 0;
return freed_mem;
}
static void find_deltas(struct object_entry **list, unsigned *list_size,
int window, int depth, unsigned *processed)
{
uint32_t i, idx = 0, count = 0;
struct unpacked *array;
unsigned long mem_usage = 0;
array = xcalloc(window, sizeof(struct unpacked));
for (;;) {
struct object_entry *entry;
struct unpacked *n = array + idx;
int j, max_depth, best_base = -1;
progress_lock();
if (!*list_size) {
progress_unlock();
break;
}
entry = *list++;
(*list_size)--;
if (!entry->preferred_base) {
(*processed)++;
display_progress(progress_state, *processed);
}
progress_unlock();
mem_usage -= free_unpacked(n);
n->entry = entry;
while (window_memory_limit &&
mem_usage > window_memory_limit &&
count > 1) {
uint32_t tail = (idx + window - count) % window;
mem_usage -= free_unpacked(array + tail);
count--;
}
/* We do not compute delta to *create* objects we are not
* going to pack.
*/
if (entry->preferred_base)
goto next;
/*
* If the current object is at pack edge, take the depth the
* objects that depend on the current object into account
* otherwise they would become too deep.
*/
max_depth = depth;
if (entry->delta_child) {
max_depth -= check_delta_limit(entry, 0);
if (max_depth <= 0)
goto next;
}
j = window;
while (--j > 0) {
int ret;
uint32_t other_idx = idx + j;
struct unpacked *m;
if (other_idx >= window)
other_idx -= window;
m = array + other_idx;
if (!m->entry)
break;
ret = try_delta(n, m, max_depth, &mem_usage);
if (ret < 0)
break;
else if (ret > 0)
best_base = other_idx;
}
/*
* If we decided to cache the delta data, then it is best
* to compress it right away. First because we have to do
* it anyway, and doing it here while we're threaded will
* save a lot of time in the non threaded write phase,
* as well as allow for caching more deltas within
* the same cache size limit.
* ...
* But only if not writing to stdout, since in that case
* the network is most likely throttling writes anyway,
* and therefore it is best to go to the write phase ASAP
* instead, as we can afford spending more time compressing
* between writes at that moment.
*/
if (entry->delta_data && !pack_to_stdout) {
entry->z_delta_size = do_compress(&entry->delta_data,
entry->delta_size);
cache_lock();
delta_cache_size -= entry->delta_size;
delta_cache_size += entry->z_delta_size;
cache_unlock();
}
/* if we made n a delta, and if n is already at max
* depth, leaving it in the window is pointless. we
* should evict it first.
*/
if (entry->delta && max_depth <= n->depth)
continue;
/*
* Move the best delta base up in the window, after the
* currently deltified object, to keep it longer. It will
* be the first base object to be attempted next.
*/
if (entry->delta) {
struct unpacked swap = array[best_base];
int dist = (window + idx - best_base) % window;
int dst = best_base;
while (dist--) {
int src = (dst + 1) % window;
array[dst] = array[src];
dst = src;
}
array[dst] = swap;
}
next:
idx++;
if (count + 1 < window)
count++;
if (idx >= window)
idx = 0;
}
for (i = 0; i < window; ++i) {
free_delta_index(array[i].index);
free(array[i].data);
}
free(array);
}
#ifdef THREADED_DELTA_SEARCH
/*
* The main thread waits on the condition that (at least) one of the workers
* has stopped working (which is indicated in the .working member of
* struct thread_params).
* When a work thread has completed its work, it sets .working to 0 and
* signals the main thread and waits on the condition that .data_ready
* becomes 1.
*/
struct thread_params {
pthread_t thread;
struct object_entry **list;
unsigned list_size;
unsigned remaining;
int window;
int depth;
int working;
int data_ready;
pthread_mutex_t mutex;
pthread_cond_t cond;
unsigned *processed;
};
static pthread_cond_t progress_cond = PTHREAD_COND_INITIALIZER;
static void *threaded_find_deltas(void *arg)
{
struct thread_params *me = arg;
while (me->remaining) {
find_deltas(me->list, &me->remaining,
me->window, me->depth, me->processed);
progress_lock();
me->working = 0;
pthread_cond_signal(&progress_cond);
progress_unlock();
/*
* We must not set ->data_ready before we wait on the
* condition because the main thread may have set it to 1
* before we get here. In order to be sure that new
* work is available if we see 1 in ->data_ready, it
* was initialized to 0 before this thread was spawned
* and we reset it to 0 right away.
*/
pthread_mutex_lock(&me->mutex);
while (!me->data_ready)
pthread_cond_wait(&me->cond, &me->mutex);
me->data_ready = 0;
pthread_mutex_unlock(&me->mutex);
}
/* leave ->working 1 so that this doesn't get more work assigned */
return NULL;
}
static void ll_find_deltas(struct object_entry **list, unsigned list_size,
int window, int depth, unsigned *processed)
{
struct thread_params p[delta_search_threads];
int i, ret, active_threads = 0;
if (delta_search_threads <= 1) {
find_deltas(list, &list_size, window, depth, processed);
return;
}
if (progress > pack_to_stdout)
fprintf(stderr, "Delta compression using up to %d threads.\n",
delta_search_threads);
/* Partition the work amongst work threads. */
for (i = 0; i < delta_search_threads; i++) {
unsigned sub_size = list_size / (delta_search_threads - i);
/* don't use too small segments or no deltas will be found */
if (sub_size < 2*window && i+1 < delta_search_threads)
sub_size = 0;
p[i].window = window;
p[i].depth = depth;
p[i].processed = processed;
p[i].working = 1;
p[i].data_ready = 0;
/* try to split chunks on "path" boundaries */
while (sub_size && sub_size < list_size &&
list[sub_size]->hash &&
list[sub_size]->hash == list[sub_size-1]->hash)
sub_size++;
p[i].list = list;
p[i].list_size = sub_size;
p[i].remaining = sub_size;
list += sub_size;
list_size -= sub_size;
}
/* Start work threads. */
for (i = 0; i < delta_search_threads; i++) {
if (!p[i].list_size)
continue;
pthread_mutex_init(&p[i].mutex, NULL);
pthread_cond_init(&p[i].cond, NULL);
ret = pthread_create(&p[i].thread, NULL,
threaded_find_deltas, &p[i]);
if (ret)
die("unable to create thread: %s", strerror(ret));
active_threads++;
}
/*
* Now let's wait for work completion. Each time a thread is done
* with its work, we steal half of the remaining work from the
* thread with the largest number of unprocessed objects and give
* it to that newly idle thread. This ensure good load balancing
* until the remaining object list segments are simply too short
* to be worth splitting anymore.
*/
while (active_threads) {
struct thread_params *target = NULL;
struct thread_params *victim = NULL;
unsigned sub_size = 0;
progress_lock();
for (;;) {
for (i = 0; !target && i < delta_search_threads; i++)
if (!p[i].working)
target = &p[i];
if (target)
break;
pthread_cond_wait(&progress_cond, &progress_mutex);
}
for (i = 0; i < delta_search_threads; i++)
if (p[i].remaining > 2*window &&
(!victim || victim->remaining < p[i].remaining))
victim = &p[i];
if (victim) {
sub_size = victim->remaining / 2;
list = victim->list + victim->list_size - sub_size;
while (sub_size && list[0]->hash &&
list[0]->hash == list[-1]->hash) {
list++;
sub_size--;
}
if (!sub_size) {
/*
* It is possible for some "paths" to have
* so many objects that no hash boundary
* might be found. Let's just steal the
* exact half in that case.
*/
sub_size = victim->remaining / 2;
list -= sub_size;
}
target->list = list;
victim->list_size -= sub_size;
victim->remaining -= sub_size;
}
target->list_size = sub_size;
target->remaining = sub_size;
target->working = 1;
progress_unlock();
pthread_mutex_lock(&target->mutex);
target->data_ready = 1;
pthread_cond_signal(&target->cond);
pthread_mutex_unlock(&target->mutex);
if (!sub_size) {
pthread_join(target->thread, NULL);
pthread_cond_destroy(&target->cond);
pthread_mutex_destroy(&target->mutex);
active_threads--;
}
}
}
#else
#define ll_find_deltas(l, s, w, d, p) find_deltas(l, &s, w, d, p)
#endif
static int add_ref_tag(const char *path, const unsigned char *sha1, int flag, void *cb_data)
{
unsigned char peeled[20];
if (!prefixcmp(path, "refs/tags/") && /* is a tag? */
!peel_ref(path, peeled) && /* peelable? */
!is_null_sha1(peeled) && /* annotated tag? */
locate_object_entry(peeled)) /* object packed? */
add_object_entry(sha1, OBJ_TAG, NULL, 0);
return 0;
}
static void prepare_pack(int window, int depth)
{
struct object_entry **delta_list;
uint32_t i, nr_deltas;
unsigned n;
get_object_details();
/*
* If we're locally repacking then we need to be doubly careful
* from now on in order to make sure no stealth corruption gets
* propagated to the new pack. Clients receiving streamed packs
* should validate everything they get anyway so no need to incur
* the additional cost here in that case.
*/
if (!pack_to_stdout)
do_check_packed_object_crc = 1;
if (!nr_objects || !window || !depth)
return;
delta_list = xmalloc(nr_objects * sizeof(*delta_list));
nr_deltas = n = 0;
for (i = 0; i < nr_objects; i++) {
struct object_entry *entry = objects + i;
if (entry->delta)
/* This happens if we decided to reuse existing
* delta from a pack. "reuse_delta &&" is implied.
*/
continue;
if (entry->size < 50)
continue;
if (entry->no_try_delta)
continue;
if (!entry->preferred_base) {
nr_deltas++;
if (entry->type < 0)
die("unable to get type of object %s",
sha1_to_hex(entry->idx.sha1));
} else {
if (entry->type < 0) {
/*
* This object is not found, but we
* don't have to include it anyway.
*/
continue;
}
}
delta_list[n++] = entry;
}
if (nr_deltas && n > 1) {
unsigned nr_done = 0;
if (progress)
progress_state = start_progress("Compressing objects",
nr_deltas);
qsort(delta_list, n, sizeof(*delta_list), type_size_sort);
ll_find_deltas(delta_list, n, window+1, depth, &nr_done);
stop_progress(&progress_state);
if (nr_done != nr_deltas)
die("inconsistency with delta count");
}
free(delta_list);
}
static int git_pack_config(const char *k, const char *v, void *cb)
{
if(!strcmp(k, "pack.window")) {
window = git_config_int(k, v);
return 0;
}
if (!strcmp(k, "pack.windowmemory")) {
window_memory_limit = git_config_ulong(k, v);
return 0;
}
if (!strcmp(k, "pack.depth")) {
depth = git_config_int(k, v);
return 0;
}
if (!strcmp(k, "pack.compression")) {
int level = git_config_int(k, v);
if (level == -1)
level = Z_DEFAULT_COMPRESSION;
else if (level < 0 || level > Z_BEST_COMPRESSION)
die("bad pack compression level %d", level);
pack_compression_level = level;
pack_compression_seen = 1;
return 0;
}
if (!strcmp(k, "pack.deltacachesize")) {
max_delta_cache_size = git_config_int(k, v);
return 0;
}
if (!strcmp(k, "pack.deltacachelimit")) {
cache_max_small_delta_size = git_config_int(k, v);
return 0;
}
if (!strcmp(k, "pack.threads")) {
delta_search_threads = git_config_int(k, v);
if (delta_search_threads < 0)
die("invalid number of threads specified (%d)",
delta_search_threads);
#ifndef THREADED_DELTA_SEARCH
if (delta_search_threads != 1)
warning("no threads support, ignoring %s", k);
#endif
return 0;
}
if (!strcmp(k, "pack.indexversion")) {
pack_idx_default_version = git_config_int(k, v);
if (pack_idx_default_version > 2)
die("bad pack.indexversion=%"PRIu32,
pack_idx_default_version);
return 0;
}
if (!strcmp(k, "pack.packsizelimit")) {
pack_size_limit_cfg = git_config_ulong(k, v);
return 0;
}
return git_default_config(k, v, cb);
}
static void read_object_list_from_stdin(void)
{
char line[40 + 1 + PATH_MAX + 2];
unsigned char sha1[20];
for (;;) {
if (!fgets(line, sizeof(line), stdin)) {
if (feof(stdin))
break;
if (!ferror(stdin))
die("fgets returned NULL, not EOF, not error!");
if (errno != EINTR)
die("fgets: %s", strerror(errno));
clearerr(stdin);
continue;
}
if (line[0] == '-') {
if (get_sha1_hex(line+1, sha1))
die("expected edge sha1, got garbage:\n %s",
line);
add_preferred_base(sha1);
continue;
}
if (get_sha1_hex(line, sha1))
die("expected sha1, got garbage:\n %s", line);
add_preferred_base_object(line+41);
add_object_entry(sha1, 0, line+41, 0);
}
}
#define OBJECT_ADDED (1u<<20)
static void show_commit(struct commit *commit, void *data)
{
add_object_entry(commit->object.sha1, OBJ_COMMIT, NULL, 0);
commit->object.flags |= OBJECT_ADDED;
}
static void show_object(struct object *obj, const struct name_path *path, const char *last)
{
char *name = path_name(path, last);
add_preferred_base_object(name);
add_object_entry(obj->sha1, obj->type, name, 0);
obj->flags |= OBJECT_ADDED;
/*
* We will have generated the hash from the name,
* but not saved a pointer to it - we can free it
*/
free((char *)name);
}
static void show_edge(struct commit *commit)
{
add_preferred_base(commit->object.sha1);
}
struct in_pack_object {
off_t offset;
struct object *object;
};
struct in_pack {
int alloc;
int nr;
struct in_pack_object *array;
};
static void mark_in_pack_object(struct object *object, struct packed_git *p, struct in_pack *in_pack)
{
in_pack->array[in_pack->nr].offset = find_pack_entry_one(object->sha1, p);
in_pack->array[in_pack->nr].object = object;
in_pack->nr++;
}
/*
* Compare the objects in the offset order, in order to emulate the
* "git rev-list --objects" output that produced the pack originally.
*/
static int ofscmp(const void *a_, const void *b_)
{
struct in_pack_object *a = (struct in_pack_object *)a_;
struct in_pack_object *b = (struct in_pack_object *)b_;
if (a->offset < b->offset)
return -1;
else if (a->offset > b->offset)
return 1;
else
return hashcmp(a->object->sha1, b->object->sha1);
}
static void add_objects_in_unpacked_packs(struct rev_info *revs)
{
struct packed_git *p;
struct in_pack in_pack;
uint32_t i;
memset(&in_pack, 0, sizeof(in_pack));
for (p = packed_git; p; p = p->next) {
const unsigned char *sha1;
struct object *o;
if (!p->pack_local || p->pack_keep)
continue;
if (open_pack_index(p))
die("cannot open pack index");
ALLOC_GROW(in_pack.array,
in_pack.nr + p->num_objects,
in_pack.alloc);
for (i = 0; i < p->num_objects; i++) {
sha1 = nth_packed_object_sha1(p, i);
o = lookup_unknown_object(sha1);
if (!(o->flags & OBJECT_ADDED))
mark_in_pack_object(o, p, &in_pack);
o->flags |= OBJECT_ADDED;
}
}
if (in_pack.nr) {
qsort(in_pack.array, in_pack.nr, sizeof(in_pack.array[0]),
ofscmp);
for (i = 0; i < in_pack.nr; i++) {
struct object *o = in_pack.array[i].object;
add_object_entry(o->sha1, o->type, "", 0);
}
}
free(in_pack.array);
}
static int has_sha1_pack_kept_or_nonlocal(const unsigned char *sha1)
{
static struct packed_git *last_found = (void *)1;
struct packed_git *p;
p = (last_found != (void *)1) ? last_found : packed_git;
while (p) {
if ((!p->pack_local || p->pack_keep) &&
find_pack_entry_one(sha1, p)) {
last_found = p;
return 1;
}
if (p == last_found)
p = packed_git;
else
p = p->next;
if (p == last_found)
p = p->next;
}
return 0;
}
static void loosen_unused_packed_objects(struct rev_info *revs)
{
struct packed_git *p;
uint32_t i;
const unsigned char *sha1;
for (p = packed_git; p; p = p->next) {
if (!p->pack_local || p->pack_keep)
continue;
if (open_pack_index(p))
die("cannot open pack index");
for (i = 0; i < p->num_objects; i++) {
sha1 = nth_packed_object_sha1(p, i);
if (!locate_object_entry(sha1) &&
!has_sha1_pack_kept_or_nonlocal(sha1))
if (force_object_loose(sha1, p->mtime))
die("unable to force loose object");
}
}
}
static void get_object_list(int ac, const char **av)
{
struct rev_info revs;
char line[1000];
int flags = 0;
init_revisions(&revs, NULL);
save_commit_buffer = 0;
setup_revisions(ac, av, &revs, NULL);
while (fgets(line, sizeof(line), stdin) != NULL) {
int len = strlen(line);
if (len && line[len - 1] == '\n')
line[--len] = 0;
if (!len)
break;
if (*line == '-') {
if (!strcmp(line, "--not")) {
flags ^= UNINTERESTING;
continue;
}
die("not a rev '%s'", line);
}
if (handle_revision_arg(line, &revs, flags, 1))
die("bad revision '%s'", line);
}
if (prepare_revision_walk(&revs))
die("revision walk setup failed");
mark_edges_uninteresting(revs.commits, &revs, show_edge);
traverse_commit_list(&revs, show_commit, show_object, NULL);
if (keep_unreachable)
add_objects_in_unpacked_packs(&revs);
if (unpack_unreachable)
loosen_unused_packed_objects(&revs);
}
static int adjust_perm(const char *path, mode_t mode)
{
if (chmod(path, mode))
return -1;
return adjust_shared_perm(path);
}
int cmd_pack_objects(int argc, const char **argv, const char *prefix)
{
int use_internal_rev_list = 0;
int thin = 0;
uint32_t i;
const char **rp_av;
int rp_ac_alloc = 64;
int rp_ac;
rp_av = xcalloc(rp_ac_alloc, sizeof(*rp_av));
rp_av[0] = "pack-objects";
rp_av[1] = "--objects"; /* --thin will make it --objects-edge */
rp_ac = 2;
git_config(git_pack_config, NULL);
if (!pack_compression_seen && core_compression_seen)
pack_compression_level = core_compression_level;
progress = isatty(2);
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (*arg != '-')
break;
if (!strcmp("--non-empty", arg)) {
non_empty = 1;
continue;
}
if (!strcmp("--local", arg)) {
local = 1;
continue;
}
if (!strcmp("--incremental", arg)) {
incremental = 1;
continue;
}
if (!strcmp("--honor-pack-keep", arg)) {
ignore_packed_keep = 1;
continue;
}
if (!prefixcmp(arg, "--compression=")) {
char *end;
int level = strtoul(arg+14, &end, 0);
if (!arg[14] || *end)
usage(pack_usage);
if (level == -1)
level = Z_DEFAULT_COMPRESSION;
else if (level < 0 || level > Z_BEST_COMPRESSION)
die("bad pack compression level %d", level);
pack_compression_level = level;
continue;
}
if (!prefixcmp(arg, "--max-pack-size=")) {
char *end;
pack_size_limit_cfg = 0;
pack_size_limit = strtoul(arg+16, &end, 0) * 1024 * 1024;
if (!arg[16] || *end)
usage(pack_usage);
continue;
}
if (!prefixcmp(arg, "--window=")) {
char *end;
window = strtoul(arg+9, &end, 0);
if (!arg[9] || *end)
usage(pack_usage);
continue;
}
if (!prefixcmp(arg, "--window-memory=")) {
if (!git_parse_ulong(arg+16, &window_memory_limit))
usage(pack_usage);
continue;
}
if (!prefixcmp(arg, "--threads=")) {
char *end;
delta_search_threads = strtoul(arg+10, &end, 0);
if (!arg[10] || *end || delta_search_threads < 0)
usage(pack_usage);
#ifndef THREADED_DELTA_SEARCH
if (delta_search_threads != 1)
warning("no threads support, "
"ignoring %s", arg);
#endif
continue;
}
if (!prefixcmp(arg, "--depth=")) {
char *end;
depth = strtoul(arg+8, &end, 0);
if (!arg[8] || *end)
usage(pack_usage);
continue;
}
if (!strcmp("--progress", arg)) {
progress = 1;
continue;
}
if (!strcmp("--all-progress", arg)) {
progress = 2;
continue;
}
if (!strcmp("-q", arg)) {
progress = 0;
continue;
}
if (!strcmp("--no-reuse-delta", arg)) {
reuse_delta = 0;
continue;
}
if (!strcmp("--no-reuse-object", arg)) {
reuse_object = reuse_delta = 0;
continue;
}
if (!strcmp("--delta-base-offset", arg)) {
allow_ofs_delta = 1;
continue;
}
if (!strcmp("--stdout", arg)) {
pack_to_stdout = 1;
continue;
}
if (!strcmp("--revs", arg)) {
use_internal_rev_list = 1;
continue;
}
if (!strcmp("--keep-unreachable", arg)) {
keep_unreachable = 1;
continue;
}
if (!strcmp("--unpack-unreachable", arg)) {
unpack_unreachable = 1;
continue;
}
if (!strcmp("--include-tag", arg)) {
include_tag = 1;
continue;
}
if (!strcmp("--unpacked", arg) ||
!strcmp("--reflog", arg) ||
!strcmp("--all", arg)) {
use_internal_rev_list = 1;
if (rp_ac >= rp_ac_alloc - 1) {
rp_ac_alloc = alloc_nr(rp_ac_alloc);
rp_av = xrealloc(rp_av,
rp_ac_alloc * sizeof(*rp_av));
}
rp_av[rp_ac++] = arg;
continue;
}
if (!strcmp("--thin", arg)) {
use_internal_rev_list = 1;
thin = 1;
rp_av[1] = "--objects-edge";
continue;
}
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);
continue;
}
usage(pack_usage);
}
/* Traditionally "pack-objects [options] base extra" failed;
* we would however want to take refs parameter that would
* have been given to upstream rev-list ourselves, which means
* we somehow want to say what the base name is. So the
* syntax would be:
*
* pack-objects [options] base <refs...>
*
* in other words, we would treat the first non-option as the
* base_name and send everything else to the internal revision
* walker.
*/
if (!pack_to_stdout)
base_name = argv[i++];
if (pack_to_stdout != !base_name)
usage(pack_usage);
if (!pack_to_stdout && !pack_size_limit)
pack_size_limit = pack_size_limit_cfg;
if (pack_to_stdout && pack_size_limit)
die("--max-pack-size cannot be used to build a pack for transfer.");
if (!pack_to_stdout && thin)
die("--thin cannot be used to build an indexable pack.");
if (keep_unreachable && unpack_unreachable)
die("--keep-unreachable and --unpack-unreachable are incompatible.");
#ifdef THREADED_DELTA_SEARCH
if (!delta_search_threads) /* --threads=0 means autodetect */
delta_search_threads = online_cpus();
#endif
prepare_packed_git();
if (progress)
progress_state = start_progress("Counting objects", 0);
if (!use_internal_rev_list)
read_object_list_from_stdin();
else {
rp_av[rp_ac] = NULL;
get_object_list(rp_ac, rp_av);
}
if (include_tag && nr_result)
for_each_ref(add_ref_tag, NULL);
stop_progress(&progress_state);
if (non_empty && !nr_result)
return 0;
if (nr_result)
prepare_pack(window, depth);
write_pack_file();
if (progress)
fprintf(stderr, "Total %"PRIu32" (delta %"PRIu32"),"
" reused %"PRIu32" (delta %"PRIu32")\n",
written, written_delta, reused, reused_delta);
return 0;
}