1 // Copyright (c) 2011 The LevelDB Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. See the AUTHORS file for names of contributors. 4 5 #include "util/logging.h" 6 7 #include <errno.h> 8 #include <stdarg.h> 9 #include <stdio.h> 10 #include <stdlib.h> 11 #include "leveldb/env.h" 12 #include "leveldb/slice.h" 13 14 namespace leveldb { 15 16 void AppendNumberTo(std::string* str, uint64_t num) { 17 char buf[30]; 18 snprintf(buf, sizeof(buf), "%llu", (unsigned long long) num); 19 str->append(buf); 20 } 21 22 void AppendEscapedStringTo(std::string* str, const Slice& value) { 23 for (size_t i = 0; i < value.size(); i++) { 24 char c = value[i]; 25 if (c >= ' ' && c <= '~') { 26 str->push_back(c); 27 } else { 28 char buf[10]; 29 snprintf(buf, sizeof(buf), "\\x%02x", 30 static_cast<unsigned int>(c) & 0xff); 31 str->append(buf); 32 } 33 } 34 } 35 36 std::string NumberToString(uint64_t num) { 37 std::string r; 38 AppendNumberTo(&r, num); 39 return r; 40 } 41 42 std::string EscapeString(const Slice& value) { 43 std::string r; 44 AppendEscapedStringTo(&r, value); 45 return r; 46 } 47 48 bool ConsumeChar(Slice* in, char c) { 49 if (!in->empty() && (*in)[0] == c) { 50 in->remove_prefix(1); 51 return true; 52 } else { 53 return false; 54 } 55 } 56 57 bool ConsumeDecimalNumber(Slice* in, uint64_t* val) { 58 uint64_t v = 0; 59 int digits = 0; 60 while (!in->empty()) { 61 char c = (*in)[0]; 62 if (c >= '0' && c <= '9') { 63 ++digits; 64 const int delta = (c - '0'); 65 static const uint64_t kMaxUint64 = ~static_cast<uint64_t>(0); 66 if (v > kMaxUint64/10 || 67 (v == kMaxUint64/10 && delta > kMaxUint64%10)) { 68 // Overflow 69 return false; 70 } 71 v = (v * 10) + delta; 72 in->remove_prefix(1); 73 } else { 74 break; 75 } 76 } 77 *val = v; 78 return (digits > 0); 79 } 80 81 } // namespace leveldb 82
