chromium/v8/src/utils/ostreams.h

// Copyright 2014 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_UTILS_OSTREAMS_H_
#define V8_UTILS_OSTREAMS_H_

#include <cstddef>
#include <cstdio>
#include <cstring>
#include <ostream>
#include <streambuf>

#include "src/base/macros.h"
#include "src/base/platform/mutex.h"
#include "src/common/globals.h"

namespace v8 {
namespace internal {

class V8_EXPORT_PRIVATE OFStreamBase : public std::streambuf { … };

// Output buffer and stream writing into debugger's command window.
class V8_EXPORT_PRIVATE DbgStreamBuf : public std::streambuf { … };

class DbgStdoutStream : public std::ostream { … };

// An output stream writing to a file.
class V8_EXPORT_PRIVATE OFStream : public std::ostream { … };

#if defined(ANDROID) && !defined(V8_ANDROID_LOG_STDOUT)
class V8_EXPORT_PRIVATE AndroidLogStream : public std::streambuf {
 public:
  virtual ~AndroidLogStream();

 protected:
  std::streamsize xsputn(const char* s, std::streamsize n) override;

 private:
  std::string line_buffer_;
};

class StdoutStream : public std::ostream {
 public:
  StdoutStream() : std::ostream(&stream_) {}

 private:
  friend class StderrStream;

  static V8_EXPORT_PRIVATE base::RecursiveMutex* GetStdoutMutex();

  AndroidLogStream stream_;
  base::RecursiveMutexGuard mutex_guard_{GetStdoutMutex()};
};
#else
class StdoutStream : public OFStream { … };
#endif

class StderrStream : public OFStream { … };

// Wrappers to disambiguate uint16_t and base::uc16.
struct AsUC16 { … };

struct AsUC32 { … };

struct AsReversiblyEscapedUC16 { … };

struct AsEscapedUC16ForJSON { … };

// Output the given value as hex, with a minimum width and optional prefix (0x).
// E.g. AsHex(23, 3, true) produces "0x017". Produces an empty string if both
// {min_width} and the value are 0.
struct AsHex { … };

// Output the given value as hex, separated in individual bytes.
// E.g. AsHexBytes(0x231712, 4) produces "12 17 23 00" if output as little
// endian (default), and "00 23 17 12" as big endian. Produces an empty string
// if both {min_bytes} and the value are 0.
struct AsHexBytes { … };

template <typename T>
struct PrintIteratorRange { … };

// Print any collection which can be iterated via std::begin and std::end.
// {Iterator} is the common type of {std::begin} and {std::end} called on a
// {const T&}. This function is only instantiable if that type exists.
template <typename T>
auto PrintCollection(const T& collection) -> PrintIteratorRange<
    typename std::common_type<decltype(std::begin(collection)),
                              decltype(std::end(collection))>::type> { … }

// Writes the given character to the output escaping everything outside of
// printable/space ASCII range. Additionally escapes '\' making escaping
// reversible.
std::ostream& operator<<(std::ostream& os, const AsReversiblyEscapedUC16& c);

// Same as AsReversiblyEscapedUC16 with additional escaping of \n, \r, " and '.
V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
                                           const AsEscapedUC16ForJSON& c);

// Writes the given character to the output escaping everything outside
// of printable ASCII range.
std::ostream& operator<<(std::ostream& os, const AsUC16& c);

// Writes the given character to the output escaping everything outside
// of printable ASCII range.
std::ostream& operator<<(std::ostream& os, const AsUC32& c);

V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os, const AsHex& v);
V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
                                           const AsHexBytes& v);

template <typename T>
std::ostream& operator<<(std::ostream& os, const PrintIteratorRange<T>& range) { … }

}  // namespace internal
}  // namespace v8

#endif  // V8_UTILS_OSTREAMS_H_