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builtin-pack-objects.c
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#include "builtin.h"
#include "cache.h"
#include "object.h"
#include "blob.h"
#include "commit.h"
#include "tag.h"
#include "tree.h"
#include "delta.h"
#include "pack.h"
#include "csum-file.h"
#include "tree-walk.h"
#include "diff.h"
#include "revision.h"
#include "list-objects.h"
static const char pack_usage[] = "\
git-pack-objects [{ -q | --progress | --all-progress }] \n\
[--local] [--incremental] [--window=N] [--depth=N] \n\
[--no-reuse-delta] [--delta-base-offset] [--non-empty] \n\
[--revs [--unpacked | --all]*] [--stdout | base-name] \n\
[<ref-list | <object-list]";
struct object_entry {
unsigned char sha1[20];
unsigned long size; /* uncompressed size */
unsigned long offset; /* offset into the final pack file;
* nonzero if already written.
*/
unsigned int depth; /* delta depth */
unsigned int delta_limit; /* base adjustment for in-pack delta */
unsigned int hash; /* name hint hash */
enum object_type type;
enum object_type in_pack_type; /* could be delta */
unsigned long delta_size; /* delta data size (uncompressed) */
#define in_pack_header_size delta_size /* only when reusing pack data */
struct object_entry *delta; /* delta base object */
struct packed_git *in_pack; /* already in pack */
unsigned int in_pack_offset;
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
*/
int preferred_base; /* we do not pack this, but is encouraged to
* be used as the base objectto delta huge
* objects against.
*/
};
/*
* 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.
*
* sorted-by-sha ans sorted-by-type are arrays of pointers that point at
* elements in the objects array. The former is used to build the pack
* index (lists object names in the ascending order to help offset lookup),
* and the latter is used to group similar things together by try_delta()
* heuristics.
*/
static unsigned char object_list_sha1[20];
static int non_empty;
static int no_reuse_delta;
static int local;
static int incremental;
static int allow_ofs_delta;
static struct object_entry **sorted_by_sha, **sorted_by_type;
static struct object_entry *objects;
static int nr_objects, nr_alloc, nr_result;
static const char *base_name;
static unsigned char pack_file_sha1[20];
static int progress = 1;
static volatile sig_atomic_t progress_update;
static int window = 10;
static int pack_to_stdout;
static int num_preferred_base;
/*
* The object names in objects array are hashed with this hashtable,
* to help looking up the entry by object name. Binary search from
* sorted_by_sha is also possible but this was easier to code and faster.
* This hashtable is built after all the objects are seen.
*/
static int *object_ix;
static int object_ix_hashsz;
/*
* Pack index for existing packs give us easy access to the offsets into
* corresponding pack file where each object's data starts, but the entries
* do not store the size of the compressed representation (uncompressed
* size is easily available by examining the pack entry header). It is
* also rather expensive to find the sha1 for an object given its offset.
*
* We build a hashtable of existing packs (pack_revindex), and keep reverse
* index here -- pack index file is sorted by object name mapping to offset;
* this pack_revindex[].revindex array is a list of offset/index_nr pairs
* ordered by offset, so if you know the offset of an object, next offset
* is where its packed representation ends and the index_nr can be used to
* get the object sha1 from the main index.
*/
struct revindex_entry {
unsigned int offset;
unsigned int nr;
};
struct pack_revindex {
struct packed_git *p;
struct revindex_entry *revindex;
};
static struct pack_revindex *pack_revindex;
static int pack_revindex_hashsz;
/*
* stats
*/
static int written;
static int written_delta;
static int reused;
static int reused_delta;
static int pack_revindex_ix(struct packed_git *p)
{
unsigned long ui = (unsigned long)p;
int i;
ui = ui ^ (ui >> 16); /* defeat structure alignment */
i = (int)(ui % pack_revindex_hashsz);
while (pack_revindex[i].p) {
if (pack_revindex[i].p == p)
return i;
if (++i == pack_revindex_hashsz)
i = 0;
}
return -1 - i;
}
static void prepare_pack_ix(void)
{
int num;
struct packed_git *p;
for (num = 0, p = packed_git; p; p = p->next)
num++;
if (!num)
return;
pack_revindex_hashsz = num * 11;
pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
for (p = packed_git; p; p = p->next) {
num = pack_revindex_ix(p);
num = - 1 - num;
pack_revindex[num].p = p;
}
/* revindex elements are lazily initialized */
}
static int cmp_offset(const void *a_, const void *b_)
{
const struct revindex_entry *a = a_;
const struct revindex_entry *b = b_;
return (a->offset < b->offset) ? -1 : (a->offset > b->offset) ? 1 : 0;
}
/*
* Ordered list of offsets of objects in the pack.
*/
static void prepare_pack_revindex(struct pack_revindex *rix)
{
struct packed_git *p = rix->p;
int num_ent = num_packed_objects(p);
int i;
void *index = p->index_base + 256;
rix->revindex = xmalloc(sizeof(*rix->revindex) * (num_ent + 1));
for (i = 0; i < num_ent; i++) {
unsigned int hl = *((unsigned int *)((char *) index + 24*i));
rix->revindex[i].offset = ntohl(hl);
rix->revindex[i].nr = i;
}
/* This knows the pack format -- the 20-byte trailer
* follows immediately after the last object data.
*/
rix->revindex[num_ent].offset = p->pack_size - 20;
rix->revindex[num_ent].nr = -1;
qsort(rix->revindex, num_ent, sizeof(*rix->revindex), cmp_offset);
}
static struct revindex_entry * find_packed_object(struct packed_git *p,
unsigned int ofs)
{
int num;
int lo, hi;
struct pack_revindex *rix;
struct revindex_entry *revindex;
num = pack_revindex_ix(p);
if (num < 0)
die("internal error: pack revindex uninitialized");
rix = &pack_revindex[num];
if (!rix->revindex)
prepare_pack_revindex(rix);
revindex = rix->revindex;
lo = 0;
hi = num_packed_objects(p) + 1;
do {
int mi = (lo + hi) / 2;
if (revindex[mi].offset == ofs) {
return revindex + mi;
}
else if (ofs < revindex[mi].offset)
hi = mi;
else
lo = mi + 1;
} while (lo < hi);
die("internal error: pack revindex corrupt");
}
static unsigned long find_packed_object_size(struct packed_git *p,
unsigned long ofs)
{
struct revindex_entry *entry = find_packed_object(p, ofs);
return entry[1].offset - ofs;
}
static unsigned char *find_packed_object_name(struct packed_git *p,
unsigned long ofs)
{
struct revindex_entry *entry = find_packed_object(p, ofs);
return (unsigned char *)(p->index_base + 256) + 24 * entry->nr + 4;
}
static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
{
unsigned long othersize, delta_size;
char type[10];
void *otherbuf = read_sha1_file(entry->delta->sha1, type, &othersize);
void *delta_buf;
if (!otherbuf)
die("unable to read %s", sha1_to_hex(entry->delta->sha1));
delta_buf = diff_delta(otherbuf, othersize,
buf, size, &delta_size, 0);
if (!delta_buf || delta_size != entry->delta_size)
die("delta size changed");
free(buf);
free(otherbuf);
return delta_buf;
}
/*
* 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_inflate(unsigned char *data, unsigned long len, unsigned long expect)
{
z_stream stream;
unsigned char fakebuf[4096];
int st;
memset(&stream, 0, sizeof(stream));
stream.next_in = data;
stream.avail_in = len;
stream.next_out = fakebuf;
stream.avail_out = sizeof(fakebuf);
inflateInit(&stream);
while (1) {
st = inflate(&stream, Z_FINISH);
if (st == Z_STREAM_END || st == Z_OK) {
st = (stream.total_out == expect &&
stream.total_in == len) ? 0 : -1;
break;
}
if (st != Z_BUF_ERROR) {
st = -1;
break;
}
stream.next_out = fakebuf;
stream.avail_out = sizeof(fakebuf);
}
inflateEnd(&stream);
return st;
}
static int revalidate_loose_object(struct object_entry *entry,
unsigned char *map,
unsigned long mapsize)
{
/* we already know this is a loose object with new type header. */
enum object_type type;
unsigned long size, used;
if (pack_to_stdout)
return 0;
used = unpack_object_header_gently(map, mapsize, &type, &size);
if (!used)
return -1;
map += used;
mapsize -= used;
return check_inflate(map, mapsize, size);
}
static unsigned long write_object(struct sha1file *f,
struct object_entry *entry)
{
unsigned long size;
char type[10];
void *buf;
unsigned char header[10];
unsigned hdrlen, datalen;
enum object_type obj_type;
int to_reuse = 0;
obj_type = entry->type;
if (! entry->in_pack)
to_reuse = 0; /* can't reuse what we don't have */
else if (obj_type == OBJ_REF_DELTA || obj_type == OBJ_OFS_DELTA)
to_reuse = 1; /* check_object() decided it for us */
else if (obj_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 (!entry->in_pack && !entry->delta) {
unsigned char *map;
unsigned long mapsize;
map = map_sha1_file(entry->sha1, &mapsize);
if (map && !legacy_loose_object(map)) {
/* We can copy straight into the pack file */
if (revalidate_loose_object(entry, map, mapsize))
die("corrupt loose object %s",
sha1_to_hex(entry->sha1));
sha1write(f, map, mapsize);
munmap(map, mapsize);
written++;
reused++;
return mapsize;
}
if (map)
munmap(map, mapsize);
}
if (!to_reuse) {
buf = read_sha1_file(entry->sha1, type, &size);
if (!buf)
die("unable to read %s", sha1_to_hex(entry->sha1));
if (size != entry->size)
die("object %s size inconsistency (%lu vs %lu)",
sha1_to_hex(entry->sha1), size, entry->size);
if (entry->delta) {
buf = delta_against(buf, size, entry);
size = entry->delta_size;
obj_type = (allow_ofs_delta && entry->delta->offset) ?
OBJ_OFS_DELTA : OBJ_REF_DELTA;
}
/*
* The object header is a byte of 'type' followed by zero or
* more bytes of length.
*/
hdrlen = encode_header(obj_type, size, header);
sha1write(f, header, hdrlen);
if (obj_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.
*/
unsigned long ofs = entry->offset - entry->delta->offset;
unsigned pos = sizeof(header) - 1;
header[pos] = ofs & 127;
while (ofs >>= 7)
header[--pos] = 128 | (--ofs & 127);
sha1write(f, header + pos, sizeof(header) - pos);
hdrlen += sizeof(header) - pos;
} else if (obj_type == OBJ_REF_DELTA) {
/*
* Deltas with a base reference contain
* an additional 20 bytes for the base sha1.
*/
sha1write(f, entry->delta->sha1, 20);
hdrlen += 20;
}
datalen = sha1write_compressed(f, buf, size);
free(buf);
}
else {
struct packed_git *p = entry->in_pack;
if (entry->delta) {
obj_type = (allow_ofs_delta && entry->delta->offset) ?
OBJ_OFS_DELTA : OBJ_REF_DELTA;
reused_delta++;
}
hdrlen = encode_header(obj_type, entry->size, header);
sha1write(f, header, hdrlen);
if (obj_type == OBJ_OFS_DELTA) {
unsigned long ofs = entry->offset - entry->delta->offset;
unsigned pos = sizeof(header) - 1;
header[pos] = ofs & 127;
while (ofs >>= 7)
header[--pos] = 128 | (--ofs & 127);
sha1write(f, header + pos, sizeof(header) - pos);
hdrlen += sizeof(header) - pos;
} else if (obj_type == OBJ_REF_DELTA) {
sha1write(f, entry->delta->sha1, 20);
hdrlen += 20;
}
use_packed_git(p);
buf = (char *) p->pack_base
+ entry->in_pack_offset
+ entry->in_pack_header_size;
datalen = find_packed_object_size(p, entry->in_pack_offset)
- entry->in_pack_header_size;
if (!pack_to_stdout && check_inflate(buf, datalen, entry->size))
die("corrupt delta in pack %s", sha1_to_hex(entry->sha1));
sha1write(f, buf, datalen);
unuse_packed_git(p);
reused++;
}
if (entry->delta)
written_delta++;
written++;
return hdrlen + datalen;
}
static unsigned long write_one(struct sha1file *f,
struct object_entry *e,
unsigned long offset)
{
if (e->offset || e->preferred_base)
/* offset starts from header size and cannot be zero
* if it is written already.
*/
return offset;
/* if we are deltified, write out its base object first. */
if (e->delta)
offset = write_one(f, e->delta, offset);
e->offset = offset;
return offset + write_object(f, e);
}
static void write_pack_file(void)
{
int i;
struct sha1file *f;
unsigned long offset;
struct pack_header hdr;
unsigned last_percent = 999;
int do_progress = progress;
if (!base_name) {
f = sha1fd(1, "<stdout>");
do_progress >>= 1;
}
else
f = sha1create("%s-%s.%s", base_name,
sha1_to_hex(object_list_sha1), "pack");
if (do_progress)
fprintf(stderr, "Writing %d objects.\n", nr_result);
hdr.hdr_signature = htonl(PACK_SIGNATURE);
hdr.hdr_version = htonl(PACK_VERSION);
hdr.hdr_entries = htonl(nr_result);
sha1write(f, &hdr, sizeof(hdr));
offset = sizeof(hdr);
if (!nr_result)
goto done;
for (i = 0; i < nr_objects; i++) {
offset = write_one(f, objects + i, offset);
if (do_progress) {
unsigned percent = written * 100 / nr_result;
if (progress_update || percent != last_percent) {
fprintf(stderr, "%4u%% (%u/%u) done\r",
percent, written, nr_result);
progress_update = 0;
last_percent = percent;
}
}
}
if (do_progress)
fputc('\n', stderr);
done:
if (written != nr_result)
die("wrote %d objects while expecting %d", written, nr_result);
sha1close(f, pack_file_sha1, 1);
}
static void write_index_file(void)
{
int i;
struct sha1file *f = sha1create("%s-%s.%s", base_name,
sha1_to_hex(object_list_sha1), "idx");
struct object_entry **list = sorted_by_sha;
struct object_entry **last = list + nr_result;
unsigned int array[256];
/*
* Write the first-level table (the list is sorted,
* but we use a 256-entry lookup to be able to avoid
* having to do eight extra binary search iterations).
*/
for (i = 0; i < 256; i++) {
struct object_entry **next = list;
while (next < last) {
struct object_entry *entry = *next;
if (entry->sha1[0] != i)
break;
next++;
}
array[i] = htonl(next - sorted_by_sha);
list = next;
}
sha1write(f, array, 256 * sizeof(int));
/*
* Write the actual SHA1 entries..
*/
list = sorted_by_sha;
for (i = 0; i < nr_result; i++) {
struct object_entry *entry = *list++;
unsigned int offset = htonl(entry->offset);
sha1write(f, &offset, 4);
sha1write(f, entry->sha1, 20);
}
sha1write(f, pack_file_sha1, 20);
sha1close(f, NULL, 1);
}
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].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)
{
int 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->sha1);
if (0 <= ix)
continue;
ix = -1 - ix;
object_ix[ix] = i + 1;
}
}
static unsigned name_hash(const char *name)
{
unsigned char c;
unsigned hash = 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 int add_object_entry(const unsigned char *sha1, unsigned hash, int exclude)
{
unsigned int idx = nr_objects;
struct object_entry *entry;
struct packed_git *p;
unsigned int found_offset = 0;
struct packed_git *found_pack = NULL;
int ix, status = 0;
if (!exclude) {
for (p = packed_git; p; p = p->next) {
unsigned long offset = find_pack_entry_one(sha1, p);
if (offset) {
if (incremental)
return 0;
if (local && !p->pack_local)
return 0;
if (!found_pack) {
found_offset = offset;
found_pack = p;
}
}
}
}
if ((entry = locate_object_entry(sha1)) != NULL)
goto already_added;
if (idx >= nr_alloc) {
unsigned int needed = (idx + 1024) * 3 / 2;
objects = xrealloc(objects, needed * sizeof(*entry));
nr_alloc = needed;
}
entry = objects + idx;
nr_objects = idx + 1;
memset(entry, 0, sizeof(*entry));
hashcpy(entry->sha1, sha1);
entry->hash = hash;
if (object_ix_hashsz * 3 <= nr_objects * 4)
rehash_objects();
else {
ix = locate_object_entry_hash(entry->sha1);
if (0 <= ix)
die("internal error in object hashing.");
object_ix[-1 - ix] = idx + 1;
}
status = 1;
already_added:
if (progress_update) {
fprintf(stderr, "Counting objects...%d\r", nr_objects);
progress_update = 0;
}
if (exclude)
entry->preferred_base = 1;
else {
if (found_pack) {
entry->in_pack = found_pack;
entry->in_pack_offset = found_offset;
}
}
return status;
}
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;
char type[20];
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 (strcmp(type, tree_type)) {
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;
while (tree_entry(tree,&entry)) {
unsigned long size;
char type[20];
if (entry.pathlen != cmplen ||
memcmp(entry.path, name, cmplen) ||
!has_sha1_file(entry.sha1) ||
sha1_object_info(entry.sha1, type, &size))
continue;
if (name[cmplen] != '/') {
unsigned hash = name_hash(fullname);
add_object_entry(entry.sha1, hash, 1);
return;
}
if (!strcmp(type, tree_type)) {
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;
sub.buf = tree->tree_data;
sub.size = 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, unsigned hash)
{
struct pbase_tree *it;
int cmplen = name_cmp_len(name);
if (check_pbase_path(hash))
return;
for (it = pbase_tree; it; it = it->next) {
if (cmplen == 0) {
hash = name_hash("");
add_object_entry(it->pcache.sha1, hash, 1);
}
else {
struct tree_desc tree;
tree.buf = it->pcache.tree_data;
tree.size = 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)
{
char type[20];
if (entry->in_pack && !entry->preferred_base) {
struct packed_git *p = entry->in_pack;
unsigned long left = p->pack_size - entry->in_pack_offset;
unsigned long size, used;
unsigned char *buf;
struct object_entry *base_entry = NULL;
use_packed_git(p);
buf = p->pack_base;
buf += entry->in_pack_offset;
/* We want in_pack_type even if we do not reuse delta.
* There is no point not reusing non-delta representations.
*/
used = unpack_object_header_gently(buf, left,
&entry->in_pack_type, &size);
if (!used || left - used <= 20)
die("corrupt pack for %s", sha1_to_hex(entry->sha1));
/* Check if it is delta, and the base is also an object
* we are going to pack. If so we will reuse the existing
* delta.
*/
if (!no_reuse_delta) {
unsigned char c, *base_name;
unsigned long ofs;
/* there is at least 20 bytes left in the pack */
switch (entry->in_pack_type) {
case OBJ_REF_DELTA:
base_name = buf + used;
used += 20;
break;
case OBJ_OFS_DELTA:
c = buf[used++];
ofs = c & 127;
while (c & 128) {
ofs += 1;
if (!ofs || ofs & ~(~0UL >> 7))
die("delta base offset overflow in pack for %s",
sha1_to_hex(entry->sha1));
c = buf[used++];
ofs = (ofs << 7) + (c & 127);
}
if (ofs >= entry->in_pack_offset)
die("delta base offset out of bound for %s",
sha1_to_hex(entry->sha1));
ofs = entry->in_pack_offset - ofs;
base_name = find_packed_object_name(p, ofs);
break;
default:
base_name = NULL;
}
if (base_name)
base_entry = locate_object_entry(base_name);
}
unuse_packed_git(p);
entry->in_pack_header_size = used;
if (base_entry) {
/* Depth value does not matter - find_deltas()
* will never consider reused delta as the
* base object to deltify other objects