shaka-packager/base/json/string_escape.cc

106 lines
2.8 KiB
C++

// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/json/string_escape.h"
#include <string>
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
namespace base {
namespace {
// Try to escape |c| as a "SingleEscapeCharacter" (\n, etc). If successful,
// returns true and appends the escape sequence to |dst|. This isn't required
// by the spec, but it's more readable by humans than the \uXXXX alternatives.
template<typename CHAR>
static bool JsonSingleEscapeChar(const CHAR c, std::string* dst) {
// WARNING: if you add a new case here, you need to update the reader as well.
// Note: \v is in the reader, but not here since the JSON spec doesn't
// allow it.
switch (c) {
case '\b':
dst->append("\\b");
break;
case '\f':
dst->append("\\f");
break;
case '\n':
dst->append("\\n");
break;
case '\r':
dst->append("\\r");
break;
case '\t':
dst->append("\\t");
break;
case '\\':
dst->append("\\\\");
break;
case '"':
dst->append("\\\"");
break;
default:
return false;
}
return true;
}
template <class STR>
void JsonDoubleQuoteT(const STR& str,
bool put_in_quotes,
std::string* dst) {
if (put_in_quotes)
dst->push_back('"');
for (typename STR::const_iterator it = str.begin(); it != str.end(); ++it) {
typename ToUnsigned<typename STR::value_type>::Unsigned c = *it;
if (!JsonSingleEscapeChar(c, dst)) {
if (c < 32 || c > 126 || c == '<' || c == '>') {
// 1. Escaping <, > to prevent script execution.
// 2. Technically, we could also pass through c > 126 as UTF8, but this
// is also optional. It would also be a pain to implement here.
unsigned int as_uint = static_cast<unsigned int>(c);
base::StringAppendF(dst, "\\u%04X", as_uint);
} else {
unsigned char ascii = static_cast<unsigned char>(*it);
dst->push_back(ascii);
}
}
}
if (put_in_quotes)
dst->push_back('"');
}
} // namespace
void JsonDoubleQuote(const std::string& str,
bool put_in_quotes,
std::string* dst) {
JsonDoubleQuoteT(str, put_in_quotes, dst);
}
std::string GetDoubleQuotedJson(const std::string& str) {
std::string dst;
JsonDoubleQuote(str, true, &dst);
return dst;
}
void JsonDoubleQuote(const string16& str,
bool put_in_quotes,
std::string* dst) {
JsonDoubleQuoteT(str, put_in_quotes, dst);
}
std::string GetDoubleQuotedJson(const string16& str) {
std::string dst;
JsonDoubleQuote(str, true, &dst);
return dst;
}
} // namespace base