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
AppendNumberTo(std::string * str,uint64_t num)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
AppendEscapedStringTo(std::string * str,const Slice & value)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
NumberToString(uint64_t num)36 std::string NumberToString(uint64_t num) {
37 std::string r;
38 AppendNumberTo(&r, num);
39 return r;
40 }
41
EscapeString(const Slice & value)42 std::string EscapeString(const Slice& value) {
43 std::string r;
44 AppendEscapedStringTo(&r, value);
45 return r;
46 }
47
ConsumeChar(Slice * in,char c)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
ConsumeDecimalNumber(Slice * in,uint64_t * val)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