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skia / external / github.com / unicode-org / icu / 67dc74143becf8107d999475e919cd1c60656d39 / . / source / common / utext.cpp
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/*
*******************************************************************************
*
* Copyright (C) 2005, International Business Machines
* Corporation and others. All Rights Reserved.
*
*******************************************************************************
* file name: utext.cpp
* encoding: US-ASCII
* tab size: 8 (not used)
* indentation:4
*
* created on: 2005apr12
* created by: Markus W. Scherer
*/
#include "unicode/utypes.h"
#include "unicode/ustring.h"
#include "unicode/unistr.h"
#include "unicode/utext.h"
#include "ustr_imp.h"
#include "cmemory.h"
#include "cstring.h"
#include "uassert.h"
#define I32_FLAG(bitIndex) ((int32_t)1<<(bitIndex))
static UBool
utext_access(UText *ut, int32_t index, UBool forward) {
return ut->access(ut, index, forward, &ut->chunk);
}
U_DRAFT UBool U_EXPORT2
utext_moveIndex32(UText *ut, int32_t delta) {
UBool retval = TRUE;
if(delta>0) {
do {
if(ut->chunk.offset>=ut->chunk.length && !utext_access(ut, ut->chunk.nativeLimit, TRUE)) {
retval = FALSE;
break;
}
U16_FWD_1(ut->chunk.contents, ut->chunk.offset, ut->chunk.length);
} while(--delta>0);
} else if (delta<0) {
do {
if(ut->chunk.offset<=0 && !utext_access(ut, ut->chunk.nativeStart, FALSE)) {
retval = FALSE;
break;
}
U16_BACK_1(ut->chunk.contents, 0, ut->chunk.offset);
} while(++delta<0);
}
return retval;
}
U_DRAFT int32_t U_EXPORT2
utext_nativeLength(UText *ut) {
return ut->nativeLength(ut);
}
U_DRAFT UBool U_EXPORT2
utext_isLengthExpensive(const UText *ut) {
UBool r = (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE)) != 0;
return r;
}
U_DRAFT int32_t U_EXPORT2
utext_getNativeIndex(UText *ut) {
if(!ut->chunk.nonUTF16Indexes || ut->chunk.offset==0) {
return ut->chunk.nativeStart+ut->chunk.offset;
} else {
return ut->mapOffsetToNative(ut, ut->chunk.offset);
}
}
U_DRAFT void U_EXPORT2
utext_setNativeIndex(UText *ut, int32_t index) {
if(index<ut->chunk.nativeStart || ut->chunk.nativeLimit<index) {
// The desired position is outside of the current chunk.
// Access the new position. Assume a forward iteration from here,
// which will also be optimimum for a single random access.
// Reverse iterations may suffer slightly.
ut->access(ut, index, TRUE, &ut->chunk);
} else if(ut->chunk.nonUTF16Indexes) {
ut->chunk.offset=ut->mapNativeIndexToUTF16(ut, index);
} else {
ut->chunk.offset=index-ut->chunk.nativeStart;
// Our convention is that the index must always be on a code point boundary.
// If we are somewhere in the middle of a utf-16 buffer, check that new index
// is not in the middle of a surrogate pair.
if (index>ut->chunk.nativeStart && index < ut->chunk.nativeLimit) {
UChar c = ut->chunk.contents[ut->chunk.offset];
if (U16_TRAIL(c)) {
utext_current32(ut); // force index to the start of the curent code point.
}
}
}
}
U_DRAFT UChar32 U_EXPORT2
utext_current32(UText *ut) {
UChar32 c = U_SENTINEL;
if (ut->chunk.offset==ut->chunk.length) {
// Current position is just off the end of the chunk.
// Can also happen at startup, with a zero length chunk at zero offset.
ut->access(ut, ut->chunk.nativeLimit, TRUE, &ut->chunk);
}
if (ut->chunk.offset < ut->chunk.length) {
c = ut->chunk.contents[ut->chunk.offset];
if (U16_IS_SURROGATE(c)) {
// looking at a surrogate. Could be unpaired, need to be careful.
// Speed doesn't matter, will be very rare.
UChar32 char16AtIndex = c;
U16_GET(ut->chunk.contents, 0, ut->chunk.offset, ut->chunk.length, c);
if (U16_IS_TRAIL(char16AtIndex) && U_IS_SUPPLEMENTARY(c)) {
// Incoming position pointed to the trailing part of a supplementary pair.
// Move offset to point to the lead surrogate. This is needed because utext_current()
// is used internally to force code point alignment. When called from
// the outside we should always be pre-aligned, but this check doesn't hurt.
ut->chunk.offset--;
}
}
}
return c;
}
U_DRAFT UChar32 U_EXPORT2
utext_char32At(UText *ut, int32_t nativeIndex) {
UChar32 c = U_SENTINEL;
utext_setNativeIndex(ut, nativeIndex);
if (ut->chunk.offset < ut->chunk.length) {
c = ut->chunk.contents[ut->chunk.offset];
if (c >= 0xd800) {
c = utext_current32(ut);
}
}
return c;
}
U_DRAFT UChar32 U_EXPORT2
utext_next32(UText *ut) {
UTextChunk *chunk = &ut->chunk;
UChar32 c = U_SENTINEL;
if (chunk->offset >= chunk->length) {
if (ut->access(ut, chunk->nativeLimit, TRUE, chunk) == FALSE) {
goto next32_return;
}
}
c = chunk->contents[chunk->offset++];
if (U16_IS_SURROGATE(c)) {
// looking at a surrogate. Could be unpaired, need to be careful.
// Speed doesn't matter, will be very rare.
chunk->offset--;
c = utext_current32(ut);
chunk->offset++;
if (U_IS_SUPPLEMENTARY(c)) {
chunk->offset++;
}
}
next32_return:
return c;
}
U_DRAFT UChar32 U_EXPORT2
utext_previous32(UText *ut) {
UTextChunk *chunk = &ut->chunk;
int32_t offset = chunk->offset;
UChar32 c = U_SENTINEL;
if (offset <= 0) {
if (ut->access(ut, chunk->nativeStart, FALSE, chunk) == FALSE) {
goto prev32_return;
}
offset = chunk->offset;
}
c = chunk->contents[--offset];
chunk->offset = offset;
if (U16_IS_SURROGATE(c)) {
// Note that utext_current() will move the chunk offset to the lead surrogate
// if we come in referring to trail half of a surrogate pair.
c = utext_current32(ut);
}
prev32_return:
return c;
}
U_DRAFT UChar32 U_EXPORT2
utext_next32From(UText *ut, int32_t index) {
UTextChunk *chunk = &ut->chunk;
UChar32 c = U_SENTINEL;
if(index<chunk->nativeStart || index>=chunk->nativeLimit) {
if(!ut->access(ut, index, TRUE, chunk)) {
// no chunk available here
goto next32return;
}
} else if(chunk->nonUTF16Indexes) {
chunk->offset = ut->mapNativeIndexToUTF16(ut, index);
} else {
chunk->offset = index - chunk->nativeStart;
}
c = chunk->contents[chunk->offset++];
if (U16_IS_SURROGATE(c)) {
// Surrogate code unit. Speed doesn't matter, let plain next32() do the work.
chunk->offset--; // undo the ++, above.
c = utext_next32(ut);
}
next32return:
return c;
}
U_DRAFT UChar32 U_EXPORT2
utext_previous32From(UText *ut, int32_t index) {
UTextChunk *chunk = &ut->chunk;
UChar32 c = U_SENTINEL;
if(index<=chunk->nativeStart || index>chunk->nativeLimit) {
// Requested native index is outside of the current chunk.
if(!ut->access(ut, index, FALSE, chunk)) {
// no chunk available here
goto prev32return;
}
} else if(chunk->nonUTF16Indexes) {
chunk->offset=ut->mapNativeIndexToUTF16(ut, index);
} else {
// This chunk uses UTF-16 indexing. Index into it.
chunk->offset = index - chunk->nativeStart;
// put offset onto a code point boundary if it isn't there already.
if (index>ut->chunk.nativeStart && index < ut->chunk.nativeLimit) {
c = chunk->contents[chunk->offset];
if (U16_TRAIL(c)) {
utext_current32(ut); // force index to the start of the curent code point.
}
}
}
if (chunk->offset<=0) {
// already at the start of text. Return U_SENTINEL.
goto prev32return;
}
// Do the operation assuming that there are no surrogates involved. Fast, common case.
chunk->offset--;
c = chunk->contents[chunk->offset];
// Check for the char being a surrogate, get the whole char if it is.
if (U16_IS_SURROGATE(c)) {
c = utext_current32(ut);
}
prev32return:
return c;
}
U_DRAFT int32_t U_EXPORT2
utext_extract(UText *ut,
int32_t start, int32_t limit,
UChar *dest, int32_t destCapacity,
UErrorCode *status) {
return ut->extract(ut, start, limit, dest, destCapacity, status);
}
U_DRAFT UBool U_EXPORT2
utext_isWritable(const UText *ut)
{
UBool b = (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_WRITABLE)) != 0;
return b;
}
U_DRAFT UBool U_EXPORT2
utext_hasMetaData(const UText *ut)
{
UBool b = (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_HAS_META_DATA)) != 0;
return b;
}
U_DRAFT int32_t U_EXPORT2
utext_replace(UText *ut,
int32_t nativeStart, int32_t nativeLimit,
const UChar *replacementText, int32_t replacementLength,
UErrorCode *status)
{
if (U_FAILURE(*status)) {
return 0;
}
if ((ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_WRITABLE)) == 0) {
*status = U_NO_WRITE_PERMISSION;
return 0;
}
int32_t i = ut->replace(ut, nativeStart, nativeLimit, replacementText, replacementLength, status);
return i;
}
U_DRAFT void U_EXPORT2
utext_copy(UText *ut,
int32_t nativeStart, int32_t nativeLimit,
int32_t destIndex,
UBool move,
UErrorCode *status)
{
if (U_FAILURE(*status)) {
return;
}
if ((ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_WRITABLE)) == 0) {
*status = U_NO_WRITE_PERMISSION;
return;
}
ut->copy(ut, nativeStart, nativeLimit, destIndex, move, status);
}
U_DRAFT UText * U_EXPORT2
utext_clone(UText *dest, const UText *src, UBool deep, UErrorCode *status) {
return src->clone(dest, src, deep, status);
}
//------------------------------------------------------------------------------
//
// UText common functions implementation
//
//------------------------------------------------------------------------------
//
// UText.flags bit definitions
//
enum {
UTEXT_HEAP_ALLOCATED = 1, // 1 if ICU has allocated this UText struct on the heap.
// 0 if caller provided storage for the UText.
UTEXT_EXTRA_HEAP_ALLOCATED = 2, // 1 if ICU has allocated extra storage as a separate
// heap block.
// 0 if there is no separate allocation. Either no extra
// storage was requested, or it is appended to the end
// of the main UText storage.
UTEXT_OPEN = 4 // 1 if this UText is currently open
// 0 if this UText is not open.
};
//
// Extended form of a UText. The purpose is to aid in computing the total size required
// when a provider asks for a UText to be allocated with extra storage.
struct ExtendedUText {
UText ut;
UAlignedMemory extension;
};
static const UText emptyText = UTEXT_INITIALIZER;
U_DRAFT UText * U_EXPORT2
utext_setup(UText *ut, int32_t extraSpace, UErrorCode *status) {
if (U_FAILURE(*status)) {
return ut;
}
if (ut == NULL) {
// We need to heap-allocate storage for the new UText
int32_t spaceRequired = sizeof(UText);
if (extraSpace > 0) {
spaceRequired = sizeof(ExtendedUText) + extraSpace - sizeof(UAlignedMemory);
}
ut = (UText *)uprv_malloc(spaceRequired);
if (ut == NULL) {
*status = U_MEMORY_ALLOCATION_ERROR;
} else {
*ut = emptyText;
ut->flags |= UTEXT_HEAP_ALLOCATED;
if (spaceRequired>0) {
ut->extraSize = extraSpace;
ut->pExtra = &((ExtendedUText *)ut)->extension;
uprv_memset(ut->pExtra, 0, extraSpace); // Purify whines about copying untouched extra [buffer]
// space when cloning, so init it now.
}
}
} else {
// We have been supplied with an already existing UText.
// Verify that it really appears to be a UText.
if (ut->magic != UTEXT_MAGIC) {
*status = U_ILLEGAL_ARGUMENT_ERROR;
return ut;
}
// If the ut is already open and there's a provider supplied close
// function, call it.
if ((ut->flags & UTEXT_OPEN) && ut->close != NULL) {
ut->close(ut);
}
ut->flags &= ~UTEXT_OPEN;
// If extra space was requested by our caller, check whether
// sufficient already exists, and allocate new if needed.
if (extraSpace > ut->extraSize) {
// Need more space. If there is existing separately allocated space,
// delete it first, then allocate new space.
if (ut->flags & UTEXT_EXTRA_HEAP_ALLOCATED) {
uprv_free(ut->pExtra);
ut->extraSize = 0;
}
ut->pExtra = uprv_malloc(extraSpace);
if (ut->pExtra == NULL) {
*status = U_MEMORY_ALLOCATION_ERROR;
} else {
ut->extraSize = extraSpace;
ut->flags |= UTEXT_EXTRA_HEAP_ALLOCATED;
uprv_memset(ut->pExtra, 0, extraSpace);
}
}
}
if (U_SUCCESS(*status)) {
ut->flags |= UTEXT_OPEN;
}
return ut;
}
U_DRAFT UText * U_EXPORT2
utext_close(UText *ut) {
if (ut==NULL ||
ut->magic != UTEXT_MAGIC ||
(ut->flags & UTEXT_OPEN) == 0)
{
// The supplied ut is not an open UText.
// Do nothing.
return ut;
}
// If the provider gave us a close function, call it now.
// This will clean up anything allocated specifically by the provider.
if (ut->close != NULL) {
ut->close(ut);
}
ut->flags &= ~UTEXT_OPEN;
// If we (the framework) allocated the UText or subsidiary storage,
// delete it.
if (ut->flags & UTEXT_EXTRA_HEAP_ALLOCATED) {
uprv_free(ut->pExtra);
ut->pExtra = NULL;
}
if (ut->flags & UTEXT_HEAP_ALLOCATED) {
// This UText was allocated by UText setup. We need to free it.
// Clear magic, so we can detect if the user messes up and immediately
// tries to reopen another UText using the deleted storage.
ut->magic = 0;
uprv_free(ut);
ut = NULL;
}
return ut;
}
//
// resetChunk When an access fails for attempting to get text that is out-of-range
// this function puts the chunk into a benign state with the index at the
// at the requested position.
//
// If there is a pre-existing chunk that is adjacent to the index
// preserve the chunk, otherwise set up a dummy zero length chunk.
//
static void
resetChunk(UTextChunk *chunk, int32_t index) {
if (index==chunk->nativeLimit) {
chunk->offset = chunk->length;
} else if (index==chunk->nativeStart) {
chunk->offset = 0;
} else {
chunk->length = 0;
chunk->nativeStart = index;
chunk->nativeLimit = index;
chunk->offset = 0;
}
}
//
// invalidateChunk Reset a chunk to have no contents, so that the next call
// to access will new data to load.
// This is needed when copy/move/replace operate directly on the
// backing text, potentially putting it out of sync with the
// contents in the chunk.
//
static void
invalidateChunk(UTextChunk *chunk) {
chunk->length = 0;
chunk->nativeLimit = 0;
chunk->nativeStart = 0;
chunk->offset = 0;
}
U_CDECL_BEGIN
//
// Clone. This is a generic copy-the-utext-by-value clone function that can be
// used as-is with some utext types, and as helper by other clones.
//
static UText * U_CALLCONV
shallowTextClone(UText * dest, const UText * src, UErrorCode * status) {
if (U_FAILURE(*status)) {
return NULL;
}
int32_t srcExtraSize = src->extraSize;
//
// Use the generic text_setup to allocate storage if required.
//
dest = utext_setup(dest, srcExtraSize, status);
if (U_FAILURE(*status)) {
return dest;
}
//
// flags (how the UText was allocated) and the pointer to the
// extra storage must retain the values in the cloned utext that
// were set up by utext_setup. Save them separately before
// copying the whole struct.
//
void *destExtra = dest->pExtra;
int32_t flags = dest->flags;
//
// Copy the whole UText struct by value.
// Any "Extra" storage is copied also.
//
int sizeToCopy = src->sizeOfStruct;
if (sizeToCopy > dest->sizeOfStruct) {
sizeToCopy = dest->sizeOfStruct;
}
uprv_memcpy(dest, src, sizeToCopy);
dest->pExtra = destExtra;
dest->flags = flags;
if (srcExtraSize > 0) {
uprv_memcpy(dest->pExtra, src->pExtra, srcExtraSize);
}
return dest;
}
U_CDECL_END
//------------------------------------------------------------------------------
//
// UText implementation for UTF-8 strings (read-only)
//
// Use of UText data members:
// context pointer to UTF-8 string
// utext.b is the input string length (bytes).
// utext.p pointer to allocated utf-8 string if owned by this utext (after a clone)
// utext.q pointer to the filled part of the Map array.
//
// TODO: make creation of the index mapping array lazy.
// Create it for a chunk the first time the user asks for an index.
//
//------------------------------------------------------------------------------
enum { UTF8_TEXT_CHUNK_SIZE=10 };
struct UTF8Extra {
/*
* Chunk UChars.
* +1 to simplify filling with surrogate pair at the end.
*/
UChar s[UTF8_TEXT_CHUNK_SIZE+1];
/*
* Index map, from UTF-16 indexes into s back to native indexes.
* +2: length of s[] + one more for chunk limit index.
*
* When accessing preceding text, chunk.contents may point into the middle
* of s[].
*/
int32_t map[UTF8_TEXT_CHUNK_SIZE+2];
};
// because backwards iteration fills the buffers starting at the end and
// working towards the front, the filled part of the buffers may not begin
// at the start of the available storage for the buffers.
U_CDECL_BEGIN
static int32_t U_CALLCONV
utf8TextLength(UText *ut) {
return ut->b;
}
static UBool U_CALLCONV
utf8TextAccess(UText *ut, int32_t index, UBool forward, UTextChunk *chunk) {
const uint8_t *s8=(const uint8_t *)ut->context;
UChar32 c;
int32_t i;
int32_t length = ut->b; // Length of original utf-8
UTF8Extra *ut8e = (UTF8Extra *)ut->pExtra;
UChar *u16buf = ut8e->s;
int32_t *map = ut8e->map;
if (index<0) {
index = 0;
} else if (index>length) {
index = length;
}
if(forward) {
if(index >= length) {
resetChunk(chunk, length);
return FALSE;
}
c=s8[index];
if(c<=0x7f) {
// get a run of ASCII characters.
// Even if we don't fill the buffer, we will stop with the first
// non-ascii char, so that the buffer can use utf-16 indexing.
chunk->nativeStart=index;
u16buf[0]=(UChar)c;
for(i=1, ++index;
i<UTF8_TEXT_CHUNK_SIZE && index<length && (c=s8[index])<=0x7f;
++i, ++index
) {
u16buf[i]=(UChar)c;
}
chunk->nonUTF16Indexes=FALSE;
} else {
// get a chunk of characters starting with a non-ASCII one
U8_SET_CP_START(s8, 0, index); // put utf-8 index at first byte of char, if not there already.
chunk->nativeStart=index;
for(i=0; i<UTF8_TEXT_CHUNK_SIZE && index<length; ) {
// i is utf-16 index into chunk buffer.
// index is utf-8 index into original string
map[i]=index;
map[i+1]=index; // in case there is a trail surrogate
U8_NEXT(s8, index, length, c);
if(c<0) {
c=0xfffd; // use SUB for illegal sequences
}
U16_APPEND_UNSAFE(u16buf, i, c); // post-increments i.
}
map[i]=index;
chunk->nonUTF16Indexes=TRUE;
}
chunk->contents = u16buf;
chunk->length = i;
chunk->nativeLimit = index;
ut->q = map;
chunk->offset = 0; // chunkOffset corresponding to index
return TRUE;
} else {
// Reverse Access. The chunk buffer must be filled so as to contain the
// character preceding the specified index.
if(index<=0) {
resetChunk(chunk, 0);
return FALSE;
}
c=s8[index-1];
if(c<=0x7f) {
// get a chunk of ASCII characters. Don't build the index map
chunk->nativeLimit=index;
i=UTF8_TEXT_CHUNK_SIZE;
do {
u16buf[--i]=(UChar)c;
--index;
} while(i>0 && index>0 && (c=s8[index-1])<=0x7f);
chunk->nonUTF16Indexes=FALSE;
} else {
// get a chunk of characters starting with a non-ASCII one
if(index<length) {
U8_SET_CP_START(s8, 0, index);
}
chunk->nativeLimit=index;
i=UTF8_TEXT_CHUNK_SIZE;
map[i]=index; // map position for char following the last one in the buffer.
do {
// i is utf-16 index into chunk buffer.
// index is utf-8 index into original string
U8_PREV(s8, 0, index, c);
if(c<0) {
c=0xfffd; // use SUB for illegal sequences
}
if(c<=0xffff) {
u16buf[--i]=(UChar)c;
map[i]=index;
} else {
// We've got a supplementary char
if (i<2) {
// Both halves of the surrogate pair wont fit in the chunk buffer.
// Stop without putting either half in.
U8_NEXT(s8, index, length, c); // restore index.
break;
}
u16buf[--i]=U16_TRAIL(c);
map[i]=index;
u16buf[--i]=U16_LEAD(c);
map[i]=index;
}
} while(i>0 && index>0);
// Because we have filled the map & chunk buffers from back to front,
// the start position for accesses may not be at the start of the
// available storage.
ut->q = map+i;
chunk->nonUTF16Indexes=TRUE;
}
// Common reverse iteration, for both UTF16 and non-UTIF16 indexes.
chunk->contents = u16buf+i;
chunk->length = (UTF8_TEXT_CHUNK_SIZE)-i;
chunk->nativeStart = index;
chunk->offset = chunk->length; // chunkOffset corresponding to index
return TRUE;
}
}
//
// This is a slightly modified copy of u_strFromUTF8,
// Inserts a Replacement Char rather than failing on invalid UTF-8
// Removes unnecessary features.
//
static UChar*
utext_strFromUTF8(UChar *dest,
int32_t destCapacity,
int32_t *pDestLength,
const char* src,
int32_t srcLength, // required. NUL terminated not supported.
UErrorCode *pErrorCode
)
{
UChar *pDest = dest;
UChar *pDestLimit = dest+destCapacity;
UChar32 ch=0;
int32_t index = 0;
int32_t reqLength = 0;
uint8_t* pSrc = (uint8_t*) src;
while((index < srcLength)&&(pDest<pDestLimit)){
ch = pSrc[index++];
if(ch <=0x7f){
*pDest++=(UChar)ch;
}else{
ch=utf8_nextCharSafeBody(pSrc, &index, srcLength, ch, -1);
if(ch<0){
ch = 0xfffd;
}
if(ch<=0xFFFF){
*(pDest++)=(UChar)ch;
}else{
*(pDest++)=UTF16_LEAD(ch);
if(pDest<pDestLimit){
*(pDest++)=UTF16_TRAIL(ch);
}else{
reqLength++;
break;
}
}
}
}
/* donot fill the dest buffer just count the UChars needed */
while(index < srcLength){
ch = pSrc[index++];
if(ch <= 0x7f){
reqLength++;
}else{
ch=utf8_nextCharSafeBody(pSrc, &index, srcLength, ch, -1);
if(ch<0){
ch = 0xfffd;
}
reqLength+=UTF_CHAR_LENGTH(ch);
}
}
reqLength+=(int32_t)(pDest - dest);
if(pDestLength){
*pDestLength = reqLength;
}
/* Terminate the buffer */
u_terminateUChars(dest,destCapacity,reqLength,pErrorCode);
return dest;
}
static int32_t U_CALLCONV
utf8TextExtract(UText *ut,
int32_t start, int32_t limit,
UChar *dest, int32_t destCapacity,
UErrorCode *pErrorCode) {
if(U_FAILURE(*pErrorCode)) {
return 0;
}
if(destCapacity<0 || (dest==NULL && destCapacity>0)) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
if(start<0 || start>limit) {
*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
if (limit>ut->b) {
limit = ut->b;
}
if (start>ut->b) {
start = ut->b;
}
// adjust the incoming indexes to land on code point boundaries if needed.
// adjust by no more than three, because that is the largest number of trail bytes
// in a well formed UTF8 character.
const uint8_t *buf = (const uint8_t *)ut->context;
int i;
if (start < ut->chunk.nativeLimit) {
for (i=0; i<3; i++) {
if (U8_IS_LEAD(buf[start]) || start==0) {
break;
}
start--;
}
}
if (limit < ut->chunk.nativeLimit) {
for (i=0; i<3; i++) {
if (U8_IS_LEAD(buf[limit]) || limit==0) {
break;
}
limit--;
}
}
// Do the actual extract.
int32_t destLength=0;
utext_strFromUTF8(dest, destCapacity, &destLength,
(const char *)ut->context+start, limit-start,
pErrorCode);
return destLength;
}
// Assume nonUTF16Indexes and 0<=offset<=chunk->length
static int32_t U_CALLCONV
utf8TextMapOffsetToNative(UText *ut, int32_t offset) {
// UText.q points to the index mapping array that is allocated in the extra storage area.
U_ASSERT(offset>=0 && offset<=ut->chunk.length);
int32_t *map=(int32_t *)(ut->q);
return map[offset];
}
// Assume nonUTF16Indexes and chunk->start<=index<=chunk->limit
static int32_t U_CALLCONV
utf8TextMapIndexToUTF16(UText *ut, int32_t index) {
int32_t *map=(int32_t *)(ut->q);
int32_t offset=0;
U_ASSERT(index>=ut->chunk.nativeStart && index<=ut->chunk.nativeLimit);
while(index>map[offset]) {
++offset;
}
if (index<map[offset]) {
// index was to a trail byte of a multi-byte utf-8 char.
// The loop above advanced offset to the start of the following char, now
// offset must be backed up to the start of the utf-16 char into which
// the utf-8 index pointed.
offset--;
if (offset>0 && map[offset] == map[offset-1]) {
// index was to a utf-8 trail byte of a supplemenary char.
// Offset now points to the trail surrogate (one in back of the following char)
// Back offset up one more time to get to the utf-16 lead surrogate.
offset--;
}
}
return offset;
}
static UText * U_CALLCONV
utf8TextClone(UText *dest, const UText *src, UBool deep, UErrorCode *status)
{
// First do a generic shallow clone. Does everything needed for the UText struct itself.
dest = shallowTextClone(dest, src, status);
// For deep clones, make a copy of the string.
// The copied storage is owned by the newly created clone.
// A non-NULL pointer in UText.p is the signal to the close() function to delete
// it.
//
if (deep && U_SUCCESS(*status)) {
int32_t len = src->b;
char *copyStr = (char *)uprv_malloc(len+1);
if (copyStr == NULL) {
*status = U_MEMORY_ALLOCATION_ERROR;
} else {
uprv_memcpy(copyStr, src->context, len+1);
dest->context = copyStr;
dest->p = copyStr;
}
}
return dest;
}
static void U_CALLCONV
utf8TextClose(UText *ut) {
// Most of the work of close is done by the generic UText framework close.
// All that needs to be done here is to delete the UTF8 string if the UText
// owns it. This occurs if the UText was created by cloning.
char *s = (char *)ut->p;
uprv_free(s);
ut->p = NULL;
}
U_DRAFT UText * U_EXPORT2
utext_openUTF8(UText *ut, const char *s, int32_t length, UErrorCode *status) {
if(U_FAILURE(*status)) {
return NULL;
}
if(s==NULL || length<-1) {
*status=U_ILLEGAL_ARGUMENT_ERROR;
return NULL;
}
ut = utext_setup(ut, sizeof(UTF8Extra), status);
if (U_FAILURE(*status)) {
return ut;
}
ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_NON_UTF16_INDEXES);
ut->clone = utf8TextClone;
ut->nativeLength = utf8TextLength;
ut->access = utf8TextAccess;
ut->extract = utf8TextExtract;
ut->mapOffsetToNative = utf8TextMapOffsetToNative;
ut->mapNativeIndexToUTF16 = utf8TextMapIndexToUTF16;
ut->close = utf8TextClose;
ut->context=s;
if(length>=0) {
ut->b=length;
} else {
// TODO: really undesirable to do this scan upfront.
ut->b=(int32_t)uprv_strlen(s);
}
return ut;
}
U_CDECL_END
//------------------------------------------------------------------------------
//
// UText implementation wrapper for Replaceable (read/write)
//
// Use of UText data members:
// context pointer to Replaceable.
// p pointer to Replaceable if it is owned by the UText.
//
//------------------------------------------------------------------------------
// minimum chunk size for this implementation: 3
// to allow for possible trimming for code point boundaries
enum { REP_TEXT_CHUNK_SIZE=10 };
struct ReplExtra {
/*
* Chunk UChars.
* +1 to simplify filling with surrogate pair at the end.
*/
UChar s[REP_TEXT_CHUNK_SIZE+1];
};
U_CDECL_BEGIN
static UText * U_CALLCONV
repTextClone(UText *dest, const UText *src, UBool deep, UErrorCode *status) {
// First do a generic shallow clone. Does everything needed for the UText struct itself.
dest = shallowTextClone(dest, src, status);
// For deep clones, make a copy of the Replaceable.
// The copied Replaceable storage is owned by the newly created UText clone.
// A non-NULL pointer in UText.p is the signal to the close() function to delete
// it.
//
if (deep && U_SUCCESS(*status)) {
const Replaceable *replSrc = (const Replaceable *)src->context;
dest->context = replSrc->clone();
dest->p = dest->context;
}
return dest;
}
static void U_CALLCONV
repTextClose(UText *ut) {
// Most of the work of close is done by the generic UText framework close.
// All that needs to be done here is delete the Replaceable if the UText
// owns it. This occurs if the UText was created by cloning.
Replaceable *rep = (Replaceable *)ut->p;
delete rep;
ut->p = NULL;
}
static int32_t U_CALLCONV
repTextLength(UText *ut) {
const Replaceable *replSrc = (const Replaceable *)ut->context;
int32_t len = replSrc->length();
return len;
}
static UBool U_CALLCONV
repTextAccess(UText *ut, int32_t index, UBool forward, UTextChunk* /* chunk*/ ) {
const Replaceable *rep=(const Replaceable *)ut->context;
int32_t length=rep->length(); // Full length of the input text (bigger than a chunk)
// clip the requested index to the limits of the text.
if (index<0) {
index = 0;
}
if (index>length) {
index = length;
}
/*
* Compute start/limit boundaries around index, for a segment of text
* to be extracted.
* To allow for the possibility that our user gave an index to the trailing
* half of a surrogate pair, we must request one extra preceding UChar when
* going in the forward direction. This will ensure that the buffer has the
* entire code point at the specified index.
*/
if(forward) {
if (index>=ut->chunk.nativeStart && index<ut->chunk.nativeLimit) {
// Buffer already contains the requested position.
ut->chunk.offset = index - ut->chunk.nativeStart;
return TRUE;
}
if (index>=length && ut->chunk.nativeLimit==length) {
// Request for end of string, and buffer already extends up to it.
// Can't get the data, but don't change the buffer.
ut->chunk.offset = length - ut->chunk.nativeStart;
return FALSE;
}
ut->chunk.nativeLimit = index + REP_TEXT_CHUNK_SIZE - 1;
// Going forward, so we want to have the buffer with stuff at and beyond
// the requested index. The -1 gets us one code point before the
// requested index also, to handle the case of the index being on
// a trail surrogate of a surrogate pair.
if(ut->chunk.nativeLimit > length) {
ut->chunk.nativeLimit = length;
}
// unless buffer ran off end, start is index-1.
ut->chunk.nativeStart = ut->chunk.nativeLimit - REP_TEXT_CHUNK_SIZE;
if(ut->chunk.nativeStart < 0) {
ut->chunk.nativeStart = 0;
}
} else {
// Reverse iteration. Fill buffer with data preceding the requested index.
if (index>ut->chunk.nativeStart && index<=ut->chunk.nativeLimit) {
// Requested position already in buffer.
ut->chunk.offset = index - ut->chunk.nativeStart;
return TRUE;
}
if (index==0 && ut->chunk.nativeStart==0) {
// Request for start, buffer already begins at start.
// No data, but keep the buffer as is.
ut->chunk.offset = 0;
return FALSE;
}
// Figure out the bounds of the chunk to extract for reverse iteration.
// Need to worry about chunk not splitting surrogate pairs, and while still
// containing the data we need.
// Fix by requesting a chunk that includes an extra UChar at the end.
// If this turns out to be a lead surrogate, we can lop it off and still have
// the data we wanted.
ut->chunk.nativeStart = index + 1 - REP_TEXT_CHUNK_SIZE;
if (ut->chunk.nativeStart < 0) {
ut->chunk.nativeStart = 0;
}
ut->chunk.nativeLimit = index + 1;
if (ut->chunk.nativeLimit > length) {
ut->chunk.nativeLimit = length;
}
}
// Extract the new chunk of text from the Replaceable source.
ReplExtra *ex = (ReplExtra *)ut->pExtra;
// UnicodeString with its buffer a writable alias to the chunk buffer
UnicodeString buffer(ex->s, 0 /*buffer length*/, REP_TEXT_CHUNK_SIZE /*buffer capacity*/);
rep->extractBetween(ut->chunk.nativeStart, ut->chunk.nativeLimit, buffer);
ut->chunk.contents = ex->s;
ut->chunk.length = ut->chunk.nativeLimit - ut->chunk.nativeStart;
ut->chunk.offset = index - ut->chunk.nativeStart;
// Surrogate pairs from the input text must not span chunk boundaries.
// If end of chunk could be the start of a surrogate, trim it off.
if (ut->chunk.nativeLimit < length &&
U16_IS_LEAD(ex->s[ut->chunk.length-1])) {
ut->chunk.length--;
ut->chunk.nativeLimit--;
if (ut->chunk.offset > ut->chunk.length) {
ut->chunk.offset = ut->chunk.length;
}
}
// if the first UChar in the chunk could be the trailing half of a surrogate pair,
// trim it off.
if(ut->chunk.nativeStart>0 && U16_IS_TRAIL(ex->s[0])) {
++(ut->chunk.contents);
++(ut->chunk.nativeStart);
--(ut->chunk.length);
--(ut->chunk.offset);
}
// adjust the index/chunkOffset to a code point boundary
U16_SET_CP_START(ut->chunk.contents, 0, ut->chunk.offset);
return TRUE;
}
static int32_t U_CALLCONV
repTextExtract(UText *ut,
int32_t start, int32_t limit,
UChar *dest, int32_t destCapacity,
UErrorCode *status) {
const Replaceable *rep=(const Replaceable *)ut->context;
int32_t length=rep->length();
if(U_FAILURE(*status)) {
return 0;
}
if(destCapacity<0 || (dest==NULL && destCapacity>0)) {
*status=U_ILLEGAL_ARGUMENT_ERROR;
}
if(start<0 || start>limit) {
*status=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
if (start>length) {
start=length;
}
if (limit>length) {
limit=length;
}
// adjust start, limit if they point to trail half of surrogates
if (start<length && U16_IS_TRAIL(rep->charAt(start)) &&
U_IS_SUPPLEMENTARY(rep->char32At(start))){
start--;
}
if (limit<length && U16_IS_TRAIL(rep->charAt(limit)) &&
U_IS_SUPPLEMENTARY(rep->char32At(limit))){
limit--;
}
length=limit-start;
if(length>destCapacity) {
limit = start + destCapacity;
}
UnicodeString buffer(dest, 0, destCapacity); // writable alias
rep->extractBetween(start, limit, buffer);
return u_terminateUChars(dest, destCapacity, length, status);
}
static int32_t U_CALLCONV
repTextReplace(UText *ut,
int32_t start, int32_t limit,
const UChar *src, int32_t length,
UErrorCode *status) {
Replaceable *rep=(Replaceable *)ut->context;
int32_t oldLength;
if(U_FAILURE(*status)) {
return 0;
}
if(src==NULL && length!=0) {
*status=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
oldLength=rep->length(); // will subtract from new length
if(start<0 || start>limit ) {
*status=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
if (start > oldLength) {
start = oldLength;
}
if (limit > oldLength) {
limit = oldLength;
}
// Do the actual replace operation using methods of the Replaceable class
UnicodeString replStr((UBool)(length<0), src, length); // read-only alias
rep->handleReplaceBetween(start, limit, replStr);
int32_t newLength = rep->length();
int32_t lengthDelta = newLength - oldLength;
// Is the UText chunk buffer OK?
if (ut->chunk.nativeLimit > start) {
// this replace operation may have impacted the current chunk.
// invalidate it, which will force a reload on the next access.
invalidateChunk(&ut->chunk);
}
// set the iteration position to the end of the newly inserted replacement text.
int32_t newIndexPos = limit + lengthDelta;
repTextAccess(ut, newIndexPos, TRUE, &ut->chunk);
return lengthDelta;
}
static void U_CALLCONV
repTextCopy(UText *ut,
int32_t start, int32_t limit,
int32_t destIndex,
UBool move,
UErrorCode *status)
{
Replaceable *rep=(Replaceable *)ut->context;
int32_t length=rep->length();
if(U_FAILURE(*status)) {
return;
}
if( start<0 || start>limit || destIndex<0 ||
(start<destIndex && destIndex<limit) )
{
*status=U_INDEX_OUTOFBOUNDS_ERROR;
return;
}
if (destIndex > length) {
destIndex = length;
}
if (limit > length) {
limit = length;
}
if (start > length) {
start = length;
}
if(move) {
// move: copy to destIndex, then replace original with nothing
int32_t segLength=limit-start;
rep->copy(start, limit, destIndex);
if(destIndex<start) {
start+=segLength;
limit+=segLength;
}
rep->handleReplaceBetween(start, limit, UnicodeString());
} else {
// copy
rep->copy(start, limit, destIndex);
}
// If the change to the text touched the region in the chunk buffer,
// invalidate the buffer.
int32_t firstAffectedIndex = destIndex;
if (move && start<firstAffectedIndex) {
firstAffectedIndex = start;
}
if (firstAffectedIndex < ut->chunk.nativeLimit) {
// changes may have affected range covered by the chunk
invalidateChunk(&ut->chunk);
}
// Put iteration position at the newly inserted (moved) block,
int32_t nativeIterIndex = destIndex + limit - start;
if (move && destIndex>start) {
// moved a block of text towards the end of the string.
nativeIterIndex = destIndex;
}
// Set position, reload chunk if needed.
repTextAccess(ut, nativeIterIndex, TRUE, &ut->chunk);
}
U_DRAFT UText * U_EXPORT2
utext_openReplaceable(UText *ut, Replaceable *rep, UErrorCode *status)
{
if(U_FAILURE(*status)) {
return NULL;
}
if(rep==NULL) {
*status=U_ILLEGAL_ARGUMENT_ERROR;
return NULL;
}
ut = utext_setup(ut, sizeof(ReplExtra), status);
ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_WRITABLE);
if(rep->hasMetaData()) {
ut->providerProperties |=I32_FLAG(UTEXT_PROVIDER_HAS_META_DATA);
}
ut->clone = repTextClone;
ut->nativeLength = repTextLength;
ut->access = repTextAccess;
ut->extract = repTextExtract;
ut->replace = repTextReplace;
ut->copy = repTextCopy;
ut->close = repTextClose;
ut->context=rep;
return ut;
}
U_CDECL_END
//------------------------------------------------------------------------------
//
// UText implementation for UnicodeString (read/write) and
// for const UnicodeString (read only)
// (same implementation, only the flags are different)
//
// Use of UText data members:
// context pointer to UnicodeString
// p pointer to UnicodeString IF this UText owns the string
// and it must be deleted on close(). NULL otherwise.
//
//------------------------------------------------------------------------------
U_CDECL_BEGIN
static UText * U_CALLCONV
unistrTextClone(UText *dest, const UText *src, UBool deep, UErrorCode *status) {
// First do a generic shallow clone. Does everything needed for the UText struct itself.
dest = shallowTextClone(dest, src, status);
// For deep clones, make a copy of the UnicodeSring.
// The copied UnicodeString storage is owned by the newly created UText clone.
// A non-NULL pointer in UText.p is the signal to the close() function to delete
// the UText.
//
if (deep && U_SUCCESS(*status)) {
const UnicodeString *srcString = (const UnicodeString *)src->context;
dest->context = new UnicodeString(*srcString);
dest->p = dest->context;
}
return dest;
}
static void U_CALLCONV
unistrTextClose(UText *ut) {
// Most of the work of close is done by the generic UText framework close.
// All that needs to be done here is delete the UnicodeString if the UText
// owns it. This occurs if the UText was created by cloning.
UnicodeString *str = (UnicodeString *)ut->p;
delete str;
ut->p = NULL;
}
static int32_t U_CALLCONV
unistrTextLength(UText *t) {
return ((const UnicodeString *)t->context)->length();
}
static UBool U_CALLCONV
unistrTextAccess(UText *ut, int32_t index, UBool forward, UTextChunk *chunk) {
const UnicodeString *us = (const UnicodeString *)ut->context;
int32_t length = us->length();
if (chunk->nativeLimit != length) {
// This chunk is not yet set up. Do it now.
// TODO: probably simplify things to move this into the open operation.
chunk->contents = us->getBuffer();
chunk->length = length;
chunk->nativeStart = 0;
chunk->nativeLimit = length;
chunk->nonUTF16Indexes = FALSE;
}
// pin the requested index to the bounds of the string,
// and set current iteration position.
if (index<0) {
index = 0;
} else if (index>length) {
index = length;
}
chunk->offset = index;
// Check whether request is at the start or end
UBool retVal = (forward && index<length) || (!forward && index>0);
return retVal;
}
static int32_t U_CALLCONV
unistrTextExtract(UText *t,
int32_t start, int32_t limit,
UChar *dest, int32_t destCapacity,
UErrorCode *pErrorCode) {
const UnicodeString *us=(const UnicodeString *)t->context;
int32_t length=us->length();
if(U_FAILURE(*pErrorCode)) {
return 0;
}
if(destCapacity<0 || (dest==NULL && destCapacity>0)) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
}
if(start<0 || start>limit) {
*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
start = start<length ? us->getChar32Start(start) : length;
limit = limit<length ? us->getChar32Start(limit) : length;
length=limit-start;
if (destCapacity>0 && dest!=NULL) {
int32_t trimmedLength = length;
if(trimmedLength>destCapacity) {
trimmedLength=destCapacity;
}
us->extract(start, trimmedLength, dest);
}
u_terminateUChars(dest, destCapacity, length, pErrorCode);
return length;
}
static int32_t U_CALLCONV
unistrTextReplace(UText *ut,
int32_t start, int32_t limit,
const UChar *src, int32_t length,
UErrorCode *pErrorCode) {
UnicodeString *us=(UnicodeString *)ut->context;
int32_t oldLength;
if(U_FAILURE(*pErrorCode)) {
return 0;
}
if(src==NULL && length!=0) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
}
oldLength=us->length(); // will subtract from new length
if(start<0 || start>limit) {
*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
start = start<oldLength ? us->getChar32Start(start) : oldLength;
limit = limit<oldLength ? us->getChar32Start(limit) : oldLength;
// replace
us->replace(start, limit-start, src, length);
int32_t newLength = us->length();
// Update the chunk description.
ut->chunk.contents = us->getBuffer();
ut->chunk.length = newLength;
ut->chunk.nativeLimit = newLength;
// Set iteration position to the point just following the newly inserted text.
int32_t lengthDelta = newLength - oldLength;
ut->chunk.offset = limit + lengthDelta;
return lengthDelta;
}
static void U_CALLCONV
unistrTextCopy(UText *ut,
int32_t start, int32_t limit,
int32_t destIndex,
UBool move,
UErrorCode *pErrorCode) {
UnicodeString *us=(UnicodeString *)ut->context;
int32_t length=us->length();
if(U_FAILURE(*pErrorCode)) {
return;
}
if( start<0 || start>limit || destIndex<0 ||
(start<destIndex && destIndex<limit)
) {
*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return;
}
if (limit>length) {
limit = length;
}
if (destIndex>length) {
destIndex = length;
}
if(move) {
// move: copy to destIndex, then replace original with nothing
int32_t segLength=limit-start;
us->copy(start, limit, destIndex);
if(destIndex<start) {
start+=segLength;
}
us->replace(start, segLength, NULL, 0);
} else {
// copy
us->copy(start, limit, destIndex);
}
// update chunk description, set iteration position.
ut->chunk.contents = us->getBuffer();
if (move==FALSE) {
// copy operation, string length grows
ut->chunk.length += limit-start;
ut->chunk.nativeLimit = ut->chunk.length;
}
// Iteration position to end of the newly inserted text.
ut->chunk.offset = destIndex+limit-start;
if (move && destIndex>start) { //TODO: backwards? check.
ut->chunk.offset = destIndex;
}
}
U_CDECL_END
U_DRAFT UText * U_EXPORT2
utext_openUnicodeString(UText *ut, UnicodeString *s, UErrorCode *status) {
ut = utext_setup(ut, 0, status);
if (U_SUCCESS(*status)) {
ut->clone = unistrTextClone;
ut->nativeLength = unistrTextLength;
ut->access = unistrTextAccess;
ut->extract = unistrTextExtract;
ut->replace = unistrTextReplace;
ut->copy = unistrTextCopy;
ut->close = unistrTextClose;
ut->context = s;
ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_STABLE_CHUNKS)|
I32_FLAG(UTEXT_PROVIDER_WRITABLE);
}
return ut;
}
U_DRAFT UText * U_EXPORT2
utext_openConstUnicodeString(UText *ut, const UnicodeString *s, UErrorCode *status) {
ut = utext_setup(ut, 0, status);
if (U_SUCCESS(*status)) {
ut->clone = unistrTextClone;
ut->nativeLength = unistrTextLength;
ut->access = unistrTextAccess;
ut->extract = unistrTextExtract;
ut->close = unistrTextClose;
ut->context = s;
ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_STABLE_CHUNKS);
}
return ut;
}
//------------------------------------------------------------------------------
//
// UText implementation for const UChar * strings
//
// Use of UText data members:
// context pointer to UnicodeString
// a length. -1 if not yet known.
//
//------------------------------------------------------------------------------
U_CDECL_BEGIN
static UText * U_CALLCONV
ucstrTextClone(UText *dest, const UText * src, UBool deep, UErrorCode * status) {
// First do a generic shallow clone.
dest = shallowTextClone(dest, src, status);
// For deep clones, make a copy of the string.
// The copied storage is owned by the newly created clone.
// A non-NULL pointer in UText.p is the signal to the close() function to delete
// it.
//
if (deep && U_SUCCESS(*status)) {
int32_t len = utext_nativeLength(dest);
// The cloned string IS going to be NUL terminated, whether or not the orginal was.
const UChar *srcStr = (const UChar *)src->context;
UChar *copyStr = (UChar *)uprv_malloc((len+1) * sizeof(UChar));
if (copyStr == NULL) {
*status = U_MEMORY_ALLOCATION_ERROR;
} else {
int i;
for (i=0; i<len; i++) {
copyStr[i] = srcStr[i];
}
copyStr[len] = 0;
dest->context = copyStr;
dest->p = copyStr;
}
}
return dest;
}
static void U_CALLCONV
ucstrTextClose(UText *ut) {
// Most of the work of close is done by the generic UText framework close.
// All that needs to be done here is delete the Replaceable if the UText
// owns it. This occurs if the UText was created by cloning.
UChar *s = (UChar *)ut->p;
uprv_free(s);
ut->p = NULL;
}
static int32_t U_CALLCONV
ucstrTextLength(UText *ut) {
if (ut->a < 0) {
// null terminated, we don't yet know the length. Scan for it.
// Access is not convenient for doing this
// because the current interation postion can't be changed.
const UChar *str = (const UChar *)ut->context;
for (;;) {
if (str[ut->chunk.nativeLimit] == 0) {
break;
}
ut->chunk.nativeLimit++;
}
ut->a = ut->chunk.nativeLimit;
ut->chunk.length = ut->chunk.nativeLimit;
ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE);
}
return ut->a;
}
static UBool U_CALLCONV
ucstrTextAccess(UText *ut, int32_t index, UBool forward, UTextChunk *chunk) {
const UChar *str = (const UChar *)ut->context;
// pin the requested index to the bounds of the string,
// and set current iteration position.
if (index<0) {
index = 0;
} else if (index < ut->chunk.nativeLimit) {
// The request data is within the chunk as it is known so far.
// There is nothing more that needs to be done within this access function.
} else if (ut->a >= 0) {
// We know the length of this string, and the user is requesting something
// at or beyond the length. Trim the requested index to the length.
index = ut->a;
} else {
// Null terminated string, length not yet known.
// Scan down another 32 UChars or to the requested index, whichever is further
int scanLimit = ut->chunk.nativeLimit + 32;
if (scanLimit <= index) {
scanLimit = index+1; // TODO: beware int overflow
}
for (; ut->chunk.nativeLimit<scanLimit; ut->chunk.nativeLimit++) {
if (str[ut->chunk.nativeLimit] == 0) {
// We found the end of the string. Remember it, trim the index to it,
// and bail out of here.
ut->a = ut->chunk.nativeLimit;
ut->chunk.length = ut->chunk.nativeLimit;
if (index > ut->chunk.nativeLimit) {
index = ut->chunk.nativeLimit;
}
ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE);
goto breakout;
}
}
// We scanned through the next batch of UChars without finding the end.
// The endpoint of a chunk must not be left in the middle of a surrogate pair.
// If the current end is on a lead surrogate, back the end up by one.
// It doesn't matter if the end char happens to be an unpaired surrogate,
// and it's simpler not to worry about it.
if (U16_IS_LEAD(str[ut->chunk.nativeLimit-1])) {
--ut->chunk.nativeLimit;
}
}
breakout:
chunk->offset = index;
// Check whether request is at the start or end
UBool retVal = (forward && index<ut->chunk.nativeLimit) || (!forward && index>0);
return retVal;
}
static int32_t U_CALLCONV
ucstrTextExtract(UText *ut,
int32_t start, int32_t limit,
UChar *dest, int32_t destCapacity,
UErrorCode *pErrorCode) {
if(U_FAILURE(*pErrorCode)) {
return 0;
}
if(destCapacity<0 || (dest==NULL && destCapacity>0)) {
*pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
return 0;
}
const UChar *s=(const UChar *)ut->context;
int32_t strLength=ut->a;
int32_t si, di;
// If text is null terminated and we haven't yet scanned down as far as the starting
// position of the extract, do it now.
if (strLength<0 && limit>=ut->chunk.nativeLimit) {
ucstrTextAccess(ut, start, TRUE, &ut->chunk);
}
// Raise an error if starting position is outside of the string.
if(start<0 || start>limit) {
*pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
return 0;
}
if (strLength >= 0 && limit > strLength) {
// String length is known. Trim requested limit to be no more than the length
limit = strLength;
}
di = 0;
for (si=start; si<limit; si++) {
if (strLength<0 && s[si]==0) {
// Just hit the end of a null-terminated string.
ut->a = si; // set string length for this UText
ut->chunk.nativeLimit = si;
ut->chunk.length = si;
//
break;
}
if (di<destCapacity) {
// only store if there is space.
dest[di] = s[si];
} else {
if (strLength>=0) {
// We have filled the destination buffer, and the string is known.
// Cut the loop short. There is no need to scan string termination.
di = strLength;
break;
}
}
di++;
}
u_terminateUChars(dest, destCapacity, di, pErrorCode);
return di;
}
U_CDECL_END
U_DRAFT UText * U_EXPORT2
utext_openUChars(UText *ut, const UChar *s, int32_t length, UErrorCode *status) {
if (U_FAILURE(*status)) {
return NULL;
}
if (length < -1) {
*status = U_ILLEGAL_ARGUMENT_ERROR;
return NULL;
}
ut = utext_setup(ut, 0, status);
if (U_SUCCESS(*status)) {
ut->clone = ucstrTextClone;
ut->nativeLength = ucstrTextLength;
ut->access = ucstrTextAccess;
ut->extract = ucstrTextExtract;
ut->replace = NULL;
ut->copy = NULL;
ut->close = ucstrTextClose;
ut->context = s;
ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_STABLE_CHUNKS);
if (length==-1) {
ut->providerProperties |= I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE);
}
ut->a = length;
ut->chunk.contents = s;
ut->chunk.nativeStart = 0;
ut->chunk.nativeLimit = length>=0? length : 0;
ut->chunk.length = ut->chunk.nativeLimit;
ut->chunk.nonUTF16Indexes = FALSE;
}
return ut;
}