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 struct commit_graph *parse_commit_graph(struct repository *r,
97 					void *graph_map, size_t graph_size);
98 
99 /*
100  * Return 1 if and only if the repository has a commit-graph
101  * file and generation numbers are computed in that file.
102  */
103 int generation_numbers_enabled(struct repository *r);
104 
105 /*
106  * Return 1 if and only if the repository has a commit-graph
107  * file and generation data chunk has been written for the file.
108  */
109 int corrected_commit_dates_enabled(struct repository *r);
110 
111 struct bloom_filter_settings *get_bloom_filter_settings(struct repository *r);
112 
113 enum commit_graph_write_flags {
114 	COMMIT_GRAPH_WRITE_APPEND     = (1 << 0),
115 	COMMIT_GRAPH_WRITE_PROGRESS   = (1 << 1),
116 	COMMIT_GRAPH_WRITE_SPLIT      = (1 << 2),
117 	COMMIT_GRAPH_WRITE_BLOOM_FILTERS = (1 << 3),
118 	COMMIT_GRAPH_NO_WRITE_BLOOM_FILTERS = (1 << 4),
119 };
120 
121 enum commit_graph_split_flags {
122 	COMMIT_GRAPH_SPLIT_UNSPECIFIED      = 0,
123 	COMMIT_GRAPH_SPLIT_MERGE_PROHIBITED = 1,
124 	COMMIT_GRAPH_SPLIT_REPLACE          = 2
125 };
126 
127 struct commit_graph_opts {
128 	int size_multiple;
129 	int max_commits;
130 	timestamp_t expire_time;
131 	enum commit_graph_split_flags split_flags;
132 	int max_new_filters;
133 };
134 
135 /*
136  * The write_commit_graph* methods return zero on success
137  * and a negative value on failure. Note that if the repository
138  * is not compatible with the commit-graph feature, then the
139  * methods will return 0 without writing a commit-graph.
140  */
141 int write_commit_graph_reachable(struct object_directory *odb,
142 				 enum commit_graph_write_flags flags,
143 				 const struct commit_graph_opts *opts);
144 int write_commit_graph(struct object_directory *odb,
145 		       struct string_list *pack_indexes,
146 		       struct oidset *commits,
147 		       enum commit_graph_write_flags flags,
148 		       const struct commit_graph_opts *opts);
149 
150 #define COMMIT_GRAPH_VERIFY_SHALLOW	(1 << 0)
151 
152 int verify_commit_graph(struct repository *r, struct commit_graph *g, int flags);
153 
154 void close_commit_graph(struct raw_object_store *);
155 void free_commit_graph(struct commit_graph *);
156 
157 /*
158  * Disable further use of the commit graph in this process when parsing a
159  * "struct commit".
160  */
161 void disable_commit_graph(struct repository *r);
162 
163 struct commit_graph_data {
164 	uint32_t graph_pos;
165 	timestamp_t generation;
166 };
167 
168 /*
169  * Commits should be parsed before accessing generation, graph positions.
170  */
171 timestamp_t commit_graph_generation(const struct commit *);
172 uint32_t commit_graph_position(const struct commit *);
173 #endif
174