NS-3 based Named Data Networking (NDN) simulator
ndnSIM 2.3: NDN, CCN, CCNx, content centric networks
API Documentation
string-helper.cpp
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1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3  * Copyright (c) 2013-2017 Regents of the University of California.
4  *
5  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
6  *
7  * ndn-cxx library is free software: you can redistribute it and/or modify it under the
8  * terms of the GNU Lesser General Public License as published by the Free Software
9  * Foundation, either version 3 of the License, or (at your option) any later version.
10  *
11  * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
12  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
13  * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
14  *
15  * You should have received copies of the GNU General Public License and GNU Lesser
16  * General Public License along with ndn-cxx, e.g., in COPYING.md file. If not, see
17  * <http://www.gnu.org/licenses/>.
18  *
19  * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
20  */
21 
22 #include "string-helper.hpp"
23 #include "../encoding/buffer.hpp"
24 #include "../encoding/buffer-stream.hpp"
25 #include "../security/transform/buffer-source.hpp"
26 #include "../security/transform/hex-decode.hpp"
27 #include "../security/transform/hex-encode.hpp"
28 #include "../security/transform/stream-sink.hpp"
29 
30 #include <sstream>
31 
32 namespace ndn {
33 
34 std::ostream&
35 operator<<(std::ostream& os, const AsHex& hex)
36 {
37  printHex(os, hex.m_value, os.flags() & std::ostream::uppercase);
38  return os;
39 }
40 
41 void
42 printHex(std::ostream& os, uint64_t num, bool wantUpperCase)
43 {
44  auto osFlags = os.flags();
45  // std::showbase doesn't work with number 0
46  os << "0x" << std::noshowbase << std::noshowpos
47  << (wantUpperCase ? std::uppercase : std::nouppercase)
48  << std::hex << num;
49  os.flags(osFlags);
50 }
51 
52 void
53 printHex(std::ostream& os, const uint8_t* buffer, size_t length, bool wantUpperCase)
54 {
55  namespace tr = security::transform;
56  BOOST_ASSERT(buffer != nullptr || length == 0);
57  tr::bufferSource(buffer, length) >> tr::hexEncode(wantUpperCase) >> tr::streamSink(os);
58 }
59 
60 void
61 printHex(std::ostream& os, const Buffer& buffer, bool wantUpperCase)
62 {
63  return printHex(os, buffer.data(), buffer.size(), wantUpperCase);
64 }
65 
66 std::string
67 toHex(const uint8_t* buffer, size_t length, bool wantUpperCase)
68 {
69  std::ostringstream result;
70  printHex(result, buffer, length, wantUpperCase);
71  return result.str();
72 }
73 
74 std::string
75 toHex(const Buffer& buffer, bool wantUpperCase)
76 {
77  return toHex(buffer.data(), buffer.size(), wantUpperCase);
78 }
79 
80 int
81 fromHexChar(char c)
82 {
83  if (c >= '0' && c <= '9')
84  return c - '0';
85  else if (c >= 'A' && c <= 'F')
86  return c - 'A' + 0xA;
87  else if (c >= 'a' && c <= 'f')
88  return c - 'a' + 0xA;
89  else
90  return -1;
91 }
92 
93 shared_ptr<Buffer>
94 fromHex(const std::string& hexString)
95 {
96  namespace tr = security::transform;
97 
98  OBufferStream os;
99  try {
100  tr::bufferSource(hexString) >> tr::hexDecode() >> tr::streamSink(os);
101  }
102  catch (const tr::Error& e) {
103  BOOST_THROW_EXCEPTION(StringHelperError(std::string("Conversion from hex failed: ") + e.what()));
104  }
105 
106  return os.buf();
107 }
108 
109 std::string
110 unescape(const std::string& str)
111 {
112  std::ostringstream result;
113 
114  for (size_t i = 0; i < str.size(); ++i) {
115  if (str[i] == '%' && i + 2 < str.size()) {
116  int hi = fromHexChar(str[i + 1]);
117  int lo = fromHexChar(str[i + 2]);
118 
119  if (hi < 0 || lo < 0)
120  // Invalid hex characters, so just keep the escaped string.
121  result << str[i] << str[i + 1] << str[i + 2];
122  else
123  result << static_cast<char>((hi << 4) | lo);
124 
125  // Skip ahead past the escaped value.
126  i += 2;
127  }
128  else {
129  // Just copy through.
130  result << str[i];
131  }
132  }
133 
134  return result.str();
135 }
136 
137 } // namespace ndn
Copyright (c) 2011-2015 Regents of the University of California.
std::string toHex(const uint8_t *buffer, size_t length, bool wantUpperCase)
Return a string containing the hex representation of the bytes in buffer.
std::ostream & operator<<(std::ostream &os, const Data &data)
Definition: data.cpp:274
unique_ptr< Transform > hexEncode(bool useUpperCase)
Definition: hex-encode.cpp:69
Helper class to convert a number to hexadecimal format, for use with stream insertion operators...
shared_ptr< Buffer > fromHex(const std::string &hexString)
Convert the hex string to buffer.
unique_ptr< Sink > streamSink(std::ostream &os)
Definition: stream-sink.cpp:53
std::string unescape(const std::string &str)
Decode a percent-encoded string.
int fromHexChar(char c)
Convert the hex character to an integer from 0 to 15, or -1 if not a hex character.
unique_ptr< Transform > hexDecode()
Definition: hex-decode.cpp:111
shared_ptr< Buffer > buf()
Flush written data to the stream and return shared pointer to the underlying buffer.
void printHex(std::ostream &os, uint64_t num, bool wantUpperCase)
Output the hex representation of num to the output stream os.
implements an output stream that constructs ndn::Buffer
General-purpose automatically managed/resized buffer.
Definition: buffer.hpp:40