commit-graph.h

   1 #ifndef COMMIT_GRAPH_H
   2 #define COMMIT_GRAPH_H
   3
   4 #include "git-compat-util.h"
   5 #include "object-store.h"
   6 #include "oidset.h"
   7
   8 #define GIT_TEST_COMMIT_GRAPH "GIT_TEST_COMMIT_GRAPH"
   9 #define GIT_TEST_COMMIT_GRAPH_DIE_ON_PARSE "GIT_TEST_COMMIT_GRAPH_DIE_ON_PARSE"
  10 #define GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS "GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS"
  11
  12 /*
  13  * This method is only used to enhance coverage of the commit-graph
  14  * feature in the test suite with the GIT_TEST_COMMIT_GRAPH and
  15  * GIT_TEST_COMMIT_GRAPH_CHANGED_PATHS environment variables. Do not
  16  * call this method oustide of a builtin, and only if you know what
  17  * you are doing!
  18  */
  19 void git_test_write_commit_graph_or_die(void);
  20
  21 struct commit;
  22 struct bloom_filter_settings;
  23 struct repository;
  24 struct raw_object_store;
  25 struct string_list;
  26
  27 char *get_commit_graph_filename(struct object_directory *odb);
  28 char *get_commit_graph_chain_filename(struct object_directory *odb);
  29 int open_commit_graph(const char *graph_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  * Look up the given commit ID in the commit-graph. This will only return a
  45  * commit if the ID exists both in the graph and in the object database such
  46  * that we don't return commits whose object has been pruned. Otherwise, this
  47  * function returns `NULL`.
  48  */
  49 struct commit *lookup_commit_in_graph(struct repository *repo, const struct object_id *id);
  50
  51 /*
  52  * It is possible that we loaded commit contents from the commit buffer,
  53  * but we also want to ensure the commit-graph content is correctly
  54  * checked and filled. Fill the graph_pos and generation members of
  55  * the given commit.
  56  */
  57 void load_commit_graph_info(struct repository *r, struct commit *item);
  58
  59 struct tree *get_commit_tree_in_graph(struct repository *r,
  60                                       const struct commit *c);
  61
  62 struct commit_graph {
  63         const unsigned char *data;
  64         size_t data_len;
  65
  66         unsigned char hash_len;
  67         unsigned char num_chunks;
  68         uint32_t num_commits;
  69         struct object_id oid;
  70         char *filename;
  71         struct object_directory *odb;
  72
  73         uint32_t num_commits_in_base;
  74         unsigned int read_generation_data;
  75         struct commit_graph *base_graph;
  76
  77         const uint32_t *chunk_oid_fanout;
  78         const unsigned char *chunk_oid_lookup;
  79         const unsigned char *chunk_commit_data;
  80         const unsigned char *chunk_generation_data;
  81         const unsigned char *chunk_generation_data_overflow;
  82         const unsigned char *chunk_extra_edges;
  83         const unsigned char *chunk_base_graphs;
  84         const unsigned char *chunk_bloom_indexes;
  85         const unsigned char *chunk_bloom_data;
  86
  87         struct topo_level_slab *topo_levels;
  88         struct bloom_filter_settings *bloom_filter_settings;
  89 };
  90
  91 struct commit_graph *load_commit_graph_one_fd_st(struct repository *r,
  92                                                  int fd, struct stat *st,
  93                                                  struct object_directory *odb);
  94 struct commit_graph *read_commit_graph_one(struct repository *r,
  95                                            struct object_directory *odb);
  96
  97 /*
  98  * Callers should initialize the repo_settings with prepare_repo_settings()
  99  * prior to calling parse_commit_graph().
 100  */
 101 struct commit_graph *parse_commit_graph(struct repo_settings *s,
 102                                         void *graph_map, size_t graph_size);
 103
 104 /*
 105  * Return 1 if and only if the repository has a commit-graph
 106  * file and generation numbers are computed in that file.
 107  */
 108 int generation_numbers_enabled(struct repository *r);
 109
 110 /*
 111  * Return 1 if and only if the repository has a commit-graph
 112  * file and generation data chunk has been written for the file.
 113  */
 114 int corrected_commit_dates_enabled(struct repository *r);
 115
 116 struct bloom_filter_settings *get_bloom_filter_settings(struct repository *r);
 117
 118 enum commit_graph_write_flags {
 119         COMMIT_GRAPH_WRITE_APPEND     = (1 << 0),
 120         COMMIT_GRAPH_WRITE_PROGRESS   = (1 << 1),
 121         COMMIT_GRAPH_WRITE_SPLIT      = (1 << 2),
 122         COMMIT_GRAPH_WRITE_BLOOM_FILTERS = (1 << 3),
 123         COMMIT_GRAPH_NO_WRITE_BLOOM_FILTERS = (1 << 4),
 124 };
 125
 126 enum commit_graph_split_flags {
 127         COMMIT_GRAPH_SPLIT_UNSPECIFIED      = 0,
 128         COMMIT_GRAPH_SPLIT_MERGE_PROHIBITED = 1,
 129         COMMIT_GRAPH_SPLIT_REPLACE          = 2
 130 };
 131
 132 struct commit_graph_opts {
 133         int size_multiple;
 134         int max_commits;
 135         timestamp_t expire_time;
 136         enum commit_graph_split_flags split_flags;
 137         int max_new_filters;
 138 };
 139
 140 /*
 141  * The write_commit_graph* methods return zero on success
 142  * and a negative value on failure. Note that if the repository
 143  * is not compatible with the commit-graph feature, then the
 144  * methods will return 0 without writing a commit-graph.
 145  */
 146 int write_commit_graph_reachable(struct object_directory *odb,
 147                                  enum commit_graph_write_flags flags,
 148                                  const struct commit_graph_opts *opts);
 149 int write_commit_graph(struct object_directory *odb,
 150                        const struct string_list *pack_indexes,
 151                        struct oidset *commits,
 152                        enum commit_graph_write_flags flags,
 153                        const struct commit_graph_opts *opts);
 154
 155 #define COMMIT_GRAPH_VERIFY_SHALLOW     (1 << 0)
 156
 157 int verify_commit_graph(struct repository *r, struct commit_graph *g, int flags);
 158
 159 void close_commit_graph(struct raw_object_store *);
 160 void free_commit_graph(struct commit_graph *);
 161
 162 /*
 163  * Disable further use of the commit graph in this process when parsing a
 164  * "struct commit".
 165  */
 166 void disable_commit_graph(struct repository *r);
 167
 168 struct commit_graph_data {
 169         uint32_t graph_pos;
 170         timestamp_t generation;
 171 };
 172
 173 /*
 174  * Commits should be parsed before accessing generation, graph positions.
 175  */
 176 timestamp_t commit_graph_generation(const struct commit *);
 177 uint32_t commit_graph_position(const struct commit *);
 178 #endif