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  * 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 *read_commit_graph_one(struct repository *r,
 110                                            struct object_directory *odb);
 111
 112 /*
 113  * Callers should initialize the repo_settings with prepare_repo_settings()
 114  * prior to calling parse_commit_graph().
 115  */
 116 struct commit_graph *parse_commit_graph(struct repo_settings *s,
 117                                         void *graph_map, size_t graph_size);
 118
 119 /*
 120  * Return 1 if and only if the repository has a commit-graph
 121  * file and generation numbers are computed in that file.
 122  */
 123 int generation_numbers_enabled(struct repository *r);
 124
 125 /*
 126  * Return 1 if and only if the repository has a commit-graph
 127  * file and generation data chunk has been written for the file.
 128  */
 129 int corrected_commit_dates_enabled(struct repository *r);
 130
 131 struct bloom_filter_settings *get_bloom_filter_settings(struct repository *r);
 132
 133 enum commit_graph_write_flags {
 134         COMMIT_GRAPH_WRITE_APPEND     = (1 << 0),
 135         COMMIT_GRAPH_WRITE_PROGRESS   = (1 << 1),
 136         COMMIT_GRAPH_WRITE_SPLIT      = (1 << 2),
 137         COMMIT_GRAPH_WRITE_BLOOM_FILTERS = (1 << 3),
 138         COMMIT_GRAPH_NO_WRITE_BLOOM_FILTERS = (1 << 4),
 139 };
 140
 141 enum commit_graph_split_flags {
 142         COMMIT_GRAPH_SPLIT_UNSPECIFIED      = 0,
 143         COMMIT_GRAPH_SPLIT_MERGE_PROHIBITED = 1,
 144         COMMIT_GRAPH_SPLIT_REPLACE          = 2
 145 };
 146
 147 struct commit_graph_opts {
 148         int size_multiple;
 149         int max_commits;
 150         timestamp_t expire_time;
 151         enum commit_graph_split_flags split_flags;
 152         int max_new_filters;
 153 };
 154
 155 /*
 156  * The write_commit_graph* methods return zero on success
 157  * and a negative value on failure. Note that if the repository
 158  * is not compatible with the commit-graph feature, then the
 159  * methods will return 0 without writing a commit-graph.
 160  */
 161 int write_commit_graph_reachable(struct object_directory *odb,
 162                                  enum commit_graph_write_flags flags,
 163                                  const struct commit_graph_opts *opts);
 164 int write_commit_graph(struct object_directory *odb,
 165                        const struct string_list *pack_indexes,
 166                        struct oidset *commits,
 167                        enum commit_graph_write_flags flags,
 168                        const struct commit_graph_opts *opts);
 169
 170 #define COMMIT_GRAPH_VERIFY_SHALLOW     (1 << 0)
 171
 172 int verify_commit_graph(struct repository *r, struct commit_graph *g, int flags);
 173
 174 void close_commit_graph(struct raw_object_store *);
 175 void free_commit_graph(struct commit_graph *);
 176
 177 /*
 178  * Disable further use of the commit graph in this process when parsing a
 179  * "struct commit".
 180  */
 181 void disable_commit_graph(struct repository *r);
 182
 183 struct commit_graph_data {
 184         uint32_t graph_pos;
 185         timestamp_t generation;
 186 };
 187
 188 /*
 189  * Commits should be parsed before accessing generation, graph positions.
 190  */
 191 timestamp_t commit_graph_generation(const struct commit *);
 192 uint32_t commit_graph_position(const struct commit *);
 193 #endif