Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "object.h"
   3#include "pack.h"
   4#include "pack-objects.h"
   5
   6static uint32_t locate_object_entry_hash(struct packing_data *pdata,
   7                                         const unsigned char *sha1,
   8                                         int *found)
   9{
  10        uint32_t i, mask = (pdata->index_size - 1);
  11
  12        i = sha1hash(sha1) & mask;
  13
  14        while (pdata->index[i] > 0) {
  15                uint32_t pos = pdata->index[i] - 1;
  16
  17                if (!hashcmp(sha1, pdata->objects[pos].idx.oid.hash)) {
  18                        *found = 1;
  19                        return i;
  20                }
  21
  22                i = (i + 1) & mask;
  23        }
  24
  25        *found = 0;
  26        return i;
  27}
  28
  29static inline uint32_t closest_pow2(uint32_t v)
  30{
  31        v = v - 1;
  32        v |= v >> 1;
  33        v |= v >> 2;
  34        v |= v >> 4;
  35        v |= v >> 8;
  36        v |= v >> 16;
  37        return v + 1;
  38}
  39
  40static void rehash_objects(struct packing_data *pdata)
  41{
  42        uint32_t i;
  43        struct object_entry *entry;
  44
  45        pdata->index_size = closest_pow2(pdata->nr_objects * 3);
  46        if (pdata->index_size < 1024)
  47                pdata->index_size = 1024;
  48
  49        free(pdata->index);
  50        pdata->index = xcalloc(pdata->index_size, sizeof(*pdata->index));
  51
  52        entry = pdata->objects;
  53
  54        for (i = 0; i < pdata->nr_objects; i++) {
  55                int found;
  56                uint32_t ix = locate_object_entry_hash(pdata,
  57                                                       entry->idx.oid.hash,
  58                                                       &found);
  59
  60                if (found)
  61                        die("BUG: Duplicate object in hash");
  62
  63                pdata->index[ix] = i + 1;
  64                entry++;
  65        }
  66}
  67
  68struct object_entry *packlist_find(struct packing_data *pdata,
  69                                   const unsigned char *sha1,
  70                                   uint32_t *index_pos)
  71{
  72        uint32_t i;
  73        int found;
  74
  75        if (!pdata->index_size)
  76                return NULL;
  77
  78        i = locate_object_entry_hash(pdata, sha1, &found);
  79
  80        if (index_pos)
  81                *index_pos = i;
  82
  83        if (!found)
  84                return NULL;
  85
  86        return &pdata->objects[pdata->index[i] - 1];
  87}
  88
  89struct object_entry *packlist_alloc(struct packing_data *pdata,
  90                                    const unsigned char *sha1,
  91                                    uint32_t index_pos)
  92{
  93        struct object_entry *new_entry;
  94
  95        if (pdata->nr_objects >= pdata->nr_alloc) {
  96                pdata->nr_alloc = (pdata->nr_alloc  + 1024) * 3 / 2;
  97                REALLOC_ARRAY(pdata->objects, pdata->nr_alloc);
  98        }
  99
 100        new_entry = pdata->objects + pdata->nr_objects++;
 101
 102        memset(new_entry, 0, sizeof(*new_entry));
 103        hashcpy(new_entry->idx.oid.hash, sha1);
 104
 105        if (pdata->index_size * 3 <= pdata->nr_objects * 4)
 106                rehash_objects(pdata);
 107        else
 108                pdata->index[index_pos] = pdata->nr_objects;
 109
 110        return new_entry;
 111}