michael@0: // Copyright 2013 Google Inc. All Rights Reserved.
michael@0: //
michael@0: // Licensed under the Apache License, Version 2.0 (the "License");
michael@0: // you may not use this file except in compliance with the License.
michael@0: // You may obtain a copy of the License at
michael@0: //
michael@0: //     http://www.apache.org/licenses/LICENSE-2.0
michael@0: //
michael@0: // Unless required by applicable law or agreed to in writing, software
michael@0: // distributed under the License is distributed on an "AS IS" BASIS,
michael@0: // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
michael@0: // See the License for the specific language governing permissions and
michael@0: // limitations under the License.
michael@0: 
michael@0: //
michael@0: // A StringPiece points to part or all of a string, double-quoted string
michael@0: // literal, or other string-like object.  A StringPiece does *not* own the
michael@0: // string to which it points.  A StringPiece is not null-terminated. [subset]
michael@0: //
michael@0: 
michael@0: #ifndef STRINGS_STRINGPIECE_H_
michael@0: #define STRINGS_STRINGPIECE_H_
michael@0: 
michael@0: #include <string.h>
michael@0: #include <string>
michael@0: 
michael@0: 
michael@0: typedef int stringpiece_ssize_type;
michael@0: 
michael@0: class StringPiece {
michael@0:  private:
michael@0:   const char* ptr_;
michael@0:   stringpiece_ssize_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: 
michael@0:   StringPiece(const char* str)  // NOLINT(runtime/explicit)
michael@0:       : ptr_(str), length_(0) {
michael@0:     if (str != NULL) {
michael@0:       length_ = strlen(str);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   StringPiece(const std::string& str)  // NOLINT(runtime/explicit)
michael@0:       : ptr_(str.data()), length_(0) {
michael@0:     length_ = str.size();
michael@0:   }
michael@0: 
michael@0:   StringPiece(const char* offset, stringpiece_ssize_type len)
michael@0:       : ptr_(offset), length_(len) {
michael@0:   }
michael@0: 
michael@0:   void remove_prefix(stringpiece_ssize_type n) {
michael@0:     ptr_ += n;
michael@0:     length_ -= n;
michael@0:   }
michael@0: 
michael@0:   void remove_suffix(stringpiece_ssize_type n) {
michael@0:     length_ -= n;
michael@0:   }
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:   stringpiece_ssize_type size() const { return length_; }
michael@0:   stringpiece_ssize_type length() const { return length_; }
michael@0:   bool empty() const { return length_ == 0; }
michael@0: };
michael@0: 
michael@0: class StringPiece;
michael@0: 
michael@0: #endif  // STRINGS_STRINGPIECE_H__