/*

 * Copyright (c) 2016, 2019, 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_LOGGING_LOGSTREAM_HPP

#define SHARE_LOGGING_LOGSTREAM_HPP

#include "logging/log.hpp"

#include "logging/logHandle.hpp"

#include "memory/resourceArea.hpp"

#include "utilities/ostream.hpp"

class LogStream : public outputStream {

  friend class LogStreamTest_TestLineBufferAllocation_test_vm_Test; // see test/native/logging/test_logStream.cpp

  friend class LogStreamTest_TestLineBufferAllocationCap_test_vm_Test; // see test/native/logging/test_logStream.cpp

  // Helper class, maintains the line buffer. For small line lengths,

  // we avoid malloc and use a fixed sized member char array. If LogStream

  // is allocated on the stack, this means small lines are assembled

  // directly on the stack.

  class LineBuffer {

    char _smallbuf[64];

    char* _buf;

    size_t _cap;

    size_t _pos;

    void try_ensure_cap(size_t cap);

  public:

    LineBuffer();

    ~LineBuffer();

    bool is_empty() const { return _pos == 0; }

    const char* buffer() const { return _buf; }

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

    void reset();

  };

  LineBuffer  _current_line;

  LogTargetHandle _log_handle;

  // Prevent operator new for LogStream.

  static void* operator new (size_t);

  static void* operator new[] (size_t);

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>

  LogStream(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>

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

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

  // Destructor writes any unfinished output left in the line buffer.

  ~LogStream();

  // Constructor to support creation from a LogTargetHandle.

  //

  // LogTarget(Debug, gc) log;

  // LogTargetHandle(log) handle;

  // LogStreamBase stream(handle);

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

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

  //

  // LogStreamBase(level, tageset);

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

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

};

// 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_LOGGING_LOGSTREAM_HPP