summaryrefslogtreecommitdiffstats
path: root/intl/icu/source/common/ucnvsel.cpp
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /intl/icu/source/common/ucnvsel.cpp
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'intl/icu/source/common/ucnvsel.cpp')
-rw-r--r--intl/icu/source/common/ucnvsel.cpp823
1 files changed, 823 insertions, 0 deletions
diff --git a/intl/icu/source/common/ucnvsel.cpp b/intl/icu/source/common/ucnvsel.cpp
new file mode 100644
index 0000000000..a286646395
--- /dev/null
+++ b/intl/icu/source/common/ucnvsel.cpp
@@ -0,0 +1,823 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+*******************************************************************************
+*
+* Copyright (C) 2008-2011, International Business Machines
+* Corporation, Google and others. All Rights Reserved.
+*
+*******************************************************************************
+*/
+// Author : eldawy@google.com (Mohamed Eldawy)
+// ucnvsel.cpp
+//
+// Purpose: To generate a list of encodings capable of handling
+// a given Unicode text
+//
+// Started 09-April-2008
+
+/**
+ * \file
+ *
+ * This is an implementation of an encoding selector.
+ * The goal is, given a unicode string, find the encodings
+ * this string can be mapped to. To make processing faster
+ * a trie is built when you call ucnvsel_open() that
+ * stores all encodings a codepoint can map to
+ */
+
+#include "unicode/ucnvsel.h"
+
+#if !UCONFIG_NO_CONVERSION
+
+#include <string.h>
+
+#include "unicode/uchar.h"
+#include "unicode/uniset.h"
+#include "unicode/ucnv.h"
+#include "unicode/ustring.h"
+#include "unicode/uchriter.h"
+#include "utrie2.h"
+#include "propsvec.h"
+#include "uassert.h"
+#include "ucmndata.h"
+#include "udataswp.h"
+#include "uenumimp.h"
+#include "cmemory.h"
+#include "cstring.h"
+
+U_NAMESPACE_USE
+
+struct UConverterSelector {
+ UTrie2 *trie; // 16 bit trie containing offsets into pv
+ uint32_t* pv; // table of bits!
+ int32_t pvCount;
+ char** encodings; // which encodings did user ask to use?
+ int32_t encodingsCount;
+ int32_t encodingStrLength;
+ uint8_t* swapped;
+ UBool ownPv, ownEncodingStrings;
+};
+
+static void generateSelectorData(UConverterSelector* result,
+ UPropsVectors *upvec,
+ const USet* excludedCodePoints,
+ const UConverterUnicodeSet whichSet,
+ UErrorCode* status) {
+ if (U_FAILURE(*status)) {
+ return;
+ }
+
+ int32_t columns = (result->encodingsCount+31)/32;
+
+ // set errorValue to all-ones
+ for (int32_t col = 0; col < columns; col++) {
+ upvec_setValue(upvec, UPVEC_ERROR_VALUE_CP, UPVEC_ERROR_VALUE_CP,
+ col, static_cast<uint32_t>(~0), static_cast<uint32_t>(~0), status);
+ }
+
+ for (int32_t i = 0; i < result->encodingsCount; ++i) {
+ uint32_t mask;
+ uint32_t column;
+ int32_t item_count;
+ int32_t j;
+ UConverter* test_converter = ucnv_open(result->encodings[i], status);
+ if (U_FAILURE(*status)) {
+ return;
+ }
+ USet* unicode_point_set;
+ unicode_point_set = uset_open(1, 0); // empty set
+
+ ucnv_getUnicodeSet(test_converter, unicode_point_set,
+ whichSet, status);
+ if (U_FAILURE(*status)) {
+ ucnv_close(test_converter);
+ return;
+ }
+
+ column = i / 32;
+ mask = 1 << (i%32);
+ // now iterate over intervals on set i!
+ item_count = uset_getItemCount(unicode_point_set);
+
+ for (j = 0; j < item_count; ++j) {
+ UChar32 start_char;
+ UChar32 end_char;
+ UErrorCode smallStatus = U_ZERO_ERROR;
+ uset_getItem(unicode_point_set, j, &start_char, &end_char, nullptr, 0,
+ &smallStatus);
+ if (U_FAILURE(smallStatus)) {
+ // this will be reached for the converters that fill the set with
+ // strings. Those should be ignored by our system
+ } else {
+ upvec_setValue(upvec, start_char, end_char, column, static_cast<uint32_t>(~0), mask,
+ status);
+ }
+ }
+ ucnv_close(test_converter);
+ uset_close(unicode_point_set);
+ if (U_FAILURE(*status)) {
+ return;
+ }
+ }
+
+ // handle excluded encodings! Simply set their values to all 1's in the upvec
+ if (excludedCodePoints) {
+ int32_t item_count = uset_getItemCount(excludedCodePoints);
+ for (int32_t j = 0; j < item_count; ++j) {
+ UChar32 start_char;
+ UChar32 end_char;
+
+ uset_getItem(excludedCodePoints, j, &start_char, &end_char, nullptr, 0,
+ status);
+ for (int32_t col = 0; col < columns; col++) {
+ upvec_setValue(upvec, start_char, end_char, col, static_cast<uint32_t>(~0), static_cast<uint32_t>(~0),
+ status);
+ }
+ }
+ }
+
+ // alright. Now, let's put things in the same exact form you'd get when you
+ // unserialize things.
+ result->trie = upvec_compactToUTrie2WithRowIndexes(upvec, status);
+ result->pv = upvec_cloneArray(upvec, &result->pvCount, nullptr, status);
+ result->pvCount *= columns; // number of uint32_t = rows * columns
+ result->ownPv = true;
+}
+
+/* open a selector. If converterListSize is 0, build for all converters.
+ If excludedCodePoints is nullptr, don't exclude any codepoints */
+U_CAPI UConverterSelector* U_EXPORT2
+ucnvsel_open(const char* const* converterList, int32_t converterListSize,
+ const USet* excludedCodePoints,
+ const UConverterUnicodeSet whichSet, UErrorCode* status) {
+ // check if already failed
+ if (U_FAILURE(*status)) {
+ return nullptr;
+ }
+ // ensure args make sense!
+ if (converterListSize < 0 || (converterList == nullptr && converterListSize != 0)) {
+ *status = U_ILLEGAL_ARGUMENT_ERROR;
+ return nullptr;
+ }
+
+ // allocate a new converter
+ LocalUConverterSelectorPointer newSelector(
+ (UConverterSelector*)uprv_malloc(sizeof(UConverterSelector)));
+ if (newSelector.isNull()) {
+ *status = U_MEMORY_ALLOCATION_ERROR;
+ return nullptr;
+ }
+ uprv_memset(newSelector.getAlias(), 0, sizeof(UConverterSelector));
+
+ if (converterListSize == 0) {
+ converterList = nullptr;
+ converterListSize = ucnv_countAvailable();
+ }
+ newSelector->encodings =
+ (char**)uprv_malloc(converterListSize * sizeof(char*));
+ if (!newSelector->encodings) {
+ *status = U_MEMORY_ALLOCATION_ERROR;
+ return nullptr;
+ }
+ newSelector->encodings[0] = nullptr; // now we can call ucnvsel_close()
+
+ // make a backup copy of the list of converters
+ int32_t totalSize = 0;
+ int32_t i;
+ for (i = 0; i < converterListSize; i++) {
+ totalSize +=
+ (int32_t)uprv_strlen(converterList != nullptr ? converterList[i] : ucnv_getAvailableName(i)) + 1;
+ }
+ // 4-align the totalSize to 4-align the size of the serialized form
+ int32_t encodingStrPadding = totalSize & 3;
+ if (encodingStrPadding != 0) {
+ encodingStrPadding = 4 - encodingStrPadding;
+ }
+ newSelector->encodingStrLength = totalSize += encodingStrPadding;
+ char* allStrings = (char*) uprv_malloc(totalSize);
+ if (!allStrings) {
+ *status = U_MEMORY_ALLOCATION_ERROR;
+ return nullptr;
+ }
+
+ for (i = 0; i < converterListSize; i++) {
+ newSelector->encodings[i] = allStrings;
+ uprv_strcpy(newSelector->encodings[i],
+ converterList != nullptr ? converterList[i] : ucnv_getAvailableName(i));
+ allStrings += uprv_strlen(newSelector->encodings[i]) + 1;
+ }
+ while (encodingStrPadding > 0) {
+ *allStrings++ = 0;
+ --encodingStrPadding;
+ }
+
+ newSelector->ownEncodingStrings = true;
+ newSelector->encodingsCount = converterListSize;
+ UPropsVectors *upvec = upvec_open((converterListSize+31)/32, status);
+ generateSelectorData(newSelector.getAlias(), upvec, excludedCodePoints, whichSet, status);
+ upvec_close(upvec);
+
+ if (U_FAILURE(*status)) {
+ return nullptr;
+ }
+
+ return newSelector.orphan();
+}
+
+/* close opened selector */
+U_CAPI void U_EXPORT2
+ucnvsel_close(UConverterSelector *sel) {
+ if (!sel) {
+ return;
+ }
+ if (sel->ownEncodingStrings) {
+ uprv_free(sel->encodings[0]);
+ }
+ uprv_free(sel->encodings);
+ if (sel->ownPv) {
+ uprv_free(sel->pv);
+ }
+ utrie2_close(sel->trie);
+ uprv_free(sel->swapped);
+ uprv_free(sel);
+}
+
+static const UDataInfo dataInfo = {
+ sizeof(UDataInfo),
+ 0,
+
+ U_IS_BIG_ENDIAN,
+ U_CHARSET_FAMILY,
+ U_SIZEOF_UCHAR,
+ 0,
+
+ { 0x43, 0x53, 0x65, 0x6c }, /* dataFormat="CSel" */
+ { 1, 0, 0, 0 }, /* formatVersion */
+ { 0, 0, 0, 0 } /* dataVersion */
+};
+
+enum {
+ UCNVSEL_INDEX_TRIE_SIZE, // trie size in bytes
+ UCNVSEL_INDEX_PV_COUNT, // number of uint32_t in the bit vectors
+ UCNVSEL_INDEX_NAMES_COUNT, // number of encoding names
+ UCNVSEL_INDEX_NAMES_LENGTH, // number of encoding name bytes including padding
+ UCNVSEL_INDEX_SIZE = 15, // bytes following the DataHeader
+ UCNVSEL_INDEX_COUNT = 16
+};
+
+/*
+ * Serialized form of a UConverterSelector, formatVersion 1:
+ *
+ * The serialized form begins with a standard ICU DataHeader with a UDataInfo
+ * as the template above.
+ * This is followed by:
+ * int32_t indexes[UCNVSEL_INDEX_COUNT]; // see index entry constants above
+ * serialized UTrie2; // indexes[UCNVSEL_INDEX_TRIE_SIZE] bytes
+ * uint32_t pv[indexes[UCNVSEL_INDEX_PV_COUNT]]; // bit vectors
+ * char* encodingNames[indexes[UCNVSEL_INDEX_NAMES_LENGTH]]; // NUL-terminated strings + padding
+ */
+
+/* serialize a selector */
+U_CAPI int32_t U_EXPORT2
+ucnvsel_serialize(const UConverterSelector* sel,
+ void* buffer, int32_t bufferCapacity, UErrorCode* status) {
+ // check if already failed
+ if (U_FAILURE(*status)) {
+ return 0;
+ }
+ // ensure args make sense!
+ uint8_t *p = (uint8_t *)buffer;
+ if (bufferCapacity < 0 ||
+ (bufferCapacity > 0 && (p == nullptr || (U_POINTER_MASK_LSB(p, 3) != 0)))
+ ) {
+ *status = U_ILLEGAL_ARGUMENT_ERROR;
+ return 0;
+ }
+ // add up the size of the serialized form
+ int32_t serializedTrieSize = utrie2_serialize(sel->trie, nullptr, 0, status);
+ if (*status != U_BUFFER_OVERFLOW_ERROR && U_FAILURE(*status)) {
+ return 0;
+ }
+ *status = U_ZERO_ERROR;
+
+ DataHeader header;
+ uprv_memset(&header, 0, sizeof(header));
+ header.dataHeader.headerSize = (uint16_t)((sizeof(header) + 15) & ~15);
+ header.dataHeader.magic1 = 0xda;
+ header.dataHeader.magic2 = 0x27;
+ uprv_memcpy(&header.info, &dataInfo, sizeof(dataInfo));
+
+ int32_t indexes[UCNVSEL_INDEX_COUNT] = {
+ serializedTrieSize,
+ sel->pvCount,
+ sel->encodingsCount,
+ sel->encodingStrLength
+ };
+
+ int32_t totalSize =
+ header.dataHeader.headerSize +
+ (int32_t)sizeof(indexes) +
+ serializedTrieSize +
+ sel->pvCount * 4 +
+ sel->encodingStrLength;
+ indexes[UCNVSEL_INDEX_SIZE] = totalSize - header.dataHeader.headerSize;
+ if (totalSize > bufferCapacity) {
+ *status = U_BUFFER_OVERFLOW_ERROR;
+ return totalSize;
+ }
+ // ok, save!
+ int32_t length = header.dataHeader.headerSize;
+ uprv_memcpy(p, &header, sizeof(header));
+ uprv_memset(p + sizeof(header), 0, length - sizeof(header));
+ p += length;
+
+ length = (int32_t)sizeof(indexes);
+ uprv_memcpy(p, indexes, length);
+ p += length;
+
+ utrie2_serialize(sel->trie, p, serializedTrieSize, status);
+ p += serializedTrieSize;
+
+ length = sel->pvCount * 4;
+ uprv_memcpy(p, sel->pv, length);
+ p += length;
+
+ uprv_memcpy(p, sel->encodings[0], sel->encodingStrLength);
+ p += sel->encodingStrLength;
+
+ return totalSize;
+}
+
+/**
+ * swap a selector into the desired Endianness and Asciiness of
+ * the system. Just as FYI, selectors are always saved in the format
+ * of the system that created them. They are only converted if used
+ * on another system. In other words, selectors created on different
+ * system can be different even if the params are identical (endianness
+ * and Asciiness differences only)
+ *
+ * @param ds pointer to data swapper containing swapping info
+ * @param inData pointer to incoming data
+ * @param length length of inData in bytes
+ * @param outData pointer to output data. Capacity should
+ * be at least equal to capacity of inData
+ * @param status an in/out ICU UErrorCode
+ * @return 0 on failure, number of bytes swapped on success
+ * number of bytes swapped can be smaller than length
+ */
+static int32_t
+ucnvsel_swap(const UDataSwapper *ds,
+ const void *inData, int32_t length,
+ void *outData, UErrorCode *status) {
+ /* udata_swapDataHeader checks the arguments */
+ int32_t headerSize = udata_swapDataHeader(ds, inData, length, outData, status);
+ if(U_FAILURE(*status)) {
+ return 0;
+ }
+
+ /* check data format and format version */
+ const UDataInfo *pInfo = (const UDataInfo *)((const char *)inData + 4);
+ if(!(
+ pInfo->dataFormat[0] == 0x43 && /* dataFormat="CSel" */
+ pInfo->dataFormat[1] == 0x53 &&
+ pInfo->dataFormat[2] == 0x65 &&
+ pInfo->dataFormat[3] == 0x6c
+ )) {
+ udata_printError(ds, "ucnvsel_swap(): data format %02x.%02x.%02x.%02x is not recognized as UConverterSelector data\n",
+ pInfo->dataFormat[0], pInfo->dataFormat[1],
+ pInfo->dataFormat[2], pInfo->dataFormat[3]);
+ *status = U_INVALID_FORMAT_ERROR;
+ return 0;
+ }
+ if(pInfo->formatVersion[0] != 1) {
+ udata_printError(ds, "ucnvsel_swap(): format version %02x is not supported\n",
+ pInfo->formatVersion[0]);
+ *status = U_UNSUPPORTED_ERROR;
+ return 0;
+ }
+
+ if(length >= 0) {
+ length -= headerSize;
+ if(length < 16*4) {
+ udata_printError(ds, "ucnvsel_swap(): too few bytes (%d after header) for UConverterSelector data\n",
+ length);
+ *status = U_INDEX_OUTOFBOUNDS_ERROR;
+ return 0;
+ }
+ }
+
+ const uint8_t *inBytes = (const uint8_t *)inData + headerSize;
+ uint8_t *outBytes = (uint8_t *)outData + headerSize;
+
+ /* read the indexes */
+ const int32_t *inIndexes = (const int32_t *)inBytes;
+ int32_t indexes[16];
+ int32_t i;
+ for(i = 0; i < 16; ++i) {
+ indexes[i] = udata_readInt32(ds, inIndexes[i]);
+ }
+
+ /* get the total length of the data */
+ int32_t size = indexes[UCNVSEL_INDEX_SIZE];
+ if(length >= 0) {
+ if(length < size) {
+ udata_printError(ds, "ucnvsel_swap(): too few bytes (%d after header) for all of UConverterSelector data\n",
+ length);
+ *status = U_INDEX_OUTOFBOUNDS_ERROR;
+ return 0;
+ }
+
+ /* copy the data for inaccessible bytes */
+ if(inBytes != outBytes) {
+ uprv_memcpy(outBytes, inBytes, size);
+ }
+
+ int32_t offset = 0, count;
+
+ /* swap the int32_t indexes[] */
+ count = UCNVSEL_INDEX_COUNT*4;
+ ds->swapArray32(ds, inBytes, count, outBytes, status);
+ offset += count;
+
+ /* swap the UTrie2 */
+ count = indexes[UCNVSEL_INDEX_TRIE_SIZE];
+ utrie2_swap(ds, inBytes + offset, count, outBytes + offset, status);
+ offset += count;
+
+ /* swap the uint32_t pv[] */
+ count = indexes[UCNVSEL_INDEX_PV_COUNT]*4;
+ ds->swapArray32(ds, inBytes + offset, count, outBytes + offset, status);
+ offset += count;
+
+ /* swap the encoding names */
+ count = indexes[UCNVSEL_INDEX_NAMES_LENGTH];
+ ds->swapInvChars(ds, inBytes + offset, count, outBytes + offset, status);
+ offset += count;
+
+ U_ASSERT(offset == size);
+ }
+
+ return headerSize + size;
+}
+
+/* unserialize a selector */
+U_CAPI UConverterSelector* U_EXPORT2
+ucnvsel_openFromSerialized(const void* buffer, int32_t length, UErrorCode* status) {
+ // check if already failed
+ if (U_FAILURE(*status)) {
+ return nullptr;
+ }
+ // ensure args make sense!
+ const uint8_t *p = (const uint8_t *)buffer;
+ if (length <= 0 ||
+ (length > 0 && (p == nullptr || (U_POINTER_MASK_LSB(p, 3) != 0)))
+ ) {
+ *status = U_ILLEGAL_ARGUMENT_ERROR;
+ return nullptr;
+ }
+ // header
+ if (length < 32) {
+ // not even enough space for a minimal header
+ *status = U_INDEX_OUTOFBOUNDS_ERROR;
+ return nullptr;
+ }
+ const DataHeader *pHeader = (const DataHeader *)p;
+ if (!(
+ pHeader->dataHeader.magic1==0xda &&
+ pHeader->dataHeader.magic2==0x27 &&
+ pHeader->info.dataFormat[0] == 0x43 &&
+ pHeader->info.dataFormat[1] == 0x53 &&
+ pHeader->info.dataFormat[2] == 0x65 &&
+ pHeader->info.dataFormat[3] == 0x6c
+ )) {
+ /* header not valid or dataFormat not recognized */
+ *status = U_INVALID_FORMAT_ERROR;
+ return nullptr;
+ }
+ if (pHeader->info.formatVersion[0] != 1) {
+ *status = U_UNSUPPORTED_ERROR;
+ return nullptr;
+ }
+ uint8_t* swapped = nullptr;
+ if (pHeader->info.isBigEndian != U_IS_BIG_ENDIAN ||
+ pHeader->info.charsetFamily != U_CHARSET_FAMILY
+ ) {
+ // swap the data
+ UDataSwapper *ds =
+ udata_openSwapperForInputData(p, length, U_IS_BIG_ENDIAN, U_CHARSET_FAMILY, status);
+ int32_t totalSize = ucnvsel_swap(ds, p, -1, nullptr, status);
+ if (U_FAILURE(*status)) {
+ udata_closeSwapper(ds);
+ return nullptr;
+ }
+ if (length < totalSize) {
+ udata_closeSwapper(ds);
+ *status = U_INDEX_OUTOFBOUNDS_ERROR;
+ return nullptr;
+ }
+ swapped = (uint8_t*)uprv_malloc(totalSize);
+ if (swapped == nullptr) {
+ udata_closeSwapper(ds);
+ *status = U_MEMORY_ALLOCATION_ERROR;
+ return nullptr;
+ }
+ ucnvsel_swap(ds, p, length, swapped, status);
+ udata_closeSwapper(ds);
+ if (U_FAILURE(*status)) {
+ uprv_free(swapped);
+ return nullptr;
+ }
+ p = swapped;
+ pHeader = (const DataHeader *)p;
+ }
+ if (length < (pHeader->dataHeader.headerSize + 16 * 4)) {
+ // not even enough space for the header and the indexes
+ uprv_free(swapped);
+ *status = U_INDEX_OUTOFBOUNDS_ERROR;
+ return nullptr;
+ }
+ p += pHeader->dataHeader.headerSize;
+ length -= pHeader->dataHeader.headerSize;
+ // indexes
+ const int32_t *indexes = (const int32_t *)p;
+ if (length < indexes[UCNVSEL_INDEX_SIZE]) {
+ uprv_free(swapped);
+ *status = U_INDEX_OUTOFBOUNDS_ERROR;
+ return nullptr;
+ }
+ p += UCNVSEL_INDEX_COUNT * 4;
+ // create and populate the selector object
+ UConverterSelector* sel = (UConverterSelector*)uprv_malloc(sizeof(UConverterSelector));
+ char **encodings =
+ (char **)uprv_malloc(
+ indexes[UCNVSEL_INDEX_NAMES_COUNT] * sizeof(char *));
+ if (sel == nullptr || encodings == nullptr) {
+ uprv_free(swapped);
+ uprv_free(sel);
+ uprv_free(encodings);
+ *status = U_MEMORY_ALLOCATION_ERROR;
+ return nullptr;
+ }
+ uprv_memset(sel, 0, sizeof(UConverterSelector));
+ sel->pvCount = indexes[UCNVSEL_INDEX_PV_COUNT];
+ sel->encodings = encodings;
+ sel->encodingsCount = indexes[UCNVSEL_INDEX_NAMES_COUNT];
+ sel->encodingStrLength = indexes[UCNVSEL_INDEX_NAMES_LENGTH];
+ sel->swapped = swapped;
+ // trie
+ sel->trie = utrie2_openFromSerialized(UTRIE2_16_VALUE_BITS,
+ p, indexes[UCNVSEL_INDEX_TRIE_SIZE], nullptr,
+ status);
+ p += indexes[UCNVSEL_INDEX_TRIE_SIZE];
+ if (U_FAILURE(*status)) {
+ ucnvsel_close(sel);
+ return nullptr;
+ }
+ // bit vectors
+ sel->pv = (uint32_t *)p;
+ p += sel->pvCount * 4;
+ // encoding names
+ char* s = (char*)p;
+ for (int32_t i = 0; i < sel->encodingsCount; ++i) {
+ sel->encodings[i] = s;
+ s += uprv_strlen(s) + 1;
+ }
+ p += sel->encodingStrLength;
+
+ return sel;
+}
+
+// a bunch of functions for the enumeration thingie! Nothing fancy here. Just
+// iterate over the selected encodings
+struct Enumerator {
+ int16_t* index;
+ int16_t length;
+ int16_t cur;
+ const UConverterSelector* sel;
+};
+
+U_CDECL_BEGIN
+
+static void U_CALLCONV
+ucnvsel_close_selector_iterator(UEnumeration *enumerator) {
+ uprv_free(((Enumerator*)(enumerator->context))->index);
+ uprv_free(enumerator->context);
+ uprv_free(enumerator);
+}
+
+
+static int32_t U_CALLCONV
+ucnvsel_count_encodings(UEnumeration *enumerator, UErrorCode *status) {
+ // check if already failed
+ if (U_FAILURE(*status)) {
+ return 0;
+ }
+ return ((Enumerator*)(enumerator->context))->length;
+}
+
+
+static const char* U_CALLCONV ucnvsel_next_encoding(UEnumeration* enumerator,
+ int32_t* resultLength,
+ UErrorCode* status) {
+ // check if already failed
+ if (U_FAILURE(*status)) {
+ return nullptr;
+ }
+
+ int16_t cur = ((Enumerator*)(enumerator->context))->cur;
+ const UConverterSelector* sel;
+ const char* result;
+ if (cur >= ((Enumerator*)(enumerator->context))->length) {
+ return nullptr;
+ }
+ sel = ((Enumerator*)(enumerator->context))->sel;
+ result = sel->encodings[((Enumerator*)(enumerator->context))->index[cur] ];
+ ((Enumerator*)(enumerator->context))->cur++;
+ if (resultLength) {
+ *resultLength = (int32_t)uprv_strlen(result);
+ }
+ return result;
+}
+
+static void U_CALLCONV ucnvsel_reset_iterator(UEnumeration* enumerator,
+ UErrorCode* status) {
+ // check if already failed
+ if (U_FAILURE(*status)) {
+ return ;
+ }
+ ((Enumerator*)(enumerator->context))->cur = 0;
+}
+
+U_CDECL_END
+
+
+static const UEnumeration defaultEncodings = {
+ nullptr,
+ nullptr,
+ ucnvsel_close_selector_iterator,
+ ucnvsel_count_encodings,
+ uenum_unextDefault,
+ ucnvsel_next_encoding,
+ ucnvsel_reset_iterator
+};
+
+
+// internal fn to intersect two sets of masks
+// returns whether the mask has reduced to all zeros
+static UBool intersectMasks(uint32_t* dest, const uint32_t* source1, int32_t len) {
+ int32_t i;
+ uint32_t oredDest = 0;
+ for (i = 0 ; i < len ; ++i) {
+ oredDest |= (dest[i] &= source1[i]);
+ }
+ return oredDest == 0;
+}
+
+// internal fn to count how many 1's are there in a mask
+// algorithm taken from http://graphics.stanford.edu/~seander/bithacks.html
+static int16_t countOnes(uint32_t* mask, int32_t len) {
+ int32_t i, totalOnes = 0;
+ for (i = 0 ; i < len ; ++i) {
+ uint32_t ent = mask[i];
+ for (; ent; totalOnes++)
+ {
+ ent &= ent - 1; // clear the least significant bit set
+ }
+ }
+ return static_cast<int16_t>(totalOnes);
+}
+
+
+/* internal function! */
+static UEnumeration *selectForMask(const UConverterSelector* sel,
+ uint32_t *theMask, UErrorCode *status) {
+ LocalMemory<uint32_t> mask(theMask);
+ // this is the context we will use. Store a table of indices to which
+ // encodings are legit.
+ LocalMemory<Enumerator> result(static_cast<Enumerator *>(uprv_malloc(sizeof(Enumerator))));
+ if (result.isNull()) {
+ *status = U_MEMORY_ALLOCATION_ERROR;
+ return nullptr;
+ }
+ result->index = nullptr; // this will be allocated later!
+ result->length = result->cur = 0;
+ result->sel = sel;
+
+ LocalMemory<UEnumeration> en(static_cast<UEnumeration *>(uprv_malloc(sizeof(UEnumeration))));
+ if (en.isNull()) {
+ // TODO(markus): Combine Enumerator and UEnumeration into one struct.
+ *status = U_MEMORY_ALLOCATION_ERROR;
+ return nullptr;
+ }
+ memcpy(en.getAlias(), &defaultEncodings, sizeof(UEnumeration));
+
+ int32_t columns = (sel->encodingsCount+31)/32;
+ int16_t numOnes = countOnes(mask.getAlias(), columns);
+ // now, we know the exact space we need for index
+ if (numOnes > 0) {
+ result->index = static_cast<int16_t*>(uprv_malloc(numOnes * sizeof(int16_t)));
+ if (result->index == nullptr) {
+ *status = U_MEMORY_ALLOCATION_ERROR;
+ return nullptr;
+ }
+ int32_t i, j;
+ int16_t k = 0;
+ for (j = 0 ; j < columns; j++) {
+ uint32_t v = mask[j];
+ for (i = 0 ; i < 32 && k < sel->encodingsCount; i++, k++) {
+ if ((v & 1) != 0) {
+ result->index[result->length++] = k;
+ }
+ v >>= 1;
+ }
+ }
+ } //otherwise, index will remain nullptr (and will never be touched by
+ //the enumerator code anyway)
+ en->context = result.orphan();
+ return en.orphan();
+}
+
+/* check a string against the selector - UTF16 version */
+U_CAPI UEnumeration * U_EXPORT2
+ucnvsel_selectForString(const UConverterSelector* sel,
+ const char16_t *s, int32_t length, UErrorCode *status) {
+ // check if already failed
+ if (U_FAILURE(*status)) {
+ return nullptr;
+ }
+ // ensure args make sense!
+ if (sel == nullptr || (s == nullptr && length != 0)) {
+ *status = U_ILLEGAL_ARGUMENT_ERROR;
+ return nullptr;
+ }
+
+ int32_t columns = (sel->encodingsCount+31)/32;
+ uint32_t* mask = (uint32_t*) uprv_malloc(columns * 4);
+ if (mask == nullptr) {
+ *status = U_MEMORY_ALLOCATION_ERROR;
+ return nullptr;
+ }
+ uprv_memset(mask, ~0, columns *4);
+
+ if(s!=nullptr) {
+ const char16_t *limit;
+ if (length >= 0) {
+ limit = s + length;
+ } else {
+ limit = nullptr;
+ }
+
+ while (limit == nullptr ? *s != 0 : s != limit) {
+ UChar32 c;
+ uint16_t pvIndex;
+ UTRIE2_U16_NEXT16(sel->trie, s, limit, c, pvIndex);
+ if (intersectMasks(mask, sel->pv+pvIndex, columns)) {
+ break;
+ }
+ }
+ }
+ return selectForMask(sel, mask, status);
+}
+
+/* check a string against the selector - UTF8 version */
+U_CAPI UEnumeration * U_EXPORT2
+ucnvsel_selectForUTF8(const UConverterSelector* sel,
+ const char *s, int32_t length, UErrorCode *status) {
+ // check if already failed
+ if (U_FAILURE(*status)) {
+ return nullptr;
+ }
+ // ensure args make sense!
+ if (sel == nullptr || (s == nullptr && length != 0)) {
+ *status = U_ILLEGAL_ARGUMENT_ERROR;
+ return nullptr;
+ }
+
+ int32_t columns = (sel->encodingsCount+31)/32;
+ uint32_t* mask = (uint32_t*) uprv_malloc(columns * 4);
+ if (mask == nullptr) {
+ *status = U_MEMORY_ALLOCATION_ERROR;
+ return nullptr;
+ }
+ uprv_memset(mask, ~0, columns *4);
+
+ if (length < 0) {
+ length = (int32_t)uprv_strlen(s);
+ }
+
+ if(s!=nullptr) {
+ const char *limit = s + length;
+
+ while (s != limit) {
+ uint16_t pvIndex;
+ UTRIE2_U8_NEXT16(sel->trie, s, limit, pvIndex);
+ if (intersectMasks(mask, sel->pv+pvIndex, columns)) {
+ break;
+ }
+ }
+ }
+ return selectForMask(sel, mask, status);
+}
+
+#endif // !UCONFIG_NO_CONVERSION