src/log-utils.cc

// Copyright 2009 the V8 project authors. All rights reserved.
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// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
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//       with the distribution.
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//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
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#include "v8.h"

#include "log-utils.h"

namespace v8 {
namespace internal {

#ifdef ENABLE_LOGGING_AND_PROFILING

LogDynamicBuffer::LogDynamicBuffer(
    int block_size, int max_size, const char* seal, int seal_size)
    : block_size_(block_size),
      max_size_(max_size - (max_size % block_size_)),
      seal_(seal),
      seal_size_(seal_size),
      blocks_(max_size_ / block_size_ + 1),
      write_pos_(0), block_index_(0), block_write_pos_(0), is_sealed_(false) {
  ASSERT(BlocksCount() > 0);
  AllocateBlock(0);
  for (int i = 1; i < BlocksCount(); ++i) {
    blocks_[i] = NULL;
  }
}


LogDynamicBuffer::~LogDynamicBuffer() {
  for (int i = 0; i < BlocksCount(); ++i) {
    DeleteArray(blocks_[i]);
  }
}


int LogDynamicBuffer::Read(int from_pos, char* dest_buf, int buf_size) {
  if (buf_size == 0) return 0;
  int read_pos = from_pos;
  int block_read_index = BlockIndex(from_pos);
  int block_read_pos = PosInBlock(from_pos);
  int dest_buf_pos = 0;
  // Read until dest_buf is filled, or write_pos_ encountered.
  while (read_pos < write_pos_ && dest_buf_pos < buf_size) {
    const int read_size = Min(write_pos_ - read_pos,
        Min(buf_size - dest_buf_pos, block_size_ - block_read_pos));
    memcpy(dest_buf + dest_buf_pos,
           blocks_[block_read_index] + block_read_pos, read_size);
    block_read_pos += read_size;
    dest_buf_pos += read_size;
    read_pos += read_size;
    if (block_read_pos == block_size_) {
      block_read_pos = 0;
      ++block_read_index;
    }
  }
  return dest_buf_pos;
}


int LogDynamicBuffer::Seal() {
  WriteInternal(seal_, seal_size_);
  is_sealed_ = true;
  return 0;
}


int LogDynamicBuffer::Write(const char* data, int data_size) {
  if (is_sealed_) {
    return 0;
  }
  if ((write_pos_ + data_size) <= (max_size_ - seal_size_)) {
    return WriteInternal(data, data_size);
  } else {
    return Seal();
  }
}


int LogDynamicBuffer::WriteInternal(const char* data, int data_size) {
  int data_pos = 0;
  while (data_pos < data_size) {
    const int write_size =
        Min(data_size - data_pos, block_size_ - block_write_pos_);
    memcpy(blocks_[block_index_] + block_write_pos_, data + data_pos,
           write_size);
    block_write_pos_ += write_size;
    data_pos += write_size;
    if (block_write_pos_ == block_size_) {
      block_write_pos_ = 0;
      AllocateBlock(++block_index_);
    }
  }
  write_pos_ += data_size;
  return data_size;
}


bool Log::is_stopped_ = false;
Log::WritePtr Log::Write = NULL;
FILE* Log::output_handle_ = NULL;
FILE* Log::output_code_handle_ = NULL;
LogDynamicBuffer* Log::output_buffer_ = NULL;
// Must be the same message as in Logger::PauseProfiler.
const char* Log::kDynamicBufferSeal = "profiler,\"pause\"\n";
Mutex* Log::mutex_ = NULL;
char* Log::message_buffer_ = NULL;


void Log::Init() {
  mutex_ = OS::CreateMutex();
  message_buffer_ = NewArray<char>(kMessageBufferSize);
}


void Log::OpenStdout() {
  ASSERT(!IsEnabled());
  output_handle_ = stdout;
  Write = WriteToFile;
  Init();
}


static const char kCodeLogExt[] = ".code";


void Log::OpenFile(const char* name) {
  ASSERT(!IsEnabled());
  output_handle_ = OS::FOpen(name, OS::LogFileOpenMode);
  if (FLAG_ll_prof) {
    // Open a file for logging the contents of code objects so that
    // they can be disassembled later.
    size_t name_len = strlen(name);
    ScopedVector<char> code_name(
        static_cast<int>(name_len + sizeof(kCodeLogExt)));
    memcpy(code_name.start(), name, name_len);
    memcpy(code_name.start() + name_len, kCodeLogExt, sizeof(kCodeLogExt));
    output_code_handle_ = OS::FOpen(code_name.start(), OS::LogFileOpenMode);
  }
  Write = WriteToFile;
  Init();
}


void Log::OpenMemoryBuffer() {
  ASSERT(!IsEnabled());
  output_buffer_ = new LogDynamicBuffer(
      kDynamicBufferBlockSize, kMaxDynamicBufferSize,
      kDynamicBufferSeal, StrLength(kDynamicBufferSeal));
  Write = WriteToMemory;
  Init();
}


void Log::Close() {
  if (Write == WriteToFile) {
    if (output_handle_ != NULL) fclose(output_handle_);
    output_handle_ = NULL;
    if (output_code_handle_ != NULL) fclose(output_code_handle_);
    output_code_handle_ = NULL;
  } else if (Write == WriteToMemory) {
    delete output_buffer_;
    output_buffer_ = NULL;
  } else {
    ASSERT(Write == NULL);
  }
  Write = NULL;

  DeleteArray(message_buffer_);
  message_buffer_ = NULL;

  delete mutex_;
  mutex_ = NULL;

  is_stopped_ = false;
}


int Log::GetLogLines(int from_pos, char* dest_buf, int max_size) {
  if (Write != WriteToMemory) return 0;
  ASSERT(output_buffer_ != NULL);
  ASSERT(from_pos >= 0);
  ASSERT(max_size >= 0);
  int actual_size = output_buffer_->Read(from_pos, dest_buf, max_size);
  ASSERT(actual_size <= max_size);
  if (actual_size == 0) return 0;

  // Find previous log line boundary.
  char* end_pos = dest_buf + actual_size - 1;
  while (end_pos >= dest_buf && *end_pos != '\n') --end_pos;
  actual_size = static_cast<int>(end_pos - dest_buf + 1);
  // If the assertion below is hit, it means that there was no line end
  // found --- something wrong has happened.
  ASSERT(actual_size > 0);
  ASSERT(actual_size <= max_size);
  return actual_size;
}


LogMessageBuilder::WriteFailureHandler
    LogMessageBuilder::write_failure_handler = NULL;


LogMessageBuilder::LogMessageBuilder(): sl(Log::mutex_), pos_(0) {
  ASSERT(Log::message_buffer_ != NULL);
}


void LogMessageBuilder::Append(const char* format, ...) {
  Vector<char> buf(Log::message_buffer_ + pos_,
                   Log::kMessageBufferSize - pos_);
  va_list args;
  va_start(args, format);
  AppendVA(format, args);
  va_end(args);
  ASSERT(pos_ <= Log::kMessageBufferSize);
}


void LogMessageBuilder::AppendVA(const char* format, va_list args) {
  Vector<char> buf(Log::message_buffer_ + pos_,
                   Log::kMessageBufferSize - pos_);
  int result = v8::internal::OS::VSNPrintF(buf, format, args);

  // Result is -1 if output was truncated.
  if (result >= 0) {
    pos_ += result;
  } else {
    pos_ = Log::kMessageBufferSize;
  }
  ASSERT(pos_ <= Log::kMessageBufferSize);
}


void LogMessageBuilder::Append(const char c) {
  if (pos_ < Log::kMessageBufferSize) {
    Log::message_buffer_[pos_++] = c;
  }
  ASSERT(pos_ <= Log::kMessageBufferSize);
}


void LogMessageBuilder::Append(String* str) {
  AssertNoAllocation no_heap_allocation;  // Ensure string stay valid.
  int length = str->length();
  for (int i = 0; i < length; i++) {
    Append(static_cast<char>(str->Get(i)));
  }
}


void LogMessageBuilder::AppendAddress(Address addr) {
  Append("0x%" V8PRIxPTR, addr);
}


void LogMessageBuilder::AppendDetailed(String* str, bool show_impl_info) {
  AssertNoAllocation no_heap_allocation;  // Ensure string stay valid.
  int len = str->length();
  if (len > 0x1000)
    len = 0x1000;
  if (show_impl_info) {
    Append(str->IsAsciiRepresentation() ? 'a' : '2');
    if (StringShape(str).IsExternal())
      Append('e');
    if (StringShape(str).IsSymbol())
      Append('#');
    Append(":%i:", str->length());
  }
  for (int i = 0; i < len; i++) {
    uc32 c = str->Get(i);
    if (c > 0xff) {
      Append("\\u%04x", c);
    } else if (c < 32 || c > 126) {
      Append("\\x%02x", c);
    } else if (c == ',') {
      Append("\\,");
    } else if (c == '\\') {
      Append("\\\\");
    } else if (c == '\"') {
      Append("\"\"");
    } else {
      Append("%lc", c);
    }
  }
}


void LogMessageBuilder::AppendStringPart(const char* str, int len) {
  if (pos_ + len > Log::kMessageBufferSize) {
    len = Log::kMessageBufferSize - pos_;
    ASSERT(len >= 0);
    if (len == 0) return;
  }
  Vector<char> buf(Log::message_buffer_ + pos_,
                   Log::kMessageBufferSize - pos_);
  OS::StrNCpy(buf, str, len);
  pos_ += len;
  ASSERT(pos_ <= Log::kMessageBufferSize);
}


void LogMessageBuilder::WriteToLogFile() {
  ASSERT(pos_ <= Log::kMessageBufferSize);
  const int written = Log::Write(Log::message_buffer_, pos_);
  if (written != pos_ && write_failure_handler != NULL) {
    write_failure_handler();
  }
}

#endif  // ENABLE_LOGGING_AND_PROFILING

} }  // namespace v8::internal