scuffed-code/icu4c/source/common/unistr_case.cpp
2017-02-09 21:15:34 +00:00

231 lines
7.3 KiB
C++

// Copyright (C) 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
*******************************************************************************
*
* Copyright (C) 1999-2014, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
* file name: unistr_case.cpp
* encoding: US-ASCII
* tab size: 8 (not used)
* indentation:2
*
* created on: 2004aug19
* created by: Markus W. Scherer
*
* Case-mapping functions moved here from unistr.cpp
*/
#include "unicode/utypes.h"
#include "unicode/casemap.h"
#include "unicode/edits.h"
#include "unicode/putil.h"
#include "cstring.h"
#include "cmemory.h"
#include "unicode/ustring.h"
#include "unicode/unistr.h"
#include "unicode/uchar.h"
#include "uassert.h"
#include "ucasemap_imp.h"
#include "uelement.h"
U_NAMESPACE_BEGIN
//========================================
// Read-only implementation
//========================================
int8_t
UnicodeString::doCaseCompare(int32_t start,
int32_t length,
const UChar *srcChars,
int32_t srcStart,
int32_t srcLength,
uint32_t options) const
{
// compare illegal string values
// treat const UChar *srcChars==NULL as an empty string
if(isBogus()) {
return -1;
}
// pin indices to legal values
pinIndices(start, length);
if(srcChars == NULL) {
srcStart = srcLength = 0;
}
// get the correct pointer
const UChar *chars = getArrayStart();
chars += start;
if(srcStart!=0) {
srcChars += srcStart;
}
if(chars != srcChars) {
UErrorCode errorCode=U_ZERO_ERROR;
int32_t result=u_strcmpFold(chars, length, srcChars, srcLength,
options|U_COMPARE_IGNORE_CASE, &errorCode);
if(result!=0) {
return (int8_t)(result >> 24 | 1);
}
} else {
// get the srcLength if necessary
if(srcLength < 0) {
srcLength = u_strlen(srcChars + srcStart);
}
if(length != srcLength) {
return (int8_t)((length - srcLength) >> 24 | 1);
}
}
return 0;
}
//========================================
// Write implementation
//========================================
UnicodeString &
UnicodeString::caseMap(int32_t caseLocale, uint32_t options, UCASEMAP_BREAK_ITERATOR_PARAM
UStringCaseMapper *stringCaseMapper) {
if(isEmpty() || !isWritable()) {
// nothing to do
return *this;
}
UChar oldBuffer[2 * US_STACKBUF_SIZE];
UChar *oldArray;
int32_t oldLength = length();
int32_t newLength;
UBool writable = isBufferWritable();
UErrorCode errorCode = U_ZERO_ERROR;
// Try to avoid heap-allocating a new character array for this string.
if (writable ? oldLength <= UPRV_LENGTHOF(oldBuffer) : oldLength < US_STACKBUF_SIZE) {
// Short string: Copy the contents into a temporary buffer and
// case-map back into the current array, or into the stack buffer.
UChar *buffer = getArrayStart();
int32_t capacity;
oldArray = oldBuffer;
u_memcpy(oldBuffer, buffer, oldLength);
if (writable) {
capacity = getCapacity();
} else {
// Switch from the read-only alias or shared heap buffer to the stack buffer.
if (!cloneArrayIfNeeded(US_STACKBUF_SIZE, US_STACKBUF_SIZE, /* doCopyArray= */ FALSE)) {
return *this;
}
U_ASSERT(fUnion.fFields.fLengthAndFlags & kUsingStackBuffer);
buffer = fUnion.fStackFields.fBuffer;
capacity = US_STACKBUF_SIZE;
}
newLength = stringCaseMapper(caseLocale, options, UCASEMAP_BREAK_ITERATOR
buffer, capacity,
oldArray, oldLength, NULL, errorCode);
if (U_SUCCESS(errorCode)) {
setLength(newLength);
return *this;
} else if (errorCode == U_BUFFER_OVERFLOW_ERROR) {
// common overflow handling below
} else {
setToBogus();
return *this;
}
} else {
// Longer string or read-only buffer:
// Collect only changes and then apply them to this string.
// Case mapping often changes only small parts of a string,
// and often does not change its length.
oldArray = getArrayStart();
Edits edits;
UChar replacementChars[200];
stringCaseMapper(caseLocale, options | UCASEMAP_OMIT_UNCHANGED_TEXT, UCASEMAP_BREAK_ITERATOR
replacementChars, UPRV_LENGTHOF(replacementChars),
oldArray, oldLength, &edits, errorCode);
if (U_SUCCESS(errorCode)) {
// Grow the buffer at most once, not for multiple doReplace() calls.
newLength = oldLength + edits.lengthDelta();
if (newLength > oldLength && !cloneArrayIfNeeded(newLength, newLength)) {
return *this;
}
for (Edits::Iterator ei = edits.getCoarseChangesIterator(); ei.next(errorCode);) {
doReplace(ei.destinationIndex(), ei.oldLength(),
replacementChars, ei.replacementIndex(), ei.newLength());
}
if (U_FAILURE(errorCode)) {
setToBogus();
}
return *this;
} else if (errorCode == U_BUFFER_OVERFLOW_ERROR) {
// common overflow handling below
newLength = oldLength + edits.lengthDelta();
} else {
setToBogus();
return *this;
}
}
// Handle buffer overflow, newLength is known.
// We need to allocate a new buffer for the internal string case mapping function.
// This is very similar to how doReplace() keeps the old array pointer
// and deletes the old array itself after it is done.
// In addition, we are forcing cloneArrayIfNeeded() to always allocate a new array.
int32_t *bufferToDelete = 0;
if (!cloneArrayIfNeeded(newLength, newLength, FALSE, &bufferToDelete, TRUE)) {
return *this;
}
errorCode = U_ZERO_ERROR;
newLength = stringCaseMapper(caseLocale, options, UCASEMAP_BREAK_ITERATOR
getArrayStart(), getCapacity(),
oldArray, oldLength, NULL, errorCode);
if (bufferToDelete) {
uprv_free(bufferToDelete);
}
if (U_SUCCESS(errorCode)) {
setLength(newLength);
} else {
setToBogus();
}
return *this;
}
UnicodeString &
UnicodeString::foldCase(uint32_t options) {
return caseMap(UCASE_LOC_ROOT, options, UCASEMAP_BREAK_ITERATOR_NULL ustrcase_internalFold);
}
U_NAMESPACE_END
// Defined here to reduce dependencies on break iterator
U_CAPI int32_t U_EXPORT2
uhash_hashCaselessUnicodeString(const UElement key) {
U_NAMESPACE_USE
const UnicodeString *str = (const UnicodeString*) key.pointer;
if (str == NULL) {
return 0;
}
// Inefficient; a better way would be to have a hash function in
// UnicodeString that does case folding on the fly.
UnicodeString copy(*str);
return copy.foldCase().hashCode();
}
// Defined here to reduce dependencies on break iterator
U_CAPI UBool U_EXPORT2
uhash_compareCaselessUnicodeString(const UElement key1, const UElement key2) {
U_NAMESPACE_USE
const UnicodeString *str1 = (const UnicodeString*) key1.pointer;
const UnicodeString *str2 = (const UnicodeString*) key2.pointer;
if (str1 == str2) {
return TRUE;
}
if (str1 == NULL || str2 == NULL) {
return FALSE;
}
return str1->caseCompare(*str2, U_FOLD_CASE_DEFAULT) == 0;
}