git / moonbite-core / src/leveldb/util/logging.cc · raw

// Copyright (c) 2011 The LevelDB Authors. All rights reserved.// Use of this source code is governed by a BSD-style license that can be// found in the LICENSE file. See the AUTHORS file for names of contributors.#include "util/logging.h"#include <errno.h>#include <stdarg.h>#include <stdio.h>#include <stdlib.h>#include <limits>#include "leveldb/env.h"#include "leveldb/slice.h"namespace leveldb {void AppendNumberTo(std::string* str, uint64_t num) {  char buf[30];  snprintf(buf, sizeof(buf), "%llu", (unsigned long long)num);  str->append(buf);}void AppendEscapedStringTo(std::string* str, const Slice& value) {  for (size_t i = 0; i < value.size(); i++) {    char c = value[i];    if (c >= ' ' && c <= '~') {      str->push_back(c);    } else {      char buf[10];      snprintf(buf, sizeof(buf), "\\x%02x",               static_cast<unsigned int>(c) & 0xff);      str->append(buf);    }  }}std::string NumberToString(uint64_t num) {  std::string r;  AppendNumberTo(&r, num);  return r;}std::string EscapeString(const Slice& value) {  std::string r;  AppendEscapedStringTo(&r, value);  return r;}bool ConsumeDecimalNumber(Slice* in, uint64_t* val) {  // Constants that will be optimized away.  constexpr const uint64_t kMaxUint64 = std::numeric_limits<uint64_t>::max();  constexpr const char kLastDigitOfMaxUint64 =      '0' + static_cast<char>(kMaxUint64 % 10);  uint64_t value = 0;  // reinterpret_cast-ing from char* to uint8_t* to avoid signedness.  const uint8_t* start = reinterpret_cast<const uint8_t*>(in->data());  const uint8_t* end = start + in->size();  const uint8_t* current = start;  for (; current != end; ++current) {    const uint8_t ch = *current;    if (ch < '0' || ch > '9') break;    // Overflow check.    // kMaxUint64 / 10 is also constant and will be optimized away.    if (value > kMaxUint64 / 10 ||        (value == kMaxUint64 / 10 && ch > kLastDigitOfMaxUint64)) {      return false;    }    value = (value * 10) + (ch - '0');  }  *val = value;  const size_t digits_consumed = current - start;  in->remove_prefix(digits_consumed);  return digits_consumed != 0;}}  // namespace leveldb