Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
		
			
				
	
	
		
			110 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			110 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (C) 2008 Linus Torvalds
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 */
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#include "cache.h"
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#ifdef NO_PTHREADS
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static void preload_index(struct index_state *index, const char **pathspec)
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{
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	; /* nothing */
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}
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#else
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#include <pthread.h>
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/*
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 * Mostly randomly chosen maximum thread counts: we
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 * cap the parallelism to 20 threads, and we want
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 * to have at least 500 lstat's per thread for it to
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 * be worth starting a thread.
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 */
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#define MAX_PARALLEL (20)
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#define THREAD_COST (500)
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struct thread_data {
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	pthread_t pthread;
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	struct index_state *index;
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	const char **pathspec;
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	int offset, nr;
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};
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static void *preload_thread(void *_data)
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{
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	int nr;
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	struct thread_data *p = _data;
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	struct index_state *index = p->index;
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	struct cache_entry **cep = index->cache + p->offset;
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	struct cache_def cache;
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	struct pathspec pathspec;
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	init_pathspec(&pathspec, p->pathspec);
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	memset(&cache, 0, sizeof(cache));
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	nr = p->nr;
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	if (nr + p->offset > index->cache_nr)
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		nr = index->cache_nr - p->offset;
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	do {
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		struct cache_entry *ce = *cep++;
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		struct stat st;
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		if (ce_stage(ce))
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			continue;
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		if (S_ISGITLINK(ce->ce_mode))
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			continue;
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		if (ce_uptodate(ce))
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			continue;
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		if (!ce_path_match(ce, &pathspec))
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			continue;
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		if (threaded_has_symlink_leading_path(&cache, ce->name, ce_namelen(ce)))
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			continue;
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		if (lstat(ce->name, &st))
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			continue;
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		if (ie_match_stat(index, ce, &st, CE_MATCH_RACY_IS_DIRTY))
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			continue;
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		ce_mark_uptodate(ce);
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	} while (--nr > 0);
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	free_pathspec(&pathspec);
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	return NULL;
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}
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static void preload_index(struct index_state *index, const char **pathspec)
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{
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	int threads, i, work, offset;
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	struct thread_data data[MAX_PARALLEL];
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	if (!core_preload_index)
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		return;
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	threads = index->cache_nr / THREAD_COST;
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	if (threads < 2)
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		return;
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	if (threads > MAX_PARALLEL)
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		threads = MAX_PARALLEL;
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	offset = 0;
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	work = DIV_ROUND_UP(index->cache_nr, threads);
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	for (i = 0; i < threads; i++) {
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		struct thread_data *p = data+i;
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		p->index = index;
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		p->pathspec = pathspec;
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		p->offset = offset;
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		p->nr = work;
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		offset += work;
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		if (pthread_create(&p->pthread, NULL, preload_thread, p))
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			die("unable to create threaded lstat");
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	}
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	for (i = 0; i < threads; i++) {
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		struct thread_data *p = data+i;
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		if (pthread_join(p->pthread, NULL))
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			die("unable to join threaded lstat");
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	}
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}
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#endif
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int read_index_preload(struct index_state *index, const char **pathspec)
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{
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	int retval = read_index(index);
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	preload_index(index, pathspec);
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	return retval;
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}
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