pseudo-merge.h · leroysheep/Socializer

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1	#ifndef PSEUDO_MERGE_H
2	#define PSEUDO_MERGE_H
3
4	#include "git-compat-util.h"
5	#include "strmap.h"
6	#include "khash.h"
7	#include "ewah/ewok.h"
8
9	struct commit;
10	struct string_list;
11	struct bitmap_index;
12	struct bitmap_writer;
13	struct repository;
14
15	/*
16	* A pseudo-merge group tracks the set of non-bitmapped reference tips
17	* that match the given pattern.
18	*
19	* Within those matches, they are further segmented by separating
20	* consecutive capture groups with '-' dash character capture groups
21	* with '-' dash characters.
22	*
23	* Those groups are then ordered by committer date and partitioned
24	* into individual pseudo-merge(s) according to the decay, max_merges,
25	* sample_rate, and threshold parameters.
26	*/
27	struct pseudo_merge_group {
28	regex_t *pattern;
29
30	/* capture group(s) -> struct pseudo_merge_matches */
31	struct strmap matches;
32
33	/*
34	* The individual pseudo-merge(s) that are generated from the
35	* above array of matches, partitioned according to the below
36	* parameters.
37	*/
38	struct commit **merges;
39	size_t merges_nr;
40	size_t merges_alloc;
41
42	/*
43	* Pseudo-merge grouping parameters. See git-config(1) for
44	* more information.
45	*/
46	double decay;
47	int max_merges;
48	double sample_rate;
49	int stable_size;
50	timestamp_t threshold;
51	timestamp_t stable_threshold;
52	};
53
54	void pseudo_merge_group_release(struct pseudo_merge_group *group);
55
56	struct pseudo_merge_matches {
57	struct commit **stable;
58	struct commit **unstable;
59	size_t stable_nr, stable_alloc;
60	size_t unstable_nr, unstable_alloc;
61	};
62
63	/*
64	* Read the repository's configuration:
65	*
66	* - bitmapPseudoMerge.<name>.pattern
67	* - bitmapPseudoMerge.<name>.decay
68	* - bitmapPseudoMerge.<name>.sampleRate
69	* - bitmapPseudoMerge.<name>.threshold
70	* - bitmapPseudoMerge.<name>.maxMerges
71	* - bitmapPseudoMerge.<name>.stableThreshold
72	* - bitmapPseudoMerge.<name>.stableSize
73	*
74	* and populates the given `list` with pseudo-merge groups. String
75	* entry keys are the pseudo-merge group names, and the values are
76	* pointers to the pseudo_merge_group structure itself.
77	*/
78	void load_pseudo_merges_from_config(struct repository r, struct string_list list);
79
80	/*
81	* A pseudo-merge commit index (pseudo_merge_commit_idx) maps a
82	* particular (non-pseudo-merge) commit to the list of pseudo-merge(s)
83	* it appears in.
84	*/
85	struct pseudo_merge_commit_idx {
86	uint32_t *pseudo_merge;
87	size_t nr, alloc;
88	};
89
90	/*
91	* Selects pseudo-merges from a list of commits, populating the given
92	* string_list of pseudo-merge groups.
93	*
94	* Populates the pseudo_merge_commits map with a commit_idx
95	* corresponding to each commit in the list. Counts the total number
96	* of pseudo-merges generated.
97	*
98	* Optionally shows a progress meter.
99	*/
100	void select_pseudo_merges(struct bitmap_writer *writer);
101
102	/*
103	* Represents a serialized view of a file containing pseudo-merge(s)
104	* (see Documentation/technical/bitmap-format.adoc for a specification
105	* of the format).
106	*/
107	struct pseudo_merge_map {
108	/*
109	* An array of pseudo-merge(s), lazily loaded from the .bitmap
110	* file.
111	*/
112	struct pseudo_merge *v;
113	size_t nr;
114	size_t commits_nr;
115
116	/*
117	* Pointers into a memory-mapped view of the .bitmap file:
118	*
119	* - map: the beginning of the .bitmap file
120	* - commits: the beginning of the pseudo-merge commit index
121	* - map_size: the size of the .bitmap file
122	*/
123	const unsigned char *map;
124	const unsigned char *commits;
125
126	size_t map_size;
127	};
128
129	/*
130	* An individual pseudo-merge, storing a pair of lazily-loaded
131	* bitmaps:
132	*
133	* - commits: the set of commit(s) that are part of the pseudo-merge
134	* - bitmap: the set of object(s) reachable from the above set of
135	* commits.
136	*
137	* The `at` and `bitmap_at` fields are used to store the locations of
138	* each of the above bitmaps in the .bitmap file.
139	*/
140	struct pseudo_merge {
141	struct ewah_bitmap *commits;
142	struct ewah_bitmap *bitmap;
143
144	off_t at;
145	off_t bitmap_at;
146
147	/*
148	* `satisfied` indicates whether the given pseudo-merge has been
149	* used.
150	*
151	* `loaded_commits` and `loaded_bitmap` indicate whether the
152	* respective bitmaps have been loaded and read from the
153	* .bitmap file.
154	*/
155	unsigned satisfied : 1,
156	loaded_commits : 1,
157	loaded_bitmap : 1;
158	};
159
160	/*
161	* Frees the given pseudo-merge map, releasing any memory held by (a)
162	* parsed EWAH bitmaps, or (b) the array of pseudo-merges itself. Does
163	* not free the memory-mapped view of the .bitmap file.
164	*/
165	void free_pseudo_merge_map(struct pseudo_merge_map *pm);
166
167	/*
168	* Loads the bitmap corresponding to the given pseudo-merge from the
169	* map, if it has not already been loaded.
170	*/
171	struct ewah_bitmap pseudo_merge_bitmap(const struct pseudo_merge_map pm,
172	struct pseudo_merge *merge);
173
174	/*
175	* Loads the pseudo-merge and its commits bitmap from the given
176	* pseudo-merge map, if it has not already been loaded.
177	*/
178	struct pseudo_merge use_pseudo_merge(const struct pseudo_merge_map pm,
179	struct pseudo_merge *merge);
180
181	/*
182	* Applies pseudo-merge(s) containing the given commit to the bitmap
183	* "result".
184	*
185	* If any pseudo-merge(s) were satisfied, returns the number
186	* satisfied, otherwise returns 0. If any were satisfied, the
187	* remaining unsatisfied pseudo-merges are cascaded (see below).
188	*/
189	int apply_pseudo_merges_for_commit(const struct pseudo_merge_map *pm,
190	struct bitmap *result,
191	struct commit *commit, uint32_t commit_pos);
192
193	/*
194	* Applies pseudo-merge(s) which are satisfied according to the
195	* current bitmap in result (or roots, see below). If any
196	* pseudo-merges were satisfied, repeat the process over unsatisfied
197	* pseudo-merge commits until no more pseudo-merges are satisfied.
198	*
199	* Result is the bitmap to which the pseudo-merge(s) are applied.
200	* Roots (if given) is a bitmap of the traversal tip(s) for either
201	* side of a reachability traversal.
202	*
203	* Roots may given instead of a populated results bitmap at the
204	* beginning of a traversal on either side where the reachability
205	* closure over tips is not yet known.
206	*/
207	int cascade_pseudo_merges(const struct pseudo_merge_map *pm,
208	struct bitmap *result,
209	struct bitmap *roots);
210
211	/*
212	* Returns a pseudo-merge which contains the exact set of commits
213	* listed in the "parents" bitmap, or NULL if none could be found.
214	*/
215	struct pseudo_merge pseudo_merge_for_parents(const struct pseudo_merge_map pm,
216	struct bitmap *parents);
217
218	#endif