pack-objects.con commit Merge branch 'jh/trace2-pretty-output' (93fc876)
   1#include "cache.h"
   2#include "object.h"
   3#include "pack.h"
   4#include "pack-objects.h"
   5#include "packfile.h"
   6#include "config.h"
   7
   8static uint32_t locate_object_entry_hash(struct packing_data *pdata,
   9                                         const struct object_id *oid,
  10                                         int *found)
  11{
  12        uint32_t i, mask = (pdata->index_size - 1);
  13
  14        i = oidhash(oid) & mask;
  15
  16        while (pdata->index[i] > 0) {
  17                uint32_t pos = pdata->index[i] - 1;
  18
  19                if (oideq(oid, &pdata->objects[pos].idx.oid)) {
  20                        *found = 1;
  21                        return i;
  22                }
  23
  24                i = (i + 1) & mask;
  25        }
  26
  27        *found = 0;
  28        return i;
  29}
  30
  31static inline uint32_t closest_pow2(uint32_t v)
  32{
  33        v = v - 1;
  34        v |= v >> 1;
  35        v |= v >> 2;
  36        v |= v >> 4;
  37        v |= v >> 8;
  38        v |= v >> 16;
  39        return v + 1;
  40}
  41
  42static void rehash_objects(struct packing_data *pdata)
  43{
  44        uint32_t i;
  45        struct object_entry *entry;
  46
  47        pdata->index_size = closest_pow2(pdata->nr_objects * 3);
  48        if (pdata->index_size < 1024)
  49                pdata->index_size = 1024;
  50
  51        free(pdata->index);
  52        pdata->index = xcalloc(pdata->index_size, sizeof(*pdata->index));
  53
  54        entry = pdata->objects;
  55
  56        for (i = 0; i < pdata->nr_objects; i++) {
  57                int found;
  58                uint32_t ix = locate_object_entry_hash(pdata,
  59                                                       &entry->idx.oid,
  60                                                       &found);
  61
  62                if (found)
  63                        BUG("Duplicate object in hash");
  64
  65                pdata->index[ix] = i + 1;
  66                entry++;
  67        }
  68}
  69
  70struct object_entry *packlist_find(struct packing_data *pdata,
  71                                   const struct object_id *oid)
  72{
  73        uint32_t i;
  74        int found;
  75
  76        if (!pdata->index_size)
  77                return NULL;
  78
  79        i = locate_object_entry_hash(pdata, oid, &found);
  80
  81        if (!found)
  82                return NULL;
  83
  84        return &pdata->objects[pdata->index[i] - 1];
  85}
  86
  87static void prepare_in_pack_by_idx(struct packing_data *pdata)
  88{
  89        struct packed_git **mapping, *p;
  90        int cnt = 0, nr = 1U << OE_IN_PACK_BITS;
  91
  92        ALLOC_ARRAY(mapping, nr);
  93        /*
  94         * oe_in_pack() on an all-zero'd object_entry
  95         * (i.e. in_pack_idx also zero) should return NULL.
  96         */
  97        mapping[cnt++] = NULL;
  98        for (p = get_all_packs(pdata->repo); p; p = p->next, cnt++) {
  99                if (cnt == nr) {
 100                        free(mapping);
 101                        return;
 102                }
 103                p->index = cnt;
 104                mapping[cnt] = p;
 105        }
 106        pdata->in_pack_by_idx = mapping;
 107}
 108
 109/*
 110 * A new pack appears after prepare_in_pack_by_idx() has been
 111 * run. This is likely a race.
 112 *
 113 * We could map this new pack to in_pack_by_idx[] array, but then we
 114 * have to deal with full array anyway. And since it's hard to test
 115 * this fall back code, just stay simple and fall back to using
 116 * in_pack[] array.
 117 */
 118void oe_map_new_pack(struct packing_data *pack)
 119{
 120        uint32_t i;
 121
 122        REALLOC_ARRAY(pack->in_pack, pack->nr_alloc);
 123
 124        for (i = 0; i < pack->nr_objects; i++)
 125                pack->in_pack[i] = oe_in_pack(pack, pack->objects + i);
 126
 127        FREE_AND_NULL(pack->in_pack_by_idx);
 128}
 129
 130/* assume pdata is already zero'd by caller */
 131void prepare_packing_data(struct repository *r, struct packing_data *pdata)
 132{
 133        pdata->repo = r;
 134
 135        if (git_env_bool("GIT_TEST_FULL_IN_PACK_ARRAY", 0)) {
 136                /*
 137                 * do not initialize in_pack_by_idx[] to force the
 138                 * slow path in oe_in_pack()
 139                 */
 140        } else {
 141                prepare_in_pack_by_idx(pdata);
 142        }
 143
 144        pdata->oe_size_limit = git_env_ulong("GIT_TEST_OE_SIZE",
 145                                             1U << OE_SIZE_BITS);
 146        pdata->oe_delta_size_limit = git_env_ulong("GIT_TEST_OE_DELTA_SIZE",
 147                                                   1UL << OE_DELTA_SIZE_BITS);
 148        init_recursive_mutex(&pdata->odb_lock);
 149}
 150
 151struct object_entry *packlist_alloc(struct packing_data *pdata,
 152                                    const struct object_id *oid)
 153{
 154        struct object_entry *new_entry;
 155
 156        if (pdata->nr_objects >= pdata->nr_alloc) {
 157                pdata->nr_alloc = (pdata->nr_alloc  + 1024) * 3 / 2;
 158                REALLOC_ARRAY(pdata->objects, pdata->nr_alloc);
 159
 160                if (!pdata->in_pack_by_idx)
 161                        REALLOC_ARRAY(pdata->in_pack, pdata->nr_alloc);
 162                if (pdata->delta_size)
 163                        REALLOC_ARRAY(pdata->delta_size, pdata->nr_alloc);
 164
 165                if (pdata->tree_depth)
 166                        REALLOC_ARRAY(pdata->tree_depth, pdata->nr_alloc);
 167
 168                if (pdata->layer)
 169                        REALLOC_ARRAY(pdata->layer, pdata->nr_alloc);
 170        }
 171
 172        new_entry = pdata->objects + pdata->nr_objects++;
 173
 174        memset(new_entry, 0, sizeof(*new_entry));
 175        oidcpy(&new_entry->idx.oid, oid);
 176
 177        if (pdata->index_size * 3 <= pdata->nr_objects * 4)
 178                rehash_objects(pdata);
 179        else {
 180                int found;
 181                uint32_t pos = locate_object_entry_hash(pdata,
 182                                                        &new_entry->idx.oid,
 183                                                        &found);
 184                if (found)
 185                        BUG("duplicate object inserted into hash");
 186                pdata->index[pos] = pdata->nr_objects;
 187        }
 188
 189        if (pdata->in_pack)
 190                pdata->in_pack[pdata->nr_objects - 1] = NULL;
 191
 192        if (pdata->tree_depth)
 193                pdata->tree_depth[pdata->nr_objects - 1] = 0;
 194
 195        if (pdata->layer)
 196                pdata->layer[pdata->nr_objects - 1] = 0;
 197
 198        return new_entry;
 199}
 200
 201void oe_set_delta_ext(struct packing_data *pdata,
 202                      struct object_entry *delta,
 203                      const unsigned char *sha1)
 204{
 205        struct object_entry *base;
 206
 207        ALLOC_GROW(pdata->ext_bases, pdata->nr_ext + 1, pdata->alloc_ext);
 208        base = &pdata->ext_bases[pdata->nr_ext++];
 209        memset(base, 0, sizeof(*base));
 210        hashcpy(base->idx.oid.hash, sha1);
 211
 212        /* These flags mark that we are not part of the actual pack output. */
 213        base->preferred_base = 1;
 214        base->filled = 1;
 215
 216        delta->ext_base = 1;
 217        delta->delta_idx = base - pdata->ext_bases + 1;
 218}