Merge branch 'bc/faq-misc'
[git] / 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  * It is possible that we loaded commit contents from the commit buffer,
45  * but we also want to ensure the commit-graph content is correctly
46  * checked and filled. Fill the graph_pos and generation members of
47  * the given commit.
48  */
49 void load_commit_graph_info(struct repository *r, struct commit *item);
50
51 struct tree *get_commit_tree_in_graph(struct repository *r,
52                                       const struct commit *c);
53
54 struct commit_graph {
55         const unsigned char *data;
56         size_t data_len;
57
58         unsigned char hash_len;
59         unsigned char num_chunks;
60         uint32_t num_commits;
61         struct object_id oid;
62         char *filename;
63         struct object_directory *odb;
64
65         uint32_t num_commits_in_base;
66         struct commit_graph *base_graph;
67
68         const uint32_t *chunk_oid_fanout;
69         const unsigned char *chunk_oid_lookup;
70         const unsigned char *chunk_commit_data;
71         const unsigned char *chunk_extra_edges;
72         const unsigned char *chunk_base_graphs;
73         const unsigned char *chunk_bloom_indexes;
74         const unsigned char *chunk_bloom_data;
75
76         struct bloom_filter_settings *bloom_filter_settings;
77 };
78
79 struct commit_graph *load_commit_graph_one_fd_st(int fd, struct stat *st,
80                                                  struct object_directory *odb);
81 struct commit_graph *read_commit_graph_one(struct repository *r,
82                                            struct object_directory *odb);
83 struct commit_graph *parse_commit_graph(void *graph_map, size_t graph_size);
84
85 /*
86  * Return 1 if and only if the repository has a commit-graph
87  * file and generation numbers are computed in that file.
88  */
89 int generation_numbers_enabled(struct repository *r);
90
91 enum commit_graph_write_flags {
92         COMMIT_GRAPH_WRITE_APPEND     = (1 << 0),
93         COMMIT_GRAPH_WRITE_PROGRESS   = (1 << 1),
94         COMMIT_GRAPH_WRITE_SPLIT      = (1 << 2),
95         COMMIT_GRAPH_WRITE_BLOOM_FILTERS = (1 << 3),
96         COMMIT_GRAPH_NO_WRITE_BLOOM_FILTERS = (1 << 4),
97 };
98
99 enum commit_graph_split_flags {
100         COMMIT_GRAPH_SPLIT_UNSPECIFIED      = 0,
101         COMMIT_GRAPH_SPLIT_MERGE_PROHIBITED = 1,
102         COMMIT_GRAPH_SPLIT_REPLACE          = 2
103 };
104
105 struct split_commit_graph_opts {
106         int size_multiple;
107         int max_commits;
108         timestamp_t expire_time;
109         enum commit_graph_split_flags flags;
110 };
111
112 /*
113  * The write_commit_graph* methods return zero on success
114  * and a negative value on failure. Note that if the repository
115  * is not compatible with the commit-graph feature, then the
116  * methods will return 0 without writing a commit-graph.
117  */
118 int write_commit_graph_reachable(struct object_directory *odb,
119                                  enum commit_graph_write_flags flags,
120                                  const struct split_commit_graph_opts *split_opts);
121 int write_commit_graph(struct object_directory *odb,
122                        struct string_list *pack_indexes,
123                        struct oidset *commits,
124                        enum commit_graph_write_flags flags,
125                        const struct split_commit_graph_opts *split_opts);
126
127 #define COMMIT_GRAPH_VERIFY_SHALLOW     (1 << 0)
128
129 int verify_commit_graph(struct repository *r, struct commit_graph *g, int flags);
130
131 void close_commit_graph(struct raw_object_store *);
132 void free_commit_graph(struct commit_graph *);
133
134 /*
135  * Disable further use of the commit graph in this process when parsing a
136  * "struct commit".
137  */
138 void disable_commit_graph(struct repository *r);
139
140 struct commit_graph_data {
141         uint32_t graph_pos;
142         uint32_t generation;
143 };
144
145 /*
146  * Commits should be parsed before accessing generation, graph positions.
147  */
148 uint32_t commit_graph_generation(const struct commit *);
149 uint32_t commit_graph_position(const struct commit *);
150 #endif