mirror of
https://git.proxmox.com/git/libgit2
synced 2025-05-06 23:26:39 +00:00
96c9b9f0e5
The indexer needs to call the packfile's free function so it takes care of freeing the caches. We still need to close the mwf descriptor manually so we can rename the packfile into its final name on Windows.
626 lines
17 KiB
C
626 lines
17 KiB
C
/*
|
|
* Copyright (C) the libgit2 contributors. All rights reserved.
|
|
*
|
|
* This file is part of libgit2, distributed under the GNU GPL v2 with
|
|
* a Linking Exception. For full terms see the included COPYING file.
|
|
*/
|
|
|
|
#include "common.h"
|
|
#include <zlib.h>
|
|
#include "git2/repository.h"
|
|
#include "git2/oid.h"
|
|
#include "fileops.h"
|
|
#include "hash.h"
|
|
#include "odb.h"
|
|
#include "delta-apply.h"
|
|
#include "sha1_lookup.h"
|
|
#include "mwindow.h"
|
|
#include "pack.h"
|
|
|
|
#include "git2/odb_backend.h"
|
|
|
|
struct pack_backend {
|
|
git_odb_backend parent;
|
|
git_vector packs;
|
|
struct git_pack_file *last_found;
|
|
char *pack_folder;
|
|
};
|
|
|
|
struct pack_writepack {
|
|
struct git_odb_writepack parent;
|
|
git_indexer_stream *indexer_stream;
|
|
};
|
|
|
|
/**
|
|
* The wonderful tale of a Packed Object lookup query
|
|
* ===================================================
|
|
* A riveting and epic story of epicness and ASCII
|
|
* art, presented by yours truly,
|
|
* Sir Vicent of Marti
|
|
*
|
|
*
|
|
* Chapter 1: Once upon a time...
|
|
* Initialization of the Pack Backend
|
|
* --------------------------------------------------
|
|
*
|
|
* # git_odb_backend_pack
|
|
* | Creates the pack backend structure, initializes the
|
|
* | callback pointers to our default read() and exist() methods,
|
|
* | and tries to preload all the known packfiles in the ODB.
|
|
* |
|
|
* |-# packfile_load_all
|
|
* | Tries to find the `pack` folder, if it exists. ODBs without
|
|
* | a pack folder are ignored altogether. If there's a `pack` folder
|
|
* | we run a `dirent` callback through every file in the pack folder
|
|
* | to find our packfiles. The packfiles are then sorted according
|
|
* | to a sorting callback.
|
|
* |
|
|
* |-# packfile_load__cb
|
|
* | | This callback is called from `dirent` with every single file
|
|
* | | inside the pack folder. We find the packs by actually locating
|
|
* | | their index (ends in ".idx"). From that index, we verify that
|
|
* | | the corresponding packfile exists and is valid, and if so, we
|
|
* | | add it to the pack list.
|
|
* | |
|
|
* | |-# packfile_check
|
|
* | Make sure that there's a packfile to back this index, and store
|
|
* | some very basic information regarding the packfile itself,
|
|
* | such as the full path, the size, and the modification time.
|
|
* | We don't actually open the packfile to check for internal consistency.
|
|
* |
|
|
* |-# packfile_sort__cb
|
|
* Sort all the preloaded packs according to some specific criteria:
|
|
* we prioritize the "newer" packs because it's more likely they
|
|
* contain the objects we are looking for, and we prioritize local
|
|
* packs over remote ones.
|
|
*
|
|
*
|
|
*
|
|
* Chapter 2: To be, or not to be...
|
|
* A standard packed `exist` query for an OID
|
|
* --------------------------------------------------
|
|
*
|
|
* # pack_backend__exists
|
|
* | Check if the given SHA1 oid exists in any of the packs
|
|
* | that have been loaded for our ODB.
|
|
* |
|
|
* |-# pack_entry_find
|
|
* | Iterate through all the packs that have been preloaded
|
|
* | (starting by the pack where the latest object was found)
|
|
* | to try to find the OID in one of them.
|
|
* |
|
|
* |-# pack_entry_find1
|
|
* | Check the index of an individual pack to see if the SHA1
|
|
* | OID can be found. If we can find the offset to that SHA1
|
|
* | inside of the index, that means the object is contained
|
|
* | inside of the packfile and we can stop searching.
|
|
* | Before returning, we verify that the packfile behing the
|
|
* | index we are searching still exists on disk.
|
|
* |
|
|
* |-# pack_entry_find_offset
|
|
* | | Mmap the actual index file to disk if it hasn't been opened
|
|
* | | yet, and run a binary search through it to find the OID.
|
|
* | | See <http://book.git-scm.com/7_the_packfile.html> for specifics
|
|
* | | on the Packfile Index format and how do we find entries in it.
|
|
* | |
|
|
* | |-# pack_index_open
|
|
* | | Guess the name of the index based on the full path to the
|
|
* | | packfile, open it and verify its contents. Only if the index
|
|
* | | has not been opened already.
|
|
* | |
|
|
* | |-# pack_index_check
|
|
* | Mmap the index file and do a quick run through the header
|
|
* | to guess the index version (right now we support v1 and v2),
|
|
* | and to verify that the size of the index makes sense.
|
|
* |
|
|
* |-# packfile_open
|
|
* See `packfile_open` in Chapter 3
|
|
*
|
|
*
|
|
*
|
|
* Chapter 3: The neverending story...
|
|
* A standard packed `lookup` query for an OID
|
|
* --------------------------------------------------
|
|
* TODO
|
|
*
|
|
*/
|
|
|
|
|
|
/***********************************************************
|
|
*
|
|
* FORWARD DECLARATIONS
|
|
*
|
|
***********************************************************/
|
|
|
|
static void pack_window_free_all(struct pack_backend *backend, struct git_pack_file *p);
|
|
static int pack_window_contains(git_mwindow *win, off_t offset);
|
|
|
|
static int packfile_sort__cb(const void *a_, const void *b_);
|
|
|
|
static int packfile_load__cb(void *_data, git_buf *path);
|
|
|
|
static int pack_entry_find(struct git_pack_entry *e,
|
|
struct pack_backend *backend, const git_oid *oid);
|
|
|
|
/* Can find the offset of an object given
|
|
* a prefix of an identifier.
|
|
* Sets GIT_EAMBIGUOUS if short oid is ambiguous.
|
|
* This method assumes that len is between
|
|
* GIT_OID_MINPREFIXLEN and GIT_OID_HEXSZ.
|
|
*/
|
|
static int pack_entry_find_prefix(
|
|
struct git_pack_entry *e,
|
|
struct pack_backend *backend,
|
|
const git_oid *short_oid,
|
|
size_t len);
|
|
|
|
|
|
|
|
/***********************************************************
|
|
*
|
|
* PACK WINDOW MANAGEMENT
|
|
*
|
|
***********************************************************/
|
|
|
|
GIT_INLINE(void) pack_window_free_all(struct pack_backend *backend, struct git_pack_file *p)
|
|
{
|
|
GIT_UNUSED(backend);
|
|
git_mwindow_free_all(&p->mwf);
|
|
}
|
|
|
|
GIT_INLINE(int) pack_window_contains(git_mwindow *win, off_t offset)
|
|
{
|
|
/* We must promise at least 20 bytes (one 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.
|
|
*/
|
|
return git_mwindow_contains(win, offset + 20);
|
|
}
|
|
|
|
static int packfile_sort__cb(const void *a_, const void *b_)
|
|
{
|
|
const struct git_pack_file *a = a_;
|
|
const struct git_pack_file *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 int packfile_load__cb(void *_data, git_buf *path)
|
|
{
|
|
struct pack_backend *backend = (struct pack_backend *)_data;
|
|
struct git_pack_file *pack;
|
|
int error;
|
|
unsigned int i;
|
|
|
|
if (git__suffixcmp(path->ptr, ".idx") != 0)
|
|
return 0; /* not an index */
|
|
|
|
for (i = 0; i < backend->packs.length; ++i) {
|
|
struct git_pack_file *p = git_vector_get(&backend->packs, i);
|
|
if (memcmp(p->pack_name, git_buf_cstr(path), git_buf_len(path) - strlen(".idx")) == 0)
|
|
return 0;
|
|
}
|
|
|
|
error = git_packfile_check(&pack, path->ptr);
|
|
if (error == GIT_ENOTFOUND)
|
|
/* ignore missing .pack file as git does */
|
|
return 0;
|
|
else if (error < 0)
|
|
return error;
|
|
|
|
return git_vector_insert(&backend->packs, pack);
|
|
}
|
|
|
|
static int pack_entry_find_inner(
|
|
struct git_pack_entry *e,
|
|
struct pack_backend *backend,
|
|
const git_oid *oid,
|
|
struct git_pack_file *last_found)
|
|
{
|
|
unsigned int i;
|
|
|
|
if (last_found &&
|
|
git_pack_entry_find(e, last_found, oid, GIT_OID_HEXSZ) == 0)
|
|
return 0;
|
|
|
|
for (i = 0; i < backend->packs.length; ++i) {
|
|
struct git_pack_file *p;
|
|
|
|
p = git_vector_get(&backend->packs, i);
|
|
if (p == last_found)
|
|
continue;
|
|
|
|
if (git_pack_entry_find(e, p, oid, GIT_OID_HEXSZ) == 0) {
|
|
backend->last_found = p;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
static int pack_entry_find(struct git_pack_entry *e, struct pack_backend *backend, const git_oid *oid)
|
|
{
|
|
struct git_pack_file *last_found = backend->last_found;
|
|
|
|
if (backend->last_found &&
|
|
git_pack_entry_find(e, backend->last_found, oid, GIT_OID_HEXSZ) == 0)
|
|
return 0;
|
|
|
|
if (!pack_entry_find_inner(e, backend, oid, last_found))
|
|
return 0;
|
|
|
|
return git_odb__error_notfound("failed to find pack entry", oid);
|
|
}
|
|
|
|
static unsigned pack_entry_find_prefix_inner(
|
|
struct git_pack_entry *e,
|
|
struct pack_backend *backend,
|
|
const git_oid *short_oid,
|
|
size_t len,
|
|
struct git_pack_file *last_found)
|
|
{
|
|
int error;
|
|
unsigned int i;
|
|
unsigned found = 0;
|
|
|
|
if (last_found) {
|
|
error = git_pack_entry_find(e, last_found, short_oid, len);
|
|
if (error == GIT_EAMBIGUOUS)
|
|
return error;
|
|
if (!error)
|
|
found = 1;
|
|
}
|
|
|
|
for (i = 0; i < backend->packs.length; ++i) {
|
|
struct git_pack_file *p;
|
|
|
|
p = git_vector_get(&backend->packs, i);
|
|
if (p == last_found)
|
|
continue;
|
|
|
|
error = git_pack_entry_find(e, p, short_oid, len);
|
|
if (error == GIT_EAMBIGUOUS)
|
|
return error;
|
|
if (!error) {
|
|
if (++found > 1)
|
|
break;
|
|
backend->last_found = p;
|
|
}
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
static int pack_entry_find_prefix(
|
|
struct git_pack_entry *e,
|
|
struct pack_backend *backend,
|
|
const git_oid *short_oid,
|
|
size_t len)
|
|
{
|
|
struct git_pack_file *last_found = backend->last_found;
|
|
unsigned int found = pack_entry_find_prefix_inner(e, backend, short_oid, len, last_found);
|
|
|
|
if (!found)
|
|
return git_odb__error_notfound("no matching pack entry for prefix", short_oid);
|
|
else if (found > 1)
|
|
return git_odb__error_ambiguous("found multiple pack entries");
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
|
|
/***********************************************************
|
|
*
|
|
* PACKED BACKEND PUBLIC API
|
|
*
|
|
* Implement the git_odb_backend API calls
|
|
*
|
|
***********************************************************/
|
|
static int pack_backend__refresh(git_odb_backend *_backend)
|
|
{
|
|
struct pack_backend *backend = (struct pack_backend *)_backend;
|
|
|
|
int error;
|
|
struct stat st;
|
|
git_buf path = GIT_BUF_INIT;
|
|
|
|
if (backend->pack_folder == NULL)
|
|
return 0;
|
|
|
|
if (p_stat(backend->pack_folder, &st) < 0 || !S_ISDIR(st.st_mode))
|
|
return git_odb__error_notfound("failed to refresh packfiles", NULL);
|
|
|
|
git_buf_sets(&path, backend->pack_folder);
|
|
|
|
/* reload all packs */
|
|
error = git_path_direach(&path, packfile_load__cb, (void *)backend);
|
|
|
|
git_buf_free(&path);
|
|
|
|
if (error < 0)
|
|
return error;
|
|
|
|
git_vector_sort(&backend->packs);
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int pack_backend__read_header(size_t *len_p, git_otype *type_p, struct git_odb_backend *backend, const git_oid *oid)
|
|
{
|
|
struct git_pack_entry e;
|
|
int error;
|
|
|
|
assert(len_p && type_p && backend && oid);
|
|
|
|
if ((error = pack_entry_find(&e, (struct pack_backend *)backend, oid)) < 0)
|
|
return error;
|
|
|
|
return git_packfile_resolve_header(len_p, type_p, e.p, e.offset);
|
|
}
|
|
|
|
static int pack_backend__read(void **buffer_p, size_t *len_p, git_otype *type_p, git_odb_backend *backend, const git_oid *oid)
|
|
{
|
|
struct git_pack_entry e;
|
|
git_rawobj raw;
|
|
int error;
|
|
|
|
if ((error = pack_entry_find(&e, (struct pack_backend *)backend, oid)) < 0 ||
|
|
(error = git_packfile_unpack(&raw, e.p, &e.offset)) < 0)
|
|
return error;
|
|
|
|
*buffer_p = raw.data;
|
|
*len_p = raw.len;
|
|
*type_p = raw.type;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pack_backend__read_prefix(
|
|
git_oid *out_oid,
|
|
void **buffer_p,
|
|
size_t *len_p,
|
|
git_otype *type_p,
|
|
git_odb_backend *backend,
|
|
const git_oid *short_oid,
|
|
size_t len)
|
|
{
|
|
int error = 0;
|
|
|
|
if (len < GIT_OID_MINPREFIXLEN)
|
|
error = git_odb__error_ambiguous("prefix length too short");
|
|
|
|
else if (len >= GIT_OID_HEXSZ) {
|
|
/* We can fall back to regular read method */
|
|
error = pack_backend__read(buffer_p, len_p, type_p, backend, short_oid);
|
|
if (!error)
|
|
git_oid_cpy(out_oid, short_oid);
|
|
} else {
|
|
struct git_pack_entry e;
|
|
git_rawobj raw;
|
|
|
|
if ((error = pack_entry_find_prefix(
|
|
&e, (struct pack_backend *)backend, short_oid, len)) == 0 &&
|
|
(error = git_packfile_unpack(&raw, e.p, &e.offset)) == 0)
|
|
{
|
|
*buffer_p = raw.data;
|
|
*len_p = raw.len;
|
|
*type_p = raw.type;
|
|
git_oid_cpy(out_oid, &e.sha1);
|
|
}
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
static int pack_backend__exists(git_odb_backend *backend, const git_oid *oid)
|
|
{
|
|
struct git_pack_entry e;
|
|
return pack_entry_find(&e, (struct pack_backend *)backend, oid) == 0;
|
|
}
|
|
|
|
static int pack_backend__foreach(git_odb_backend *_backend, git_odb_foreach_cb cb, void *data)
|
|
{
|
|
int error;
|
|
struct git_pack_file *p;
|
|
struct pack_backend *backend;
|
|
unsigned int i;
|
|
|
|
assert(_backend && cb);
|
|
backend = (struct pack_backend *)_backend;
|
|
|
|
/* Make sure we know about the packfiles */
|
|
if ((error = pack_backend__refresh(_backend)) < 0)
|
|
return error;
|
|
|
|
git_vector_foreach(&backend->packs, i, p) {
|
|
if ((error = git_pack_foreach_entry(p, cb, data)) < 0)
|
|
return error;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pack_backend__writepack_add(struct git_odb_writepack *_writepack, const void *data, size_t size, git_transfer_progress *stats)
|
|
{
|
|
struct pack_writepack *writepack = (struct pack_writepack *)_writepack;
|
|
|
|
assert(writepack);
|
|
|
|
return git_indexer_stream_add(writepack->indexer_stream, data, size, stats);
|
|
}
|
|
|
|
static int pack_backend__writepack_commit(struct git_odb_writepack *_writepack, git_transfer_progress *stats)
|
|
{
|
|
struct pack_writepack *writepack = (struct pack_writepack *)_writepack;
|
|
|
|
assert(writepack);
|
|
|
|
return git_indexer_stream_finalize(writepack->indexer_stream, stats);
|
|
}
|
|
|
|
static void pack_backend__writepack_free(struct git_odb_writepack *_writepack)
|
|
{
|
|
struct pack_writepack *writepack = (struct pack_writepack *)_writepack;
|
|
|
|
assert(writepack);
|
|
|
|
git_indexer_stream_free(writepack->indexer_stream);
|
|
git__free(writepack);
|
|
}
|
|
|
|
static int pack_backend__writepack(struct git_odb_writepack **out,
|
|
git_odb_backend *_backend,
|
|
git_transfer_progress_callback progress_cb,
|
|
void *progress_payload)
|
|
{
|
|
struct pack_backend *backend;
|
|
struct pack_writepack *writepack;
|
|
|
|
assert(out && _backend);
|
|
|
|
*out = NULL;
|
|
|
|
backend = (struct pack_backend *)_backend;
|
|
|
|
writepack = git__calloc(1, sizeof(struct pack_writepack));
|
|
GITERR_CHECK_ALLOC(writepack);
|
|
|
|
if (git_indexer_stream_new(&writepack->indexer_stream,
|
|
backend->pack_folder, progress_cb, progress_payload) < 0) {
|
|
git__free(writepack);
|
|
return -1;
|
|
}
|
|
|
|
writepack->parent.backend = _backend;
|
|
writepack->parent.add = pack_backend__writepack_add;
|
|
writepack->parent.commit = pack_backend__writepack_commit;
|
|
writepack->parent.free = pack_backend__writepack_free;
|
|
|
|
*out = (git_odb_writepack *)writepack;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void pack_backend__free(git_odb_backend *_backend)
|
|
{
|
|
struct pack_backend *backend;
|
|
unsigned int i;
|
|
|
|
assert(_backend);
|
|
|
|
backend = (struct pack_backend *)_backend;
|
|
|
|
for (i = 0; i < backend->packs.length; ++i) {
|
|
struct git_pack_file *p = git_vector_get(&backend->packs, i);
|
|
git_packfile_free(p);
|
|
}
|
|
|
|
git_vector_free(&backend->packs);
|
|
git__free(backend->pack_folder);
|
|
git__free(backend);
|
|
}
|
|
|
|
int git_odb_backend_one_pack(git_odb_backend **backend_out, const char *idx)
|
|
{
|
|
struct pack_backend *backend = NULL;
|
|
struct git_pack_file *packfile = NULL;
|
|
|
|
if (git_packfile_check(&packfile, idx) < 0)
|
|
return -1;
|
|
|
|
backend = git__calloc(1, sizeof(struct pack_backend));
|
|
GITERR_CHECK_ALLOC(backend);
|
|
backend->parent.version = GIT_ODB_BACKEND_VERSION;
|
|
|
|
if (git_vector_init(&backend->packs, 1, NULL) < 0)
|
|
goto on_error;
|
|
|
|
if (git_vector_insert(&backend->packs, packfile) < 0)
|
|
goto on_error;
|
|
|
|
backend->parent.read = &pack_backend__read;
|
|
backend->parent.read_prefix = &pack_backend__read_prefix;
|
|
backend->parent.read_header = &pack_backend__read_header;
|
|
backend->parent.exists = &pack_backend__exists;
|
|
backend->parent.refresh = &pack_backend__refresh;
|
|
backend->parent.foreach = &pack_backend__foreach;
|
|
backend->parent.free = &pack_backend__free;
|
|
|
|
*backend_out = (git_odb_backend *)backend;
|
|
|
|
return 0;
|
|
|
|
on_error:
|
|
git_vector_free(&backend->packs);
|
|
git__free(backend);
|
|
git__free(packfile);
|
|
return -1;
|
|
}
|
|
|
|
int git_odb_backend_pack(git_odb_backend **backend_out, const char *objects_dir)
|
|
{
|
|
struct pack_backend *backend = NULL;
|
|
git_buf path = GIT_BUF_INIT;
|
|
|
|
backend = git__calloc(1, sizeof(struct pack_backend));
|
|
GITERR_CHECK_ALLOC(backend);
|
|
backend->parent.version = GIT_ODB_BACKEND_VERSION;
|
|
|
|
if (git_vector_init(&backend->packs, 8, packfile_sort__cb) < 0 ||
|
|
git_buf_joinpath(&path, objects_dir, "pack") < 0)
|
|
{
|
|
git__free(backend);
|
|
return -1;
|
|
}
|
|
|
|
if (git_path_isdir(git_buf_cstr(&path)) == true) {
|
|
int error;
|
|
|
|
backend->pack_folder = git_buf_detach(&path);
|
|
error = pack_backend__refresh((git_odb_backend *)backend);
|
|
if (error < 0)
|
|
return error;
|
|
}
|
|
|
|
backend->parent.read = &pack_backend__read;
|
|
backend->parent.read_prefix = &pack_backend__read_prefix;
|
|
backend->parent.read_header = &pack_backend__read_header;
|
|
backend->parent.exists = &pack_backend__exists;
|
|
backend->parent.refresh = &pack_backend__refresh;
|
|
backend->parent.foreach = &pack_backend__foreach;
|
|
backend->parent.writepack = &pack_backend__writepack;
|
|
backend->parent.free = &pack_backend__free;
|
|
|
|
*backend_out = (git_odb_backend *)backend;
|
|
|
|
git_buf_free(&path);
|
|
|
|
return 0;
|
|
}
|