michael@0: // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: // Copied from strings/stringpiece.h with modifications
michael@0: //
michael@0: // A string-like object that points to a sized piece of memory.
michael@0: //
michael@0: // Functions or methods may use const StringPiece& parameters to accept either
michael@0: // a "const char*" or a "string" value that will be implicitly converted to
michael@0: // a StringPiece.  The implicit conversion means that it is often appropriate
michael@0: // to include this .h file in other files rather than forward-declaring
michael@0: // StringPiece as would be appropriate for most other Google classes.
michael@0: //
michael@0: // Systematic usage of StringPiece is encouraged as it will reduce unnecessary
michael@0: // conversions from "const char*" to "string" and back again.
michael@0: //
michael@0: 
michael@0: #ifndef BASE_STRING_PIECE_H_
michael@0: #define BASE_STRING_PIECE_H_
michael@0: 
michael@0: #include <algorithm>
michael@0: #include <iosfwd>
michael@0: #include <string>
michael@0: 
michael@0: #include "base/basictypes.h"
michael@0: 
michael@0: class StringPiece {
michael@0:  public:
michael@0:   typedef size_t size_type;
michael@0: 
michael@0:  private:
michael@0:   const char*   ptr_;
michael@0:   size_type     length_;
michael@0: 
michael@0:  public:
michael@0:   // We provide non-explicit singleton constructors so users can pass
michael@0:   // in a "const char*" or a "string" wherever a "StringPiece" is
michael@0:   // expected.
michael@0:   StringPiece() : ptr_(NULL), length_(0) { }
michael@0:   StringPiece(const char* str)
michael@0:     : ptr_(str), length_((str == NULL) ? 0 : strlen(str)) { }
michael@0:   StringPiece(const std::string& str)
michael@0:     : ptr_(str.data()), length_(str.size()) { }
michael@0:   StringPiece(const char* offset, size_type len)
michael@0:     : ptr_(offset), length_(len) { }
michael@0: 
michael@0:   // data() may return a pointer to a buffer with embedded NULs, and the
michael@0:   // returned buffer may or may not be null terminated.  Therefore it is
michael@0:   // typically a mistake to pass data() to a routine that expects a NUL
michael@0:   // terminated string.
michael@0:   const char* data() const { return ptr_; }
michael@0:   size_type size() const { return length_; }
michael@0:   size_type length() const { return length_; }
michael@0:   bool empty() const { return length_ == 0; }
michael@0: 
michael@0:   void clear() { ptr_ = NULL; length_ = 0; }
michael@0:   void set(const char* data, size_type len) { ptr_ = data; length_ = len; }
michael@0:   void set(const char* str) {
michael@0:     ptr_ = str;
michael@0:     length_ = str ? strlen(str) : 0;
michael@0:   }
michael@0:   void set(const void* data, size_type len) {
michael@0:     ptr_ = reinterpret_cast<const char*>(data);
michael@0:     length_ = len;
michael@0:   }
michael@0: 
michael@0:   char operator[](size_type i) const { return ptr_[i]; }
michael@0: 
michael@0:   void remove_prefix(size_type n) {
michael@0:     ptr_ += n;
michael@0:     length_ -= n;
michael@0:   }
michael@0: 
michael@0:   void remove_suffix(size_type n) {
michael@0:     length_ -= n;
michael@0:   }
michael@0: 
michael@0:   int compare(const StringPiece& x) const {
michael@0:     int r = wordmemcmp(ptr_, x.ptr_, std::min(length_, x.length_));
michael@0:     if (r == 0) {
michael@0:       if (length_ < x.length_) r = -1;
michael@0:       else if (length_ > x.length_) r = +1;
michael@0:     }
michael@0:     return r;
michael@0:   }
michael@0: 
michael@0:   std::string as_string() const {
michael@0:     // std::string doesn't like to take a NULL pointer even with a 0 size.
michael@0:     return std::string(!empty() ? data() : "", size());
michael@0:   }
michael@0: 
michael@0:   void CopyToString(std::string* target) const;
michael@0:   void AppendToString(std::string* target) const;
michael@0: 
michael@0:   // Does "this" start with "x"
michael@0:   bool starts_with(const StringPiece& x) const {
michael@0:     return ((length_ >= x.length_) &&
michael@0:             (wordmemcmp(ptr_, x.ptr_, x.length_) == 0));
michael@0:   }
michael@0: 
michael@0:   // Does "this" end with "x"
michael@0:   bool ends_with(const StringPiece& x) const {
michael@0:     return ((length_ >= x.length_) &&
michael@0:             (wordmemcmp(ptr_ + (length_-x.length_), x.ptr_, x.length_) == 0));
michael@0:   }
michael@0: 
michael@0:   // standard STL container boilerplate
michael@0:   typedef char value_type;
michael@0:   typedef const char* pointer;
michael@0:   typedef const char& reference;
michael@0:   typedef const char& const_reference;
michael@0:   typedef ptrdiff_t difference_type;
michael@0:   static const size_type npos;
michael@0:   typedef const char* const_iterator;
michael@0:   typedef const char* iterator;
michael@0:   typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
michael@0:   typedef std::reverse_iterator<iterator> reverse_iterator;
michael@0:   iterator begin() const { return ptr_; }
michael@0:   iterator end() const { return ptr_ + length_; }
michael@0:   const_reverse_iterator rbegin() const {
michael@0:     return const_reverse_iterator(ptr_ + length_);
michael@0:   }
michael@0:   const_reverse_iterator rend() const {
michael@0:     return const_reverse_iterator(ptr_);
michael@0:   }
michael@0: 
michael@0:   size_type max_size() const { return length_; }
michael@0:   size_type capacity() const { return length_; }
michael@0: 
michael@0:   size_type copy(char* buf, size_type n, size_type pos = 0) const;
michael@0: 
michael@0:   size_type find(const StringPiece& s, size_type pos = 0) const;
michael@0:   size_type find(char c, size_type pos = 0) const;
michael@0:   size_type rfind(const StringPiece& s, size_type pos = npos) const;
michael@0:   size_type rfind(char c, size_type pos = npos) const;
michael@0: 
michael@0:   size_type find_first_of(const StringPiece& s, size_type pos = 0) const;
michael@0:   size_type find_first_of(char c, size_type pos = 0) const {
michael@0:     return find(c, pos);
michael@0:   }
michael@0:   size_type find_first_not_of(const StringPiece& s, size_type pos = 0) const;
michael@0:   size_type find_first_not_of(char c, size_type pos = 0) const;
michael@0:   size_type find_last_of(const StringPiece& s, size_type pos = npos) const;
michael@0:   size_type find_last_of(char c, size_type pos = npos) const {
michael@0:     return rfind(c, pos);
michael@0:   }
michael@0:   size_type find_last_not_of(const StringPiece& s, size_type pos = npos) const;
michael@0:   size_type find_last_not_of(char c, size_type pos = npos) const;
michael@0: 
michael@0:   StringPiece substr(size_type pos, size_type n = npos) const;
michael@0: 
michael@0:   static int wordmemcmp(const char* p, const char* p2, size_type N) {
michael@0:     return memcmp(p, p2, N);
michael@0:   }
michael@0: };
michael@0: 
michael@0: bool operator==(const ::StringPiece& x, const ::StringPiece& y);
michael@0: 
michael@0: inline bool operator!=(const ::StringPiece& x, const ::StringPiece& y) {
michael@0:   return !(x == y);
michael@0: }
michael@0: 
michael@0: inline bool operator<(const ::StringPiece& x, const ::StringPiece& y) {
michael@0:   const int r = ::StringPiece::wordmemcmp(x.data(), y.data(),
michael@0:                                         std::min(x.size(), y.size()));
michael@0:   return ((r < 0) || ((r == 0) && (x.size() < y.size())));
michael@0: }
michael@0: 
michael@0: inline bool operator>(const ::StringPiece& x, const ::StringPiece& y) {
michael@0:   return y < x;
michael@0: }
michael@0: 
michael@0: inline bool operator<=(const ::StringPiece& x, const ::StringPiece& y) {
michael@0:   return !(x > y);
michael@0: }
michael@0: 
michael@0: inline bool operator>=(const ::StringPiece& x, const ::StringPiece& y) {
michael@0:   return !(x < y);
michael@0: }
michael@0: 
michael@0: // allow StringPiece to be logged (needed for unit testing).
michael@0: extern std::ostream& operator<<(std::ostream& o, const ::StringPiece& piece);
michael@0: 
michael@0: #endif  // BASE_STRING_PIECE_H_