ecency-mobile/ios/Pods/Folly/folly/json_pointer.cpp
2019-05-29 14:32:35 +03:00

114 lines
3.0 KiB
C++

/*
* Copyright 2011-present Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <folly/json_pointer.h>
#include <folly/String.h>
namespace folly {
// static, public
Expected<json_pointer, json_pointer::parse_error> json_pointer::try_parse(
StringPiece const str) {
// pointer describes complete document
if (str.empty()) {
return json_pointer{};
}
if (str.at(0) != '/') {
return makeUnexpected(parse_error::invalid_first_character);
}
std::vector<std::string> tokens;
splitTo<std::string>("/", str, std::inserter(tokens, tokens.begin()));
tokens.erase(tokens.begin());
for (auto& token : tokens) {
if (!unescape(token)) {
return makeUnexpected(parse_error::invalid_escape_sequence);
}
}
return json_pointer(std::move(tokens));
}
// static, public
json_pointer json_pointer::parse(StringPiece const str) {
auto res = try_parse(str);
if (res.hasValue()) {
return std::move(res.value());
}
switch (res.error()) {
case parse_error::invalid_first_character:
throw json_pointer::parse_exception(
"non-empty JSON pointer string does not start with '/'");
case parse_error::invalid_escape_sequence:
throw json_pointer::parse_exception(
"Invalid escape sequence in JSON pointer string");
default:
assume_unreachable();
}
}
bool json_pointer::is_prefix_of(json_pointer const& other) const noexcept {
auto const& other_tokens = other.tokens();
if (tokens_.size() > other_tokens.size()) {
return false;
}
auto const other_begin = other_tokens.cbegin();
auto const other_end = other_tokens.cbegin() + tokens_.size();
return std::equal(tokens_.cbegin(), tokens_.cend(), other_begin, other_end);
}
std::vector<std::string> const& json_pointer::tokens() const {
return tokens_;
}
// private
json_pointer::json_pointer(std::vector<std::string> tokens) noexcept
: tokens_{std::move(tokens)} {}
// private, static
bool json_pointer::unescape(std::string& str) {
char const* end = &str[str.size()];
char* out = &str.front();
char const* decode = out;
while (decode < end) {
if (*decode != '~') {
*out++ = *decode++;
continue;
}
if (decode + 1 == end) {
return false;
}
switch (decode[1]) {
case '1':
*out++ = '/';
break;
case '0':
*out++ = '~';
break;
default:
return false;
}
decode += 2;
}
str.resize(out - &str.front());
return true;
}
} // namespace folly