// © 2016 and later: Unicode, Inc. and others. // License & terms of use: http://www.unicode.org/copyright.html // Copyright (C) 2009-2013, International Business Machines // Corporation and others. All Rights Reserved. // // Copyright 2004 and onwards Google Inc. // // Author: wilsonh@google.com (Wilson Hsieh) // #include "unicode/utypes.h" #include "unicode/stringpiece.h" #include "cstring.h" #include "cmemory.h" U_NAMESPACE_BEGIN StringPiece::StringPiece(const char* str) : ptr_(str), length_((str == NULL) ? 0 : static_cast<int32_t>(uprv_strlen(str))) { } StringPiece::StringPiece(const StringPiece& x, int32_t pos) { if (pos < 0) { pos = 0; } else if (pos > x.length_) { pos = x.length_; } ptr_ = x.ptr_ + pos; length_ = x.length_ - pos; } StringPiece::StringPiece(const StringPiece& x, int32_t pos, int32_t len) { if (pos < 0) { pos = 0; } else if (pos > x.length_) { pos = x.length_; } if (len < 0) { len = 0; } else if (len > x.length_ - pos) { len = x.length_ - pos; } ptr_ = x.ptr_ + pos; length_ = len; } void StringPiece::set(const char* str) { ptr_ = str; if (str != NULL) length_ = static_cast<int32_t>(uprv_strlen(str)); else length_ = 0; } int32_t StringPiece::find(StringPiece needle, int32_t offset) { if (length() == 0 && needle.length() == 0) { return 0; } // TODO: Improve to be better than O(N^2)? for (int32_t i = offset; i < length(); i++) { int32_t j = 0; for (; j < needle.length(); i++, j++) { if (data()[i] != needle.data()[j]) { i -= j; goto outer_end; } } return i - j; outer_end: void(); } return -1; } int32_t StringPiece::compare(StringPiece other) { int32_t i = 0; for (; i < length(); i++) { if (i == other.length()) { // this is longer return 1; } char a = data()[i]; char b = other.data()[i]; if (a < b) { return -1; } else if (a > b) { return 1; } } if (i < other.length()) { // other is longer return -1; } return 0; } U_EXPORT UBool U_EXPORT2 operator==(const StringPiece& x, const StringPiece& y) { int32_t len = x.size(); if (len != y.size()) { return false; } if (len == 0) { return true; } const char* p = x.data(); const char* p2 = y.data(); // Test last byte in case strings share large common prefix --len; if (p[len] != p2[len]) return false; // At this point we can, but don't have to, ignore the last byte. return uprv_memcmp(p, p2, len) == 0; } const int32_t StringPiece::npos = 0x7fffffff; U_NAMESPACE_END