reps-table.c

linux subdivision ying gai ke yi le ba

/* reps-table.c : operations on the `representations' table
 *
 * ====================================================================
 * Copyright (c) 2000-2004 CollabNet.  All rights reserved.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution.  The terms
 * are also available at http://subversion.tigris.org/license-1.html.
 * If newer versions of this license are posted there, you may use a
 * newer version instead, at your option.
 *
 * This software consists of voluntary contributions made by many
 * individuals.  For exact contribution history, see the revision
 * history and logs, available at http://subversion.tigris.org/.
 * ====================================================================
 */

#include "bdb_compat.h"
#include "svn_fs.h"
#include "../fs.h"
#include "../util/fs_skels.h"
#include "../err.h"
#include "dbt.h"
#include "../trail.h"
#include "../key-gen.h"
#include "../../libsvn_fs/fs-loader.h"
#include "bdb-err.h"
#include "reps-table.h"
#include "strings-table.h"



/*** Creating and opening the representations table. ***/

int
svn_fs_bdb__open_reps_table (DB **reps_p,
                             DB_ENV *env,
                             svn_boolean_t create)
{
  const u_int32_t open_flags = (create ? (DB_CREATE | DB_EXCL) : 0);
  DB *reps;

  BDB_ERR (svn_fs_bdb__check_version());
  BDB_ERR (db_create (&reps, env, 0));
  BDB_ERR (reps->open (SVN_BDB_OPEN_PARAMS(reps, NULL),
                      "representations", 0, DB_BTREE,
                      open_flags | SVN_BDB_AUTO_COMMIT,
                      0666));

  /* Create the `next-key' table entry.  */
  if (create)
  {
    DBT key, value;

    BDB_ERR (reps->put
            (reps, 0,
             svn_fs_base__str_to_dbt (&key, NEXT_KEY_KEY),
             svn_fs_base__str_to_dbt (&value, "0"),
             SVN_BDB_AUTO_COMMIT));
  }

  *reps_p = reps;
  return 0;
}



/*** Storing and retrieving reps.  ***/

svn_error_t *
svn_fs_bdb__read_rep (representation_t **rep_p,
                      svn_fs_t *fs,
                      const char *key,
                      trail_t *trail)
{
  base_fs_data_t *bfd = fs->fsap_data;
  skel_t *skel;
  int db_err;
  DBT query, result;

  svn_fs_base__trail_debug (trail, "representations", "get");
  db_err = bfd->representations->get
    (bfd->representations,
     trail->db_txn,
     svn_fs_base__str_to_dbt (&query, key),
     svn_fs_base__result_dbt (&result), 0);

  svn_fs_base__track_dbt (&result, trail->pool);

  /* If there's no such node, return an appropriately specific error.  */
  if (db_err == DB_NOTFOUND)
    return svn_error_createf
      (SVN_ERR_FS_NO_SUCH_REPRESENTATION, 0,
       "No such representation '%s'", key);

  /* Handle any other error conditions.  */
  SVN_ERR (BDB_WRAP (fs, "reading representation", db_err));

  /* Parse the REPRESENTATION skel.  */
  skel = svn_fs_base__parse_skel (result.data, result.size, trail->pool);

  /* Convert to a native type.  */
  SVN_ERR (svn_fs_base__parse_representation_skel (rep_p, skel, trail->pool));

  return SVN_NO_ERROR;
}


svn_error_t *
svn_fs_bdb__write_rep (svn_fs_t *fs,
                       const char *key,
                       const representation_t *rep,
                       trail_t *trail)
{
  base_fs_data_t *bfd = fs->fsap_data;
  DBT query, result;
  skel_t *skel;

  /* Convert from native type to skel. */
  SVN_ERR (svn_fs_base__unparse_representation_skel (&skel, rep, trail->pool));

  /* Now write the record. */
  svn_fs_base__trail_debug (trail, "representations", "put");
  SVN_ERR (BDB_WRAP (fs, "storing representation",
                     bfd->representations->put
                     (bfd->representations, trail->db_txn,
                      svn_fs_base__str_to_dbt (&query, key),
                      svn_fs_base__skel_to_dbt (&result, skel, trail->pool),
                      0)));

  return SVN_NO_ERROR;
}


svn_error_t *
svn_fs_bdb__write_new_rep (const char **key,
                           svn_fs_t *fs,
                           const representation_t *rep,
                           trail_t *trail)
{
  base_fs_data_t *bfd = fs->fsap_data;
  DBT query, result;
  int db_err;
  apr_size_t len;
  char next_key[MAX_KEY_SIZE];

  /* ### todo: see issue #409 for why bumping the key as part of this
     trail is problematic. */

  /* Get the current value associated with `next-key'.  */
  svn_fs_base__str_to_dbt (&query, NEXT_KEY_KEY);
  svn_fs_base__trail_debug (trail, "representations", "get");
  SVN_ERR (BDB_WRAP (fs, "allocating new representation (getting next-key)",
                     bfd->representations->get
                     (bfd->representations, trail->db_txn, &query,
                      svn_fs_base__result_dbt (&result), 0)));

  svn_fs_base__track_dbt (&result, trail->pool);

  /* Store the new rep. */
  *key = apr_pstrmemdup (trail->pool, result.data, result.size);
  SVN_ERR (svn_fs_bdb__write_rep (fs, *key, rep, trail));

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

  SVN_ERR (BDB_WRAP (fs, "bumping next representation key", db_err));

  return SVN_NO_ERROR;
}


svn_error_t *
svn_fs_bdb__delete_rep (svn_fs_t *fs, const char *key, trail_t *trail)
{
  base_fs_data_t *bfd = fs->fsap_data;
  int db_err;
  DBT query;

  svn_fs_base__trail_debug (trail, "representations", "del");
  db_err = bfd->representations->del
    (bfd->representations, trail->db_txn,
     svn_fs_base__str_to_dbt (&query, key), 0);

  /* If there's no such node, return an appropriately specific error.  */
  if (db_err == DB_NOTFOUND)
    return svn_error_createf
      (SVN_ERR_FS_NO_SUCH_REPRESENTATION, 0,
       "No such representation '%s'", key);

  /* Handle any other error conditions.  */
  SVN_ERR (BDB_WRAP (fs, "deleting representation", db_err));

  return SVN_NO_ERROR;
}