| // 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. |
| // 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 <algorithm> |
| #include <iosfwd> |
| #include <string> |
| |
| #include "base/basictypes.h" |
| |
| namespace base { |
| |
| class StringPiece { |
| public: |
| typedef size_t size_type; |
| |
| private: |
| const char* ptr_; |
| size_type length_; |
| |
| 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_, std::min(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)); |
| } |
| |
| // standard STL container boilerplate |
| typedef char value_type; |
| typedef const char* pointer; |
| typedef const char& reference; |
| typedef const char& const_reference; |
| typedef ptrdiff_t difference_type; |
| static const size_type npos; |
| 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; |
| 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); |
| } |
| }; |
| |
| 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(), |
| std::min(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); |
| } |
| |
| // allow StringPiece to be logged (needed for unit testing). |
| extern std::ostream& operator<<(std::ostream& o, const StringPiece& piece); |
| |
| } // namespace base |
| |
| #endif // BASE_STRING_PIECE_H_ |