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
  10 #include "git2/object.h"
  11 #include "git2/sys/odb_backend.h"
  12 #include "git2/sys/mempack.h"
  13 #include "fileops.h"
  14 #include "hash.h"
  15 #include "odb.h"
  16 #include "array.h"
  17 #include "oidmap.h"
  18
  19 #include "git2/odb_backend.h"
  20 #include "git2/types.h"
  21 #include "git2/pack.h"
  22
  23 struct memobject {
  24         git_oid oid;
  25         size_t len;
  26         git_object_t type;
  27         char data[GIT_FLEX_ARRAY];
  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_object_t type)
  37 {
  38         struct memory_packer_db *db = (struct memory_packer_db *)_backend;
  39         struct memobject *obj = NULL;
  40         size_t pos;
  41         size_t alloc_len;
  42         int rval;
  43
  44         pos = git_oidmap_put(db->objects, oid, &rval);
  45         if (rval < 0)
  46                 return -1;
  47
  48         if (rval == 0)
  49                 return 0;
  50
  51         GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, sizeof(struct memobject), len);
  52         obj = git__malloc(alloc_len);
  53         GIT_ERROR_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         git_oidmap_set_key_at(db->objects, pos, &obj->oid);
  61         git_oidmap_set_value_at(db->objects, pos, obj);
  62
  63         if (type == GIT_OBJECT_COMMIT) {
  64                 struct memobject **store = git_array_alloc(db->commits);
  65                 GIT_ERROR_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
  76         return git_oidmap_exists(db->objects, oid);
  77 }
  78
  79 static int impl__read(void **buffer_p, size_t *len_p, git_object_t *type_p, git_odb_backend *backend, const git_oid *oid)
  80 {
  81         struct memory_packer_db *db = (struct memory_packer_db *)backend;
  82         struct memobject *obj = NULL;
  83         size_t pos;
  84
  85         pos = git_oidmap_lookup_index(db->objects, oid);
  86         if (!git_oidmap_valid_index(db->objects, pos))
  87                 return GIT_ENOTFOUND;
  88
  89         obj = git_oidmap_value_at(db->objects, pos);
  90
  91         *len_p = obj->len;
  92         *type_p = obj->type;
  93         *buffer_p = git__malloc(obj->len);
  94         GIT_ERROR_CHECK_ALLOC(*buffer_p);
  95
  96         memcpy(*buffer_p, obj->data, obj->len);
  97         return 0;
  98 }
  99
 100 static int impl__read_header(size_t *len_p, git_object_t *type_p, git_odb_backend *backend, const git_oid *oid)
 101 {
 102         struct memory_packer_db *db = (struct memory_packer_db *)backend;
 103         struct memobject *obj = NULL;
 104         size_t pos;
 105
 106         pos = git_oidmap_lookup_index(db->objects, oid);
 107         if (!git_oidmap_valid_index(db->objects, pos))
 108                 return GIT_ENOTFOUND;
 109
 110         obj = git_oidmap_value_at(db->objects, pos);
 111
 112         *len_p = obj->len;
 113         *type_p = obj->type;
 114         return 0;
 115 }
 116
 117 int git_mempack_dump(git_buf *pack, git_repository *repo, git_odb_backend *_backend)
 118 {
 119         struct memory_packer_db *db = (struct memory_packer_db *)_backend;
 120         git_packbuilder *packbuilder;
 121         uint32_t i;
 122         int err = -1;
 123
 124         if (git_packbuilder_new(&packbuilder, repo) < 0)
 125                 return -1;
 126
 127         for (i = 0; i < db->commits.size; ++i) {
 128                 struct memobject *commit = db->commits.ptr[i];
 129
 130                 err = git_packbuilder_insert_commit(packbuilder, &commit->oid);
 131                 if (err < 0)
 132                         goto cleanup;
 133         }
 134
 135         err = git_packbuilder_write_buf(pack, packbuilder);
 136
 137 cleanup:
 138         git_packbuilder_free(packbuilder);
 139         return err;
 140 }
 141
 142 void git_mempack_reset(git_odb_backend *_backend)
 143 {
 144         struct memory_packer_db *db = (struct memory_packer_db *)_backend;
 145         struct memobject *object = NULL;
 146
 147         git_oidmap_foreach_value(db->objects, object, {
 148                 git__free(object);
 149         });
 150
 151         git_array_clear(db->commits);
 152
 153         git_oidmap_clear(db->objects);
 154 }
 155
 156 static void impl__free(git_odb_backend *_backend)
 157 {
 158         struct memory_packer_db *db = (struct memory_packer_db *)_backend;
 159
 160         git_mempack_reset(_backend);
 161         git_oidmap_free(db->objects);
 162         git__free(db);
 163 }
 164
 165 int git_mempack_new(git_odb_backend **out)
 166 {
 167         struct memory_packer_db *db;
 168
 169         assert(out);
 170
 171         db = git__calloc(1, sizeof(struct memory_packer_db));
 172         GIT_ERROR_CHECK_ALLOC(db);
 173
 174         db->objects = git_oidmap_alloc();
 175
 176         db->parent.version = GIT_ODB_BACKEND_VERSION;
 177         db->parent.read = &impl__read;
 178         db->parent.write = &impl__write;
 179         db->parent.read_header = &impl__read_header;
 180         db->parent.exists = &impl__exists;
 181         db->parent.free = &impl__free;
 182
 183         *out = (git_odb_backend *)db;
 184         return 0;
 185 }