git/commit-graph.h
Derrick Stolee 118bd57002 commit-graph: add base graphs chunk
To quickly verify a commit-graph chain is valid on load, we will
read from the new "Base Graphs Chunk" of each file in the chain.
This will prevent accidentally loading incorrect data from manually
editing the commit-graph-chain file or renaming graph-{hash}.graph
files.

The commit_graph struct already had an object_id struct "oid", but
it was never initialized or used. Add a line to read the hash from
the end of the commit-graph file and into the oid member.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-06-19 20:46:26 -07:00

93 lines
2.6 KiB
C

#ifndef COMMIT_GRAPH_H
#define COMMIT_GRAPH_H
#include "git-compat-util.h"
#include "repository.h"
#include "string-list.h"
#include "cache.h"
#define GIT_TEST_COMMIT_GRAPH "GIT_TEST_COMMIT_GRAPH"
#define GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD "GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD"
struct commit;
char *get_commit_graph_filename(const char *obj_dir);
int open_commit_graph(const char *graph_file, int *fd, struct stat *st);
/*
* Given a commit struct, try to fill the commit struct info, including:
* 1. tree object
* 2. date
* 3. parents.
*
* Returns 1 if and only if the commit was found in the packed graph.
*
* See parse_commit_buffer() for the fallback after this call.
*/
int parse_commit_in_graph(struct repository *r, struct commit *item);
/*
* It is possible that we loaded commit contents from the commit buffer,
* but we also want to ensure the commit-graph content is correctly
* checked and filled. Fill the graph_pos and generation members of
* the given commit.
*/
void load_commit_graph_info(struct repository *r, struct commit *item);
struct tree *get_commit_tree_in_graph(struct repository *r,
const struct commit *c);
struct commit_graph {
int graph_fd;
const unsigned char *data;
size_t data_len;
unsigned char hash_len;
unsigned char num_chunks;
uint32_t num_commits;
struct object_id oid;
uint32_t num_commits_in_base;
struct commit_graph *base_graph;
const uint32_t *chunk_oid_fanout;
const unsigned char *chunk_oid_lookup;
const unsigned char *chunk_commit_data;
const unsigned char *chunk_extra_edges;
const unsigned char *chunk_base_graphs;
};
struct commit_graph *load_commit_graph_one_fd_st(int fd, struct stat *st);
struct commit_graph *parse_commit_graph(void *graph_map, int fd,
size_t graph_size);
/*
* Return 1 if and only if the repository has a commit-graph
* file and generation numbers are computed in that file.
*/
int generation_numbers_enabled(struct repository *r);
#define COMMIT_GRAPH_APPEND (1 << 0)
#define COMMIT_GRAPH_PROGRESS (1 << 1)
/*
* The write_commit_graph* methods return zero on success
* and a negative value on failure. Note that if the repository
* is not compatible with the commit-graph feature, then the
* methods will return 0 without writing a commit-graph.
*/
int write_commit_graph_reachable(const char *obj_dir, unsigned int flags);
int write_commit_graph(const char *obj_dir,
struct string_list *pack_indexes,
struct string_list *commit_hex,
unsigned int flags);
int verify_commit_graph(struct repository *r, struct commit_graph *g);
void close_commit_graph(struct raw_object_store *);
void free_commit_graph(struct commit_graph *);
#endif