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// © 2016 and later: Unicode, Inc. and others.
// 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