rcpp_framework/core/log/log_stream.cpp

/**
 *
 *  LogStream.cc
 *  An Tao
 *
 *  Public header file in trantor lib.
 *
 *  Copyright 2018, An Tao.  All rights reserved.
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the License file.
 *
 *
 */

// taken from muduo lib

#include <assert.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "log_stream.h"
#include <algorithm>
#include <iostream>
#include <limits>

using namespace trantor;
using namespace trantor::detail;

namespace trantor {
namespace detail {
const char digits[] = "9876543210123456789";
const char *zero = digits + 9;

const char digitsHex[] = "0123456789ABCDEF";

// Efficient Integer to String Conversions, by Matthew Wilson.
template <typename T>
size_t convert(char buf[], T value) {
	T i = value;
	char *p = buf;

	do {
		int lsd = static_cast<int>(i % 10);
		i /= 10;
		*p++ = zero[lsd];
	} while (i != 0);

	if (value < 0) {
		*p++ = '-';
	}
	*p = '\0';
	std::reverse(buf, p);

	return p - buf;
}

size_t convertHex(char buf[], uintptr_t value) {
	uintptr_t i = value;
	char *p = buf;

	do {
		int lsd = static_cast<int>(i % 16);
		i /= 16;
		*p++ = digitsHex[lsd];
	} while (i != 0);

	*p = '\0';
	std::reverse(buf, p);

	return p - buf;
}

template class FixedBuffer<kSmallBuffer>;
template class FixedBuffer<kLargeBuffer>;

} // namespace detail
} // namespace trantor

template <int SIZE>
const char *FixedBuffer<SIZE>::debugString() {
	*cur_ = '\0';
	return data_;
}

template <int SIZE>
void FixedBuffer<SIZE>::cookieStart() {
}

template <int SIZE>
void FixedBuffer<SIZE>::cookieEnd() {
}

template <typename T>
void LogStream::formatInteger(T v) {
	constexpr static int kMaxNumericSize = std::numeric_limits<T>::digits10 + 4;
	if (exBuffer_.empty()) {
		if (buffer_.avail() >= kMaxNumericSize) {
			size_t len = convert(buffer_.current(), v);
			buffer_.add(len);
			return;
		} else {
			exBuffer_.append(buffer_.data(), buffer_.length());
		}
	}
	auto oldLen = exBuffer_.length();
	exBuffer_.resize(oldLen + kMaxNumericSize);
	size_t len = convert(&exBuffer_[oldLen], v);
	exBuffer_.resize(oldLen + len);
}

LogStream &LogStream::operator<<(short v) {
	*this << static_cast<int>(v);
	return *this;
}

LogStream &LogStream::operator<<(unsigned short v) {
	*this << static_cast<unsigned int>(v);
	return *this;
}

LogStream &LogStream::operator<<(int v) {
	formatInteger(v);
	return *this;
}

LogStream &LogStream::operator<<(unsigned int v) {
	formatInteger(v);
	return *this;
}

LogStream &LogStream::operator<<(long v) {
	formatInteger(v);
	return *this;
}

LogStream &LogStream::operator<<(unsigned long v) {
	formatInteger(v);
	return *this;
}

LogStream &LogStream::operator<<(const long long &v) {
	formatInteger(v);
	return *this;
}

LogStream &LogStream::operator<<(const unsigned long long &v) {
	formatInteger(v);
	return *this;
}

LogStream &LogStream::operator<<(const void *p) {
	uintptr_t v = reinterpret_cast<uintptr_t>(p);
	constexpr static int kMaxNumericSize =
			std::numeric_limits<uintptr_t>::digits / 4 + 4;
	if (exBuffer_.empty()) {
		if (buffer_.avail() >= kMaxNumericSize) {
			char *buf = buffer_.current();
			buf[0] = '0';
			buf[1] = 'x';
			size_t len = convertHex(buf + 2, v);
			buffer_.add(len + 2);
			return *this;
		} else {
			exBuffer_.append(buffer_.data(), buffer_.length());
		}
	}
	auto oldLen = exBuffer_.length();
	exBuffer_.resize(oldLen + kMaxNumericSize);
	char *buf = &exBuffer_[oldLen];
	buf[0] = '0';
	buf[1] = 'x';
	size_t len = convertHex(buf + 2, v);
	exBuffer_.resize(oldLen + len + 2);
	return *this;
}

// TODO: replace this with Grisu3 by Florian Loitsch.
LogStream &LogStream::operator<<(const double &v) {
	constexpr static int kMaxNumericSize = 32;
	if (exBuffer_.empty()) {
		if (buffer_.avail() >= kMaxNumericSize) {
			int len = snprintf(buffer_.current(), kMaxNumericSize, "%.12g", v);
			buffer_.add(len);
			return *this;
		} else {
			exBuffer_.append(buffer_.data(), buffer_.length());
		}
	}
	auto oldLen = exBuffer_.length();
	exBuffer_.resize(oldLen + kMaxNumericSize);
	int len = snprintf(&(exBuffer_[oldLen]), kMaxNumericSize, "%.12g", v);
	exBuffer_.resize(oldLen + len);
	return *this;
}

LogStream &LogStream::operator<<(const long double &v) {
	constexpr static int kMaxNumericSize = 48;
	if (exBuffer_.empty()) {
		if (buffer_.avail() >= kMaxNumericSize) {
			int len = snprintf(buffer_.current(), kMaxNumericSize, "%.12Lg", v);
			buffer_.add(len);
			return *this;
		} else {
			exBuffer_.append(buffer_.data(), buffer_.length());
		}
	}
	auto oldLen = exBuffer_.length();
	exBuffer_.resize(oldLen + kMaxNumericSize);
	int len = snprintf(&(exBuffer_[oldLen]), kMaxNumericSize, "%.12Lg", v);
	exBuffer_.resize(oldLen + len);
	return *this;
}

template <typename T>
Fmt::Fmt(const char *fmt, T val) {
	length_ = snprintf(buf_, sizeof buf_, fmt, val);
	assert(static_cast<size_t>(length_) < sizeof buf_);
}

// Explicit instantiations

template Fmt::Fmt(const char *fmt, char);

template Fmt::Fmt(const char *fmt, short);
template Fmt::Fmt(const char *fmt, unsigned short);
template Fmt::Fmt(const char *fmt, int);
template Fmt::Fmt(const char *fmt, unsigned int);
template Fmt::Fmt(const char *fmt, long);
template Fmt::Fmt(const char *fmt, unsigned long);
template Fmt::Fmt(const char *fmt, long long);
template Fmt::Fmt(const char *fmt, unsigned long long);

template Fmt::Fmt(const char *fmt, float);
template Fmt::Fmt(const char *fmt, double);