src/odb_mempack.c

   1 /*
   2  * Copyright (C) the libgit2 contributors. All rights reserved.
   3  *
   4  * This file is part of libgit2, distributed under the GNU GPL v2 with
   5  * a Linking Exception. For full terms see the included COPYING file.
   6  */
   7
   8 #include "common.h"
   9 #include "git2/object.h"
  10 #include "git2/sys/odb_backend.h"
  11 #include "fileops.h"
  12 #include "hash.h"
  13 #include "odb.h"
  14 #include "array.h"
  15 #include "oidmap.h"
  16
  17 #include "git2/odb_backend.h"
  18 #include "git2/types.h"
  19 #include "git2/pack.h"
  20
  21 GIT__USE_OIDMAP
  22
  23 struct memobject {
  24         git_oid oid;
  25         size_t len;
  26         git_otype type;
  27         char data[];
  28 };
  29
  30 struct memory_packer_db {
  31         git_odb_backend parent;
  32         git_oidmap *objects;
  33         git_array_t(struct memobject *) commits;
  34 };
  35
  36 static int impl__write(git_odb_backend *_backend, const git_oid *oid, const void *data, size_t len, git_otype type)
  37 {
  38         struct memory_packer_db *db = (struct memory_packer_db *)_backend;
  39         struct memobject *obj = NULL;
  40         khiter_t pos;
  41         size_t alloc_len;
  42         int rval;
  43
  44         pos = kh_put(oid, db->objects, oid, &rval);
  45         if (rval < 0)
  46                 return -1;
  47
  48         if (rval == 0)
  49                 return 0;
  50
  51         GITERR_CHECK_ALLOC_ADD(&alloc_len, sizeof(struct memobject), len);
  52         obj = git__malloc(alloc_len);
  53         GITERR_CHECK_ALLOC(obj);
  54
  55         memcpy(obj->data, data, len);
  56         git_oid_cpy(&obj->oid, oid);
  57         obj->len = len;
  58         obj->type = type;
  59
  60         kh_key(db->objects, pos) = &obj->oid;
  61         kh_val(db->objects, pos) = obj;
  62
  63         if (type == GIT_OBJ_COMMIT) {
  64                 struct memobject **store = git_array_alloc(db->commits);
  65                 GITERR_CHECK_ALLOC(store);
  66                 *store = obj;
  67         }
  68
  69         return 0;
  70 }
  71
  72 static int impl__exists(git_odb_backend *backend, const git_oid *oid)
  73 {
  74         struct memory_packer_db *db = (struct memory_packer_db *)backend;
  75         khiter_t pos;
  76
  77         pos = kh_get(oid, db->objects, oid);
  78         if (pos != kh_end(db->objects))
  79                 return 1;
  80
  81         return 0;
  82 }
  83
  84 static int impl__read(void **buffer_p, size_t *len_p, git_otype *type_p, git_odb_backend *backend, const git_oid *oid)
  85 {
  86         struct memory_packer_db *db = (struct memory_packer_db *)backend;
  87         struct memobject *obj = NULL;
  88         khiter_t pos;
  89
  90         pos = kh_get(oid, db->objects, oid);
  91         if (pos == kh_end(db->objects))
  92                 return GIT_ENOTFOUND;
  93
  94         obj = kh_val(db->objects, pos);
  95
  96         *len_p = obj->len;
  97         *type_p = obj->type;
  98         *buffer_p = git__malloc(obj->len);
  99         GITERR_CHECK_ALLOC(*buffer_p);
 100
 101         memcpy(*buffer_p, obj->data, obj->len);
 102         return 0;
 103 }
 104
 105 static int impl__read_header(size_t *len_p, git_otype *type_p, git_odb_backend *backend, const git_oid *oid)
 106 {
 107         struct memory_packer_db *db = (struct memory_packer_db *)backend;
 108         struct memobject *obj = NULL;
 109         khiter_t pos;
 110
 111         pos = kh_get(oid, db->objects, oid);
 112         if (pos == kh_end(db->objects))
 113                 return GIT_ENOTFOUND;
 114
 115         obj = kh_val(db->objects, pos);
 116
 117         *len_p = obj->len;
 118         *type_p = obj->type;
 119         return 0;
 120 }
 121
 122 int git_mempack_dump(git_buf *pack, git_repository *repo, git_odb_backend *_backend)
 123 {
 124         struct memory_packer_db *db = (struct memory_packer_db *)_backend;
 125         git_packbuilder *packbuilder;
 126         uint32_t i;
 127         int err = -1;
 128
 129         if (git_packbuilder_new(&packbuilder, repo) < 0)
 130                 return -1;
 131
 132         for (i = 0; i < db->commits.size; ++i) {
 133                 struct memobject *commit = db->commits.ptr[i];
 134
 135                 err = git_packbuilder_insert_commit(packbuilder, &commit->oid);
 136                 if (err < 0)
 137                         goto cleanup;
 138         }
 139
 140         err = git_packbuilder_write_buf(pack, packbuilder);
 141
 142 cleanup:
 143         git_packbuilder_free(packbuilder);
 144         return err;
 145 }
 146
 147 void git_mempack_reset(git_odb_backend *_backend)
 148 {
 149         struct memory_packer_db *db = (struct memory_packer_db *)_backend;
 150         struct memobject *object = NULL;
 151
 152         kh_foreach_value(db->objects, object, {
 153                 git__free(object);
 154         });
 155
 156         git_array_clear(db->commits);
 157
 158         git_oidmap_free(db->objects);
 159         db->objects = git_oidmap_alloc();
 160 }
 161
 162 static void impl__free(git_odb_backend *_backend)
 163 {
 164         git_mempack_reset(_backend);
 165         git__free(_backend);
 166 }
 167
 168 int git_mempack_new(git_odb_backend **out)
 169 {
 170         struct memory_packer_db *db;
 171
 172         assert(out);
 173
 174         db = git__calloc(1, sizeof(struct memory_packer_db));
 175         GITERR_CHECK_ALLOC(db);
 176
 177         db->objects = git_oidmap_alloc();
 178
 179         db->parent.read = &impl__read;
 180         db->parent.write = &impl__write;
 181         db->parent.read_header = &impl__read_header;
 182         db->parent.exists = &impl__exists;
 183         db->parent.free = &impl__free;
 184
 185         *out = (git_odb_backend *)db;
 186         return 0;
 187 }