/*

 * Copyright (c) 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

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 */

#ifndef SHARE_VM_LOGGING_LOGSTREAM_HPP

#define SHARE_VM_LOGGING_LOGSTREAM_HPP

#include "logging/log.hpp"

#include "logging/logHandle.hpp"

#include "memory/resourceArea.hpp"

#include "utilities/ostream.hpp"

// The base class of an output stream that logs to the logging framework.

template <class streamClass>

class LogStreamBase : public outputStream {

  streamClass     _current_line;

  LogTargetHandle _log_handle;

public:

  // Constructor to support creation from a LogTarget instance.

  //

  // LogTarget(Debug, gc) log;

  // LogStreamBase(log) stream;

  template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>

  LogStreamBase(const LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>& type_carrier) :

      _log_handle(level, &LogTagSetMapping<T0, T1, T2, T3, T4>::tagset()) {}

  // Constructor to support creation from typed (likely NULL) pointer. Mostly used by the logging framework.

  //

  // LogStreamBase stream(log.debug());

  //  or

  // LogStreamBase stream((LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>*)NULL);

  template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>

  LogStreamBase(const LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>* type_carrier) :

      _log_handle(level, &LogTagSetMapping<T0, T1, T2, T3, T4>::tagset()) {}

  // Constructor to support creation from a LogTargetHandle.

  //

  // LogTarget(Debug, gc) log;

  // LogTargetHandle(log) handle;

  // LogStreamBase stream(handle);

  LogStreamBase(LogTargetHandle handle) : _log_handle(handle) {}

  // Constructor to support creation from a log level and tagset.

  //

  // LogStreamBase(level, tageset);

  LogStreamBase(LogLevelType level, LogTagSet* tagset) : _log_handle(level, tagset) {}

  ~LogStreamBase() {

    guarantee(_current_line.size() == 0, "Buffer not flushed. Missing call to print_cr()?");

  }

public:

  void write(const char* s, size_t len);

};

// A stringStream with an embedded ResourceMark.

class stringStreamWithResourceMark : outputStream {

 private:

  // The stringStream Resource allocate in the constructor,

  // so the order of the fields is important.

  ResourceMark _embedded_resource_mark;

  stringStream _stream;

 public:

  stringStreamWithResourceMark(size_t initial_bufsize = 256) :

      _embedded_resource_mark(),

      _stream(initial_bufsize) {}

  virtual void write(const char* c, size_t len) { _stream.write(c, len); }

  size_t      size()                            { return _stream.size(); }

  const char* base()                            { return _stream.base(); }

  void  reset()                                 { _stream.reset(); }

  char* as_string()                             { return _stream.as_string(); }

};

// An output stream that logs to the logging framework.

//

// The backing buffer is allocated in Resource memory.

// The caller is required to have a ResourceMark on the stack.

typedef LogStreamBase<stringStream> LogStreamNoResourceMark;

// An output stream that logs to the logging framework.

//

// The backing buffer is allocated in CHeap memory.

typedef LogStreamBase<bufferedStream> LogStreamCHeap;

// An output stream that logs to the logging framework, and embeds a ResourceMark.

//

// The backing buffer is allocated in Resource memory.

// The class is intended to be stack allocated.

// The class provides its own ResourceMark,

//  so care needs to be taken when nested ResourceMarks are used.

typedef LogStreamBase<stringStreamWithResourceMark> LogStream;

// Support creation of a LogStream without having to provide a LogTarget pointer.

#define LogStreamHandle(level, ...) LogStreamTemplate<LogLevel::level, LOG_TAGS(__VA_ARGS__)>

template <LogLevelType level, LogTagType T0, LogTagType T1, LogTagType T2, LogTagType T3, LogTagType T4, LogTagType GuardTag>

class LogStreamTemplate : public LogStream {

public:

  LogStreamTemplate() : LogStream((LogTargetImpl<level, T0, T1, T2, T3, T4, GuardTag>*)NULL) {}

};

#endif // SHARE_VM_LOGGING_LOGSTREAM_HPP