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// Copyright (c) 2011 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.
// Copied from strings/stringpiece.h with modifications
//
// A string-like object that points to a sized piece of memory.
//
// Functions or methods may use const StringPiece& parameters to accept either
// a "const char*" or a "string" value that will be implicitly converted to
// a StringPiece. The implicit conversion means that it is often appropriate
// to include this .h file in other files rather than forward-declaring
// StringPiece as would be appropriate for most other Google classes.
//
// Systematic usage of StringPiece is encouraged as it will reduce unnecessary
// conversions from "const char*" to "string" and back again.
//
#ifndef BASE_STRING_PIECE_H_
#define BASE_STRING_PIECE_H_
#pragma once
#include <string>
#include "base/base_api.h"
#include "base/basictypes.h"
namespace base {
class BASE_API StringPiece {
public:
// standard STL container boilerplate
typedef size_t size_type;
typedef char value_type;
typedef const char* pointer;
typedef const char& reference;
typedef const char& const_reference;
typedef ptrdiff_t difference_type;
typedef const char* const_iterator;
typedef const char* iterator;
typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
typedef std::reverse_iterator<iterator> reverse_iterator;
static const size_type npos;
public:
// We provide non-explicit singleton constructors so users can pass
// in a "const char*" or a "string" wherever a "StringPiece" is
// expected.
StringPiece() : ptr_(NULL), length_(0) { }
StringPiece(const char* str)
: ptr_(str), length_((str == NULL) ? 0 : strlen(str)) { }
StringPiece(const std::string& str)
: ptr_(str.data()), length_(str.size()) { }
StringPiece(const char* offset, size_type len)
: ptr_(offset), length_(len) { }
// data() may return a pointer to a buffer with embedded NULs, and the
// returned buffer may or may not be null terminated. Therefore it is
// typically a mistake to pass data() to a routine that expects a NUL
// terminated string.
const char* data() const { return ptr_; }
size_type size() const { return length_; }
size_type length() const { return length_; }
bool empty() const { return length_ == 0; }
void clear() {
ptr_ = NULL;
length_ = 0;
}
void set(const char* data, size_type len) {
ptr_ = data;
length_ = len;
}
void set(const char* str) {
ptr_ = str;
length_ = str ? strlen(str) : 0;
}
void set(const void* data, size_type len) {
ptr_ = reinterpret_cast<const char*>(data);
length_ = len;
}
char operator[](size_type i) const { return ptr_[i]; }
void remove_prefix(size_type n) {
ptr_ += n;
length_ -= n;
}
void remove_suffix(size_type n) {
length_ -= n;
}
int compare(const StringPiece& x) const {
int r = wordmemcmp(
ptr_, x.ptr_, (length_ < x.length_ ? length_ : x.length_));
if (r == 0) {
if (length_ < x.length_) r = -1;
else if (length_ > x.length_) r = +1;
}
return r;
}
std::string as_string() const {
// std::string doesn't like to take a NULL pointer even with a 0 size.
return std::string(!empty() ? data() : "", size());
}
void CopyToString(std::string* target) const;
void AppendToString(std::string* target) const;
// Does "this" start with "x"
bool starts_with(const StringPiece& x) const {
return ((length_ >= x.length_) &&
(wordmemcmp(ptr_, x.ptr_, x.length_) == 0));
}
// Does "this" end with "x"
bool ends_with(const StringPiece& x) const {
return ((length_ >= x.length_) &&
(wordmemcmp(ptr_ + (length_-x.length_), x.ptr_, x.length_) == 0));
}
iterator begin() const { return ptr_; }
iterator end() const { return ptr_ + length_; }
const_reverse_iterator rbegin() const {
return const_reverse_iterator(ptr_ + length_);
}
const_reverse_iterator rend() const {
return const_reverse_iterator(ptr_);
}
size_type max_size() const { return length_; }
size_type capacity() const { return length_; }
size_type copy(char* buf, size_type n, size_type pos = 0) const;
size_type find(const StringPiece& s, size_type pos = 0) const;
size_type find(char c, size_type pos = 0) const;
size_type rfind(const StringPiece& s, size_type pos = npos) const;
size_type rfind(char c, size_type pos = npos) const;
size_type find_first_of(const StringPiece& s, size_type pos = 0) const;
size_type find_first_of(char c, size_type pos = 0) const {
return find(c, pos);
}
size_type find_first_not_of(const StringPiece& s, size_type pos = 0) const;
size_type find_first_not_of(char c, size_type pos = 0) const;
size_type find_last_of(const StringPiece& s, size_type pos = npos) const;
size_type find_last_of(char c, size_type pos = npos) const {
return rfind(c, pos);
}
size_type find_last_not_of(const StringPiece& s, size_type pos = npos) const;
size_type find_last_not_of(char c, size_type pos = npos) const;
StringPiece substr(size_type pos, size_type n = npos) const;
static int wordmemcmp(const char* p, const char* p2, size_type N) {
return memcmp(p, p2, N);
}
private:
const char* ptr_;
size_type length_;
};
BASE_API bool operator==(const StringPiece& x, const StringPiece& y);
inline bool operator!=(const StringPiece& x, const StringPiece& y) {
return !(x == y);
}
inline bool operator<(const StringPiece& x, const StringPiece& y) {
const int r = StringPiece::wordmemcmp(
x.data(), y.data(), (x.size() < y.size() ? x.size() : y.size()));
return ((r < 0) || ((r == 0) && (x.size() < y.size())));
}
inline bool operator>(const StringPiece& x, const StringPiece& y) {
return y < x;
}
inline bool operator<=(const StringPiece& x, const StringPiece& y) {
return !(x > y);
}
inline bool operator>=(const StringPiece& x, const StringPiece& y) {
return !(x < y);
}
} // namespace base
#endif // BASE_STRING_PIECE_H_
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