michael@0: // Copyright (C) 2009-2013, International Business Machines
michael@0: // Corporation and others. All Rights Reserved.
michael@0: //
michael@0: // Copyright 2004 and onwards Google Inc.
michael@0: //
michael@0: // Author: wilsonh@google.com (Wilson Hsieh)
michael@0: //
michael@0: 
michael@0: #include "unicode/utypes.h"
michael@0: #include "unicode/stringpiece.h"
michael@0: #include "cstring.h"
michael@0: #include "cmemory.h"
michael@0: 
michael@0: U_NAMESPACE_BEGIN
michael@0: 
michael@0: StringPiece::StringPiece(const char* str)
michael@0:     : ptr_(str), length_((str == NULL) ? 0 : static_cast<int32_t>(uprv_strlen(str))) { }
michael@0: 
michael@0: StringPiece::StringPiece(const StringPiece& x, int32_t pos) {
michael@0:   if (pos < 0) {
michael@0:     pos = 0;
michael@0:   } else if (pos > x.length_) {
michael@0:     pos = x.length_;
michael@0:   }
michael@0:   ptr_ = x.ptr_ + pos;
michael@0:   length_ = x.length_ - pos;
michael@0: }
michael@0: 
michael@0: StringPiece::StringPiece(const StringPiece& x, int32_t pos, int32_t len) {
michael@0:   if (pos < 0) {
michael@0:     pos = 0;
michael@0:   } else if (pos > x.length_) {
michael@0:     pos = x.length_;
michael@0:   }
michael@0:   if (len < 0) {
michael@0:     len = 0;
michael@0:   } else if (len > x.length_ - pos) {
michael@0:     len = x.length_ - pos;
michael@0:   }
michael@0:   ptr_ = x.ptr_ + pos;
michael@0:   length_ = len;
michael@0: }
michael@0: 
michael@0: void StringPiece::set(const char* str) {
michael@0:   ptr_ = str;
michael@0:   if (str != NULL)
michael@0:     length_ = static_cast<int32_t>(uprv_strlen(str));
michael@0:   else
michael@0:     length_ = 0;
michael@0: }
michael@0: 
michael@0: U_EXPORT UBool U_EXPORT2
michael@0: operator==(const StringPiece& x, const StringPiece& y) {
michael@0:   int32_t len = x.size();
michael@0:   if (len != y.size()) {
michael@0:     return false;
michael@0:   }
michael@0:   if (len == 0) {
michael@0:     return true;
michael@0:   }
michael@0:   const char* p = x.data();
michael@0:   const char* p2 = y.data();
michael@0:   // Test last byte in case strings share large common prefix
michael@0:   --len;
michael@0:   if (p[len] != p2[len]) return false;
michael@0:   // At this point we can, but don't have to, ignore the last byte.
michael@0:   return uprv_memcmp(p, p2, len) == 0;
michael@0: }
michael@0: 
michael@0: 
michael@0: const int32_t StringPiece::npos = 0x7fffffff;
michael@0: 
michael@0: U_NAMESPACE_END