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https://github.com/git/git
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![Junio C Hamano](/assets/img/avatar_default.png)
* jc/rev-list: rev-list --objects: use full pathname to help hashing. rev-list --objects-edge: remove duplicated edge commit output. rev-list --objects-edge * jc/pack-thin: pack-objects: hash basename and direname a bit differently. pack-objects: allow "thin" packs to exceed depth limits pack-objects: use full pathname to help hashing with "thin" pack. pack-objects: thin pack micro-optimization. Use thin pack transfer in "git fetch". Add git-push --thin. send-pack --thin: use "thin pack" delta transfer. Thin pack - create packfile with missing delta base. Conflicts: pack-objects.c (taking "next") send-pack.c (taking "next")
1171 lines
29 KiB
C
1171 lines
29 KiB
C
#include "cache.h"
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#include "object.h"
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#include "delta.h"
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#include "pack.h"
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#include "csum-file.h"
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#include "diff.h"
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#include <sys/time.h>
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#include <signal.h>
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static const char pack_usage[] = "git-pack-objects [-q] [--no-reuse-delta] [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] {--stdout | base-name} < object-list";
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struct object_entry {
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unsigned char sha1[20];
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unsigned long size; /* uncompressed size */
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unsigned long offset; /* offset into the final pack file;
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* nonzero if already written.
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*/
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unsigned int depth; /* delta depth */
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unsigned int delta_limit; /* base adjustment for in-pack delta */
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unsigned int hash; /* name hint hash */
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enum object_type type;
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enum object_type in_pack_type; /* could be delta */
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unsigned long delta_size; /* delta data size (uncompressed) */
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struct object_entry *delta; /* delta base object */
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struct packed_git *in_pack; /* already in pack */
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unsigned int in_pack_offset;
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struct object_entry *delta_child; /* delitified objects who bases me */
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struct object_entry *delta_sibling; /* other deltified objects who
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* uses the same base as me
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*/
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int preferred_base; /* we do not pack this, but is encouraged to
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* be used as the base objectto delta huge
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* objects against.
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*/
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int based_on_preferred; /* current delta candidate is a preferred
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* one, or delta against a preferred one.
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*/
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};
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/*
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* Objects we are going to pack are colected in objects array (dynamically
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* expanded). nr_objects & nr_alloc controls this array. They are stored
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* in the order we see -- typically rev-list --objects order that gives us
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* nice "minimum seek" order.
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*
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* sorted-by-sha ans sorted-by-type are arrays of pointers that point at
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* elements in the objects array. The former is used to build the pack
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* index (lists object names in the ascending order to help offset lookup),
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* and the latter is used to group similar things together by try_delta()
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* heuristics.
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*/
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static unsigned char object_list_sha1[20];
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static int non_empty = 0;
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static int no_reuse_delta = 0;
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static int local = 0;
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static int incremental = 0;
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static struct object_entry **sorted_by_sha, **sorted_by_type;
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static struct object_entry *objects = NULL;
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static int nr_objects = 0, nr_alloc = 0, nr_result = 0;
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static const char *base_name;
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static unsigned char pack_file_sha1[20];
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static int progress = 1;
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static volatile int progress_update = 0;
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/*
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* The object names in objects array are hashed with this hashtable,
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* to help looking up the entry by object name. Binary search from
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* sorted_by_sha is also possible but this was easier to code and faster.
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* This hashtable is built after all the objects are seen.
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*/
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static int *object_ix = NULL;
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static int object_ix_hashsz = 0;
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/*
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* Pack index for existing packs give us easy access to the offsets into
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* corresponding pack file where each object's data starts, but the entries
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* do not store the size of the compressed representation (uncompressed
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* size is easily available by examining the pack entry header). We build
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* a hashtable of existing packs (pack_revindex), and keep reverse index
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* here -- pack index file is sorted by object name mapping to offset; this
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* pack_revindex[].revindex array is an ordered list of offsets, so if you
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* know the offset of an object, next offset is where its packed
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* representation ends.
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*/
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struct pack_revindex {
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struct packed_git *p;
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unsigned long *revindex;
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} *pack_revindex = NULL;
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static int pack_revindex_hashsz = 0;
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/*
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* stats
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*/
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static int written = 0;
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static int written_delta = 0;
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static int reused = 0;
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static int reused_delta = 0;
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static int pack_revindex_ix(struct packed_git *p)
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{
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unsigned int ui = (unsigned int) p;
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int i;
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ui = ui ^ (ui >> 16); /* defeat structure alignment */
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i = (int)(ui % pack_revindex_hashsz);
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while (pack_revindex[i].p) {
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if (pack_revindex[i].p == p)
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return i;
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if (++i == pack_revindex_hashsz)
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i = 0;
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}
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return -1 - i;
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}
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static void prepare_pack_ix(void)
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{
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int num;
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struct packed_git *p;
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for (num = 0, p = packed_git; p; p = p->next)
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num++;
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if (!num)
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return;
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pack_revindex_hashsz = num * 11;
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pack_revindex = xcalloc(sizeof(*pack_revindex), pack_revindex_hashsz);
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for (p = packed_git; p; p = p->next) {
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num = pack_revindex_ix(p);
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num = - 1 - num;
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pack_revindex[num].p = p;
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}
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/* revindex elements are lazily initialized */
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}
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static int cmp_offset(const void *a_, const void *b_)
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{
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unsigned long a = *(unsigned long *) a_;
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unsigned long b = *(unsigned long *) b_;
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if (a < b)
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return -1;
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else if (a == b)
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return 0;
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else
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return 1;
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}
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/*
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* Ordered list of offsets of objects in the pack.
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*/
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static void prepare_pack_revindex(struct pack_revindex *rix)
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{
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struct packed_git *p = rix->p;
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int num_ent = num_packed_objects(p);
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int i;
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void *index = p->index_base + 256;
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rix->revindex = xmalloc(sizeof(unsigned long) * (num_ent + 1));
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for (i = 0; i < num_ent; i++) {
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long hl = *((long *)(index + 24 * i));
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rix->revindex[i] = ntohl(hl);
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}
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/* This knows the pack format -- the 20-byte trailer
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* follows immediately after the last object data.
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*/
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rix->revindex[num_ent] = p->pack_size - 20;
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qsort(rix->revindex, num_ent, sizeof(unsigned long), cmp_offset);
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}
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static unsigned long find_packed_object_size(struct packed_git *p,
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unsigned long ofs)
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{
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int num;
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int lo, hi;
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struct pack_revindex *rix;
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unsigned long *revindex;
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num = pack_revindex_ix(p);
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if (num < 0)
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die("internal error: pack revindex uninitialized");
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rix = &pack_revindex[num];
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if (!rix->revindex)
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prepare_pack_revindex(rix);
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revindex = rix->revindex;
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lo = 0;
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hi = num_packed_objects(p) + 1;
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do {
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int mi = (lo + hi) / 2;
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if (revindex[mi] == ofs) {
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return revindex[mi+1] - ofs;
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}
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else if (ofs < revindex[mi])
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hi = mi;
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else
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lo = mi + 1;
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} while (lo < hi);
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die("internal error: pack revindex corrupt");
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}
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static void *delta_against(void *buf, unsigned long size, struct object_entry *entry)
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{
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unsigned long othersize, delta_size;
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char type[10];
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void *otherbuf = read_sha1_file(entry->delta->sha1, type, &othersize);
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void *delta_buf;
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if (!otherbuf)
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die("unable to read %s", sha1_to_hex(entry->delta->sha1));
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delta_buf = diff_delta(otherbuf, othersize,
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buf, size, &delta_size, 0);
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if (!delta_buf || delta_size != entry->delta_size)
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die("delta size changed");
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free(buf);
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free(otherbuf);
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return delta_buf;
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}
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/*
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* The per-object header is a pretty dense thing, which is
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* - first byte: low four bits are "size", then three bits of "type",
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* and the high bit is "size continues".
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* - each byte afterwards: low seven bits are size continuation,
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* with the high bit being "size continues"
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*/
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static int encode_header(enum object_type type, unsigned long size, unsigned char *hdr)
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{
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int n = 1;
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unsigned char c;
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if (type < OBJ_COMMIT || type > OBJ_DELTA)
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die("bad type %d", type);
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c = (type << 4) | (size & 15);
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size >>= 4;
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while (size) {
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*hdr++ = c | 0x80;
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c = size & 0x7f;
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size >>= 7;
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n++;
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}
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*hdr = c;
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return n;
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}
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static unsigned long write_object(struct sha1file *f,
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struct object_entry *entry)
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{
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unsigned long size;
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char type[10];
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void *buf;
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unsigned char header[10];
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unsigned hdrlen, datalen;
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enum object_type obj_type;
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int to_reuse = 0;
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if (entry->preferred_base)
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return 0;
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obj_type = entry->type;
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if (! entry->in_pack)
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to_reuse = 0; /* can't reuse what we don't have */
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else if (obj_type == OBJ_DELTA)
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to_reuse = 1; /* check_object() decided it for us */
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else if (obj_type != entry->in_pack_type)
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to_reuse = 0; /* pack has delta which is unusable */
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else if (entry->delta)
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to_reuse = 0; /* we want to pack afresh */
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else
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to_reuse = 1; /* we have it in-pack undeltified,
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* and we do not need to deltify it.
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*/
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if (! to_reuse) {
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buf = read_sha1_file(entry->sha1, type, &size);
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if (!buf)
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die("unable to read %s", sha1_to_hex(entry->sha1));
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if (size != entry->size)
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die("object %s size inconsistency (%lu vs %lu)",
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sha1_to_hex(entry->sha1), size, entry->size);
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if (entry->delta) {
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buf = delta_against(buf, size, entry);
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size = entry->delta_size;
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obj_type = OBJ_DELTA;
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}
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/*
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* The object header is a byte of 'type' followed by zero or
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* more bytes of length. For deltas, the 20 bytes of delta
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* sha1 follows that.
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*/
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hdrlen = encode_header(obj_type, size, header);
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sha1write(f, header, hdrlen);
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if (entry->delta) {
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sha1write(f, entry->delta, 20);
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hdrlen += 20;
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}
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datalen = sha1write_compressed(f, buf, size);
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free(buf);
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}
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else {
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struct packed_git *p = entry->in_pack;
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use_packed_git(p);
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datalen = find_packed_object_size(p, entry->in_pack_offset);
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buf = p->pack_base + entry->in_pack_offset;
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sha1write(f, buf, datalen);
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unuse_packed_git(p);
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hdrlen = 0; /* not really */
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if (obj_type == OBJ_DELTA)
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reused_delta++;
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reused++;
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}
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if (obj_type == OBJ_DELTA)
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written_delta++;
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written++;
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return hdrlen + datalen;
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}
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static unsigned long write_one(struct sha1file *f,
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struct object_entry *e,
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unsigned long offset)
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{
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if (e->offset)
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/* offset starts from header size and cannot be zero
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* if it is written already.
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*/
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return offset;
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e->offset = offset;
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offset += write_object(f, e);
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/* if we are deltified, write out its base object. */
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if (e->delta)
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offset = write_one(f, e->delta, offset);
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return offset;
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}
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static void write_pack_file(void)
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{
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int i;
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struct sha1file *f;
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unsigned long offset;
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struct pack_header hdr;
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unsigned last_percent = 999;
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int do_progress = 0;
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if (!base_name)
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f = sha1fd(1, "<stdout>");
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else {
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f = sha1create("%s-%s.%s", base_name,
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sha1_to_hex(object_list_sha1), "pack");
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do_progress = progress;
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}
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if (do_progress)
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fprintf(stderr, "Writing %d objects.\n", nr_result);
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hdr.hdr_signature = htonl(PACK_SIGNATURE);
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hdr.hdr_version = htonl(PACK_VERSION);
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hdr.hdr_entries = htonl(nr_result);
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sha1write(f, &hdr, sizeof(hdr));
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offset = sizeof(hdr);
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if (!nr_result)
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goto done;
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for (i = 0; i < nr_objects; i++) {
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offset = write_one(f, objects + i, offset);
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if (do_progress) {
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unsigned percent = written * 100 / nr_result;
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if (progress_update || percent != last_percent) {
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fprintf(stderr, "%4u%% (%u/%u) done\r",
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percent, written, nr_result);
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progress_update = 0;
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last_percent = percent;
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}
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}
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}
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if (do_progress)
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fputc('\n', stderr);
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done:
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sha1close(f, pack_file_sha1, 1);
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}
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static void write_index_file(void)
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{
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int i;
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struct sha1file *f = sha1create("%s-%s.%s", base_name,
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sha1_to_hex(object_list_sha1), "idx");
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struct object_entry **list = sorted_by_sha;
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struct object_entry **last = list + nr_result;
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unsigned int array[256];
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/*
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* Write the first-level table (the list is sorted,
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* but we use a 256-entry lookup to be able to avoid
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* having to do eight extra binary search iterations).
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*/
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for (i = 0; i < 256; i++) {
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struct object_entry **next = list;
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while (next < last) {
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struct object_entry *entry = *next;
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if (entry->sha1[0] != i)
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break;
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next++;
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}
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array[i] = htonl(next - sorted_by_sha);
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list = next;
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}
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sha1write(f, array, 256 * sizeof(int));
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/*
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* Write the actual SHA1 entries..
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*/
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list = sorted_by_sha;
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for (i = 0; i < nr_result; i++) {
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struct object_entry *entry = *list++;
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unsigned int offset = htonl(entry->offset);
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sha1write(f, &offset, 4);
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sha1write(f, entry->sha1, 20);
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}
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sha1write(f, pack_file_sha1, 20);
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sha1close(f, NULL, 1);
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}
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static int locate_object_entry_hash(const unsigned char *sha1)
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{
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int i;
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unsigned int ui;
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memcpy(&ui, sha1, sizeof(unsigned int));
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i = ui % object_ix_hashsz;
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while (0 < object_ix[i]) {
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if (!memcmp(sha1, objects[object_ix[i]-1].sha1, 20))
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return i;
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if (++i == object_ix_hashsz)
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i = 0;
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}
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return -1 - i;
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}
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static struct object_entry *locate_object_entry(const unsigned char *sha1)
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{
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int i;
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if (!object_ix_hashsz)
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return NULL;
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i = locate_object_entry_hash(sha1);
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if (0 <= i)
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return &objects[object_ix[i]-1];
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return NULL;
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}
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static void rehash_objects(void)
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{
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int i;
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struct object_entry *oe;
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object_ix_hashsz = nr_objects * 3;
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if (object_ix_hashsz < 1024)
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object_ix_hashsz = 1024;
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object_ix = xrealloc(object_ix, sizeof(int) * object_ix_hashsz);
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object_ix = memset(object_ix, 0, sizeof(int) * object_ix_hashsz);
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for (i = 0, oe = objects; i < nr_objects; i++, oe++) {
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int ix = locate_object_entry_hash(oe->sha1);
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if (0 <= ix)
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continue;
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ix = -1 - ix;
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object_ix[ix] = i + 1;
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}
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}
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struct name_path {
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struct name_path *up;
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const char *elem;
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int len;
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};
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#define DIRBITS 12
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static unsigned name_hash(struct name_path *path, const char *name)
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{
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struct name_path *p = path;
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const char *n = name + strlen(name);
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unsigned hash = 0, name_hash = 0, name_done = 0;
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if (n != name && n[-1] == '\n')
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n--;
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while (name <= --n) {
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unsigned char c = *n;
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if (c == '/' && !name_done) {
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name_hash = hash;
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name_done = 1;
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hash = 0;
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}
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hash = hash * 11 + c;
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}
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if (!name_done) {
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name_hash = hash;
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hash = 0;
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}
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for (p = path; p; p = p->up) {
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hash = hash * 11 + '/';
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n = p->elem + p->len;
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while (p->elem <= --n) {
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unsigned char c = *n;
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hash = hash * 11 + c;
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}
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}
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/*
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* Make sure "Makefile" and "t/Makefile" are hashed separately
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* but close enough.
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*/
|
|
hash = (name_hash<<DIRBITS) | (hash & ((1U<<DIRBITS )-1));
|
|
|
|
if (0) { /* debug */
|
|
n = name + strlen(name);
|
|
if (n != name && n[-1] == '\n')
|
|
n--;
|
|
while (name <= --n)
|
|
fputc(*n, stderr);
|
|
for (p = path; p; p = p->up) {
|
|
fputc('/', stderr);
|
|
n = p->elem + p->len;
|
|
while (p->elem <= --n)
|
|
fputc(*n, stderr);
|
|
}
|
|
fprintf(stderr, "\t%08x\n", hash);
|
|
}
|
|
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) {
|
|
struct pack_entry e;
|
|
if (find_pack_entry_one(sha1, &e, p)) {
|
|
if (incremental)
|
|
return 0;
|
|
if (local && !p->pack_local)
|
|
return 0;
|
|
if (!found_pack) {
|
|
found_offset = e.offset;
|
|
found_pack = e.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));
|
|
memcpy(entry->sha1, sha1, 20);
|
|
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;
|
|
}
|
|
|
|
static void add_pbase_tree(struct tree_desc *tree, struct name_path *up)
|
|
{
|
|
while (tree->size) {
|
|
const unsigned char *sha1;
|
|
const char *name;
|
|
unsigned mode, hash;
|
|
unsigned long size;
|
|
char type[20];
|
|
|
|
sha1 = tree_entry_extract(tree, &name, &mode);
|
|
update_tree_entry(tree);
|
|
if (!has_sha1_file(sha1))
|
|
continue;
|
|
if (sha1_object_info(sha1, type, &size))
|
|
continue;
|
|
|
|
hash = name_hash(up, name);
|
|
if (!add_object_entry(sha1, hash, 1))
|
|
continue;
|
|
|
|
if (!strcmp(type, "tree")) {
|
|
struct tree_desc sub;
|
|
void *elem;
|
|
struct name_path me;
|
|
|
|
elem = read_sha1_file(sha1, type, &sub.size);
|
|
sub.buf = elem;
|
|
if (sub.buf) {
|
|
me.up = up;
|
|
me.elem = name;
|
|
me.len = strlen(name);
|
|
add_pbase_tree(&sub, &me);
|
|
free(elem);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void add_preferred_base(unsigned char *sha1)
|
|
{
|
|
struct tree_desc tree;
|
|
void *elem;
|
|
|
|
elem = read_object_with_reference(sha1, "tree", &tree.size, NULL);
|
|
tree.buf = elem;
|
|
if (!tree.buf)
|
|
return;
|
|
if (add_object_entry(sha1, name_hash(NULL, ""), 1))
|
|
add_pbase_tree(&tree, NULL);
|
|
free(elem);
|
|
}
|
|
|
|
static void check_object(struct object_entry *entry)
|
|
{
|
|
char type[20];
|
|
|
|
if (entry->in_pack && !entry->preferred_base) {
|
|
unsigned char base[20];
|
|
unsigned long size;
|
|
struct object_entry *base_entry;
|
|
|
|
/* We want in_pack_type even if we do not reuse delta.
|
|
* There is no point not reusing non-delta representations.
|
|
*/
|
|
check_reuse_pack_delta(entry->in_pack,
|
|
entry->in_pack_offset,
|
|
base, &size,
|
|
&entry->in_pack_type);
|
|
|
|
/* 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 &&
|
|
entry->in_pack_type == OBJ_DELTA &&
|
|
(base_entry = locate_object_entry(base)) &&
|
|
(!base_entry->preferred_base)) {
|
|
|
|
/* 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.
|
|
*/
|
|
|
|
/* uncompressed size of the delta data */
|
|
entry->size = entry->delta_size = size;
|
|
entry->delta = base_entry;
|
|
entry->type = OBJ_DELTA;
|
|
|
|
entry->delta_sibling = base_entry->delta_child;
|
|
base_entry->delta_child = entry;
|
|
|
|
return;
|
|
}
|
|
/* Otherwise we would do the usual */
|
|
}
|
|
|
|
if (sha1_object_info(entry->sha1, type, &entry->size))
|
|
die("unable to get type of object %s",
|
|
sha1_to_hex(entry->sha1));
|
|
|
|
if (!strcmp(type, "commit")) {
|
|
entry->type = OBJ_COMMIT;
|
|
} else if (!strcmp(type, "tree")) {
|
|
entry->type = OBJ_TREE;
|
|
} else if (!strcmp(type, "blob")) {
|
|
entry->type = OBJ_BLOB;
|
|
} else if (!strcmp(type, "tag")) {
|
|
entry->type = OBJ_TAG;
|
|
} else
|
|
die("unable to pack object %s of type %s",
|
|
sha1_to_hex(entry->sha1), type);
|
|
}
|
|
|
|
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 void get_object_details(void)
|
|
{
|
|
int i;
|
|
struct object_entry *entry;
|
|
|
|
prepare_pack_ix();
|
|
for (i = 0, entry = objects; i < nr_objects; i++, entry++)
|
|
check_object(entry);
|
|
|
|
if (nr_objects == nr_result) {
|
|
/*
|
|
* Depth of objects that depend on the entry -- this
|
|
* is subtracted from depth-max to break too deep
|
|
* delta chain because of delta data reusing.
|
|
* However, we loosen this restriction when we know we
|
|
* are creating a thin pack -- it will have to be
|
|
* expanded on the other end anyway, so do not
|
|
* artificially cut the delta chain and let it go as
|
|
* deep as it wants.
|
|
*/
|
|
for (i = 0, entry = objects; i < nr_objects; i++, entry++)
|
|
if (!entry->delta && entry->delta_child)
|
|
entry->delta_limit =
|
|
check_delta_limit(entry, 1);
|
|
}
|
|
}
|
|
|
|
typedef int (*entry_sort_t)(const struct object_entry *, const struct object_entry *);
|
|
|
|
static entry_sort_t current_sort;
|
|
|
|
static int sort_comparator(const void *_a, const void *_b)
|
|
{
|
|
struct object_entry *a = *(struct object_entry **)_a;
|
|
struct object_entry *b = *(struct object_entry **)_b;
|
|
return current_sort(a,b);
|
|
}
|
|
|
|
static struct object_entry **create_sorted_list(entry_sort_t sort)
|
|
{
|
|
struct object_entry **list = xmalloc(nr_objects * sizeof(struct object_entry *));
|
|
int i;
|
|
|
|
for (i = 0; i < nr_objects; i++)
|
|
list[i] = objects + i;
|
|
current_sort = sort;
|
|
qsort(list, nr_objects, sizeof(struct object_entry *), sort_comparator);
|
|
return list;
|
|
}
|
|
|
|
static int sha1_sort(const struct object_entry *a, const struct object_entry *b)
|
|
{
|
|
return memcmp(a->sha1, b->sha1, 20);
|
|
}
|
|
|
|
static struct object_entry **create_final_object_list()
|
|
{
|
|
struct object_entry **list;
|
|
int i, j;
|
|
|
|
for (i = nr_result = 0; i < nr_objects; i++)
|
|
if (!objects[i].preferred_base)
|
|
nr_result++;
|
|
list = xmalloc(nr_result * sizeof(struct object_entry *));
|
|
for (i = j = 0; i < nr_objects; i++) {
|
|
if (!objects[i].preferred_base)
|
|
list[j++] = objects + i;
|
|
}
|
|
current_sort = sha1_sort;
|
|
qsort(list, nr_result, sizeof(struct object_entry *), sort_comparator);
|
|
return list;
|
|
}
|
|
|
|
static int type_size_sort(const struct object_entry *a, const 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);
|
|
}
|
|
|
|
struct unpacked {
|
|
struct object_entry *entry;
|
|
void *data;
|
|
};
|
|
|
|
/*
|
|
* We search for deltas _backwards_ in a list sorted by type and
|
|
* 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.
|
|
*/
|
|
static int try_delta(struct unpacked *cur, struct unpacked *old, unsigned max_depth)
|
|
{
|
|
struct object_entry *cur_entry = cur->entry;
|
|
struct object_entry *old_entry = old->entry;
|
|
int old_preferred = (old_entry->preferred_base ||
|
|
old_entry->based_on_preferred);
|
|
unsigned long size, oldsize, delta_size, sizediff;
|
|
long max_size;
|
|
void *delta_buf;
|
|
|
|
/* Don't bother doing diffs between different types */
|
|
if (cur_entry->type != old_entry->type)
|
|
return -1;
|
|
|
|
/* We do not compute delta to *create* objects we are not
|
|
* going to pack.
|
|
*/
|
|
if (cur_entry->preferred_base)
|
|
return -1;
|
|
|
|
/* 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.
|
|
*/
|
|
if (cur_entry->delta_child) {
|
|
if (max_depth <= cur_entry->delta_limit)
|
|
return 0;
|
|
max_depth -= cur_entry->delta_limit;
|
|
}
|
|
|
|
size = cur_entry->size;
|
|
oldsize = old_entry->size;
|
|
sizediff = oldsize > size ? oldsize - size : size - oldsize;
|
|
|
|
if (size < 50)
|
|
return -1;
|
|
if (old_entry->depth >= max_depth)
|
|
return 0;
|
|
|
|
/*
|
|
* NOTE!
|
|
*
|
|
* We always delta from the bigger to the smaller, since that's
|
|
* more space-efficient (deletes don't have to say _what_ they
|
|
* delete).
|
|
*/
|
|
max_size = size / 2 - 20;
|
|
if (cur_entry->delta) {
|
|
if (cur_entry->based_on_preferred) {
|
|
if (old_preferred)
|
|
max_size = cur_entry->delta_size-1;
|
|
else
|
|
/* trying with non-preferred one when we
|
|
* already have a delta based on preferred
|
|
* one is pointless.
|
|
*/
|
|
return -1;
|
|
}
|
|
else if (!old_preferred)
|
|
max_size = cur_entry->delta_size-1;
|
|
else
|
|
/* otherwise... even if delta with a
|
|
* preferred one produces a bigger result than
|
|
* what we currently have, which is based on a
|
|
* non-preferred one, it is OK.
|
|
*/
|
|
;
|
|
}
|
|
if (sizediff >= max_size)
|
|
return -1;
|
|
delta_buf = diff_delta(old->data, oldsize,
|
|
cur->data, size, &delta_size, max_size);
|
|
if (!delta_buf)
|
|
return 0;
|
|
cur_entry->delta = old_entry;
|
|
cur_entry->delta_size = delta_size;
|
|
cur_entry->depth = old_entry->depth + 1;
|
|
cur_entry->based_on_preferred = old_preferred;
|
|
free(delta_buf);
|
|
return 0;
|
|
}
|
|
|
|
static void progress_interval(int signum)
|
|
{
|
|
signal(SIGALRM, progress_interval);
|
|
progress_update = 1;
|
|
}
|
|
|
|
static void find_deltas(struct object_entry **list, int window, int depth)
|
|
{
|
|
int i, idx;
|
|
unsigned int array_size = window * sizeof(struct unpacked);
|
|
struct unpacked *array = xmalloc(array_size);
|
|
unsigned processed = 0;
|
|
unsigned last_percent = 999;
|
|
|
|
memset(array, 0, array_size);
|
|
i = nr_objects;
|
|
idx = 0;
|
|
if (progress)
|
|
fprintf(stderr, "Deltifying %d objects.\n", nr_result);
|
|
|
|
while (--i >= 0) {
|
|
struct object_entry *entry = list[i];
|
|
struct unpacked *n = array + idx;
|
|
unsigned long size;
|
|
char type[10];
|
|
int j;
|
|
|
|
if (!entry->preferred_base)
|
|
processed++;
|
|
|
|
if (progress) {
|
|
unsigned percent = processed * 100 / nr_result;
|
|
if (percent != last_percent || progress_update) {
|
|
fprintf(stderr, "%4u%% (%u/%u) done\r",
|
|
percent, processed, nr_result);
|
|
progress_update = 0;
|
|
last_percent = percent;
|
|
}
|
|
}
|
|
|
|
if (entry->delta)
|
|
/* This happens if we decided to reuse existing
|
|
* delta from a pack. "!no_reuse_delta &&" is implied.
|
|
*/
|
|
continue;
|
|
|
|
free(n->data);
|
|
n->entry = entry;
|
|
n->data = read_sha1_file(entry->sha1, type, &size);
|
|
if (size != entry->size)
|
|
die("object %s inconsistent object length (%lu vs %lu)", sha1_to_hex(entry->sha1), size, entry->size);
|
|
|
|
j = window;
|
|
while (--j > 0) {
|
|
unsigned int other_idx = idx + j;
|
|
struct unpacked *m;
|
|
if (other_idx >= window)
|
|
other_idx -= window;
|
|
m = array + other_idx;
|
|
if (!m->entry)
|
|
break;
|
|
if (try_delta(n, m, depth) < 0)
|
|
break;
|
|
}
|
|
idx++;
|
|
if (idx >= window)
|
|
idx = 0;
|
|
}
|
|
|
|
if (progress)
|
|
fputc('\n', stderr);
|
|
|
|
for (i = 0; i < window; ++i)
|
|
free(array[i].data);
|
|
free(array);
|
|
}
|
|
|
|
static void prepare_pack(int window, int depth)
|
|
{
|
|
get_object_details();
|
|
sorted_by_type = create_sorted_list(type_size_sort);
|
|
if (window && depth)
|
|
find_deltas(sorted_by_type, window+1, depth);
|
|
}
|
|
|
|
static int reuse_cached_pack(unsigned char *sha1, int pack_to_stdout)
|
|
{
|
|
static const char cache[] = "pack-cache/pack-%s.%s";
|
|
char *cached_pack, *cached_idx;
|
|
int ifd, ofd, ifd_ix = -1;
|
|
|
|
cached_pack = git_path(cache, sha1_to_hex(sha1), "pack");
|
|
ifd = open(cached_pack, O_RDONLY);
|
|
if (ifd < 0)
|
|
return 0;
|
|
|
|
if (!pack_to_stdout) {
|
|
cached_idx = git_path(cache, sha1_to_hex(sha1), "idx");
|
|
ifd_ix = open(cached_idx, O_RDONLY);
|
|
if (ifd_ix < 0) {
|
|
close(ifd);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
if (progress)
|
|
fprintf(stderr, "Reusing %d objects pack %s\n", nr_objects,
|
|
sha1_to_hex(sha1));
|
|
|
|
if (pack_to_stdout) {
|
|
if (copy_fd(ifd, 1))
|
|
exit(1);
|
|
close(ifd);
|
|
}
|
|
else {
|
|
char name[PATH_MAX];
|
|
snprintf(name, sizeof(name),
|
|
"%s-%s.%s", base_name, sha1_to_hex(sha1), "pack");
|
|
ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
|
|
if (ofd < 0)
|
|
die("unable to open %s (%s)", name, strerror(errno));
|
|
if (copy_fd(ifd, ofd))
|
|
exit(1);
|
|
close(ifd);
|
|
|
|
snprintf(name, sizeof(name),
|
|
"%s-%s.%s", base_name, sha1_to_hex(sha1), "idx");
|
|
ofd = open(name, O_CREAT | O_EXCL | O_WRONLY, 0666);
|
|
if (ofd < 0)
|
|
die("unable to open %s (%s)", name, strerror(errno));
|
|
if (copy_fd(ifd_ix, ofd))
|
|
exit(1);
|
|
close(ifd_ix);
|
|
puts(sha1_to_hex(sha1));
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
SHA_CTX ctx;
|
|
char line[PATH_MAX + 20];
|
|
int window = 10, depth = 10, pack_to_stdout = 0;
|
|
struct object_entry **list;
|
|
int i;
|
|
|
|
setup_git_directory();
|
|
|
|
for (i = 1; i < argc; i++) {
|
|
const char *arg = argv[i];
|
|
|
|
if (*arg == '-') {
|
|
if (!strcmp("--non-empty", arg)) {
|
|
non_empty = 1;
|
|
continue;
|
|
}
|
|
if (!strcmp("--local", arg)) {
|
|
local = 1;
|
|
continue;
|
|
}
|
|
if (!strcmp("--incremental", arg)) {
|
|
incremental = 1;
|
|
continue;
|
|
}
|
|
if (!strncmp("--window=", arg, 9)) {
|
|
char *end;
|
|
window = strtoul(arg+9, &end, 0);
|
|
if (!arg[9] || *end)
|
|
usage(pack_usage);
|
|
continue;
|
|
}
|
|
if (!strncmp("--depth=", arg, 8)) {
|
|
char *end;
|
|
depth = strtoul(arg+8, &end, 0);
|
|
if (!arg[8] || *end)
|
|
usage(pack_usage);
|
|
continue;
|
|
}
|
|
if (!strcmp("-q", arg)) {
|
|
progress = 0;
|
|
continue;
|
|
}
|
|
if (!strcmp("--no-reuse-delta", arg)) {
|
|
no_reuse_delta = 1;
|
|
continue;
|
|
}
|
|
if (!strcmp("--stdout", arg)) {
|
|
pack_to_stdout = 1;
|
|
continue;
|
|
}
|
|
usage(pack_usage);
|
|
}
|
|
if (base_name)
|
|
usage(pack_usage);
|
|
base_name = arg;
|
|
}
|
|
|
|
if (pack_to_stdout != !base_name)
|
|
usage(pack_usage);
|
|
|
|
prepare_packed_git();
|
|
|
|
if (progress) {
|
|
struct itimerval v;
|
|
v.it_interval.tv_sec = 1;
|
|
v.it_interval.tv_usec = 0;
|
|
v.it_value = v.it_interval;
|
|
signal(SIGALRM, progress_interval);
|
|
setitimer(ITIMER_REAL, &v, NULL);
|
|
fprintf(stderr, "Generating pack...\n");
|
|
}
|
|
|
|
while (fgets(line, sizeof(line), stdin) != NULL) {
|
|
unsigned char sha1[20];
|
|
|
|
if (line[0] == '-') {
|
|
if (get_sha1_hex(line+1, sha1))
|
|
die("expected edge sha1, got garbage:\n %s",
|
|
line+1);
|
|
add_preferred_base(sha1);
|
|
continue;
|
|
}
|
|
if (get_sha1_hex(line, sha1))
|
|
die("expected sha1, got garbage:\n %s", line);
|
|
add_object_entry(sha1, name_hash(NULL, line+41), 0);
|
|
}
|
|
if (progress)
|
|
fprintf(stderr, "Done counting %d objects.\n", nr_objects);
|
|
sorted_by_sha = create_final_object_list();
|
|
if (non_empty && !nr_result)
|
|
return 0;
|
|
|
|
SHA1_Init(&ctx);
|
|
list = sorted_by_sha;
|
|
for (i = 0; i < nr_result; i++) {
|
|
struct object_entry *entry = *list++;
|
|
SHA1_Update(&ctx, entry->sha1, 20);
|
|
}
|
|
SHA1_Final(object_list_sha1, &ctx);
|
|
if (progress && (nr_objects != nr_result))
|
|
fprintf(stderr, "Result has %d objects.\n", nr_result);
|
|
|
|
if (reuse_cached_pack(object_list_sha1, pack_to_stdout))
|
|
;
|
|
else {
|
|
if (nr_result)
|
|
prepare_pack(window, depth);
|
|
if (progress && pack_to_stdout) {
|
|
/* the other end usually displays progress itself */
|
|
struct itimerval v = {{0,},};
|
|
setitimer(ITIMER_REAL, &v, NULL);
|
|
signal(SIGALRM, SIG_IGN );
|
|
progress_update = 0;
|
|
}
|
|
write_pack_file();
|
|
if (!pack_to_stdout) {
|
|
write_index_file();
|
|
puts(sha1_to_hex(object_list_sha1));
|
|
}
|
|
}
|
|
if (progress)
|
|
fprintf(stderr, "Total %d, written %d (delta %d), reused %d (delta %d)\n",
|
|
nr_result, written, written_delta, reused, reused_delta);
|
|
return 0;
|
|
}
|