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git/builtin/pack-objects.c

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#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"
#include "streaming.h"
#include "thread-utils.h"
static const char *pack_usage[] = {
N_("git pack-objects --stdout [options...] [< ref-list | < object-list]"),
N_("git pack-objects [options...] base-name [< ref-list | < object-list]"),
NULL
};
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;
unsigned char tagged; /* near the very tip of refs */
unsigned char filled; /* assigned write-order */
};
/*
* 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 unsigned long unpack_unreachable_expiration;
static int local;
static int incremental;
static int ignore_packed_keep;
static int allow_ofs_delta;
static struct pack_idx_option pack_idx_opts;
static const char *base_name;
static int progress = 1;
static int window = 10;
static unsigned long pack_size_limit;
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 = 256 * 1024 * 1024;
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;
static struct object_entry *locate_object_entry(const unsigned char *sha1);
/*
* 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)
{
git_zstream stream;
void *in, *out;
unsigned long maxsize;
memset(&stream, 0, sizeof(stream));
git_deflate_init(&stream, pack_compression_level);
maxsize = git_deflate_bound(&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 (git_deflate(&stream, Z_FINISH) == Z_OK)
; /* nothing */
git_deflate_end(&stream);
free(in);
return stream.total_out;
}
static unsigned long write_large_blob_data(struct git_istream *st, struct sha1file *f,
const unsigned char *sha1)
{
git_zstream stream;
unsigned char ibuf[1024 * 16];
unsigned char obuf[1024 * 16];
unsigned long olen = 0;
memset(&stream, 0, sizeof(stream));
git_deflate_init(&stream, pack_compression_level);
for (;;) {
ssize_t readlen;
int zret = Z_OK;
readlen = read_istream(st, ibuf, sizeof(ibuf));
if (readlen == -1)
die(_("unable to read %s"), sha1_to_hex(sha1));
stream.next_in = ibuf;
stream.avail_in = readlen;
while ((stream.avail_in || readlen == 0) &&
(zret == Z_OK || zret == Z_BUF_ERROR)) {
stream.next_out = obuf;
stream.avail_out = sizeof(obuf);
zret = git_deflate(&stream, readlen ? 0 : Z_FINISH);
sha1write(f, obuf, stream.next_out - obuf);
olen += stream.next_out - obuf;
}
if (stream.avail_in)
die(_("deflate error (%d)"), zret);
if (readlen == 0) {
if (zret != Z_STREAM_END)
die(_("deflate error (%d)"), zret);
break;
}
}
git_deflate_end(&stream);
return olen;
}
/*
* 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)
{
git_zstream 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 long avail;
while (len) {
in = use_pack(p, w_curs, offset, &avail);
if (avail > len)
avail = (unsigned long)len;
sha1write(f, in, avail);
offset += avail;
len -= avail;
}
}
/* Return 0 if we will bust the pack-size limit */
static unsigned long write_no_reuse_object(struct sha1file *f, struct object_entry *entry,
unsigned long limit, int usable_delta)
{
unsigned long size, datalen;
unsigned char header[10], dheader[10];
unsigned hdrlen;
enum object_type type;
void *buf;
struct git_istream *st = NULL;
if (!usable_delta) {
if (entry->type == OBJ_BLOB &&
entry->size > big_file_threshold &&
(st = open_istream(entry->idx.sha1, &type, &size, NULL)) != NULL)
buf = NULL;
else {
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 (st) /* large blob case, just assume we don't compress well */
datalen = size;
else 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_in_pack_object_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) {
if (st)
close_istream(st);
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) {
if (st)
close_istream(st);
free(buf);
return 0;
}
sha1write(f, header, hdrlen);
sha1write(f, entry->delta->idx.sha1, 20);
hdrlen += 20;
} else {
if (limit && hdrlen + datalen + 20 >= limit) {
if (st)
close_istream(st);
free(buf);
return 0;
}
sha1write(f, header, hdrlen);
}
if (st) {
datalen = write_large_blob_data(st, f, entry->idx.sha1);
close_istream(st);
} else {
sha1write(f, buf, datalen);
free(buf);
}
return hdrlen + datalen;
}
/* Return 0 if we will bust the pack-size limit */
static unsigned long write_reuse_object(struct sha1file *f, struct object_entry *entry,
unsigned long limit, int usable_delta)
{
struct packed_git *p = entry->in_pack;
struct pack_window *w_curs = NULL;
struct revindex_entry *revidx;
off_t offset;
enum object_type type = entry->type;
unsigned long datalen;
unsigned char header[10], dheader[10];
unsigned hdrlen;
if (entry->delta)
type = (allow_ofs_delta && entry->delta->idx.offset) ?
OBJ_OFS_DELTA : OBJ_REF_DELTA;
hdrlen = encode_in_pack_object_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);
return write_no_reuse_object(f, entry, limit, usable_delta);
}
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);
return write_no_reuse_object(f, entry, limit, usable_delta);
}
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++;
return hdrlen + datalen;
}
/* Return 0 if we will bust the pack-size limit */
static unsigned long write_object(struct sha1file *f,
struct object_entry *entry,
off_t write_offset)
{
unsigned long limit, len;
int usable_delta, to_reuse;
if (!pack_to_stdout)
crc32_begin(f);
/* apply size 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 (entry->type == OBJ_REF_DELTA || entry->type == OBJ_OFS_DELTA)
/* check_object() decided it for us ... */
to_reuse = usable_delta;
/* ... but pack split may override that */
else if (entry->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)
len = write_no_reuse_object(f, entry, limit, usable_delta);
else
len = write_reuse_object(f, entry, limit, usable_delta);
if (!len)
return 0;
if (usable_delta)
written_delta++;
written++;
if (!pack_to_stdout)
entry->idx.crc32 = crc32_end(f);
return len;
}
enum write_one_status {
WRITE_ONE_SKIP = -1, /* already written */
WRITE_ONE_BREAK = 0, /* writing this will bust the limit; not written */
WRITE_ONE_WRITTEN = 1, /* normal */
WRITE_ONE_RECURSIVE = 2 /* already scheduled to be written */
};
static enum write_one_status write_one(struct sha1file *f,
struct object_entry *e,
off_t *offset)
{
unsigned long size;
int recursing;
/*
* we set offset to 1 (which is an impossible value) to mark
* the fact that this object is involved in "write its base
* first before writing a deltified object" recursion.
*/
recursing = (e->idx.offset == 1);
if (recursing) {
warning("recursive delta detected for object %s",
sha1_to_hex(e->idx.sha1));
return WRITE_ONE_RECURSIVE;
} else if (e->idx.offset || e->preferred_base) {
/* offset is non zero if object is written already. */
return WRITE_ONE_SKIP;
}
/* if we are deltified, write out base object first. */
if (e->delta) {
e->idx.offset = 1; /* now recurse */
switch (write_one(f, e->delta, offset)) {
case WRITE_ONE_RECURSIVE:
/* we cannot depend on this one */
e->delta = NULL;
break;
default:
break;
case WRITE_ONE_BREAK:
e->idx.offset = recursing;
return WRITE_ONE_BREAK;
}
}
e->idx.offset = *offset;
size = write_object(f, e, *offset);
if (!size) {
e->idx.offset = recursing;
return WRITE_ONE_BREAK;
}
written_list[nr_written++] = &e->idx;
/* make sure off_t is sufficiently large not to wrap */
if (signed_add_overflows(*offset, size))
die("pack too large for current definition of off_t");
*offset += size;
return WRITE_ONE_WRITTEN;
}
static int mark_tagged(const char *path, const unsigned char *sha1, int flag,
void *cb_data)
{
unsigned char peeled[20];
struct object_entry *entry = locate_object_entry(sha1);
if (entry)
entry->tagged = 1;
if (!peel_ref(path, peeled)) {
entry = locate_object_entry(peeled);
if (entry)
entry->tagged = 1;
}
return 0;
}
static inline void add_to_write_order(struct object_entry **wo,
unsigned int *endp,
struct object_entry *e)
{
if (e->filled)
return;
wo[(*endp)++] = e;
e->filled = 1;
}
static void add_descendants_to_write_order(struct object_entry **wo,
unsigned int *endp,
struct object_entry *e)
{
int add_to_order = 1;
while (e) {
if (add_to_order) {
struct object_entry *s;
/* add this node... */
add_to_write_order(wo, endp, e);
/* all its siblings... */
for (s = e->delta_sibling; s; s = s->delta_sibling) {
add_to_write_order(wo, endp, s);
}
}
/* drop down a level to add left subtree nodes if possible */
if (e->delta_child) {
add_to_order = 1;
e = e->delta_child;
} else {
add_to_order = 0;
/* our sibling might have some children, it is next */
if (e->delta_sibling) {
e = e->delta_sibling;
continue;
}
/* go back to our parent node */
e = e->delta;
while (e && !e->delta_sibling) {
/* we're on the right side of a subtree, keep
* going up until we can go right again */
e = e->delta;
}
if (!e) {
/* done- we hit our original root node */
return;
}
/* pass it off to sibling at this level */
e = e->delta_sibling;
}
};
}
static void add_family_to_write_order(struct object_entry **wo,
unsigned int *endp,
struct object_entry *e)
{
struct object_entry *root;
for (root = e; root->delta; root = root->delta)
; /* nothing */
add_descendants_to_write_order(wo, endp, root);
}
static struct object_entry **compute_write_order(void)
{
unsigned int i, wo_end, last_untagged;
struct object_entry **wo = xmalloc(nr_objects * sizeof(*wo));
for (i = 0; i < nr_objects; i++) {
objects[i].tagged = 0;
objects[i].filled = 0;
objects[i].delta_child = NULL;
objects[i].delta_sibling = NULL;
}
/*
* Fully connect delta_child/delta_sibling network.
* Make sure delta_sibling is sorted in the original
* recency order.
*/
for (i = nr_objects; i > 0;) {
struct object_entry *e = &objects[--i];
if (!e->delta)
continue;
/* Mark me as the first child */
e->delta_sibling = e->delta->delta_child;
e->delta->delta_child = e;
}
/*
* Mark objects that are at the tip of tags.
*/
for_each_tag_ref(mark_tagged, NULL);
/*
* Give the objects in the original recency order until
* we see a tagged tip.
*/
for (i = wo_end = 0; i < nr_objects; i++) {
if (objects[i].tagged)
break;
add_to_write_order(wo, &wo_end, &objects[i]);
}
last_untagged = i;
/*
* Then fill all the tagged tips.
*/
for (; i < nr_objects; i++) {
if (objects[i].tagged)
add_to_write_order(wo, &wo_end, &objects[i]);
}
/*
* And then all remaining commits and tags.
*/
for (i = last_untagged; i < nr_objects; i++) {
if (objects[i].type != OBJ_COMMIT &&
objects[i].type != OBJ_TAG)
continue;
add_to_write_order(wo, &wo_end, &objects[i]);
}
/*
* And then all the trees.
*/
for (i = last_untagged; i < nr_objects; i++) {
if (objects[i].type != OBJ_TREE)
continue;
add_to_write_order(wo, &wo_end, &objects[i]);
}
/*
* Finally all the rest in really tight order
*/
for (i = last_untagged; i < nr_objects; i++) {
if (!objects[i].filled)
add_family_to_write_order(wo, &wo_end, &objects[i]);
}
if (wo_end != nr_objects)
die("ordered %u objects, expected %"PRIu32, wo_end, nr_objects);
return wo;
}
static void write_pack_file(void)
{
uint32_t i = 0, j;
struct sha1file *f;
off_t offset;
uint32_t nr_remaining = nr_result;
time_t last_mtime = 0;
struct object_entry **write_order;
if (progress > pack_to_stdout)
progress_state = start_progress("Writing objects", nr_result);
written_list = xmalloc(nr_objects * sizeof(*written_list));
write_order = compute_write_order();
do {
unsigned char sha1[20];
char *pack_tmp_name = NULL;
if (pack_to_stdout)
f = sha1fd_throughput(1, "<stdout>", progress_state);
else
f = create_tmp_packfile(&pack_tmp_name);
offset = write_pack_header(f, nr_remaining);
if (!offset)
die_errno("unable to write pack header");
nr_written = 0;
for (; i < nr_objects; i++) {
struct object_entry *e = write_order[i];
if (write_one(f, e, &offset) == WRITE_ONE_BREAK)
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) {
struct stat st;
char tmpname[PATH_MAX];
/*
* 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(pack_tmp_name, &st) < 0) {
warning("failed to stat %s: %s",
pack_tmp_name, 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(pack_tmp_name, &utb) < 0)
warning("failed utime() on %s: %s",
tmpname, strerror(errno));
}
/* Enough space for "-<sha-1>.pack"? */
if (sizeof(tmpname) <= strlen(base_name) + 50)
die("pack base name '%s' too long", base_name);
snprintf(tmpname, sizeof(tmpname), "%s-", base_name);
finish_tmp_packfile(tmpname, pack_tmp_name,
written_list, nr_written,
&pack_idx_opts, sha1);
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);
free(write_order);
stop_progress(&progress_state);
if (written != nr_result)
die("wrote %"PRIu32" objects while expecting %"PRIu32,
written, nr_result);
}
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");
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_check_attr(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) {
if (!is_pack_valid(p)) {
warning("packfile %s cannot be accessed", p->pack_name);
continue;
}
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) != 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 cleanup_preferred_base(void)
{
struct pbase_tree *it;
unsigned i;
it = pbase_tree;
pbase_tree = NULL;
while (it) {
struct pbase_tree *this = it;
it = this->next;
free(this->pcache.tree_data);
free(this);
}
for (i = 0; i < ARRAY_SIZE(pbase_tree_cache); i++) {
if (!pbase_tree_cache[i])
continue;
free(pbase_tree_cache[i]->tree_data);
free(pbase_tree_cache[i]);
pbase_tree_cache[i] = NULL;
}
free(done_pbase_paths);
done_pbase_paths = NULL;
done_pbase_paths_num = done_pbase_paths_alloc = 0;
}
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 long 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++) {
struct object_entry *entry = sorted_by_offset[i];
check_object(entry);
if (big_file_threshold < entry->size)
entry->no_try_delta = 1;
}
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;
}
#ifndef NO_PTHREADS
static pthread_mutex_t read_mutex;
#define read_lock() pthread_mutex_lock(&read_mutex)
#define read_unlock() pthread_mutex_unlock(&read_mutex)
static pthread_mutex_t cache_mutex;
#define cache_lock() pthread_mutex_lock(&cache_mutex)
#define cache_unlock() pthread_mutex_unlock(&cache_mutex)
static pthread_mutex_t progress_mutex;
#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. Note that
* src_entry that is marked as the preferred_base should always
* be considered, as even if we produce a suboptimal delta against
* it, we will still save the transfer cost, as we already know
* the other side has it and we won't send src_entry at all.
*/
if (reuse_delta && trg_entry->in_pack &&
trg_entry->in_pack == src_entry->in_pack &&
!src_entry->preferred_base &&
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) {
if (src_entry->preferred_base) {
static int warned = 0;
if (!warned++)
warning("object %s cannot be read",
sha1_to_hex(src_entry->idx.sha1));
/*
* Those objects are not included in the
* resulting pack. Be resilient and ignore
* them if they can't be read, in case the
* pack could be created nevertheless.
*/
return 0;
}
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 NO_PTHREADS is 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);
}
#ifndef NO_PTHREADS
static void try_to_free_from_threads(size_t size)
{
read_lock();
release_pack_memory(size, -1);
read_unlock();
}
static try_to_free_t old_try_to_free_routine;
/*
* 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;
/*
* Mutex and conditional variable can't be statically-initialized on Windows.
*/
static void init_threaded_search(void)
{
init_recursive_mutex(&read_mutex);
pthread_mutex_init(&cache_mutex, NULL);
pthread_mutex_init(&progress_mutex, NULL);
pthread_cond_init(&progress_cond, NULL);
old_try_to_free_routine = set_try_to_free_routine(try_to_free_from_threads);
}
static void cleanup_threaded_search(void)
{
set_try_to_free_routine(old_try_to_free_routine);
pthread_cond_destroy(&progress_cond);
pthread_mutex_destroy(&read_mutex);
pthread_mutex_destroy(&cache_mutex);
pthread_mutex_destroy(&progress_mutex);
}
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;
int i, ret, active_threads = 0;
init_threaded_search();
if (!delta_search_threads) /* --threads=0 means autodetect */
delta_search_threads = online_cpus();
if (delta_search_threads <= 1) {
find_deltas(list, &list_size, window, depth, processed);
cleanup_threaded_search();
return;
}
if (progress > pack_to_stdout)
fprintf(stderr, "Delta compression using up to %d threads.\n",
delta_search_threads);
p = xcalloc(delta_search_threads, sizeof(*p));
/* 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--;
}
}
cleanup_threaded_search();
free(p);
}
#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? */
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);
#ifdef NO_PTHREADS
if (delta_search_threads != 1)
warning("no threads support, ignoring %s", k);
#endif
return 0;
}
if (!strcmp(k, "pack.indexversion")) {
pack_idx_opts.version = git_config_int(k, v);
if (pack_idx_opts.version > 2)
die("bad pack.indexversion=%"PRIu32,
pack_idx_opts.version);
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_errno("fgets");
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,
void *data)
{
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 (unpack_unreachable_expiration &&
p->mtime < unpack_unreachable_expiration)
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, REVARG_CANNOT_BE_FILENAME))
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 option_parse_index_version(const struct option *opt,
const char *arg, int unset)
{
char *c;
const char *val = arg;
pack_idx_opts.version = strtoul(val, &c, 10);
if (pack_idx_opts.version > 2)
die(_("unsupported index version %s"), val);
if (*c == ',' && c[1])
pack_idx_opts.off32_limit = strtoul(c+1, &c, 0);
if (*c || pack_idx_opts.off32_limit & 0x80000000)
die(_("bad index version '%s'"), val);
return 0;
}
static int option_parse_unpack_unreachable(const struct option *opt,
const char *arg, int unset)
{
if (unset) {
unpack_unreachable = 0;
unpack_unreachable_expiration = 0;
}
else {
unpack_unreachable = 1;
if (arg)
unpack_unreachable_expiration = approxidate(arg);
}
return 0;
}
static int option_parse_ulong(const struct option *opt,
const char *arg, int unset)
{
if (unset)
die(_("option %s does not accept negative form"),
opt->long_name);
if (!git_parse_ulong(arg, opt->value))
die(_("unable to parse value '%s' for option %s"),
arg, opt->long_name);
return 0;
}
#define OPT_ULONG(s, l, v, h) \
{ OPTION_CALLBACK, (s), (l), (v), "n", (h), \
PARSE_OPT_NONEG, option_parse_ulong }
int cmd_pack_objects(int argc, const char **argv, const char *prefix)
{
int use_internal_rev_list = 0;
int thin = 0;
int all_progress_implied = 0;
const char *rp_av[6];
int rp_ac = 0;
int rev_list_unpacked = 0, rev_list_all = 0, rev_list_reflog = 0;
struct option pack_objects_options[] = {
OPT_SET_INT('q', "quiet", &progress,
N_("do not show progress meter"), 0),
OPT_SET_INT(0, "progress", &progress,
N_("show progress meter"), 1),
OPT_SET_INT(0, "all-progress", &progress,
N_("show progress meter during object writing phase"), 2),
OPT_BOOL(0, "all-progress-implied",
&all_progress_implied,
N_("similar to --all-progress when progress meter is shown")),
{ OPTION_CALLBACK, 0, "index-version", NULL, N_("version[,offset]"),
N_("write the pack index file in the specified idx format version"),
0, option_parse_index_version },
OPT_ULONG(0, "max-pack-size", &pack_size_limit,
N_("maximum size of each output pack file")),
OPT_BOOL(0, "local", &local,
N_("ignore borrowed objects from alternate object store")),
OPT_BOOL(0, "incremental", &incremental,
N_("ignore packed objects")),
OPT_INTEGER(0, "window", &window,
N_("limit pack window by objects")),
OPT_ULONG(0, "window-memory", &window_memory_limit,
N_("limit pack window by memory in addition to object limit")),
OPT_INTEGER(0, "depth", &depth,
N_("maximum length of delta chain allowed in the resulting pack")),
OPT_BOOL(0, "reuse-delta", &reuse_delta,
N_("reuse existing deltas")),
OPT_BOOL(0, "reuse-object", &reuse_object,
N_("reuse existing objects")),
OPT_BOOL(0, "delta-base-offset", &allow_ofs_delta,
N_("use OFS_DELTA objects")),
OPT_INTEGER(0, "threads", &delta_search_threads,
N_("use threads when searching for best delta matches")),
OPT_BOOL(0, "non-empty", &non_empty,
N_("do not create an empty pack output")),
OPT_BOOL(0, "revs", &use_internal_rev_list,
N_("read revision arguments from standard input")),
{ OPTION_SET_INT, 0, "unpacked", &rev_list_unpacked, NULL,
N_("limit the objects to those that are not yet packed"),
PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
{ OPTION_SET_INT, 0, "all", &rev_list_all, NULL,
N_("include objects reachable from any reference"),
PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
{ OPTION_SET_INT, 0, "reflog", &rev_list_reflog, NULL,
N_("include objects referred by reflog entries"),
PARSE_OPT_NOARG | PARSE_OPT_NONEG, NULL, 1 },
OPT_BOOL(0, "stdout", &pack_to_stdout,
N_("output pack to stdout")),
OPT_BOOL(0, "include-tag", &include_tag,
N_("include tag objects that refer to objects to be packed")),
OPT_BOOL(0, "keep-unreachable", &keep_unreachable,
N_("keep unreachable objects")),
{ OPTION_CALLBACK, 0, "unpack-unreachable", NULL, N_("time"),
N_("unpack unreachable objects newer than <time>"),
PARSE_OPT_OPTARG, option_parse_unpack_unreachable },
OPT_BOOL(0, "thin", &thin,
N_("create thin packs")),
OPT_BOOL(0, "honor-pack-keep", &ignore_packed_keep,
N_("ignore packs that have companion .keep file")),
OPT_INTEGER(0, "compression", &pack_compression_level,
N_("pack compression level")),
OPT_SET_INT(0, "keep-true-parents", &grafts_replace_parents,
N_("do not hide commits by grafts"), 0),
OPT_END(),
};
read_replace_refs = 0;
reset_pack_idx_option(&pack_idx_opts);
git_config(git_pack_config, NULL);
if (!pack_compression_seen && core_compression_seen)
pack_compression_level = core_compression_level;
progress = isatty(2);
argc = parse_options(argc, argv, prefix, pack_objects_options,
pack_usage, 0);
if (argc) {
base_name = argv[0];
argc--;
}
if (pack_to_stdout != !base_name || argc)
usage_with_options(pack_usage, pack_objects_options);
rp_av[rp_ac++] = "pack-objects";
if (thin) {
use_internal_rev_list = 1;
rp_av[rp_ac++] = "--objects-edge";
} else
rp_av[rp_ac++] = "--objects";
if (rev_list_all) {
use_internal_rev_list = 1;
rp_av[rp_ac++] = "--all";
}
if (rev_list_reflog) {
use_internal_rev_list = 1;
rp_av[rp_ac++] = "--reflog";
}
if (rev_list_unpacked) {
use_internal_rev_list = 1;
rp_av[rp_ac++] = "--unpacked";
}
if (!reuse_object)
reuse_delta = 0;
if (pack_compression_level == -1)
pack_compression_level = Z_DEFAULT_COMPRESSION;
else if (pack_compression_level < 0 || pack_compression_level > Z_BEST_COMPRESSION)
die("bad pack compression level %d", pack_compression_level);
#ifdef NO_PTHREADS
if (delta_search_threads != 1)
warning("no threads support, ignoring --threads");
#endif
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_size_limit && pack_size_limit < 1024*1024) {
warning("minimum pack size limit is 1 MiB");
pack_size_limit = 1024*1024;
}
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.");
if (progress && all_progress_implied)
progress = 2;
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);
}
cleanup_preferred_base();
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;
}