112 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
			
		
		
	
	
			112 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
| #include "cache.h"
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| #include "object.h"
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| #include "pack.h"
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| #include "pack-objects.h"
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| 
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| static uint32_t locate_object_entry_hash(struct packing_data *pdata,
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| 					 const unsigned char *sha1,
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| 					 int *found)
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| {
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| 	uint32_t i, hash, mask = (pdata->index_size - 1);
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| 
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| 	memcpy(&hash, sha1, sizeof(uint32_t));
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| 	i = hash & mask;
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| 
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| 	while (pdata->index[i] > 0) {
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| 		uint32_t pos = pdata->index[i] - 1;
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| 
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| 		if (!hashcmp(sha1, pdata->objects[pos].idx.sha1)) {
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| 			*found = 1;
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| 			return i;
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| 		}
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| 
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| 		i = (i + 1) & mask;
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| 	}
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| 
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| 	*found = 0;
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| 	return i;
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| }
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| 
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| static inline uint32_t closest_pow2(uint32_t v)
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| {
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| 	v = v - 1;
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| 	v |= v >> 1;
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| 	v |= v >> 2;
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| 	v |= v >> 4;
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| 	v |= v >> 8;
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| 	v |= v >> 16;
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| 	return v + 1;
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| }
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| 
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| static void rehash_objects(struct packing_data *pdata)
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| {
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| 	uint32_t i;
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| 	struct object_entry *entry;
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| 
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| 	pdata->index_size = closest_pow2(pdata->nr_objects * 3);
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| 	if (pdata->index_size < 1024)
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| 		pdata->index_size = 1024;
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| 
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| 	pdata->index = xrealloc(pdata->index, sizeof(uint32_t) * pdata->index_size);
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| 	memset(pdata->index, 0, sizeof(int) * pdata->index_size);
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| 
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| 	entry = pdata->objects;
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| 
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| 	for (i = 0; i < pdata->nr_objects; i++) {
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| 		int found;
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| 		uint32_t ix = locate_object_entry_hash(pdata, entry->idx.sha1, &found);
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| 
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| 		if (found)
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| 			die("BUG: Duplicate object in hash");
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| 
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| 		pdata->index[ix] = i + 1;
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| 		entry++;
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| 	}
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| }
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| 
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| struct object_entry *packlist_find(struct packing_data *pdata,
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| 				   const unsigned char *sha1,
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| 				   uint32_t *index_pos)
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| {
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| 	uint32_t i;
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| 	int found;
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| 
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| 	if (!pdata->index_size)
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| 		return NULL;
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| 
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| 	i = locate_object_entry_hash(pdata, sha1, &found);
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| 
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| 	if (index_pos)
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| 		*index_pos = i;
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| 
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| 	if (!found)
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| 		return NULL;
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| 
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| 	return &pdata->objects[pdata->index[i] - 1];
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| }
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| 
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| struct object_entry *packlist_alloc(struct packing_data *pdata,
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| 				    const unsigned char *sha1,
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| 				    uint32_t index_pos)
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| {
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| 	struct object_entry *new_entry;
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| 
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| 	if (pdata->nr_objects >= pdata->nr_alloc) {
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| 		pdata->nr_alloc = (pdata->nr_alloc  + 1024) * 3 / 2;
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| 		pdata->objects = xrealloc(pdata->objects,
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| 					  pdata->nr_alloc * sizeof(*new_entry));
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| 	}
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| 
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| 	new_entry = pdata->objects + pdata->nr_objects++;
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| 
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| 	memset(new_entry, 0, sizeof(*new_entry));
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| 	hashcpy(new_entry->idx.sha1, sha1);
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| 
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| 	if (pdata->index_size * 3 <= pdata->nr_objects * 4)
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| 		rehash_objects(pdata);
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| 	else
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| 		pdata->index[index_pos] = pdata->nr_objects;
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| 
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| 	return new_entry;
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| }
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