/*

 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

#ifndef SHARE_VM_LOGGING_LOGCONFIGURATION_HPP

#define SHARE_VM_LOGGING_LOGCONFIGURATION_HPP

#include "logging/logLevel.hpp"

#include "memory/allocation.hpp"

#include "utilities/globalDefinitions.hpp"

class LogOutput;

class LogDecorators;

class LogTagLevelExpression;

// Global configuration of logging. Handles parsing and configuration of the logging framework,

// and manages the list of configured log outputs. The actual tag and level configuration is

// kept implicitly in the LogTagSets and their LogOutputLists. During configuration the tagsets

// are iterated over and updated accordingly.

class LogConfiguration : public AllStatic {

 friend class VMError;

 public:

  // Function for listeners

  typedef void (*UpdateListenerFunction)(void);

  // Register callback for config change.

  // The callback is always called with ConfigurationLock held,

  // hence doing log reconfiguration from the callback will deadlock.

  // The main Java thread may call this callback if there is an early registration

  // else the attach listener JavaThread, started via diagnostic command, will be executing thread.

  // The main purpose of this callback is to see if a loglevel have been changed.

  // There is no way to unregister.

  static void register_update_listener(UpdateListenerFunction cb);

 private:

  static LogOutput**  _outputs;

  static size_t       _n_outputs;

  static UpdateListenerFunction*    _listener_callbacks;

  static size_t                     _n_listener_callbacks;

  // Create a new output. Returns NULL if failed.

  static LogOutput* new_output(const char* name, const char* options, outputStream* errstream);

  // Add an output to the list of configured outputs. Returns the assigned index.

  static size_t add_output(LogOutput* out);

  // Delete a configured output. The stderr/stdout outputs can not be removed.

  // Output should be completely disabled before it is deleted.

  static void delete_output(size_t idx);

  // Disable all logging to the specified output and then delete it (unless it is stdout/stderr).

  static void disable_output(size_t idx);

  // Get output index by name. Returns SIZE_MAX if output not found.

  static size_t find_output(const char* name);

  // Configure output (add or update existing configuration) to log on tag-level combination using specified decorators.

  static void configure_output(size_t idx, const LogTagLevelExpression& tag_level_expression, const LogDecorators& decorators);

  // This should be called after any configuration change while still holding ConfigurationLock

  static void notify_update_listeners();

  // Respectively describe the built-in and runtime dependent portions of the configuration.

  static void describe_available(outputStream* out);

  static void describe_current_configuration(outputStream* out);

 public:

  // Initialization and finalization of log configuration, to be run at vm startup and shutdown respectively.

  static void initialize(jlong vm_start_time);

  static void finalize();

  // Perform necessary post-initialization after VM startup. Enables reconfiguration of logging.

  static void post_initialize();

  // Disable all logging, equivalent to -Xlog:disable.

  static void disable_logging();

  // Configures logging on stdout for the given tags and level combination.

  // Intended for mappings between -XX: flags and Unified Logging configuration.

  // If exact_match is true, only tagsets with precisely the specified tags will be configured

  // (exact_match=false is the same as "-Xlog:<tags>*=<level>", and exact_match=true is "-Xlog:<tags>=<level>").

  // Tags should be specified using the LOG_TAGS macro, e.g.

  // LogConfiguration::configure_stdout(LogLevel::<level>, <true/false>, LOG_TAGS(<tags>));

  // Parse command line configuration. Parameter 'opts' is the string immediately following the -Xlog: argument ("gc" for -Xlog:gc).

  static bool parse_command_line_arguments(const char* opts = "all");

  // Parse separated configuration arguments (from JCmd/MBean and command line).

  static bool parse_log_arguments(const char* outputstr,

                                  const char* what,

                                  const char* decoratorstr,

                                  const char* output_options,

                                  outputStream* errstream);

  // Prints log configuration to outputStream, used by JCmd/MBean.

  static void describe(outputStream* out);

  // Prints usage help for command line log configuration.

  static void print_command_line_help(FILE* out);

  // Rotates all LogOutput

  static void rotate_all_outputs();

};

#endif // SHARE_VM_LOGGING_LOGCONFIGURATION_HPP