FileManager.h

/** @file

  A brief file description

  @section license License

  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.
 */

#pragma once

/****************************************************************************
 *
 *  FileManager.h - Interface for class to manage configuration updates
 *
 *
 ****************************************************************************/

#include <stdio.h>

#include "ts/ink_hash_table.h"
#include "ts/List.h"
#include "Rollback.h"

class Rollback;

typedef void (*FileCallbackFunc)(char *, bool);

struct callbackListable {
public:
  FileCallbackFunc func;
  LINK(callbackListable, link);
};

enum lockAction_t {
  ACQUIRE_LOCK,
  RELEASE_LOCK,
};
class ExpandingArray;

//  class FileManager
//
//  public functions:
//
//  addFile(char*, configFileInfo*) - adds a new config file to be
//       managed.  A rollback object is created for the file.
//       if the file_info ptr is not NULL, a WebFileEdit object
//       is also created
//
//  getRollbckObj(char* , RollbackPtr**) - sets *rbPtr to Rollback
//       object bound to fileName.  Returns true if there is
//       a binding and false otherwise
//
//  getWFEObj(char*, WebFileEdit**)  - sets *wfePtr to WebFileEdit
//       object bound to fileName.  Returns true if there is
//       a binding and false otherwise
//
//  registerCallback(FileCallbackFunc) - registers a callback function
//       which will get called everytime a managed file changes.  The
//       callback function should NOT use the calling thread to
//       access any Rollback objects or block for a long time
//
//  fileChanged(const char* fileName) - called by Rollback objects
//       when their contents change.  Triggers callbacks to FileCallbackFuncs
//
//  isConfigStale() - returns whether the in-memory files might be stale
//       compared to what is on disk.
//
//  rereadConfig() - Checks all managed files to see if they have been
//       updated
//  addConfigFileGroup(char* data_str, int data_size) - update config file group infos
class FileManager
{
public:
  FileManager();
  ~FileManager();
  void addFile(const char *fileName, bool root_access_needed, Rollback *parentRollback = nullptr, unsigned flags = 0);
  bool getRollbackObj(const char *fileName, Rollback **rbPtr);
  void registerCallback(FileCallbackFunc func);
  void fileChanged(const char *fileName, bool incVersion);
  void rereadConfig();
  bool isConfigStale();
  void configFileChild(const char *parent, const char *child, unsigned int options);

private:
  ink_mutex accessLock; // Protects bindings hashtable
  ink_mutex cbListLock; // Protects the CallBack List
  DLL<callbackListable> cblist;
  InkHashTable *bindings;
  void addFileHelper(const char *fileName, bool root_access_needed, Rollback *parentRollback, unsigned flags = 0);
};

void initializeRegistry(); // implemented in AddConfigFilesHere.cc