ClickHouse/contrib/libre2/util/stringpiece.cc

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// Copyright 2004 The RE2 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 "re2/stringpiece.h"
#include "util/util.h"
using re2::StringPiece;
std::ostream& operator<<(std::ostream& o, const StringPiece& piece) {
o.write(piece.data(), piece.size());
return o;
}
bool StringPiece::_equal(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;
}
void StringPiece::CopyToString(string* target) const {
target->assign(ptr_, length_);
}
int StringPiece::copy(char* buf, size_type n, size_type pos) const {
int ret = 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_;
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return xpos + s.length_ <= static_cast<size_type>(length_) ? xpos : npos;
}
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 min(ulen, pos);
const char* last = ptr_ + 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 = 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 {
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if (pos > static_cast<size_type>(length_)) pos = length_;
if (n > length_ - pos) n = length_ - pos;
return StringPiece(ptr_ + pos, n);
}
const StringPiece::size_type StringPiece::npos = size_type(-1);