commit-graph.h

   1 #ifndef COMMIT_GRAPH_H
   2 #define COMMIT_GRAPH_H
   3
   4 #include "object-store-ll.h"
   5 #include "oidset.h"
   6
   7 #define GIT_TEST_COMMIT_GRAPH "GIT_TEST_COMMIT_GRAPH"
   8 #define GIT_TEST_COMMIT_GRAPH_DIE_ON_PARSE "GIT_TEST_COMMIT_GRAPH_DIE_ON_PARSE"
   9 #define GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS "GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS"
  10
  11 /*
  12  * This method is only used to enhance coverage of the commit-graph
  13  * feature in the test suite with the GIT_TEST_COMMIT_GRAPH and
  14  * GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS environment variables. Do not
  15  * call this method oustide of a builtin, and only if you know what
  16  * you are doing!
  17  */
  18 void git_test_write_commit_graph_or_die(void);
  19
  20 struct commit;
  21 struct bloom_filter_settings;
  22 struct repository;
  23 struct raw_object_store;
  24 struct string_list;
  25
  26 char *get_commit_graph_filename(struct object_directory *odb);
  27 char *get_commit_graph_chain_filename(struct object_directory *odb);
  28 int open_commit_graph(const char *graph_file, int *fd, struct stat *st);
  29 int open_commit_graph_chain(const char *chain_file, int *fd, struct stat *st);
  30
  31 /*
  32  * Given a commit struct, try to fill the commit struct info, including:
  33  *  1. tree object
  34  *  2. date
  35  *  3. parents.
  36  *
  37  * Returns 1 if and only if the commit was found in the packed graph.
  38  *
  39  * See parse_commit_buffer() for the fallback after this call.
  40  */
  41 int parse_commit_in_graph(struct repository *r, struct commit *item);
  42
  43 /*
  44  * Fills `*pos` with the graph position of `c`, and returns 1 if `c` is
  45  * found in the commit-graph belonging to `r`, or 0 otherwise.
  46  * Initializes the commit-graph belonging to `r` if it hasn't been
  47  * already.
  48  *
  49  * Note: this is a low-level helper that does not alter any slab data
  50  * associated with `c`. Useful in circumstances where the slab data is
  51  * already being modified (e.g., writing the commit-graph itself).
  52  *
  53  * In most cases, callers should use `parse_commit_in_graph()` instead.
  54  */
  55 int repo_find_commit_pos_in_graph(struct repository *r, struct commit *c,
  56                                   uint32_t *pos);
  57
  58 /*
  59  * Look up the given commit ID in the commit-graph. This will only return a
  60  * commit if the ID exists both in the graph and in the object database such
  61  * that we don't return commits whose object has been pruned. Otherwise, this
  62  * function returns `NULL`.
  63  */
  64 struct commit *lookup_commit_in_graph(struct repository *repo, const struct object_id *id);
  65
  66 /*
  67  * It is possible that we loaded commit contents from the commit buffer,
  68  * but we also want to ensure the commit-graph content is correctly
  69  * checked and filled. Fill the graph_pos and generation members of
  70  * the given commit.
  71  */
  72 void load_commit_graph_info(struct repository *r, struct commit *item);
  73
  74 struct tree *get_commit_tree_in_graph(struct repository *r,
  75                                       const struct commit *c);
  76
  77 struct commit_graph {
  78         const unsigned char *data;
  79         size_t data_len;
  80
  81         unsigned char hash_len;
  82         unsigned char num_chunks;
  83         uint32_t num_commits;
  84         struct object_id oid;
  85         char *filename;
  86         struct object_directory *odb;
  87
  88         uint32_t num_commits_in_base;
  89         unsigned int read_generation_data;
  90         struct commit_graph *base_graph;
  91
  92         const uint32_t *chunk_oid_fanout;
  93         const unsigned char *chunk_oid_lookup;
  94         const unsigned char *chunk_commit_data;
  95         const unsigned char *chunk_generation_data;
  96         const unsigned char *chunk_generation_data_overflow;
  97         const unsigned char *chunk_extra_edges;
  98         const unsigned char *chunk_base_graphs;
  99         const unsigned char *chunk_bloom_indexes;
 100         const unsigned char *chunk_bloom_data;
 101
 102         struct topo_level_slab *topo_levels;
 103         struct bloom_filter_settings *bloom_filter_settings;
 104 };
 105
 106 struct commit_graph *load_commit_graph_one_fd_st(struct repository *r,
 107                                                  int fd, struct stat *st,
 108                                                  struct object_directory *odb);
 109 struct commit_graph *load_commit_graph_chain_fd_st(struct repository *r,
 110                                                    int fd, struct stat *st,
 111                                                    int *incomplete_chain);
 112 struct commit_graph *read_commit_graph_one(struct repository *r,
 113                                            struct object_directory *odb);
 114
 115 /*
 116  * Callers should initialize the repo_settings with prepare_repo_settings()
 117  * prior to calling parse_commit_graph().
 118  */
 119 struct commit_graph *parse_commit_graph(struct repo_settings *s,
 120                                         void *graph_map, size_t graph_size);
 121
 122 /*
 123  * Return 1 if and only if the repository has a commit-graph
 124  * file and generation numbers are computed in that file.
 125  */
 126 int generation_numbers_enabled(struct repository *r);
 127
 128 /*
 129  * Return 1 if and only if the repository has a commit-graph
 130  * file and generation data chunk has been written for the file.
 131  */
 132 int corrected_commit_dates_enabled(struct repository *r);
 133
 134 struct bloom_filter_settings *get_bloom_filter_settings(struct repository *r);
 135
 136 enum commit_graph_write_flags {
 137         COMMIT_GRAPH_WRITE_APPEND     = (1 << 0),
 138         COMMIT_GRAPH_WRITE_PROGRESS   = (1 << 1),
 139         COMMIT_GRAPH_WRITE_SPLIT      = (1 << 2),
 140         COMMIT_GRAPH_WRITE_BLOOM_FILTERS = (1 << 3),
 141         COMMIT_GRAPH_NO_WRITE_BLOOM_FILTERS = (1 << 4),
 142 };
 143
 144 enum commit_graph_split_flags {
 145         COMMIT_GRAPH_SPLIT_UNSPECIFIED      = 0,
 146         COMMIT_GRAPH_SPLIT_MERGE_PROHIBITED = 1,
 147         COMMIT_GRAPH_SPLIT_REPLACE          = 2
 148 };
 149
 150 struct commit_graph_opts {
 151         int size_multiple;
 152         int max_commits;
 153         timestamp_t expire_time;
 154         enum commit_graph_split_flags split_flags;
 155         int max_new_filters;
 156 };
 157
 158 /*
 159  * The write_commit_graph* methods return zero on success
 160  * and a negative value on failure. Note that if the repository
 161  * is not compatible with the commit-graph feature, then the
 162  * methods will return 0 without writing a commit-graph.
 163  */
 164 int write_commit_graph_reachable(struct object_directory *odb,
 165                                  enum commit_graph_write_flags flags,
 166                                  const struct commit_graph_opts *opts);
 167 int write_commit_graph(struct object_directory *odb,
 168                        const struct string_list *pack_indexes,
 169                        struct oidset *commits,
 170                        enum commit_graph_write_flags flags,
 171                        const struct commit_graph_opts *opts);
 172
 173 #define COMMIT_GRAPH_VERIFY_SHALLOW     (1 << 0)
 174
 175 int verify_commit_graph(struct repository *r, struct commit_graph *g, int flags);
 176
 177 void close_commit_graph(struct raw_object_store *);
 178 void free_commit_graph(struct commit_graph *);
 179
 180 /*
 181  * Disable further use of the commit graph in this process when parsing a
 182  * "struct commit".
 183  */
 184 void disable_commit_graph(struct repository *r);
 185
 186 struct commit_graph_data {
 187         uint32_t graph_pos;
 188         timestamp_t generation;
 189 };
 190
 191 /*
 192  * Commits should be parsed before accessing generation, graph positions.
 193  */
 194 timestamp_t commit_graph_generation(const struct commit *);
 195 uint32_t commit_graph_position(const struct commit *);
 196
 197 /*
 198  * After this method, all commits reachable from those in the given
 199  * list will have non-zero, non-infinite generation numbers.
 200  */
 201 void ensure_generations_valid(struct repository *r,
 202                               struct commit **commits, size_t nr);
 203
 204 #endif