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stringpiece.cc
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stringpiece.cc
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// Copyright 2010 Google
// 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 <iostream>
#include <utility>
#include "base/stringpiece.h"
std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
o.write(piece.data(), piece.size());
return o;
}
bool operator==(const StringPiece& x, const StringPiece& y) {
int len = x.size();
if (len != y.size()) {
return false;
}
const char* p = x.data();
const char* p2 = y.data();
// Test last byte in case strings share large common prefix
if ((len > 0) && (p[len-1] != p2[len-1])) return false;
const char* p_limit = p + len;
for (; p < p_limit; p++, p2++) {
if (*p != *p2)
return false;
}
return true;
}
bool operator<(const StringPiece& x,
const StringPiece& y) {
const int r = memcmp(x.data(), y.data(),
std::min(x.size(), y.size()));
return ((r < 0) || ((r == 0) && (x.size() < y.size())));
}
void StringPiece::CopyToString(std::string* target) const {
target->assign(ptr_, length_);
}
int StringPiece::copy(char* buf, size_type n, size_type pos) const {
int ret = std::min(length_ - pos, n);
memcpy(buf, ptr_ + pos, ret);
return ret;
}
int StringPiece::find(const StringPiece& s, size_type pos) const {
if (length_ < 0 || pos > static_cast<size_type>(length_))
return npos;
const char* result = std::search(ptr_ + pos, ptr_ + length_,
s.ptr_, s.ptr_ + s.length_);
const size_type xpos = result - ptr_;
return xpos + s.length_ <= length_ ? xpos : npos;
}
int StringPiece::compare(const StringPiece& x) const {
int r = memcmp(ptr_, x.ptr_, std::min(length_, x.length_));
if (r == 0) {
if (length_ < x.length_) r = -1;
else if (length_ > x.length_) r = +1;
}
return r;
}
int StringPiece::find(char c, size_type pos) const {
if (length_ <= 0 || pos >= static_cast<size_type>(length_)) {
return npos;
}
const char* result = std::find(ptr_ + pos, ptr_ + length_, c);
return result != ptr_ + length_ ? result - ptr_ : npos;
}
int StringPiece::rfind(const StringPiece& s, size_type pos) const {
if (length_ < s.length_) return npos;
const size_t ulen = length_;
if (s.length_ == 0) return std::min(ulen, pos);
const char* last = ptr_ + std::min(ulen - s.length_, pos) + s.length_;
const char* result = std::find_end(ptr_, last, s.ptr_, s.ptr_ + s.length_);
return result != last ? result - ptr_ : npos;
}
int StringPiece::rfind(char c, size_type pos) const {
if (length_ <= 0) return npos;
for (int i = std::min(pos, static_cast<size_type>(length_ - 1));
i >= 0; --i) {
if (ptr_[i] == c) {
return i;
}
}
return npos;
}
StringPiece StringPiece::substr(size_type pos, size_type n) const {
if (pos > length_) pos = length_;
if (n > length_ - pos) n = length_ - pos;
return StringPiece(ptr_ + pos, n);
}
const StringPiece::size_type StringPiece::npos = size_type(-1);