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https://github.com/git/git.git
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2f4ba2a867
Specify the format of the on-disk reverse index 'pack-*.rev' file, as well as prepare the code for the existence of such files. The reverse index maps from pack relative positions (i.e., an index into the array of object which is sorted by their offsets within the packfile) to their position within the 'pack-*.idx' file. Today, this is done by building up a list of (off_t, uint32_t) tuples for each object (the off_t corresponding to that object's offset, and the uint32_t corresponding to its position in the index). To convert between pack and index position quickly, this array of tuples is radix sorted based on its offset. This has two major drawbacks: First, the in-memory cost scales linearly with the number of objects in a pack. Each 'struct revindex_entry' is sizeof(off_t) + sizeof(uint32_t) + padding bytes for a total of 16. To observe this, force Git to load the reverse index by, for e.g., running 'git cat-file --batch-check="%(objectsize:disk)"'. When asking for a single object in a fresh clone of the kernel, Git needs to allocate 120+ MB of memory in order to hold the reverse index in memory. Second, the cost to sort also scales with the size of the pack. Luckily, this is a linear function since 'load_pack_revindex()' uses a radix sort, but this cost still must be paid once per pack per process. As an example, it takes ~60x longer to print the _size_ of an object as it does to print that entire object's _contents_: Benchmark #1: git.compile cat-file --batch <obj Time (mean ± σ): 3.4 ms ± 0.1 ms [User: 3.3 ms, System: 2.1 ms] Range (min … max): 3.2 ms … 3.7 ms 726 runs Benchmark #2: git.compile cat-file --batch-check="%(objectsize:disk)" <obj Time (mean ± σ): 210.3 ms ± 8.9 ms [User: 188.2 ms, System: 23.2 ms] Range (min … max): 193.7 ms … 224.4 ms 13 runs Instead, avoid computing and sorting the revindex once per process by writing it to a file when the pack itself is generated. The format is relatively straightforward. It contains an array of uint32_t's, the length of which is equal to the number of objects in the pack. The ith entry in this table contains the index position of the ith object in the pack, where "ith object in the pack" is determined by pack offset. One thing that the on-disk format does _not_ contain is the full (up to) eight-byte offset corresponding to each object. This is something that the in-memory revindex contains (it stores an off_t in 'struct revindex_entry' along with the same uint32_t that the on-disk format has). Omit it in the on-disk format, since knowing the index position for some object is sufficient to get a constant-time lookup in the pack-*.idx file to ask for an object's offset within the pack. This trades off between the on-disk size of the 'pack-*.rev' file for runtime to chase down the offset for some object. Even though the lookup is constant time, the constant is heavier, since it can potentially involve two pointer walks in v2 indexes (one to access the 4-byte offset table, and potentially a second to access the double wide offset table). Consider trying to map an object's pack offset to a relative position within that pack. In a cold-cache scenario, more page faults occur while switching between binary searching through the reverse index and searching through the *.idx file for an object's offset. Sure enough, with a cold cache (writing '3' into '/proc/sys/vm/drop_caches' after 'sync'ing), printing out the entire object's contents is still marginally faster than printing its size: Benchmark #1: git.compile cat-file --batch-check="%(objectsize:disk)" <obj >/dev/null Time (mean ± σ): 22.6 ms ± 0.5 ms [User: 2.4 ms, System: 7.9 ms] Range (min … max): 21.4 ms … 23.5 ms 41 runs Benchmark #2: git.compile cat-file --batch <obj >/dev/null Time (mean ± σ): 17.2 ms ± 0.7 ms [User: 2.8 ms, System: 5.5 ms] Range (min … max): 15.6 ms … 18.2 ms 45 runs (Numbers taken in the kernel after cheating and using the next patch to generate a reverse index). There are a couple of approaches to improve cold cache performance not pursued here: - We could include the object offsets in the reverse index format. Predictably, this does result in fewer page faults, but it triples the size of the file, while simultaneously duplicating a ton of data already available in the .idx file. (This was the original way I implemented the format, and it did show `--batch-check='%(objectsize:disk)'` winning out against `--batch`.) On the other hand, this increase in size also results in a large block-cache footprint, which could potentially hurt other workloads. - We could store the mapping from pack to index position in more cache-friendly way, like constructing a binary search tree from the table and writing the values in breadth-first order. This would result in much better locality, but the price you pay is trading O(1) lookup in 'pack_pos_to_index()' for an O(log n) one (since you can no longer directly index the table). So, neither of these approaches are taken here. (Thankfully, the format is versioned, so we are free to pursue these in the future.) But, cold cache performance likely isn't interesting outside of one-off cases like asking for the size of an object directly. In real-world usage, Git is often performing many operations in the revindex (i.e., asking about many objects rather than a single one). The trade-off is worth it, since we will avoid the vast majority of the cost of generating the revindex that the extra pointer chase will look like noise in the following patch's benchmarks. This patch describes the format and prepares callers (like in pack-revindex.c) to be able to read *.rev files once they exist. An implementation of the writer will appear in the next patch, and callers will gradually begin to start using the writer in the patches that follow after that. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2209 lines
56 KiB
C
2209 lines
56 KiB
C
#include "cache.h"
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#include "list.h"
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#include "pack.h"
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#include "repository.h"
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#include "dir.h"
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#include "mergesort.h"
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#include "packfile.h"
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#include "delta.h"
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#include "streaming.h"
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#include "hash-lookup.h"
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#include "commit.h"
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#include "object.h"
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#include "tag.h"
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#include "tree-walk.h"
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#include "tree.h"
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#include "object-store.h"
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#include "midx.h"
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#include "commit-graph.h"
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#include "promisor-remote.h"
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char *odb_pack_name(struct strbuf *buf,
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const unsigned char *hash,
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const char *ext)
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{
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strbuf_reset(buf);
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strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
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hash_to_hex(hash), ext);
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return buf->buf;
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}
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char *sha1_pack_name(const unsigned char *sha1)
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{
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static struct strbuf buf = STRBUF_INIT;
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return odb_pack_name(&buf, sha1, "pack");
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}
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char *sha1_pack_index_name(const unsigned char *sha1)
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{
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static struct strbuf buf = STRBUF_INIT;
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return odb_pack_name(&buf, sha1, "idx");
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}
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static unsigned int pack_used_ctr;
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static unsigned int pack_mmap_calls;
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static unsigned int peak_pack_open_windows;
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static unsigned int pack_open_windows;
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static unsigned int pack_open_fds;
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static unsigned int pack_max_fds;
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static size_t peak_pack_mapped;
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static size_t pack_mapped;
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#define SZ_FMT PRIuMAX
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static inline uintmax_t sz_fmt(size_t s) { return s; }
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void pack_report(void)
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{
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fprintf(stderr,
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"pack_report: getpagesize() = %10" SZ_FMT "\n"
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"pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
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"pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
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sz_fmt(getpagesize()),
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sz_fmt(packed_git_window_size),
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sz_fmt(packed_git_limit));
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fprintf(stderr,
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"pack_report: pack_used_ctr = %10u\n"
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"pack_report: pack_mmap_calls = %10u\n"
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"pack_report: pack_open_windows = %10u / %10u\n"
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"pack_report: pack_mapped = "
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"%10" SZ_FMT " / %10" SZ_FMT "\n",
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pack_used_ctr,
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pack_mmap_calls,
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pack_open_windows, peak_pack_open_windows,
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sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
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}
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/*
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* Open and mmap the index file at path, perform a couple of
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* consistency checks, then record its information to p. Return 0 on
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* success.
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*/
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static int check_packed_git_idx(const char *path, struct packed_git *p)
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{
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void *idx_map;
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size_t idx_size;
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int fd = git_open(path), ret;
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struct stat st;
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const unsigned int hashsz = the_hash_algo->rawsz;
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if (fd < 0)
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return -1;
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if (fstat(fd, &st)) {
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close(fd);
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return -1;
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}
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idx_size = xsize_t(st.st_size);
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if (idx_size < 4 * 256 + hashsz + hashsz) {
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close(fd);
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return error("index file %s is too small", path);
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}
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idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
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close(fd);
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ret = load_idx(path, hashsz, idx_map, idx_size, p);
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if (ret)
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munmap(idx_map, idx_size);
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return ret;
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}
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int load_idx(const char *path, const unsigned int hashsz, void *idx_map,
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size_t idx_size, struct packed_git *p)
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{
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struct pack_idx_header *hdr = idx_map;
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uint32_t version, nr, i, *index;
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if (idx_size < 4 * 256 + hashsz + hashsz)
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return error("index file %s is too small", path);
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if (idx_map == NULL)
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return error("empty data");
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if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
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version = ntohl(hdr->idx_version);
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if (version < 2 || version > 2)
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return error("index file %s is version %"PRIu32
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" and is not supported by this binary"
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" (try upgrading GIT to a newer version)",
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path, version);
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} else
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version = 1;
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nr = 0;
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index = idx_map;
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if (version > 1)
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index += 2; /* skip index header */
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for (i = 0; i < 256; i++) {
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uint32_t n = ntohl(index[i]);
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if (n < nr)
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return error("non-monotonic index %s", path);
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nr = n;
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}
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if (version == 1) {
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/*
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* Total size:
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* - 256 index entries 4 bytes each
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* - 24-byte entries * nr (object ID + 4-byte offset)
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* - hash of the packfile
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* - file checksum
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*/
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if (idx_size != st_add(4 * 256 + hashsz + hashsz, st_mult(nr, hashsz + 4)))
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return error("wrong index v1 file size in %s", path);
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} else if (version == 2) {
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/*
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* Minimum size:
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* - 8 bytes of header
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* - 256 index entries 4 bytes each
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* - object ID entry * nr
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* - 4-byte crc entry * nr
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* - 4-byte offset entry * nr
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* - hash of the packfile
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* - file checksum
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* And after the 4-byte offset table might be a
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* variable sized table containing 8-byte entries
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* for offsets larger than 2^31.
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*/
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size_t min_size = st_add(8 + 4*256 + hashsz + hashsz, st_mult(nr, hashsz + 4 + 4));
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size_t max_size = min_size;
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if (nr)
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max_size = st_add(max_size, st_mult(nr - 1, 8));
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if (idx_size < min_size || idx_size > max_size)
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return error("wrong index v2 file size in %s", path);
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if (idx_size != min_size &&
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/*
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* make sure we can deal with large pack offsets.
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* 31-bit signed offset won't be enough, neither
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* 32-bit unsigned one will be.
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*/
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(sizeof(off_t) <= 4))
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return error("pack too large for current definition of off_t in %s", path);
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p->crc_offset = 8 + 4 * 256 + nr * hashsz;
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}
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p->index_version = version;
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p->index_data = idx_map;
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p->index_size = idx_size;
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p->num_objects = nr;
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return 0;
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}
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int open_pack_index(struct packed_git *p)
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{
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char *idx_name;
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size_t len;
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int ret;
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if (p->index_data)
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return 0;
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if (!strip_suffix(p->pack_name, ".pack", &len))
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BUG("pack_name does not end in .pack");
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idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
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ret = check_packed_git_idx(idx_name, p);
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free(idx_name);
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return ret;
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}
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uint32_t get_pack_fanout(struct packed_git *p, uint32_t value)
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{
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const uint32_t *level1_ofs = p->index_data;
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if (!level1_ofs) {
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if (open_pack_index(p))
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return 0;
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level1_ofs = p->index_data;
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}
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if (p->index_version > 1) {
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level1_ofs += 2;
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}
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return ntohl(level1_ofs[value]);
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}
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static struct packed_git *alloc_packed_git(int extra)
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{
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struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
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memset(p, 0, sizeof(*p));
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p->pack_fd = -1;
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return p;
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}
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struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
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{
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const char *path = sha1_pack_name(sha1);
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size_t alloc = st_add(strlen(path), 1);
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struct packed_git *p = alloc_packed_git(alloc);
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memcpy(p->pack_name, path, alloc); /* includes NUL */
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hashcpy(p->hash, sha1);
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if (check_packed_git_idx(idx_path, p)) {
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free(p);
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return NULL;
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}
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return p;
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}
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static void scan_windows(struct packed_git *p,
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struct packed_git **lru_p,
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struct pack_window **lru_w,
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struct pack_window **lru_l)
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{
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struct pack_window *w, *w_l;
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for (w_l = NULL, w = p->windows; w; w = w->next) {
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if (!w->inuse_cnt) {
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if (!*lru_w || w->last_used < (*lru_w)->last_used) {
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*lru_p = p;
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*lru_w = w;
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*lru_l = w_l;
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}
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}
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w_l = w;
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}
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}
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static int unuse_one_window(struct packed_git *current)
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{
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struct packed_git *p, *lru_p = NULL;
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struct pack_window *lru_w = NULL, *lru_l = NULL;
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if (current)
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scan_windows(current, &lru_p, &lru_w, &lru_l);
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for (p = the_repository->objects->packed_git; p; p = p->next)
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scan_windows(p, &lru_p, &lru_w, &lru_l);
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if (lru_p) {
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munmap(lru_w->base, lru_w->len);
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pack_mapped -= lru_w->len;
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if (lru_l)
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lru_l->next = lru_w->next;
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else
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lru_p->windows = lru_w->next;
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free(lru_w);
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pack_open_windows--;
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return 1;
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}
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return 0;
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}
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void close_pack_windows(struct packed_git *p)
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{
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while (p->windows) {
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struct pack_window *w = p->windows;
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if (w->inuse_cnt)
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die("pack '%s' still has open windows to it",
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p->pack_name);
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munmap(w->base, w->len);
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pack_mapped -= w->len;
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pack_open_windows--;
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p->windows = w->next;
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free(w);
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}
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}
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int close_pack_fd(struct packed_git *p)
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{
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if (p->pack_fd < 0)
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return 0;
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close(p->pack_fd);
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pack_open_fds--;
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p->pack_fd = -1;
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return 1;
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}
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void close_pack_index(struct packed_git *p)
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{
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if (p->index_data) {
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munmap((void *)p->index_data, p->index_size);
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p->index_data = NULL;
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}
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}
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void close_pack_revindex(struct packed_git *p) {
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if (!p->revindex_map)
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return;
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munmap((void *)p->revindex_map, p->revindex_size);
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p->revindex_map = NULL;
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p->revindex_data = NULL;
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}
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void close_pack(struct packed_git *p)
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{
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close_pack_windows(p);
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close_pack_fd(p);
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close_pack_index(p);
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close_pack_revindex(p);
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}
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void close_object_store(struct raw_object_store *o)
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{
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struct packed_git *p;
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for (p = o->packed_git; p; p = p->next)
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if (p->do_not_close)
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BUG("want to close pack marked 'do-not-close'");
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else
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close_pack(p);
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if (o->multi_pack_index) {
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close_midx(o->multi_pack_index);
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o->multi_pack_index = NULL;
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}
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close_commit_graph(o);
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}
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void unlink_pack_path(const char *pack_name, int force_delete)
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{
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static const char *exts[] = {".pack", ".idx", ".rev", ".keep", ".bitmap", ".promisor"};
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int i;
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struct strbuf buf = STRBUF_INIT;
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size_t plen;
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strbuf_addstr(&buf, pack_name);
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strip_suffix_mem(buf.buf, &buf.len, ".pack");
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plen = buf.len;
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if (!force_delete) {
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strbuf_addstr(&buf, ".keep");
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if (!access(buf.buf, F_OK)) {
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strbuf_release(&buf);
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return;
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}
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}
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for (i = 0; i < ARRAY_SIZE(exts); i++) {
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strbuf_setlen(&buf, plen);
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strbuf_addstr(&buf, exts[i]);
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unlink(buf.buf);
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}
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strbuf_release(&buf);
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}
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/*
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* The LRU pack is the one with the oldest MRU window, preferring packs
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* with no used windows, or the oldest mtime if it has no windows allocated.
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*/
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static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
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{
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struct pack_window *w, *this_mru_w;
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int has_windows_inuse = 0;
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/*
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* Reject this pack if it has windows and the previously selected
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* one does not. If this pack does not have windows, reject
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* it if the pack file is newer than the previously selected one.
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*/
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if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
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return;
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for (w = this_mru_w = p->windows; w; w = w->next) {
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/*
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* Reject this pack if any of its windows are in use,
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* but the previously selected pack did not have any
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* inuse windows. Otherwise, record that this pack
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* has windows in use.
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*/
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if (w->inuse_cnt) {
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if (*accept_windows_inuse)
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has_windows_inuse = 1;
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else
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return;
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}
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|
|
if (w->last_used > this_mru_w->last_used)
|
|
this_mru_w = w;
|
|
|
|
/*
|
|
* Reject this pack if it has windows that have been
|
|
* used more recently than the previously selected pack.
|
|
* If the previously selected pack had windows inuse and
|
|
* we have not encountered a window in this pack that is
|
|
* inuse, skip this check since we prefer a pack with no
|
|
* inuse windows to one that has inuse windows.
|
|
*/
|
|
if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
|
|
this_mru_w->last_used > (*mru_w)->last_used)
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Select this pack.
|
|
*/
|
|
*mru_w = this_mru_w;
|
|
*lru_p = p;
|
|
*accept_windows_inuse = has_windows_inuse;
|
|
}
|
|
|
|
static int close_one_pack(void)
|
|
{
|
|
struct packed_git *p, *lru_p = NULL;
|
|
struct pack_window *mru_w = NULL;
|
|
int accept_windows_inuse = 1;
|
|
|
|
for (p = the_repository->objects->packed_git; p; p = p->next) {
|
|
if (p->pack_fd == -1)
|
|
continue;
|
|
find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
|
|
}
|
|
|
|
if (lru_p)
|
|
return close_pack_fd(lru_p);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned int get_max_fd_limit(void)
|
|
{
|
|
#ifdef RLIMIT_NOFILE
|
|
{
|
|
struct rlimit lim;
|
|
|
|
if (!getrlimit(RLIMIT_NOFILE, &lim))
|
|
return lim.rlim_cur;
|
|
}
|
|
#endif
|
|
|
|
#ifdef _SC_OPEN_MAX
|
|
{
|
|
long open_max = sysconf(_SC_OPEN_MAX);
|
|
if (0 < open_max)
|
|
return open_max;
|
|
/*
|
|
* Otherwise, we got -1 for one of the two
|
|
* reasons:
|
|
*
|
|
* (1) sysconf() did not understand _SC_OPEN_MAX
|
|
* and signaled an error with -1; or
|
|
* (2) sysconf() said there is no limit.
|
|
*
|
|
* We _could_ clear errno before calling sysconf() to
|
|
* tell these two cases apart and return a huge number
|
|
* in the latter case to let the caller cap it to a
|
|
* value that is not so selfish, but letting the
|
|
* fallback OPEN_MAX codepath take care of these cases
|
|
* is a lot simpler.
|
|
*/
|
|
}
|
|
#endif
|
|
|
|
#ifdef OPEN_MAX
|
|
return OPEN_MAX;
|
|
#else
|
|
return 1; /* see the caller ;-) */
|
|
#endif
|
|
}
|
|
|
|
const char *pack_basename(struct packed_git *p)
|
|
{
|
|
const char *ret = strrchr(p->pack_name, '/');
|
|
if (ret)
|
|
ret = ret + 1; /* skip past slash */
|
|
else
|
|
ret = p->pack_name; /* we only have a base */
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Do not call this directly as this leaks p->pack_fd on error return;
|
|
* call open_packed_git() instead.
|
|
*/
|
|
static int open_packed_git_1(struct packed_git *p)
|
|
{
|
|
struct stat st;
|
|
struct pack_header hdr;
|
|
unsigned char hash[GIT_MAX_RAWSZ];
|
|
unsigned char *idx_hash;
|
|
ssize_t read_result;
|
|
const unsigned hashsz = the_hash_algo->rawsz;
|
|
|
|
if (open_pack_index(p))
|
|
return error("packfile %s index unavailable", p->pack_name);
|
|
|
|
if (!pack_max_fds) {
|
|
unsigned int max_fds = get_max_fd_limit();
|
|
|
|
/* Save 3 for stdin/stdout/stderr, 22 for work */
|
|
if (25 < max_fds)
|
|
pack_max_fds = max_fds - 25;
|
|
else
|
|
pack_max_fds = 1;
|
|
}
|
|
|
|
while (pack_max_fds <= pack_open_fds && close_one_pack())
|
|
; /* nothing */
|
|
|
|
p->pack_fd = git_open(p->pack_name);
|
|
if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
|
|
return -1;
|
|
pack_open_fds++;
|
|
|
|
/* If we created the struct before we had the pack we lack size. */
|
|
if (!p->pack_size) {
|
|
if (!S_ISREG(st.st_mode))
|
|
return error("packfile %s not a regular file", p->pack_name);
|
|
p->pack_size = st.st_size;
|
|
} else if (p->pack_size != st.st_size)
|
|
return error("packfile %s size changed", p->pack_name);
|
|
|
|
/* Verify we recognize this pack file format. */
|
|
read_result = read_in_full(p->pack_fd, &hdr, sizeof(hdr));
|
|
if (read_result < 0)
|
|
return error_errno("error reading from %s", p->pack_name);
|
|
if (read_result != sizeof(hdr))
|
|
return error("file %s is far too short to be a packfile", p->pack_name);
|
|
if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
|
|
return error("file %s is not a GIT packfile", p->pack_name);
|
|
if (!pack_version_ok(hdr.hdr_version))
|
|
return error("packfile %s is version %"PRIu32" and not"
|
|
" supported (try upgrading GIT to a newer version)",
|
|
p->pack_name, ntohl(hdr.hdr_version));
|
|
|
|
/* Verify the pack matches its index. */
|
|
if (p->num_objects != ntohl(hdr.hdr_entries))
|
|
return error("packfile %s claims to have %"PRIu32" objects"
|
|
" while index indicates %"PRIu32" objects",
|
|
p->pack_name, ntohl(hdr.hdr_entries),
|
|
p->num_objects);
|
|
read_result = pread_in_full(p->pack_fd, hash, hashsz,
|
|
p->pack_size - hashsz);
|
|
if (read_result < 0)
|
|
return error_errno("error reading from %s", p->pack_name);
|
|
if (read_result != hashsz)
|
|
return error("packfile %s signature is unavailable", p->pack_name);
|
|
idx_hash = ((unsigned char *)p->index_data) + p->index_size - hashsz * 2;
|
|
if (!hasheq(hash, idx_hash))
|
|
return error("packfile %s does not match index", p->pack_name);
|
|
return 0;
|
|
}
|
|
|
|
static int open_packed_git(struct packed_git *p)
|
|
{
|
|
if (!open_packed_git_1(p))
|
|
return 0;
|
|
close_pack_fd(p);
|
|
return -1;
|
|
}
|
|
|
|
static int in_window(struct pack_window *win, off_t offset)
|
|
{
|
|
/* We must promise at least one full hash after the
|
|
* offset is available from this window, otherwise the offset
|
|
* is not actually in this window and a different window (which
|
|
* has that one hash excess) must be used. This is to support
|
|
* the object header and delta base parsing routines below.
|
|
*/
|
|
off_t win_off = win->offset;
|
|
return win_off <= offset
|
|
&& (offset + the_hash_algo->rawsz) <= (win_off + win->len);
|
|
}
|
|
|
|
unsigned char *use_pack(struct packed_git *p,
|
|
struct pack_window **w_cursor,
|
|
off_t offset,
|
|
unsigned long *left)
|
|
{
|
|
struct pack_window *win = *w_cursor;
|
|
|
|
/* Since packfiles end in a hash of their content and it's
|
|
* pointless to ask for an offset into the middle of that
|
|
* hash, and the in_window function above wouldn't match
|
|
* don't allow an offset too close to the end of the file.
|
|
*/
|
|
if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
|
|
die("packfile %s cannot be accessed", p->pack_name);
|
|
if (offset > (p->pack_size - the_hash_algo->rawsz))
|
|
die("offset beyond end of packfile (truncated pack?)");
|
|
if (offset < 0)
|
|
die(_("offset before end of packfile (broken .idx?)"));
|
|
|
|
if (!win || !in_window(win, offset)) {
|
|
if (win)
|
|
win->inuse_cnt--;
|
|
for (win = p->windows; win; win = win->next) {
|
|
if (in_window(win, offset))
|
|
break;
|
|
}
|
|
if (!win) {
|
|
size_t window_align = packed_git_window_size / 2;
|
|
off_t len;
|
|
|
|
if (p->pack_fd == -1 && open_packed_git(p))
|
|
die("packfile %s cannot be accessed", p->pack_name);
|
|
|
|
win = xcalloc(1, sizeof(*win));
|
|
win->offset = (offset / window_align) * window_align;
|
|
len = p->pack_size - win->offset;
|
|
if (len > packed_git_window_size)
|
|
len = packed_git_window_size;
|
|
win->len = (size_t)len;
|
|
pack_mapped += win->len;
|
|
while (packed_git_limit < pack_mapped
|
|
&& unuse_one_window(p))
|
|
; /* nothing */
|
|
win->base = xmmap_gently(NULL, win->len,
|
|
PROT_READ, MAP_PRIVATE,
|
|
p->pack_fd, win->offset);
|
|
if (win->base == MAP_FAILED)
|
|
die_errno("packfile %s cannot be mapped",
|
|
p->pack_name);
|
|
if (!win->offset && win->len == p->pack_size
|
|
&& !p->do_not_close)
|
|
close_pack_fd(p);
|
|
pack_mmap_calls++;
|
|
pack_open_windows++;
|
|
if (pack_mapped > peak_pack_mapped)
|
|
peak_pack_mapped = pack_mapped;
|
|
if (pack_open_windows > peak_pack_open_windows)
|
|
peak_pack_open_windows = pack_open_windows;
|
|
win->next = p->windows;
|
|
p->windows = win;
|
|
}
|
|
}
|
|
if (win != *w_cursor) {
|
|
win->last_used = pack_used_ctr++;
|
|
win->inuse_cnt++;
|
|
*w_cursor = win;
|
|
}
|
|
offset -= win->offset;
|
|
if (left)
|
|
*left = win->len - xsize_t(offset);
|
|
return win->base + offset;
|
|
}
|
|
|
|
void unuse_pack(struct pack_window **w_cursor)
|
|
{
|
|
struct pack_window *w = *w_cursor;
|
|
if (w) {
|
|
w->inuse_cnt--;
|
|
*w_cursor = NULL;
|
|
}
|
|
}
|
|
|
|
struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
|
|
{
|
|
struct stat st;
|
|
size_t alloc;
|
|
struct packed_git *p;
|
|
|
|
/*
|
|
* Make sure a corresponding .pack file exists and that
|
|
* the index looks sane.
|
|
*/
|
|
if (!strip_suffix_mem(path, &path_len, ".idx"))
|
|
return NULL;
|
|
|
|
/*
|
|
* ".promisor" is long enough to hold any suffix we're adding (and
|
|
* the use xsnprintf double-checks that)
|
|
*/
|
|
alloc = st_add3(path_len, strlen(".promisor"), 1);
|
|
p = alloc_packed_git(alloc);
|
|
memcpy(p->pack_name, path, path_len);
|
|
|
|
xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
|
|
if (!access(p->pack_name, F_OK))
|
|
p->pack_keep = 1;
|
|
|
|
xsnprintf(p->pack_name + path_len, alloc - path_len, ".promisor");
|
|
if (!access(p->pack_name, F_OK))
|
|
p->pack_promisor = 1;
|
|
|
|
xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
|
|
if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
|
|
free(p);
|
|
return NULL;
|
|
}
|
|
|
|
/* ok, it looks sane as far as we can check without
|
|
* actually mapping the pack file.
|
|
*/
|
|
p->pack_size = st.st_size;
|
|
p->pack_local = local;
|
|
p->mtime = st.st_mtime;
|
|
if (path_len < the_hash_algo->hexsz ||
|
|
get_sha1_hex(path + path_len - the_hash_algo->hexsz, p->hash))
|
|
hashclr(p->hash);
|
|
return p;
|
|
}
|
|
|
|
void install_packed_git(struct repository *r, struct packed_git *pack)
|
|
{
|
|
if (pack->pack_fd != -1)
|
|
pack_open_fds++;
|
|
|
|
pack->next = r->objects->packed_git;
|
|
r->objects->packed_git = pack;
|
|
|
|
hashmap_entry_init(&pack->packmap_ent, strhash(pack->pack_name));
|
|
hashmap_add(&r->objects->pack_map, &pack->packmap_ent);
|
|
}
|
|
|
|
void (*report_garbage)(unsigned seen_bits, const char *path);
|
|
|
|
static void report_helper(const struct string_list *list,
|
|
int seen_bits, int first, int last)
|
|
{
|
|
if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
|
|
return;
|
|
|
|
for (; first < last; first++)
|
|
report_garbage(seen_bits, list->items[first].string);
|
|
}
|
|
|
|
static void report_pack_garbage(struct string_list *list)
|
|
{
|
|
int i, baselen = -1, first = 0, seen_bits = 0;
|
|
|
|
if (!report_garbage)
|
|
return;
|
|
|
|
string_list_sort(list);
|
|
|
|
for (i = 0; i < list->nr; i++) {
|
|
const char *path = list->items[i].string;
|
|
if (baselen != -1 &&
|
|
strncmp(path, list->items[first].string, baselen)) {
|
|
report_helper(list, seen_bits, first, i);
|
|
baselen = -1;
|
|
seen_bits = 0;
|
|
}
|
|
if (baselen == -1) {
|
|
const char *dot = strrchr(path, '.');
|
|
if (!dot) {
|
|
report_garbage(PACKDIR_FILE_GARBAGE, path);
|
|
continue;
|
|
}
|
|
baselen = dot - path + 1;
|
|
first = i;
|
|
}
|
|
if (!strcmp(path + baselen, "pack"))
|
|
seen_bits |= 1;
|
|
else if (!strcmp(path + baselen, "idx"))
|
|
seen_bits |= 2;
|
|
}
|
|
report_helper(list, seen_bits, first, list->nr);
|
|
}
|
|
|
|
void for_each_file_in_pack_dir(const char *objdir,
|
|
each_file_in_pack_dir_fn fn,
|
|
void *data)
|
|
{
|
|
struct strbuf path = STRBUF_INIT;
|
|
size_t dirnamelen;
|
|
DIR *dir;
|
|
struct dirent *de;
|
|
|
|
strbuf_addstr(&path, objdir);
|
|
strbuf_addstr(&path, "/pack");
|
|
dir = opendir(path.buf);
|
|
if (!dir) {
|
|
if (errno != ENOENT)
|
|
error_errno("unable to open object pack directory: %s",
|
|
path.buf);
|
|
strbuf_release(&path);
|
|
return;
|
|
}
|
|
strbuf_addch(&path, '/');
|
|
dirnamelen = path.len;
|
|
while ((de = readdir(dir)) != NULL) {
|
|
if (is_dot_or_dotdot(de->d_name))
|
|
continue;
|
|
|
|
strbuf_setlen(&path, dirnamelen);
|
|
strbuf_addstr(&path, de->d_name);
|
|
|
|
fn(path.buf, path.len, de->d_name, data);
|
|
}
|
|
|
|
closedir(dir);
|
|
strbuf_release(&path);
|
|
}
|
|
|
|
struct prepare_pack_data {
|
|
struct repository *r;
|
|
struct string_list *garbage;
|
|
int local;
|
|
struct multi_pack_index *m;
|
|
};
|
|
|
|
static void prepare_pack(const char *full_name, size_t full_name_len,
|
|
const char *file_name, void *_data)
|
|
{
|
|
struct prepare_pack_data *data = (struct prepare_pack_data *)_data;
|
|
struct packed_git *p;
|
|
size_t base_len = full_name_len;
|
|
|
|
if (strip_suffix_mem(full_name, &base_len, ".idx") &&
|
|
!(data->m && midx_contains_pack(data->m, file_name))) {
|
|
struct hashmap_entry hent;
|
|
char *pack_name = xstrfmt("%.*s.pack", (int)base_len, full_name);
|
|
unsigned int hash = strhash(pack_name);
|
|
hashmap_entry_init(&hent, hash);
|
|
|
|
/* Don't reopen a pack we already have. */
|
|
if (!hashmap_get(&data->r->objects->pack_map, &hent, pack_name)) {
|
|
p = add_packed_git(full_name, full_name_len, data->local);
|
|
if (p)
|
|
install_packed_git(data->r, p);
|
|
}
|
|
free(pack_name);
|
|
}
|
|
|
|
if (!report_garbage)
|
|
return;
|
|
|
|
if (!strcmp(file_name, "multi-pack-index"))
|
|
return;
|
|
if (ends_with(file_name, ".idx") ||
|
|
ends_with(file_name, ".rev") ||
|
|
ends_with(file_name, ".pack") ||
|
|
ends_with(file_name, ".bitmap") ||
|
|
ends_with(file_name, ".keep") ||
|
|
ends_with(file_name, ".promisor"))
|
|
string_list_append(data->garbage, full_name);
|
|
else
|
|
report_garbage(PACKDIR_FILE_GARBAGE, full_name);
|
|
}
|
|
|
|
static void prepare_packed_git_one(struct repository *r, char *objdir, int local)
|
|
{
|
|
struct prepare_pack_data data;
|
|
struct string_list garbage = STRING_LIST_INIT_DUP;
|
|
|
|
data.m = r->objects->multi_pack_index;
|
|
|
|
/* look for the multi-pack-index for this object directory */
|
|
while (data.m && strcmp(data.m->object_dir, objdir))
|
|
data.m = data.m->next;
|
|
|
|
data.r = r;
|
|
data.garbage = &garbage;
|
|
data.local = local;
|
|
|
|
for_each_file_in_pack_dir(objdir, prepare_pack, &data);
|
|
|
|
report_pack_garbage(data.garbage);
|
|
string_list_clear(data.garbage, 0);
|
|
}
|
|
|
|
static void prepare_packed_git(struct repository *r);
|
|
/*
|
|
* Give a fast, rough count of the number of objects in the repository. This
|
|
* ignores loose objects completely. If you have a lot of them, then either
|
|
* you should repack because your performance will be awful, or they are
|
|
* all unreachable objects about to be pruned, in which case they're not really
|
|
* interesting as a measure of repo size in the first place.
|
|
*/
|
|
unsigned long repo_approximate_object_count(struct repository *r)
|
|
{
|
|
if (!r->objects->approximate_object_count_valid) {
|
|
unsigned long count;
|
|
struct multi_pack_index *m;
|
|
struct packed_git *p;
|
|
|
|
prepare_packed_git(r);
|
|
count = 0;
|
|
for (m = get_multi_pack_index(r); m; m = m->next)
|
|
count += m->num_objects;
|
|
for (p = r->objects->packed_git; p; p = p->next) {
|
|
if (open_pack_index(p))
|
|
continue;
|
|
count += p->num_objects;
|
|
}
|
|
r->objects->approximate_object_count = count;
|
|
r->objects->approximate_object_count_valid = 1;
|
|
}
|
|
return r->objects->approximate_object_count;
|
|
}
|
|
|
|
static void *get_next_packed_git(const void *p)
|
|
{
|
|
return ((const struct packed_git *)p)->next;
|
|
}
|
|
|
|
static void set_next_packed_git(void *p, void *next)
|
|
{
|
|
((struct packed_git *)p)->next = next;
|
|
}
|
|
|
|
static int sort_pack(const void *a_, const void *b_)
|
|
{
|
|
const struct packed_git *a = a_;
|
|
const struct packed_git *b = b_;
|
|
int st;
|
|
|
|
/*
|
|
* Local packs tend to contain objects specific to our
|
|
* variant of the project than remote ones. In addition,
|
|
* remote ones could be on a network mounted filesystem.
|
|
* Favor local ones for these reasons.
|
|
*/
|
|
st = a->pack_local - b->pack_local;
|
|
if (st)
|
|
return -st;
|
|
|
|
/*
|
|
* Younger packs tend to contain more recent objects,
|
|
* and more recent objects tend to get accessed more
|
|
* often.
|
|
*/
|
|
if (a->mtime < b->mtime)
|
|
return 1;
|
|
else if (a->mtime == b->mtime)
|
|
return 0;
|
|
return -1;
|
|
}
|
|
|
|
static void rearrange_packed_git(struct repository *r)
|
|
{
|
|
r->objects->packed_git = llist_mergesort(
|
|
r->objects->packed_git, get_next_packed_git,
|
|
set_next_packed_git, sort_pack);
|
|
}
|
|
|
|
static void prepare_packed_git_mru(struct repository *r)
|
|
{
|
|
struct packed_git *p;
|
|
|
|
INIT_LIST_HEAD(&r->objects->packed_git_mru);
|
|
|
|
for (p = r->objects->packed_git; p; p = p->next)
|
|
list_add_tail(&p->mru, &r->objects->packed_git_mru);
|
|
}
|
|
|
|
static void prepare_packed_git(struct repository *r)
|
|
{
|
|
struct object_directory *odb;
|
|
|
|
if (r->objects->packed_git_initialized)
|
|
return;
|
|
|
|
prepare_alt_odb(r);
|
|
for (odb = r->objects->odb; odb; odb = odb->next) {
|
|
int local = (odb == r->objects->odb);
|
|
prepare_multi_pack_index_one(r, odb->path, local);
|
|
prepare_packed_git_one(r, odb->path, local);
|
|
}
|
|
rearrange_packed_git(r);
|
|
|
|
prepare_packed_git_mru(r);
|
|
r->objects->packed_git_initialized = 1;
|
|
}
|
|
|
|
void reprepare_packed_git(struct repository *r)
|
|
{
|
|
struct object_directory *odb;
|
|
|
|
obj_read_lock();
|
|
for (odb = r->objects->odb; odb; odb = odb->next)
|
|
odb_clear_loose_cache(odb);
|
|
|
|
r->objects->approximate_object_count_valid = 0;
|
|
r->objects->packed_git_initialized = 0;
|
|
prepare_packed_git(r);
|
|
obj_read_unlock();
|
|
}
|
|
|
|
struct packed_git *get_packed_git(struct repository *r)
|
|
{
|
|
prepare_packed_git(r);
|
|
return r->objects->packed_git;
|
|
}
|
|
|
|
struct multi_pack_index *get_multi_pack_index(struct repository *r)
|
|
{
|
|
prepare_packed_git(r);
|
|
return r->objects->multi_pack_index;
|
|
}
|
|
|
|
struct multi_pack_index *get_local_multi_pack_index(struct repository *r)
|
|
{
|
|
struct multi_pack_index *m = get_multi_pack_index(r);
|
|
|
|
/* no need to iterate; we always put the local one first (if any) */
|
|
if (m && m->local)
|
|
return m;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
struct packed_git *get_all_packs(struct repository *r)
|
|
{
|
|
struct multi_pack_index *m;
|
|
|
|
prepare_packed_git(r);
|
|
for (m = r->objects->multi_pack_index; m; m = m->next) {
|
|
uint32_t i;
|
|
for (i = 0; i < m->num_packs; i++)
|
|
prepare_midx_pack(r, m, i);
|
|
}
|
|
|
|
return r->objects->packed_git;
|
|
}
|
|
|
|
struct list_head *get_packed_git_mru(struct repository *r)
|
|
{
|
|
prepare_packed_git(r);
|
|
return &r->objects->packed_git_mru;
|
|
}
|
|
|
|
unsigned long unpack_object_header_buffer(const unsigned char *buf,
|
|
unsigned long len, enum object_type *type, unsigned long *sizep)
|
|
{
|
|
unsigned shift;
|
|
unsigned long size, c;
|
|
unsigned long used = 0;
|
|
|
|
c = buf[used++];
|
|
*type = (c >> 4) & 7;
|
|
size = c & 15;
|
|
shift = 4;
|
|
while (c & 0x80) {
|
|
if (len <= used || bitsizeof(long) <= shift) {
|
|
error("bad object header");
|
|
size = used = 0;
|
|
break;
|
|
}
|
|
c = buf[used++];
|
|
size += (c & 0x7f) << shift;
|
|
shift += 7;
|
|
}
|
|
*sizep = size;
|
|
return used;
|
|
}
|
|
|
|
unsigned long get_size_from_delta(struct packed_git *p,
|
|
struct pack_window **w_curs,
|
|
off_t curpos)
|
|
{
|
|
const unsigned char *data;
|
|
unsigned char delta_head[20], *in;
|
|
git_zstream stream;
|
|
int st;
|
|
|
|
memset(&stream, 0, sizeof(stream));
|
|
stream.next_out = delta_head;
|
|
stream.avail_out = sizeof(delta_head);
|
|
|
|
git_inflate_init(&stream);
|
|
do {
|
|
in = use_pack(p, w_curs, curpos, &stream.avail_in);
|
|
stream.next_in = in;
|
|
/*
|
|
* Note: the window section returned by use_pack() must be
|
|
* available throughout git_inflate()'s unlocked execution. To
|
|
* ensure no other thread will modify the window in the
|
|
* meantime, we rely on the packed_window.inuse_cnt. This
|
|
* counter is incremented before window reading and checked
|
|
* before window disposal.
|
|
*
|
|
* Other worrying sections could be the call to close_pack_fd(),
|
|
* which can close packs even with in-use windows, and to
|
|
* reprepare_packed_git(). Regarding the former, mmap doc says:
|
|
* "closing the file descriptor does not unmap the region". And
|
|
* for the latter, it won't re-open already available packs.
|
|
*/
|
|
obj_read_unlock();
|
|
st = git_inflate(&stream, Z_FINISH);
|
|
obj_read_lock();
|
|
curpos += stream.next_in - in;
|
|
} while ((st == Z_OK || st == Z_BUF_ERROR) &&
|
|
stream.total_out < sizeof(delta_head));
|
|
git_inflate_end(&stream);
|
|
if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
|
|
error("delta data unpack-initial failed");
|
|
return 0;
|
|
}
|
|
|
|
/* Examine the initial part of the delta to figure out
|
|
* the result size.
|
|
*/
|
|
data = delta_head;
|
|
|
|
/* ignore base size */
|
|
get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
|
|
|
|
/* Read the result size */
|
|
return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
|
|
}
|
|
|
|
int unpack_object_header(struct packed_git *p,
|
|
struct pack_window **w_curs,
|
|
off_t *curpos,
|
|
unsigned long *sizep)
|
|
{
|
|
unsigned char *base;
|
|
unsigned long left;
|
|
unsigned long used;
|
|
enum object_type type;
|
|
|
|
/* use_pack() assures us we have [base, base + 20) available
|
|
* as a range that we can look at. (Its actually the hash
|
|
* size that is assured.) With our object header encoding
|
|
* the maximum deflated object size is 2^137, which is just
|
|
* insane, so we know won't exceed what we have been given.
|
|
*/
|
|
base = use_pack(p, w_curs, *curpos, &left);
|
|
used = unpack_object_header_buffer(base, left, &type, sizep);
|
|
if (!used) {
|
|
type = OBJ_BAD;
|
|
} else
|
|
*curpos += used;
|
|
|
|
return type;
|
|
}
|
|
|
|
void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1)
|
|
{
|
|
unsigned i;
|
|
const unsigned hashsz = the_hash_algo->rawsz;
|
|
for (i = 0; i < p->num_bad_objects; i++)
|
|
if (hasheq(sha1, p->bad_object_sha1 + hashsz * i))
|
|
return;
|
|
p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
|
|
st_mult(GIT_MAX_RAWSZ,
|
|
st_add(p->num_bad_objects, 1)));
|
|
hashcpy(p->bad_object_sha1 + hashsz * p->num_bad_objects, sha1);
|
|
p->num_bad_objects++;
|
|
}
|
|
|
|
const struct packed_git *has_packed_and_bad(struct repository *r,
|
|
const unsigned char *sha1)
|
|
{
|
|
struct packed_git *p;
|
|
unsigned i;
|
|
|
|
for (p = r->objects->packed_git; p; p = p->next)
|
|
for (i = 0; i < p->num_bad_objects; i++)
|
|
if (hasheq(sha1,
|
|
p->bad_object_sha1 + the_hash_algo->rawsz * i))
|
|
return p;
|
|
return NULL;
|
|
}
|
|
|
|
off_t get_delta_base(struct packed_git *p,
|
|
struct pack_window **w_curs,
|
|
off_t *curpos,
|
|
enum object_type type,
|
|
off_t delta_obj_offset)
|
|
{
|
|
unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
|
|
off_t base_offset;
|
|
|
|
/* use_pack() assured us we have [base_info, base_info + 20)
|
|
* as a range that we can look at without walking off the
|
|
* end of the mapped window. Its actually the hash size
|
|
* that is assured. An OFS_DELTA longer than the hash size
|
|
* is stupid, as then a REF_DELTA would be smaller to store.
|
|
*/
|
|
if (type == OBJ_OFS_DELTA) {
|
|
unsigned used = 0;
|
|
unsigned char c = base_info[used++];
|
|
base_offset = c & 127;
|
|
while (c & 128) {
|
|
base_offset += 1;
|
|
if (!base_offset || MSB(base_offset, 7))
|
|
return 0; /* overflow */
|
|
c = base_info[used++];
|
|
base_offset = (base_offset << 7) + (c & 127);
|
|
}
|
|
base_offset = delta_obj_offset - base_offset;
|
|
if (base_offset <= 0 || base_offset >= delta_obj_offset)
|
|
return 0; /* out of bound */
|
|
*curpos += used;
|
|
} else if (type == OBJ_REF_DELTA) {
|
|
/* The base entry _must_ be in the same pack */
|
|
base_offset = find_pack_entry_one(base_info, p);
|
|
*curpos += the_hash_algo->rawsz;
|
|
} else
|
|
die("I am totally screwed");
|
|
return base_offset;
|
|
}
|
|
|
|
/*
|
|
* Like get_delta_base above, but we return the sha1 instead of the pack
|
|
* offset. This means it is cheaper for REF deltas (we do not have to do
|
|
* the final object lookup), but more expensive for OFS deltas (we
|
|
* have to load the revidx to convert the offset back into a sha1).
|
|
*/
|
|
static int get_delta_base_oid(struct packed_git *p,
|
|
struct pack_window **w_curs,
|
|
off_t curpos,
|
|
struct object_id *oid,
|
|
enum object_type type,
|
|
off_t delta_obj_offset)
|
|
{
|
|
if (type == OBJ_REF_DELTA) {
|
|
unsigned char *base = use_pack(p, w_curs, curpos, NULL);
|
|
oidread(oid, base);
|
|
return 0;
|
|
} else if (type == OBJ_OFS_DELTA) {
|
|
uint32_t base_pos;
|
|
off_t base_offset = get_delta_base(p, w_curs, &curpos,
|
|
type, delta_obj_offset);
|
|
|
|
if (!base_offset)
|
|
return -1;
|
|
|
|
if (offset_to_pack_pos(p, base_offset, &base_pos) < 0)
|
|
return -1;
|
|
|
|
return nth_packed_object_id(oid, p,
|
|
pack_pos_to_index(p, base_pos));
|
|
} else
|
|
return -1;
|
|
}
|
|
|
|
static int retry_bad_packed_offset(struct repository *r,
|
|
struct packed_git *p,
|
|
off_t obj_offset)
|
|
{
|
|
int type;
|
|
uint32_t pos;
|
|
struct object_id oid;
|
|
if (offset_to_pack_pos(p, obj_offset, &pos) < 0)
|
|
return OBJ_BAD;
|
|
nth_packed_object_id(&oid, p, pack_pos_to_index(p, pos));
|
|
mark_bad_packed_object(p, oid.hash);
|
|
type = oid_object_info(r, &oid, NULL);
|
|
if (type <= OBJ_NONE)
|
|
return OBJ_BAD;
|
|
return type;
|
|
}
|
|
|
|
#define POI_STACK_PREALLOC 64
|
|
|
|
static enum object_type packed_to_object_type(struct repository *r,
|
|
struct packed_git *p,
|
|
off_t obj_offset,
|
|
enum object_type type,
|
|
struct pack_window **w_curs,
|
|
off_t curpos)
|
|
{
|
|
off_t small_poi_stack[POI_STACK_PREALLOC];
|
|
off_t *poi_stack = small_poi_stack;
|
|
int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
|
|
|
|
while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
|
|
off_t base_offset;
|
|
unsigned long size;
|
|
/* Push the object we're going to leave behind */
|
|
if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
|
|
poi_stack_alloc = alloc_nr(poi_stack_nr);
|
|
ALLOC_ARRAY(poi_stack, poi_stack_alloc);
|
|
COPY_ARRAY(poi_stack, small_poi_stack, poi_stack_nr);
|
|
} else {
|
|
ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
|
|
}
|
|
poi_stack[poi_stack_nr++] = obj_offset;
|
|
/* If parsing the base offset fails, just unwind */
|
|
base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
|
|
if (!base_offset)
|
|
goto unwind;
|
|
curpos = obj_offset = base_offset;
|
|
type = unpack_object_header(p, w_curs, &curpos, &size);
|
|
if (type <= OBJ_NONE) {
|
|
/* If getting the base itself fails, we first
|
|
* retry the base, otherwise unwind */
|
|
type = retry_bad_packed_offset(r, p, base_offset);
|
|
if (type > OBJ_NONE)
|
|
goto out;
|
|
goto unwind;
|
|
}
|
|
}
|
|
|
|
switch (type) {
|
|
case OBJ_BAD:
|
|
case OBJ_COMMIT:
|
|
case OBJ_TREE:
|
|
case OBJ_BLOB:
|
|
case OBJ_TAG:
|
|
break;
|
|
default:
|
|
error("unknown object type %i at offset %"PRIuMAX" in %s",
|
|
type, (uintmax_t)obj_offset, p->pack_name);
|
|
type = OBJ_BAD;
|
|
}
|
|
|
|
out:
|
|
if (poi_stack != small_poi_stack)
|
|
free(poi_stack);
|
|
return type;
|
|
|
|
unwind:
|
|
while (poi_stack_nr) {
|
|
obj_offset = poi_stack[--poi_stack_nr];
|
|
type = retry_bad_packed_offset(r, p, obj_offset);
|
|
if (type > OBJ_NONE)
|
|
goto out;
|
|
}
|
|
type = OBJ_BAD;
|
|
goto out;
|
|
}
|
|
|
|
static struct hashmap delta_base_cache;
|
|
static size_t delta_base_cached;
|
|
|
|
static LIST_HEAD(delta_base_cache_lru);
|
|
|
|
struct delta_base_cache_key {
|
|
struct packed_git *p;
|
|
off_t base_offset;
|
|
};
|
|
|
|
struct delta_base_cache_entry {
|
|
struct hashmap_entry ent;
|
|
struct delta_base_cache_key key;
|
|
struct list_head lru;
|
|
void *data;
|
|
unsigned long size;
|
|
enum object_type type;
|
|
};
|
|
|
|
static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
|
|
{
|
|
unsigned int hash;
|
|
|
|
hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
|
|
hash += (hash >> 8) + (hash >> 16);
|
|
return hash;
|
|
}
|
|
|
|
static struct delta_base_cache_entry *
|
|
get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
|
|
{
|
|
struct hashmap_entry entry, *e;
|
|
struct delta_base_cache_key key;
|
|
|
|
if (!delta_base_cache.cmpfn)
|
|
return NULL;
|
|
|
|
hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
|
|
key.p = p;
|
|
key.base_offset = base_offset;
|
|
e = hashmap_get(&delta_base_cache, &entry, &key);
|
|
return e ? container_of(e, struct delta_base_cache_entry, ent) : NULL;
|
|
}
|
|
|
|
static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
|
|
const struct delta_base_cache_key *b)
|
|
{
|
|
return a->p == b->p && a->base_offset == b->base_offset;
|
|
}
|
|
|
|
static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
|
|
const struct hashmap_entry *va,
|
|
const struct hashmap_entry *vb,
|
|
const void *vkey)
|
|
{
|
|
const struct delta_base_cache_entry *a, *b;
|
|
const struct delta_base_cache_key *key = vkey;
|
|
|
|
a = container_of(va, const struct delta_base_cache_entry, ent);
|
|
b = container_of(vb, const struct delta_base_cache_entry, ent);
|
|
|
|
if (key)
|
|
return !delta_base_cache_key_eq(&a->key, key);
|
|
else
|
|
return !delta_base_cache_key_eq(&a->key, &b->key);
|
|
}
|
|
|
|
static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
|
|
{
|
|
return !!get_delta_base_cache_entry(p, base_offset);
|
|
}
|
|
|
|
/*
|
|
* Remove the entry from the cache, but do _not_ free the associated
|
|
* entry data. The caller takes ownership of the "data" buffer, and
|
|
* should copy out any fields it wants before detaching.
|
|
*/
|
|
static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
|
|
{
|
|
hashmap_remove(&delta_base_cache, &ent->ent, &ent->key);
|
|
list_del(&ent->lru);
|
|
delta_base_cached -= ent->size;
|
|
free(ent);
|
|
}
|
|
|
|
static void *cache_or_unpack_entry(struct repository *r, struct packed_git *p,
|
|
off_t base_offset, unsigned long *base_size,
|
|
enum object_type *type)
|
|
{
|
|
struct delta_base_cache_entry *ent;
|
|
|
|
ent = get_delta_base_cache_entry(p, base_offset);
|
|
if (!ent)
|
|
return unpack_entry(r, p, base_offset, type, base_size);
|
|
|
|
if (type)
|
|
*type = ent->type;
|
|
if (base_size)
|
|
*base_size = ent->size;
|
|
return xmemdupz(ent->data, ent->size);
|
|
}
|
|
|
|
static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
|
|
{
|
|
free(ent->data);
|
|
detach_delta_base_cache_entry(ent);
|
|
}
|
|
|
|
void clear_delta_base_cache(void)
|
|
{
|
|
struct list_head *lru, *tmp;
|
|
list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
|
|
struct delta_base_cache_entry *entry =
|
|
list_entry(lru, struct delta_base_cache_entry, lru);
|
|
release_delta_base_cache(entry);
|
|
}
|
|
}
|
|
|
|
static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
|
|
void *base, unsigned long base_size, enum object_type type)
|
|
{
|
|
struct delta_base_cache_entry *ent;
|
|
struct list_head *lru, *tmp;
|
|
|
|
/*
|
|
* Check required to avoid redundant entries when more than one thread
|
|
* is unpacking the same object, in unpack_entry() (since its phases I
|
|
* and III might run concurrently across multiple threads).
|
|
*/
|
|
if (in_delta_base_cache(p, base_offset)) {
|
|
free(base);
|
|
return;
|
|
}
|
|
|
|
delta_base_cached += base_size;
|
|
|
|
list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
|
|
struct delta_base_cache_entry *f =
|
|
list_entry(lru, struct delta_base_cache_entry, lru);
|
|
if (delta_base_cached <= delta_base_cache_limit)
|
|
break;
|
|
release_delta_base_cache(f);
|
|
}
|
|
|
|
ent = xmalloc(sizeof(*ent));
|
|
ent->key.p = p;
|
|
ent->key.base_offset = base_offset;
|
|
ent->type = type;
|
|
ent->data = base;
|
|
ent->size = base_size;
|
|
list_add_tail(&ent->lru, &delta_base_cache_lru);
|
|
|
|
if (!delta_base_cache.cmpfn)
|
|
hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
|
|
hashmap_entry_init(&ent->ent, pack_entry_hash(p, base_offset));
|
|
hashmap_add(&delta_base_cache, &ent->ent);
|
|
}
|
|
|
|
int packed_object_info(struct repository *r, struct packed_git *p,
|
|
off_t obj_offset, struct object_info *oi)
|
|
{
|
|
struct pack_window *w_curs = NULL;
|
|
unsigned long size;
|
|
off_t curpos = obj_offset;
|
|
enum object_type type;
|
|
|
|
/*
|
|
* We always get the representation type, but only convert it to
|
|
* a "real" type later if the caller is interested.
|
|
*/
|
|
if (oi->contentp) {
|
|
*oi->contentp = cache_or_unpack_entry(r, p, obj_offset, oi->sizep,
|
|
&type);
|
|
if (!*oi->contentp)
|
|
type = OBJ_BAD;
|
|
} else {
|
|
type = unpack_object_header(p, &w_curs, &curpos, &size);
|
|
}
|
|
|
|
if (!oi->contentp && oi->sizep) {
|
|
if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
|
|
off_t tmp_pos = curpos;
|
|
off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
|
|
type, obj_offset);
|
|
if (!base_offset) {
|
|
type = OBJ_BAD;
|
|
goto out;
|
|
}
|
|
*oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
|
|
if (*oi->sizep == 0) {
|
|
type = OBJ_BAD;
|
|
goto out;
|
|
}
|
|
} else {
|
|
*oi->sizep = size;
|
|
}
|
|
}
|
|
|
|
if (oi->disk_sizep) {
|
|
uint32_t pos;
|
|
if (offset_to_pack_pos(p, obj_offset, &pos) < 0) {
|
|
error("could not find object at offset %"PRIuMAX" "
|
|
"in pack %s", (uintmax_t)obj_offset, p->pack_name);
|
|
type = OBJ_BAD;
|
|
goto out;
|
|
}
|
|
|
|
*oi->disk_sizep = pack_pos_to_offset(p, pos + 1) - obj_offset;
|
|
}
|
|
|
|
if (oi->typep || oi->type_name) {
|
|
enum object_type ptot;
|
|
ptot = packed_to_object_type(r, p, obj_offset,
|
|
type, &w_curs, curpos);
|
|
if (oi->typep)
|
|
*oi->typep = ptot;
|
|
if (oi->type_name) {
|
|
const char *tn = type_name(ptot);
|
|
if (tn)
|
|
strbuf_addstr(oi->type_name, tn);
|
|
}
|
|
if (ptot < 0) {
|
|
type = OBJ_BAD;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
if (oi->delta_base_oid) {
|
|
if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
|
|
if (get_delta_base_oid(p, &w_curs, curpos,
|
|
oi->delta_base_oid,
|
|
type, obj_offset) < 0) {
|
|
type = OBJ_BAD;
|
|
goto out;
|
|
}
|
|
} else
|
|
oidclr(oi->delta_base_oid);
|
|
}
|
|
|
|
oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
|
|
OI_PACKED;
|
|
|
|
out:
|
|
unuse_pack(&w_curs);
|
|
return type;
|
|
}
|
|
|
|
static void *unpack_compressed_entry(struct packed_git *p,
|
|
struct pack_window **w_curs,
|
|
off_t curpos,
|
|
unsigned long size)
|
|
{
|
|
int st;
|
|
git_zstream stream;
|
|
unsigned char *buffer, *in;
|
|
|
|
buffer = xmallocz_gently(size);
|
|
if (!buffer)
|
|
return NULL;
|
|
memset(&stream, 0, sizeof(stream));
|
|
stream.next_out = buffer;
|
|
stream.avail_out = size + 1;
|
|
|
|
git_inflate_init(&stream);
|
|
do {
|
|
in = use_pack(p, w_curs, curpos, &stream.avail_in);
|
|
stream.next_in = in;
|
|
/*
|
|
* Note: we must ensure the window section returned by
|
|
* use_pack() will be available throughout git_inflate()'s
|
|
* unlocked execution. Please refer to the comment at
|
|
* get_size_from_delta() to see how this is done.
|
|
*/
|
|
obj_read_unlock();
|
|
st = git_inflate(&stream, Z_FINISH);
|
|
obj_read_lock();
|
|
if (!stream.avail_out)
|
|
break; /* the payload is larger than it should be */
|
|
curpos += stream.next_in - in;
|
|
} while (st == Z_OK || st == Z_BUF_ERROR);
|
|
git_inflate_end(&stream);
|
|
if ((st != Z_STREAM_END) || stream.total_out != size) {
|
|
free(buffer);
|
|
return NULL;
|
|
}
|
|
|
|
/* versions of zlib can clobber unconsumed portion of outbuf */
|
|
buffer[size] = '\0';
|
|
|
|
return buffer;
|
|
}
|
|
|
|
static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
|
|
{
|
|
static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
|
|
trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
|
|
p->pack_name, (uintmax_t)obj_offset);
|
|
}
|
|
|
|
int do_check_packed_object_crc;
|
|
|
|
#define UNPACK_ENTRY_STACK_PREALLOC 64
|
|
struct unpack_entry_stack_ent {
|
|
off_t obj_offset;
|
|
off_t curpos;
|
|
unsigned long size;
|
|
};
|
|
|
|
static void *read_object(struct repository *r,
|
|
const struct object_id *oid,
|
|
enum object_type *type,
|
|
unsigned long *size)
|
|
{
|
|
struct object_info oi = OBJECT_INFO_INIT;
|
|
void *content;
|
|
oi.typep = type;
|
|
oi.sizep = size;
|
|
oi.contentp = &content;
|
|
|
|
if (oid_object_info_extended(r, oid, &oi, 0) < 0)
|
|
return NULL;
|
|
return content;
|
|
}
|
|
|
|
void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
|
|
enum object_type *final_type, unsigned long *final_size)
|
|
{
|
|
struct pack_window *w_curs = NULL;
|
|
off_t curpos = obj_offset;
|
|
void *data = NULL;
|
|
unsigned long size;
|
|
enum object_type type;
|
|
struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
|
|
struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
|
|
int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
|
|
int base_from_cache = 0;
|
|
|
|
write_pack_access_log(p, obj_offset);
|
|
|
|
/* PHASE 1: drill down to the innermost base object */
|
|
for (;;) {
|
|
off_t base_offset;
|
|
int i;
|
|
struct delta_base_cache_entry *ent;
|
|
|
|
ent = get_delta_base_cache_entry(p, curpos);
|
|
if (ent) {
|
|
type = ent->type;
|
|
data = ent->data;
|
|
size = ent->size;
|
|
detach_delta_base_cache_entry(ent);
|
|
base_from_cache = 1;
|
|
break;
|
|
}
|
|
|
|
if (do_check_packed_object_crc && p->index_version > 1) {
|
|
uint32_t pack_pos, index_pos;
|
|
off_t len;
|
|
|
|
if (offset_to_pack_pos(p, obj_offset, &pack_pos) < 0) {
|
|
error("could not find object at offset %"PRIuMAX" in pack %s",
|
|
(uintmax_t)obj_offset, p->pack_name);
|
|
data = NULL;
|
|
goto out;
|
|
}
|
|
|
|
len = pack_pos_to_offset(p, pack_pos + 1) - obj_offset;
|
|
index_pos = pack_pos_to_index(p, pack_pos);
|
|
if (check_pack_crc(p, &w_curs, obj_offset, len, index_pos)) {
|
|
struct object_id oid;
|
|
nth_packed_object_id(&oid, p, index_pos);
|
|
error("bad packed object CRC for %s",
|
|
oid_to_hex(&oid));
|
|
mark_bad_packed_object(p, oid.hash);
|
|
data = NULL;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
type = unpack_object_header(p, &w_curs, &curpos, &size);
|
|
if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
|
|
break;
|
|
|
|
base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
|
|
if (!base_offset) {
|
|
error("failed to validate delta base reference "
|
|
"at offset %"PRIuMAX" from %s",
|
|
(uintmax_t)curpos, p->pack_name);
|
|
/* bail to phase 2, in hopes of recovery */
|
|
data = NULL;
|
|
break;
|
|
}
|
|
|
|
/* push object, proceed to base */
|
|
if (delta_stack_nr >= delta_stack_alloc
|
|
&& delta_stack == small_delta_stack) {
|
|
delta_stack_alloc = alloc_nr(delta_stack_nr);
|
|
ALLOC_ARRAY(delta_stack, delta_stack_alloc);
|
|
COPY_ARRAY(delta_stack, small_delta_stack,
|
|
delta_stack_nr);
|
|
} else {
|
|
ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
|
|
}
|
|
i = delta_stack_nr++;
|
|
delta_stack[i].obj_offset = obj_offset;
|
|
delta_stack[i].curpos = curpos;
|
|
delta_stack[i].size = size;
|
|
|
|
curpos = obj_offset = base_offset;
|
|
}
|
|
|
|
/* PHASE 2: handle the base */
|
|
switch (type) {
|
|
case OBJ_OFS_DELTA:
|
|
case OBJ_REF_DELTA:
|
|
if (data)
|
|
BUG("unpack_entry: left loop at a valid delta");
|
|
break;
|
|
case OBJ_COMMIT:
|
|
case OBJ_TREE:
|
|
case OBJ_BLOB:
|
|
case OBJ_TAG:
|
|
if (!base_from_cache)
|
|
data = unpack_compressed_entry(p, &w_curs, curpos, size);
|
|
break;
|
|
default:
|
|
data = NULL;
|
|
error("unknown object type %i at offset %"PRIuMAX" in %s",
|
|
type, (uintmax_t)obj_offset, p->pack_name);
|
|
}
|
|
|
|
/* PHASE 3: apply deltas in order */
|
|
|
|
/* invariants:
|
|
* 'data' holds the base data, or NULL if there was corruption
|
|
*/
|
|
while (delta_stack_nr) {
|
|
void *delta_data;
|
|
void *base = data;
|
|
void *external_base = NULL;
|
|
unsigned long delta_size, base_size = size;
|
|
int i;
|
|
off_t base_obj_offset = obj_offset;
|
|
|
|
data = NULL;
|
|
|
|
if (!base) {
|
|
/*
|
|
* We're probably in deep shit, but let's try to fetch
|
|
* the required base anyway from another pack or loose.
|
|
* This is costly but should happen only in the presence
|
|
* of a corrupted pack, and is better than failing outright.
|
|
*/
|
|
uint32_t pos;
|
|
struct object_id base_oid;
|
|
if (!(offset_to_pack_pos(p, obj_offset, &pos))) {
|
|
nth_packed_object_id(&base_oid, p,
|
|
pack_pos_to_index(p, pos));
|
|
error("failed to read delta base object %s"
|
|
" at offset %"PRIuMAX" from %s",
|
|
oid_to_hex(&base_oid), (uintmax_t)obj_offset,
|
|
p->pack_name);
|
|
mark_bad_packed_object(p, base_oid.hash);
|
|
base = read_object(r, &base_oid, &type, &base_size);
|
|
external_base = base;
|
|
}
|
|
}
|
|
|
|
i = --delta_stack_nr;
|
|
obj_offset = delta_stack[i].obj_offset;
|
|
curpos = delta_stack[i].curpos;
|
|
delta_size = delta_stack[i].size;
|
|
|
|
if (!base)
|
|
continue;
|
|
|
|
delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
|
|
|
|
if (!delta_data) {
|
|
error("failed to unpack compressed delta "
|
|
"at offset %"PRIuMAX" from %s",
|
|
(uintmax_t)curpos, p->pack_name);
|
|
data = NULL;
|
|
} else {
|
|
data = patch_delta(base, base_size, delta_data,
|
|
delta_size, &size);
|
|
|
|
/*
|
|
* We could not apply the delta; warn the user, but
|
|
* keep going. Our failure will be noticed either in
|
|
* the next iteration of the loop, or if this is the
|
|
* final delta, in the caller when we return NULL.
|
|
* Those code paths will take care of making a more
|
|
* explicit warning and retrying with another copy of
|
|
* the object.
|
|
*/
|
|
if (!data)
|
|
error("failed to apply delta");
|
|
}
|
|
|
|
/*
|
|
* We delay adding `base` to the cache until the end of the loop
|
|
* because unpack_compressed_entry() momentarily releases the
|
|
* obj_read_mutex, giving another thread the chance to access
|
|
* the cache. Therefore, if `base` was already there, this other
|
|
* thread could free() it (e.g. to make space for another entry)
|
|
* before we are done using it.
|
|
*/
|
|
if (!external_base)
|
|
add_delta_base_cache(p, base_obj_offset, base, base_size, type);
|
|
|
|
free(delta_data);
|
|
free(external_base);
|
|
}
|
|
|
|
if (final_type)
|
|
*final_type = type;
|
|
if (final_size)
|
|
*final_size = size;
|
|
|
|
out:
|
|
unuse_pack(&w_curs);
|
|
|
|
if (delta_stack != small_delta_stack)
|
|
free(delta_stack);
|
|
|
|
return data;
|
|
}
|
|
|
|
int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result)
|
|
{
|
|
const unsigned char *index_fanout = p->index_data;
|
|
const unsigned char *index_lookup;
|
|
const unsigned int hashsz = the_hash_algo->rawsz;
|
|
int index_lookup_width;
|
|
|
|
if (!index_fanout)
|
|
BUG("bsearch_pack called without a valid pack-index");
|
|
|
|
index_lookup = index_fanout + 4 * 256;
|
|
if (p->index_version == 1) {
|
|
index_lookup_width = hashsz + 4;
|
|
index_lookup += 4;
|
|
} else {
|
|
index_lookup_width = hashsz;
|
|
index_fanout += 8;
|
|
index_lookup += 8;
|
|
}
|
|
|
|
return bsearch_hash(oid->hash, (const uint32_t*)index_fanout,
|
|
index_lookup, index_lookup_width, result);
|
|
}
|
|
|
|
int nth_packed_object_id(struct object_id *oid,
|
|
struct packed_git *p,
|
|
uint32_t n)
|
|
{
|
|
const unsigned char *index = p->index_data;
|
|
const unsigned int hashsz = the_hash_algo->rawsz;
|
|
if (!index) {
|
|
if (open_pack_index(p))
|
|
return -1;
|
|
index = p->index_data;
|
|
}
|
|
if (n >= p->num_objects)
|
|
return -1;
|
|
index += 4 * 256;
|
|
if (p->index_version == 1) {
|
|
oidread(oid, index + (hashsz + 4) * n + 4);
|
|
} else {
|
|
index += 8;
|
|
oidread(oid, index + hashsz * n);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
|
|
{
|
|
const unsigned char *ptr = vptr;
|
|
const unsigned char *start = p->index_data;
|
|
const unsigned char *end = start + p->index_size;
|
|
if (ptr < start)
|
|
die(_("offset before start of pack index for %s (corrupt index?)"),
|
|
p->pack_name);
|
|
/* No need to check for underflow; .idx files must be at least 8 bytes */
|
|
if (ptr >= end - 8)
|
|
die(_("offset beyond end of pack index for %s (truncated index?)"),
|
|
p->pack_name);
|
|
}
|
|
|
|
off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
|
|
{
|
|
const unsigned char *index = p->index_data;
|
|
const unsigned int hashsz = the_hash_algo->rawsz;
|
|
index += 4 * 256;
|
|
if (p->index_version == 1) {
|
|
return ntohl(*((uint32_t *)(index + (hashsz + 4) * (size_t)n)));
|
|
} else {
|
|
uint32_t off;
|
|
index += 8 + (size_t)p->num_objects * (hashsz + 4);
|
|
off = ntohl(*((uint32_t *)(index + 4 * n)));
|
|
if (!(off & 0x80000000))
|
|
return off;
|
|
index += (size_t)p->num_objects * 4 + (off & 0x7fffffff) * 8;
|
|
check_pack_index_ptr(p, index);
|
|
return get_be64(index);
|
|
}
|
|
}
|
|
|
|
off_t find_pack_entry_one(const unsigned char *sha1,
|
|
struct packed_git *p)
|
|
{
|
|
const unsigned char *index = p->index_data;
|
|
struct object_id oid;
|
|
uint32_t result;
|
|
|
|
if (!index) {
|
|
if (open_pack_index(p))
|
|
return 0;
|
|
}
|
|
|
|
hashcpy(oid.hash, sha1);
|
|
if (bsearch_pack(&oid, p, &result))
|
|
return nth_packed_object_offset(p, result);
|
|
return 0;
|
|
}
|
|
|
|
int is_pack_valid(struct packed_git *p)
|
|
{
|
|
/* An already open pack is known to be valid. */
|
|
if (p->pack_fd != -1)
|
|
return 1;
|
|
|
|
/* If the pack has one window completely covering the
|
|
* file size, the pack is known to be valid even if
|
|
* the descriptor is not currently open.
|
|
*/
|
|
if (p->windows) {
|
|
struct pack_window *w = p->windows;
|
|
|
|
if (!w->offset && w->len == p->pack_size)
|
|
return 1;
|
|
}
|
|
|
|
/* Force the pack to open to prove its valid. */
|
|
return !open_packed_git(p);
|
|
}
|
|
|
|
struct packed_git *find_sha1_pack(const unsigned char *sha1,
|
|
struct packed_git *packs)
|
|
{
|
|
struct packed_git *p;
|
|
|
|
for (p = packs; p; p = p->next) {
|
|
if (find_pack_entry_one(sha1, p))
|
|
return p;
|
|
}
|
|
return NULL;
|
|
|
|
}
|
|
|
|
static int fill_pack_entry(const struct object_id *oid,
|
|
struct pack_entry *e,
|
|
struct packed_git *p)
|
|
{
|
|
off_t offset;
|
|
|
|
if (p->num_bad_objects) {
|
|
unsigned i;
|
|
for (i = 0; i < p->num_bad_objects; i++)
|
|
if (hasheq(oid->hash,
|
|
p->bad_object_sha1 + the_hash_algo->rawsz * i))
|
|
return 0;
|
|
}
|
|
|
|
offset = find_pack_entry_one(oid->hash, p);
|
|
if (!offset)
|
|
return 0;
|
|
|
|
/*
|
|
* We are about to tell the caller where they can locate the
|
|
* requested object. We better make sure the packfile is
|
|
* still here and can be accessed before supplying that
|
|
* answer, as it may have been deleted since the index was
|
|
* loaded!
|
|
*/
|
|
if (!is_pack_valid(p))
|
|
return 0;
|
|
e->offset = offset;
|
|
e->p = p;
|
|
return 1;
|
|
}
|
|
|
|
int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
|
|
{
|
|
struct list_head *pos;
|
|
struct multi_pack_index *m;
|
|
|
|
prepare_packed_git(r);
|
|
if (!r->objects->packed_git && !r->objects->multi_pack_index)
|
|
return 0;
|
|
|
|
for (m = r->objects->multi_pack_index; m; m = m->next) {
|
|
if (fill_midx_entry(r, oid, e, m))
|
|
return 1;
|
|
}
|
|
|
|
list_for_each(pos, &r->objects->packed_git_mru) {
|
|
struct packed_git *p = list_entry(pos, struct packed_git, mru);
|
|
if (!p->multi_pack_index && fill_pack_entry(oid, e, p)) {
|
|
list_move(&p->mru, &r->objects->packed_git_mru);
|
|
return 1;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int has_object_pack(const struct object_id *oid)
|
|
{
|
|
struct pack_entry e;
|
|
return find_pack_entry(the_repository, oid, &e);
|
|
}
|
|
|
|
int has_pack_index(const unsigned char *sha1)
|
|
{
|
|
struct stat st;
|
|
if (stat(sha1_pack_index_name(sha1), &st))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
int for_each_object_in_pack(struct packed_git *p,
|
|
each_packed_object_fn cb, void *data,
|
|
enum for_each_object_flags flags)
|
|
{
|
|
uint32_t i;
|
|
int r = 0;
|
|
|
|
if (flags & FOR_EACH_OBJECT_PACK_ORDER) {
|
|
if (load_pack_revindex(p))
|
|
return -1;
|
|
}
|
|
|
|
for (i = 0; i < p->num_objects; i++) {
|
|
uint32_t index_pos;
|
|
struct object_id oid;
|
|
|
|
/*
|
|
* We are iterating "i" from 0 up to num_objects, but its
|
|
* meaning may be different, depending on the requested output
|
|
* order:
|
|
*
|
|
* - in object-name order, it is the same as the index order
|
|
* used by nth_packed_object_id(), so we can pass it
|
|
* directly
|
|
*
|
|
* - in pack-order, it is pack position, which we must
|
|
* convert to an index position in order to get the oid.
|
|
*/
|
|
if (flags & FOR_EACH_OBJECT_PACK_ORDER)
|
|
index_pos = pack_pos_to_index(p, i);
|
|
else
|
|
index_pos = i;
|
|
|
|
if (nth_packed_object_id(&oid, p, index_pos) < 0)
|
|
return error("unable to get sha1 of object %u in %s",
|
|
index_pos, p->pack_name);
|
|
|
|
r = cb(&oid, p, index_pos, data);
|
|
if (r)
|
|
break;
|
|
}
|
|
return r;
|
|
}
|
|
|
|
int for_each_packed_object(each_packed_object_fn cb, void *data,
|
|
enum for_each_object_flags flags)
|
|
{
|
|
struct packed_git *p;
|
|
int r = 0;
|
|
int pack_errors = 0;
|
|
|
|
prepare_packed_git(the_repository);
|
|
for (p = get_all_packs(the_repository); p; p = p->next) {
|
|
if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
|
|
continue;
|
|
if ((flags & FOR_EACH_OBJECT_PROMISOR_ONLY) &&
|
|
!p->pack_promisor)
|
|
continue;
|
|
if (open_pack_index(p)) {
|
|
pack_errors = 1;
|
|
continue;
|
|
}
|
|
r = for_each_object_in_pack(p, cb, data, flags);
|
|
if (r)
|
|
break;
|
|
}
|
|
return r ? r : pack_errors;
|
|
}
|
|
|
|
static int add_promisor_object(const struct object_id *oid,
|
|
struct packed_git *pack,
|
|
uint32_t pos,
|
|
void *set_)
|
|
{
|
|
struct oidset *set = set_;
|
|
struct object *obj = parse_object(the_repository, oid);
|
|
if (!obj)
|
|
return 1;
|
|
|
|
oidset_insert(set, oid);
|
|
|
|
/*
|
|
* If this is a tree, commit, or tag, the objects it refers
|
|
* to are also promisor objects. (Blobs refer to no objects->)
|
|
*/
|
|
if (obj->type == OBJ_TREE) {
|
|
struct tree *tree = (struct tree *)obj;
|
|
struct tree_desc desc;
|
|
struct name_entry entry;
|
|
if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
|
|
/*
|
|
* Error messages are given when packs are
|
|
* verified, so do not print any here.
|
|
*/
|
|
return 0;
|
|
while (tree_entry_gently(&desc, &entry))
|
|
oidset_insert(set, &entry.oid);
|
|
} else if (obj->type == OBJ_COMMIT) {
|
|
struct commit *commit = (struct commit *) obj;
|
|
struct commit_list *parents = commit->parents;
|
|
|
|
oidset_insert(set, get_commit_tree_oid(commit));
|
|
for (; parents; parents = parents->next)
|
|
oidset_insert(set, &parents->item->object.oid);
|
|
} else if (obj->type == OBJ_TAG) {
|
|
struct tag *tag = (struct tag *) obj;
|
|
oidset_insert(set, get_tagged_oid(tag));
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int is_promisor_object(const struct object_id *oid)
|
|
{
|
|
static struct oidset promisor_objects;
|
|
static int promisor_objects_prepared;
|
|
|
|
if (!promisor_objects_prepared) {
|
|
if (has_promisor_remote()) {
|
|
for_each_packed_object(add_promisor_object,
|
|
&promisor_objects,
|
|
FOR_EACH_OBJECT_PROMISOR_ONLY);
|
|
}
|
|
promisor_objects_prepared = 1;
|
|
}
|
|
return oidset_contains(&promisor_objects, oid);
|
|
}
|