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