lock.c

subversion-1.4.3-1.tar.gz 配置svn的源码

  const char *token;
  svn_boolean_t break_lock;
};


static svn_error_t *
txn_body_unlock(void *baton, trail_t *trail)
{
  struct unlock_args *args = baton;
  const char *lock_token;
  svn_lock_t *lock;

  /* This could return SVN_ERR_FS_BAD_LOCK_TOKEN or SVN_ERR_FS_LOCK_EXPIRED. */
  SVN_ERR(svn_fs_bdb__lock_token_get(&lock_token, trail->fs, args->path,
                                     trail, trail->pool));

  /* If not breaking the lock, we need to do some more checking. */
  if (!args->break_lock)
    {
      /* Sanity check: The lock token must exist, and must match. */
      if (args->token == NULL)
        return svn_fs_base__err_no_lock_token(trail->fs, args->path);
      else if (strcmp(lock_token, args->token) != 0)
        return svn_fs_base__err_no_such_lock(trail->fs, args->path);

      SVN_ERR(svn_fs_bdb__lock_get(&lock, trail->fs, lock_token, 
                                   trail, trail->pool));

      /* There better be a username attached to the fs. */
      if (!trail->fs->access_ctx || !trail->fs->access_ctx->username)
        return svn_fs_base__err_no_user(trail->fs);

      /* And that username better be the same as the lock's owner. */
      if (strcmp(trail->fs->access_ctx->username, lock->owner) != 0)
        return svn_fs_base__err_lock_owner_mismatch
          (trail->fs,
           trail->fs->access_ctx->username,
           lock->owner);
    }

  /* Remove a row from each of the locking tables. */
  SVN_ERR(delete_lock_and_token(lock_token, args->path, trail));
  return SVN_NO_ERROR;
}


svn_error_t *
svn_fs_base__unlock(svn_fs_t *fs,
                    const char *path,
                    const char *token,
                    svn_boolean_t break_lock,
                    apr_pool_t *pool)
{
  struct unlock_args args;

  SVN_ERR(svn_fs_base__check_fs(fs));

  args.path = svn_fs_base__canonicalize_abspath(path, pool);
  args.token = token;
  args.break_lock = break_lock;
  return svn_fs_base__retry_txn(fs, txn_body_unlock, &args, pool);
}


svn_error_t *
svn_fs_base__get_lock_helper(svn_lock_t **lock_p,
                             const char *path,
                             trail_t *trail,
                             apr_pool_t *pool)
{
  const char *lock_token;
  svn_error_t *err;
  
  err = svn_fs_bdb__lock_token_get(&lock_token, trail->fs, path,
                                   trail, pool);

  /* We've deliberately decided that this function doesn't tell the
     caller *why* the lock is unavailable.  */
  if (err && ((err->apr_err == SVN_ERR_FS_NO_SUCH_LOCK)
              || (err->apr_err == SVN_ERR_FS_LOCK_EXPIRED)
              || (err->apr_err == SVN_ERR_FS_BAD_LOCK_TOKEN)))
    {
      svn_error_clear(err);
      *lock_p = NULL;
      return SVN_NO_ERROR;
    }
  else
    SVN_ERR(err);

  /* Same situation here.  */
  err = svn_fs_bdb__lock_get(lock_p, trail->fs, lock_token, trail, pool);
  if (err && ((err->apr_err == SVN_ERR_FS_LOCK_EXPIRED)
              || (err->apr_err == SVN_ERR_FS_BAD_LOCK_TOKEN)))
    {
      svn_error_clear(err);
      *lock_p = NULL;
      return SVN_NO_ERROR;
    }
  else
    SVN_ERR(err);

  return err;
}


struct lock_token_get_args
{
  svn_lock_t **lock_p;
  const char *path;
};


static svn_error_t *
txn_body_get_lock(void *baton, trail_t *trail)
{
  struct lock_token_get_args *args = baton;
  return svn_fs_base__get_lock_helper(args->lock_p, args->path, 
                                      trail, trail->pool);
}


svn_error_t *
svn_fs_base__get_lock(svn_lock_t **lock,
                      svn_fs_t *fs,
                      const char *path,
                      apr_pool_t *pool)
{
  struct lock_token_get_args args;

  SVN_ERR(svn_fs_base__check_fs(fs));
  
  args.path = svn_fs_base__canonicalize_abspath(path, pool);
  args.lock_p = lock;  
  return svn_fs_base__retry_txn(fs, txn_body_get_lock, &args, pool);
}


struct locks_get_args
{
  const char *path;
  svn_fs_get_locks_callback_t get_locks_func;
  void *get_locks_baton;
};


static svn_error_t *
txn_body_get_locks(void *baton, trail_t *trail)
{
  struct locks_get_args *args = baton;
  return svn_fs_bdb__locks_get(trail->fs, args->path,
                               args->get_locks_func, args->get_locks_baton,
                               trail, trail->pool);
}


svn_error_t *
svn_fs_base__get_locks(svn_fs_t *fs,
                       const char *path,
                       svn_fs_get_locks_callback_t get_locks_func,
                       void *get_locks_baton,
                       apr_pool_t *pool)
{
  struct locks_get_args args;

  SVN_ERR(svn_fs_base__check_fs(fs));
  args.path = svn_fs_base__canonicalize_abspath(path, pool);
  args.get_locks_func = get_locks_func;
  args.get_locks_baton = get_locks_baton;
  return svn_fs_base__retry_txn(fs, txn_body_get_locks, &args, pool);
}



/* Utility function:  verify that a lock can be used.

   If no username is attached to the FS, return SVN_ERR_FS_NO_USER.

   If the FS username doesn't match LOCK's owner, return
   SVN_ERR_FS_LOCK_OWNER_MISMATCH.

   If FS hasn't been supplied with a matching lock-token for LOCK,
   return SVN_ERR_FS_BAD_LOCK_TOKEN.

   Otherwise return SVN_NO_ERROR.
 */
static svn_error_t *
verify_lock(svn_fs_t *fs,
            svn_lock_t *lock,
            apr_pool_t *pool)
{
  if ((! fs->access_ctx) || (! fs->access_ctx->username))
    return svn_error_createf 
      (SVN_ERR_FS_NO_USER, NULL,
       _("Cannot verify lock on path '%s'; no username available"),
       lock->path);
  
  else if (strcmp(fs->access_ctx->username, lock->owner) != 0)
    return svn_error_createf 
      (SVN_ERR_FS_LOCK_OWNER_MISMATCH, NULL,
       _("User %s does not own lock on path '%s' (currently locked by %s)"),
       fs->access_ctx->username, lock->path, lock->owner);

  else if (apr_hash_get(fs->access_ctx->lock_tokens, lock->token,
                        APR_HASH_KEY_STRING) == NULL)
    return svn_error_createf 
      (SVN_ERR_FS_BAD_LOCK_TOKEN, NULL,
       _("Cannot verify lock on path '%s'; no matching lock-token available"),
       lock->path);
    
  return SVN_NO_ERROR;
}


/* This implements the svn_fs_get_locks_callback_t interface, where
   BATON is just an svn_fs_t object. */
static svn_error_t *
get_locks_callback(void *baton, 
                   svn_lock_t *lock, 
                   apr_pool_t *pool)
{
  return verify_lock(baton, lock, pool);
}


/* The main routine for lock enforcement, used throughout libsvn_fs_base. */
svn_error_t *
svn_fs_base__allow_locked_operation(const char *path,
                                    svn_boolean_t recurse,
                                    trail_t *trail,
                                    apr_pool_t *pool)
{
  if (recurse)
    {
      /* Discover all locks at or below the path. */
      SVN_ERR(svn_fs_bdb__locks_get(trail->fs, path, get_locks_callback, 
                                    trail->fs, trail, pool));
    }
  else
    {
      svn_lock_t *lock;

      /* Discover any lock attached to the path. */
      SVN_ERR(svn_fs_base__get_lock_helper(&lock, path, trail, pool));
      if (lock)
        SVN_ERR(verify_lock(trail->fs, lock, pool));
    }
  return SVN_NO_ERROR;
}