/* copies-table.c : operations on the `copies' table
 *
 * ====================================================================
 *    Licensed to the Apache Software Foundation (ASF) under one
 *    or more contributor license agreements.  See the NOTICE file
 *    distributed with this work for additional information
 *    regarding copyright ownership.  The ASF licenses this file
 *    to you under the Apache License, Version 2.0 (the
 *    "License"); you may not use this file except in compliance
 *    with the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing,
 *    software distributed under the License is distributed on an
 *    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *    KIND, either express or implied.  See the License for the
 *    specific language governing permissions and limitations
 *    under the License.
 * ====================================================================
 */

#include <string.h>

#include "bdb_compat.h"

#include "private/svn_skel.h"

#include "../fs.h"
#include "../err.h"
#include "../key-gen.h"
#include "dbt.h"
#include "../util/fs_skels.h"
#include "../trail.h"
#include "../../libsvn_fs/fs-loader.h"
#include "bdb-err.h"
#include "copies-table.h"
#include "rev-table.h"

#include "svn_private_config.h"


int
svn_fs_bdb__open_copies_table(DB **copies_p,
                              DB_ENV *env,
                              svn_boolean_t create)
{
  const u_int32_t open_flags = (create ? (DB_CREATE | DB_EXCL) : 0);
  DB *copies;

  BDB_ERR(svn_fs_bdb__check_version());
  BDB_ERR(db_create(&copies, env, 0));
  BDB_ERR((copies->open)(SVN_BDB_OPEN_PARAMS(copies, NULL),
                         "copies", 0, DB_BTREE,
                         open_flags, 0666));

  /* Create the initial `next-key' table entry.  */
  if (create)
  {
    DBT key, value;
    BDB_ERR(copies->put(copies, 0,
                        svn_fs_base__str_to_dbt(&key, NEXT_KEY_KEY),
                        svn_fs_base__str_to_dbt(&value, "0"), 0));
  }

  *copies_p = copies;
  return 0;
}


/* Store COPY as a copy named COPY_ID in FS as part of TRAIL.  */
/* ### only has one caller; might not need to be abstracted */
static svn_error_t *
put_copy(svn_fs_t *fs,
         const copy_t *copy,
         const char *copy_id,
         trail_t *trail,
         apr_pool_t *pool)
{
  base_fs_data_t *bfd = fs->fsap_data;
  svn_skel_t *copy_skel;
  DBT key, value;

  /* Convert native type to skel. */
  SVN_ERR(svn_fs_base__unparse_copy_skel(&copy_skel, copy, pool));

  /* Only in the context of this function do we know that the DB call
     will not attempt to modify COPY_ID, so the cast belongs here.  */
  svn_fs_base__str_to_dbt(&key, copy_id);
  svn_fs_base__skel_to_dbt(&value, copy_skel, pool);
  svn_fs_base__trail_debug(trail, "copies", "put");
  return BDB_WRAP(fs, N_("storing copy record"),
                  bfd->copies->put(bfd->copies, trail->db_txn,
                                   &key, &value, 0));
}


svn_error_t *
svn_fs_bdb__reserve_copy_id(const char **id_p,
                            svn_fs_t *fs,
                            trail_t *trail,
                            apr_pool_t *pool)
{
  base_fs_data_t *bfd = fs->fsap_data;
  DBT query, result;
  apr_size_t len;
  char next_key[MAX_KEY_SIZE];
  int db_err;

  svn_fs_base__str_to_dbt(&query, NEXT_KEY_KEY);

  /* Get the current value associated with the `next-key' key in the
     copies table.  */
  svn_fs_base__trail_debug(trail, "copies", "get");
  SVN_ERR(BDB_WRAP(fs, N_("allocating new copy ID (getting 'next-key')"),
                   bfd->copies->get(bfd->copies, trail->db_txn, &query,
                                    svn_fs_base__result_dbt(&result),
                                    0)));
  svn_fs_base__track_dbt(&result, pool);

  /* Set our return value. */
  *id_p = apr_pstrmemdup(pool, result.data, result.size);

  /* Bump to future key. */
  len = result.size;
  svn_fs_base__next_key(result.data, &len, next_key);
  svn_fs_base__trail_debug(trail, "copies", "put");
  db_err = bfd->copies->put(bfd->copies, trail->db_txn,
                            svn_fs_base__str_to_dbt(&query, NEXT_KEY_KEY),
                            svn_fs_base__str_to_dbt(&result, next_key),
                            0);

  return BDB_WRAP(fs, N_("bumping next copy key"), db_err);
}


svn_error_t *
svn_fs_bdb__create_copy(svn_fs_t *fs,
                        const char *copy_id,
                        const char *src_path,
                        const char *src_txn_id,
                        const svn_fs_id_t *dst_noderev_id,
                        copy_kind_t kind,
                        trail_t *trail,
                        apr_pool_t *pool)
{
  copy_t copy;
  copy.kind = kind;
  copy.src_path = src_path;
  copy.src_txn_id = src_txn_id;
  copy.dst_noderev_id = dst_noderev_id;
  return put_copy(fs, &copy, copy_id, trail, pool);
}


svn_error_t *
svn_fs_bdb__delete_copy(svn_fs_t *fs,
                        const char *copy_id,
                        trail_t *trail,
                        apr_pool_t *pool)
{
  base_fs_data_t *bfd = fs->fsap_data;
  DBT key;
  int db_err;

  svn_fs_base__str_to_dbt(&key, copy_id);
  svn_fs_base__trail_debug(trail, "copies", "del");
  db_err = bfd->copies->del(bfd->copies, trail->db_txn, &key, 0);
  if (db_err == DB_NOTFOUND)
    return svn_fs_base__err_no_such_copy(fs, copy_id);
  return BDB_WRAP(fs, N_("deleting entry from 'copies' table"), db_err);
}


svn_error_t *
svn_fs_bdb__get_copy(copy_t **copy_p,
                     svn_fs_t *fs,
                     const char *copy_id,
                     trail_t *trail,
                     apr_pool_t *pool)
{
  base_fs_data_t *bfd = fs->fsap_data;
  DBT key, value;
  int db_err;
  svn_skel_t *skel;
  copy_t *copy;

  /* Only in the context of this function do we know that the DB call
     will not attempt to modify copy_id, so the cast belongs here.  */
  svn_fs_base__trail_debug(trail, "copies", "get");
  db_err = bfd->copies->get(bfd->copies, trail->db_txn,
                            svn_fs_base__str_to_dbt(&key, copy_id),
                            svn_fs_base__result_dbt(&value),
                            0);
  svn_fs_base__track_dbt(&value, pool);

  if (db_err == DB_NOTFOUND)
    return svn_fs_base__err_no_such_copy(fs, copy_id);
  SVN_ERR(BDB_WRAP(fs, N_("reading copy"), db_err));

  /* Unparse COPY skel */
  skel = svn_skel__parse(value.data, value.size, pool);
  if (! skel)
    return svn_fs_base__err_corrupt_copy(fs, copy_id);

  /* Convert skel to native type. */
  SVN_ERR(svn_fs_base__parse_copy_skel(&copy, skel, pool));
  *copy_p = copy;
  return SVN_NO_ERROR;
}