/*

 * Copyright (c) 2012, 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

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

 * questions.

 *

 */

#include "precompiled.hpp"

#include "jfr/recorder/repository/jfrChunk.hpp"

#include "jfr/recorder/repository/jfrChunkWriter.hpp"

#include "jfr/utilities/jfrTime.hpp"

#include "runtime/mutexLocker.hpp"

#include "runtime/os.inline.hpp"

static const int64_t MAGIC_OFFSET = 0;

static const int64_t MAGIC_LEN = 4;

static const int64_t VERSION_OFFSET = MAGIC_LEN;

static const int64_t SIZE_OFFSET = 8;

static const int64_t SLOT_SIZE = 8;

static const int64_t CHECKPOINT_OFFSET = SIZE_OFFSET + SLOT_SIZE;

static const int64_t METADATA_OFFSET = CHECKPOINT_OFFSET + SLOT_SIZE;

static const int64_t START_NANOS_OFFSET = METADATA_OFFSET + SLOT_SIZE;

static const int64_t DURATION_NANOS_OFFSET = START_NANOS_OFFSET + SLOT_SIZE;

static const int64_t START_TICKS_OFFSET = DURATION_NANOS_OFFSET + SLOT_SIZE;

static const int64_t CPU_FREQUENCY_OFFSET = START_TICKS_OFFSET + SLOT_SIZE;

static const int64_t GENERATION_OFFSET = CPU_FREQUENCY_OFFSET + SLOT_SIZE;

static const int64_t CAPABILITY_OFFSET = GENERATION_OFFSET + 2;

static const int64_t HEADER_SIZE = CAPABILITY_OFFSET + 2;

static fio_fd open_chunk(const char* path) {

  return path != NULL ? os::open(path, O_CREAT | O_RDWR, S_IREAD | S_IWRITE) : invalid_fd;

}

#ifdef ASSERT

static void assert_writer_position(JfrChunkWriter* writer, int64_t offset) {

  assert(writer != NULL, "invariant");

  assert(offset == writer->current_offset(), "invariant");

}

#endif

class JfrChunkHeadWriter : public StackObj {

 private:

  JfrChunkWriter* _writer;

  JfrChunk* _chunk;

 public:

  void write_magic() {

    _writer->bytes(_chunk->magic(), MAGIC_LEN);

  }

  void write_version() {

    _writer->be_write(_chunk->major_version());

    _writer->be_write(_chunk->minor_version());

  }

  void write_size(int64_t size) {

    _writer->be_write(size);

  }

  void write_checkpoint() {

    _writer->be_write(_chunk->last_checkpoint_offset());

  }

  void write_metadata() {

    _writer->be_write(_chunk->last_metadata_offset());

  }

  void write_time(bool finalize) {

    if (finalize) {

      _writer->be_write(_chunk->previous_start_nanos());

      _writer->be_write(_chunk->last_chunk_duration());

      _writer->be_write(_chunk->previous_start_ticks());

      return;

    }

    _writer->be_write(_chunk->start_nanos());

    _writer->be_write(_chunk->duration());

    _writer->be_write(_chunk->start_ticks());

  }

  void write_cpu_frequency() {

    _writer->be_write(_chunk->cpu_frequency());

  }

  void write_generation(bool finalize) {

    _writer->be_write(finalize ? COMPLETE : _chunk->generation());

    _writer->be_write(PAD);

  }

  void write_next_generation() {

    _writer->be_write(_chunk->next_generation());

    _writer->be_write(PAD);

  }

  void write_guard() {

    _writer->be_write(GUARD);

    _writer->be_write(PAD);

  }

  void write_guard_flush() {

    write_guard();

    _writer->flush();

  }

  void write_capabilities() {

    _writer->be_write(_chunk->capabilities());

  }

  void write_size_to_generation(int64_t size, bool finalize) {

    write_size(size);

    write_checkpoint();

    write_metadata();

    write_time(finalize);

    write_cpu_frequency();

    write_generation(finalize);

  }

  void flush(int64_t size, bool finalize) {

    assert(_writer->is_valid(), "invariant");

    assert(_chunk != NULL, "invariant");

    DEBUG_ONLY(assert_writer_position(_writer, SIZE_OFFSET);)

    write_size_to_generation(size, finalize);

    // no need to write capabilities

    _writer->seek(size); // implicit flush

  }

  void initialize() {

    assert(_writer->is_valid(), "invariant");

    assert(_chunk != NULL, "invariant");

    DEBUG_ONLY(assert_writer_position(_writer, 0);)

    write_magic();

    write_version();

    write_size_to_generation(HEADER_SIZE, false);

    write_capabilities();

    DEBUG_ONLY(assert_writer_position(_writer, HEADER_SIZE);)

    _writer->flush();

  }

  JfrChunkHeadWriter(JfrChunkWriter* writer, int64_t offset, bool guard = true) : _writer(writer), _chunk(writer->_chunk) {

    assert(_writer != NULL, "invariant");

    assert(_writer->is_valid(), "invariant");

    assert(_chunk != NULL, "invariant");

    if (0 == _writer->current_offset()) {

      assert(HEADER_SIZE == offset, "invariant");

      initialize();

    } else {

      if (guard) {

        _writer->seek(GENERATION_OFFSET);

        write_guard();

        _writer->seek(offset);

      } else {

        _chunk->update_current_nanos();

      }

    }

    DEBUG_ONLY(assert_writer_position(_writer, offset);)

  }

};

static int64_t prepare_chunk_header_constant_pool(JfrChunkWriter& cw, int64_t event_offset, bool flushpoint) {

  const int64_t delta = cw.last_checkpoint_offset() == 0 ? 0 : cw.last_checkpoint_offset() - event_offset;

  const u4 checkpoint_type = flushpoint ? (u4)(FLUSH | HEADER) : (u4)HEADER;

  cw.reserve(sizeof(u4));

  cw.write<u8>(EVENT_CHECKPOINT);

  cw.write<u8>(JfrTicks::now().value());

  cw.write<u8>(0); // duration

  cw.write<u8>(delta); // to previous checkpoint

  cw.write<u4>(checkpoint_type);

  cw.write<u4>(1); // pool count

  cw.write<u8>(TYPE_CHUNKHEADER);

  cw.write<u4>(1); // count

  cw.write<u8>(1); // key

  cw.write<u4>(HEADER_SIZE); // length of byte array

  return cw.current_offset();

}

int64_t JfrChunkWriter::write_chunk_header_checkpoint(bool flushpoint) {

  assert(this->has_valid_fd(), "invariant");

  const int64_t event_size_offset = current_offset();

  const int64_t header_content_pos = prepare_chunk_header_constant_pool(*this, event_size_offset, flushpoint);

  JfrChunkHeadWriter head(this, header_content_pos, false);

  head.write_magic();

  head.write_version();

  const int64_t chunk_size_offset = reserve(sizeof(int64_t)); // size to be decided when we are done

  be_write(event_size_offset); // last checkpoint offset will be this checkpoint

  head.write_metadata();

  head.write_time(false);

  head.write_cpu_frequency();

  head.write_next_generation();

  head.write_capabilities();

  assert(current_offset() - header_content_pos == HEADER_SIZE, "invariant");

  const u4 checkpoint_size = current_offset() - event_size_offset;

  write_padded_at_offset<u4>(checkpoint_size, event_size_offset);

  set_last_checkpoint_offset(event_size_offset);

  const size_t sz_written = size_written();

  write_be_at_offset(sz_written, chunk_size_offset);

  return sz_written;

}

int64_t JfrChunkWriter::flush_chunk(bool flushpoint) {

  assert(_chunk != NULL, "invariant");

  const int64_t sz_written = write_chunk_header_checkpoint(flushpoint);

  assert(size_written() == sz_written, "invariant");

  JfrChunkHeadWriter head(this, SIZE_OFFSET);

  head.flush(sz_written, !flushpoint);

  return sz_written;

}

JfrChunkWriter::JfrChunkWriter() : JfrChunkWriterBase(NULL), _chunk(new JfrChunk()) {}

JfrChunkWriter::~JfrChunkWriter() {

  assert(_chunk != NULL, "invariant");

  delete _chunk;

}

void JfrChunkWriter::set_path(const char* path) {

  assert(_chunk != NULL, "invariant");

  _chunk->set_path(path);

}

void JfrChunkWriter::set_time_stamp() {

  assert(_chunk != NULL, "invariant");

  _chunk->set_time_stamp();

}

int64_t JfrChunkWriter::size_written() const {

  return this->is_valid() ? this->current_offset() : 0;

}

int64_t JfrChunkWriter::last_checkpoint_offset() const {

  assert(_chunk != NULL, "invariant");

  return _chunk->last_checkpoint_offset();

}

int64_t JfrChunkWriter::current_chunk_start_nanos() const {

  assert(_chunk != NULL, "invariant");

  return this->is_valid() ? _chunk->start_nanos() : invalid_time;

}

void JfrChunkWriter::set_last_checkpoint_offset(int64_t offset) {

  assert(_chunk != NULL, "invariant");

  _chunk->set_last_checkpoint_offset(offset);

}

void JfrChunkWriter::set_last_metadata_offset(int64_t offset) {

  assert(_chunk != NULL, "invariant");

  _chunk->set_last_metadata_offset(offset);

}

bool JfrChunkWriter::has_metadata() const {

  assert(_chunk != NULL, "invariant");

  return _chunk->has_metadata();

}

bool JfrChunkWriter::open() {

  assert(_chunk != NULL, "invariant");

  JfrChunkWriterBase::reset(open_chunk(_chunk->path()));

  const bool is_open = this->has_valid_fd();

  if (is_open) {

    assert(0 == this->current_offset(), "invariant");

    _chunk->reset();

    JfrChunkHeadWriter head(this, HEADER_SIZE);

  }

  return is_open;

}

int64_t JfrChunkWriter::close() {

  assert(this->has_valid_fd(), "invariant");

  const int64_t size_written = flush_chunk(false);

  this->close_fd();

  assert(!this->is_valid(), "invariant");

  return size_written;

}