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