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Diffstat (limited to 'intl/icu/source/common/stringpiece.cpp')
-rw-r--r-- | intl/icu/source/common/stringpiece.cpp | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/intl/icu/source/common/stringpiece.cpp b/intl/icu/source/common/stringpiece.cpp new file mode 100644 index 0000000000..eb9766c018 --- /dev/null +++ b/intl/icu/source/common/stringpiece.cpp @@ -0,0 +1,116 @@ +// © 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 == nullptr) ? 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 != nullptr) + 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 |