read-cache: update TEST_GIT_INDEX_VERSION support
[git/git.git] / preload-index.c
CommitLineData
671c9b7e
LT
1/*
2 * Copyright (C) 2008 Linus Torvalds
3 */
4#include "cache.h"
64acde94 5#include "pathspec.h"
429bb40a 6#include "dir.h"
883e248b 7#include "fsmonitor.h"
5aacc63f 8#include "config.h"
46059cc6
JH
9
10#ifdef NO_PTHREADS
5ab2a2da
NTND
11static void preload_index(struct index_state *index,
12 const struct pathspec *pathspec)
46059cc6
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13{
14 ; /* nothing */
15}
16#else
17
671c9b7e
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18#include <pthread.h>
19
20/*
21 * Mostly randomly chosen maximum thread counts: we
22 * cap the parallelism to 20 threads, and we want
23 * to have at least 500 lstat's per thread for it to
24 * be worth starting a thread.
25 */
26#define MAX_PARALLEL (20)
27#define THREAD_COST (500)
28
29struct thread_data {
30 pthread_t pthread;
31 struct index_state *index;
5ab2a2da 32 struct pathspec pathspec;
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33 int offset, nr;
34};
35
36static void *preload_thread(void *_data)
37{
38 int nr;
39 struct thread_data *p = _data;
40 struct index_state *index = p->index;
41 struct cache_entry **cep = index->cache + p->offset;
e7c73053 42 struct cache_def cache = CACHE_DEF_INIT;
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43
44 nr = p->nr;
45 if (nr + p->offset > index->cache_nr)
46 nr = index->cache_nr - p->offset;
47
48 do {
49 struct cache_entry *ce = *cep++;
50 struct stat st;
51
52 if (ce_stage(ce))
53 continue;
125fd984
JH
54 if (S_ISGITLINK(ce->ce_mode))
55 continue;
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56 if (ce_uptodate(ce))
57 continue;
e596acc2
JH
58 if (ce_skip_worktree(ce))
59 continue;
883e248b
BP
60 if (ce->ce_flags & CE_FSMONITOR_VALID)
61 continue;
f9beff03 62 if (!ce_path_match(index, ce, &p->pathspec, NULL))
671c9b7e 63 continue;
f62ce3de
LT
64 if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
65 continue;
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66 if (lstat(ce->name, &st))
67 continue;
883e248b 68 if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY|CE_MATCH_IGNORE_FSMONITOR))
671c9b7e
LT
69 continue;
70 ce_mark_uptodate(ce);
883e248b 71 mark_fsmonitor_valid(ce);
671c9b7e 72 } while (--nr > 0);
2a608391 73 cache_def_clear(&cache);
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74 return NULL;
75}
76
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NTND
77static void preload_index(struct index_state *index,
78 const struct pathspec *pathspec)
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79{
80 int threads, i, work, offset;
81 struct thread_data data[MAX_PARALLEL];
ca54d9ba 82 uint64_t start = getnanotime();
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83
84 if (!core_preload_index)
85 return;
86
87 threads = index->cache_nr / THREAD_COST;
5aacc63f 88 if ((index->cache_nr > 1) && (threads < 2) && git_env_bool("GIT_FORCE_PRELOAD_TEST", 0))
3e2c6696 89 threads = 2;
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90 if (threads < 2)
91 return;
92 if (threads > MAX_PARALLEL)
93 threads = MAX_PARALLEL;
94 offset = 0;
98cb6f30 95 work = DIV_ROUND_UP(index->cache_nr, threads);
5ab2a2da 96 memset(&data, 0, sizeof(data));
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97 for (i = 0; i < threads; i++) {
98 struct thread_data *p = data+i;
99 p->index = index;
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100 if (pathspec)
101 copy_pathspec(&p->pathspec, pathspec);
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102 p->offset = offset;
103 p->nr = work;
104 offset += work;
105 if (pthread_create(&p->pthread, NULL, preload_thread, p))
106 die("unable to create threaded lstat");
107 }
108 for (i = 0; i < threads; i++) {
109 struct thread_data *p = data+i;
110 if (pthread_join(p->pthread, NULL))
111 die("unable to join threaded lstat");
112 }
ca54d9ba 113 trace_performance_since(start, "preload index");
671c9b7e 114}
46059cc6 115#endif
671c9b7e 116
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117int read_index_preload(struct index_state *index,
118 const struct pathspec *pathspec)
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119{
120 int retval = read_index(index);
121
122 preload_index(index, pathspec);
123 return retval;
124}