////////////////////////////////////////////////////////////////////////////////
/// @brief file functions
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2004-2012 triagens GmbH, Cologne, Germany
///
/// Licensed 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.
///
/// Copyright holder is triAGENS GmbH, Cologne, Germany
///
/// @author Dr. Frank Celler
/// @author Copyright 2011-2012, triAGENS GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#ifndef TRIAGENS_BASICS_C_FILES_H
#define TRIAGENS_BASICS_C_FILES_H 1

#include "BasicsC/common.h"

#include "BasicsC/vector.h"

#ifdef __cplusplus
extern "C" {
#endif

// -----------------------------------------------------------------------------
// --SECTION--                                                  public functions
// -----------------------------------------------------------------------------

////////////////////////////////////////////////////////////////////////////////
/// @addtogroup Files
/// @{
////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////
/// @brief checks if path is a directory
////////////////////////////////////////////////////////////////////////////////

bool TRI_IsDirectory (char const* path);

////////////////////////////////////////////////////////////////////////////////
/// @brief checks if file exists
////////////////////////////////////////////////////////////////////////////////

bool TRI_ExistsFile (char const* path);

////////////////////////////////////////////////////////////////////////////////
/// @brief creates a directory
////////////////////////////////////////////////////////////////////////////////

bool TRI_CreateDirectory (char const* path);

////////////////////////////////////////////////////////////////////////////////
/// @brief extracts the dirname
////////////////////////////////////////////////////////////////////////////////

char* TRI_Dirname (char const* path);

////////////////////////////////////////////////////////////////////////////////
/// @brief extracts the basename
////////////////////////////////////////////////////////////////////////////////

char* TRI_Basename (char const* path);

////////////////////////////////////////////////////////////////////////////////
/// @brief creates a filename
////////////////////////////////////////////////////////////////////////////////

char* TRI_Concatenate2File (char const* path, char const* name);

////////////////////////////////////////////////////////////////////////////////
/// @brief creates a filename
////////////////////////////////////////////////////////////////////////////////

char* TRI_Concatenate3File (char const* path1, char const* path2, char const* name);

////////////////////////////////////////////////////////////////////////////////
/// @brief returns a list of files in path
////////////////////////////////////////////////////////////////////////////////

TRI_vector_string_t TRI_FilesDirectory (char const* path);

////////////////////////////////////////////////////////////////////////////////
/// @brief renames a file
////////////////////////////////////////////////////////////////////////////////

bool TRI_RenameFile (char const* old, char const* filename);

////////////////////////////////////////////////////////////////////////////////
/// @brief unlinks a file
////////////////////////////////////////////////////////////////////////////////

bool TRI_UnlinkFile (char const* filename);

////////////////////////////////////////////////////////////////////////////////
/// @brief reads into a buffer from a file
////////////////////////////////////////////////////////////////////////////////

bool TRI_ReadPointer (int fd, void* buffer, size_t length);

////////////////////////////////////////////////////////////////////////////////
/// @brief writes buffer to a file
////////////////////////////////////////////////////////////////////////////////

bool TRI_WritePointer (int fd, void const* buffer, size_t length);

////////////////////////////////////////////////////////////////////////////////
/// @brief fsyncs a file
////////////////////////////////////////////////////////////////////////////////

bool TRI_fsync (int fd);

////////////////////////////////////////////////////////////////////////////////
/// @brief slurps in a file
////////////////////////////////////////////////////////////////////////////////

char* TRI_SlurpFile (char const* filename);

////////////////////////////////////////////////////////////////////////////////
/// @brief creates a lock file based on the PID
///
/// Creates a file containing a the current process identifier and locks
/// that file. Under Unix the call uses the @FN{open} system call with
/// O_EXCL to ensure that the file is created atomically. Then the
/// file is filled with the process identifier as decimal number and a
/// lock on the file is obtained using @FN{flock}.
///
/// On success 0 is returned. An error number is returned on failure. See
/// @FN{TRI_errno} for details.
///
/// Internally, the functions keeps a list of open pid files. Calling the
/// function twice with the same @FA{filename} will succeed and will not
/// create a new entry in this list. The system uses @FN{atexit} to release
/// all open locks upon exit.
////////////////////////////////////////////////////////////////////////////////

int TRI_CreateLockFile (char const* filename);

////////////////////////////////////////////////////////////////////////////////
/// @brief verifies a lock file based on the PID
///
/// The function checks if the file named @FA{filename} exists. If it does not
/// then TRI_ERROR_NO_ERROR is returned.  If the file exists, then the
/// following checks are performed:
///
/// - Does the file contain a valid decimal number? Otherwise
///   TRI_ERROR_ILLEGAL_NUMBER is returned.
///
/// - Does this number belong to a living process? Otherwise
///   TRI_ERROR_DEAD_PID is returned.
///
/// - Is it possible to lock the file using @FN{flock}. This should failed.
///   If the lock can be obtained, then TRI_ERROR_UNLOCKED_FILE is returned and
///   the lock is released.
///
/// If the verification returns an error, than @FN{TRI_UnlinkFile} should be
/// used to remove the lock file.
////////////////////////////////////////////////////////////////////////////////

int VerifyLockFile (char const* filename);

////////////////////////////////////////////////////////////////////////////////
/// @brief releases a lock file based on the PID
////////////////////////////////////////////////////////////////////////////////

int TRI_DestroyLockFile (char const* filename);

////////////////////////////////////////////////////////////////////////////////
/// @}
////////////////////////////////////////////////////////////////////////////////

#ifdef __cplusplus
}
#endif

#endif

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