1 // Copyright (C) 2009-2013, International Business Machines 2 // Corporation and others. All Rights Reserved. 3 // 4 // Copyright 2004 and onwards Google Inc. 5 // 6 // Author: wilsonh (at) google.com (Wilson Hsieh) 7 // 8 9 #include "unicode/utypes.h" 10 #include "unicode/stringpiece.h" 11 #include "cstring.h" 12 #include "cmemory.h" 13 14 U_NAMESPACE_BEGIN 15 16 StringPiece::StringPiece(const char* str) 17 : ptr_(str), length_((str == NULL) ? 0 : static_cast<int32_t>(uprv_strlen(str))) { } 18 19 StringPiece::StringPiece(const StringPiece& x, int32_t pos) { 20 if (pos < 0) { 21 pos = 0; 22 } else if (pos > x.length_) { 23 pos = x.length_; 24 } 25 ptr_ = x.ptr_ + pos; 26 length_ = x.length_ - pos; 27 } 28 29 StringPiece::StringPiece(const StringPiece& x, int32_t pos, int32_t len) { 30 if (pos < 0) { 31 pos = 0; 32 } else if (pos > x.length_) { 33 pos = x.length_; 34 } 35 if (len < 0) { 36 len = 0; 37 } else if (len > x.length_ - pos) { 38 len = x.length_ - pos; 39 } 40 ptr_ = x.ptr_ + pos; 41 length_ = len; 42 } 43 44 void StringPiece::set(const char* str) { 45 ptr_ = str; 46 if (str != NULL) 47 length_ = static_cast<int32_t>(uprv_strlen(str)); 48 else 49 length_ = 0; 50 } 51 52 U_EXPORT UBool U_EXPORT2 53 operator==(const StringPiece& x, const StringPiece& y) { 54 int32_t len = x.size(); 55 if (len != y.size()) { 56 return false; 57 } 58 if (len == 0) { 59 return true; 60 } 61 const char* p = x.data(); 62 const char* p2 = y.data(); 63 // Test last byte in case strings share large common prefix 64 --len; 65 if (p[len] != p2[len]) return false; 66 // At this point we can, but don't have to, ignore the last byte. 67 return uprv_memcmp(p, p2, len) == 0; 68 } 69 70 71 const int32_t StringPiece::npos = 0x7fffffff; 72 73 U_NAMESPACE_END 74
