1/* 2 * Copyright (C) 2014 Apple Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS 17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 23 * THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include "config.h" 27#include "UTextProviderUTF16.h" 28 29#include "UTextProvider.h" 30 31namespace WebCore { 32 33// UTF16ContextAware provider 34 35static UText* uTextUTF16ContextAwareClone(UText*, const UText*, UBool, UErrorCode*); 36static int64_t uTextUTF16ContextAwareNativeLength(UText*); 37static UBool uTextUTF16ContextAwareAccess(UText*, int64_t, UBool); 38static int32_t uTextUTF16ContextAwareExtract(UText*, int64_t, int64_t, UChar*, int32_t, UErrorCode*); 39static void uTextUTF16ContextAwareClose(UText*); 40 41static const struct UTextFuncs textUTF16ContextAwareFuncs = { 42 sizeof(UTextFuncs), 43 0, 44 0, 45 0, 46 uTextUTF16ContextAwareClone, 47 uTextUTF16ContextAwareNativeLength, 48 uTextUTF16ContextAwareAccess, 49 uTextUTF16ContextAwareExtract, 50 nullptr, 51 nullptr, 52 nullptr, 53 nullptr, 54 uTextUTF16ContextAwareClose, 55 nullptr, 56 nullptr, 57 nullptr 58}; 59 60static inline UTextProviderContext textUTF16ContextAwareGetCurrentContext(const UText* text) 61{ 62 if (!text->chunkContents) 63 return UTextProviderContext::NoContext; 64 return text->chunkContents == text->p ? UTextProviderContext::PrimaryContext : UTextProviderContext::PriorContext; 65} 66 67static void textUTF16ContextAwareMoveInPrimaryContext(UText* text, int64_t nativeIndex, int64_t nativeLength, UBool forward) 68{ 69 ASSERT(text->chunkContents == text->p); 70 ASSERT_UNUSED(forward, forward ? nativeIndex >= text->b : nativeIndex > text->b); 71 ASSERT_UNUSED(forward, forward ? nativeIndex < nativeLength : nativeIndex <= nativeLength); 72 text->chunkNativeStart = text->b; 73 text->chunkNativeLimit = nativeLength; 74 int64_t length = text->chunkNativeLimit - text->chunkNativeStart; 75 // Ensure chunk length is well defined if computed length exceeds int32_t range. 76 ASSERT(length < std::numeric_limits<int32_t>::max()); 77 text->chunkLength = length < std::numeric_limits<int32_t>::max() ? static_cast<int32_t>(length) : 0; 78 text->nativeIndexingLimit = text->chunkLength; 79 int64_t offset = nativeIndex - text->chunkNativeStart; 80 // Ensure chunk offset is well defined if computed offset exceeds int32_t range or chunk length. 81 ASSERT(offset < std::numeric_limits<int32_t>::max()); 82 text->chunkOffset = std::min(offset < std::numeric_limits<int32_t>::max() ? static_cast<int32_t>(offset) : 0, text->chunkLength); 83} 84 85static void textUTF16ContextAwareSwitchToPrimaryContext(UText* text, int64_t nativeIndex, int64_t nativeLength, UBool forward) 86{ 87 ASSERT(!text->chunkContents || text->chunkContents == text->q); 88 text->chunkContents = static_cast<const UChar*>(text->p); 89 textUTF16ContextAwareMoveInPrimaryContext(text, nativeIndex, nativeLength, forward); 90} 91 92static void textUTF16ContextAwareMoveInPriorContext(UText* text, int64_t nativeIndex, int64_t nativeLength, UBool forward) 93{ 94 ASSERT(text->chunkContents == text->q); 95 ASSERT(forward ? nativeIndex < text->b : nativeIndex <= text->b); 96 ASSERT_UNUSED(nativeLength, forward ? nativeIndex < nativeLength : nativeIndex <= nativeLength); 97 ASSERT_UNUSED(forward, forward ? nativeIndex < nativeLength : nativeIndex <= nativeLength); 98 text->chunkNativeStart = 0; 99 text->chunkNativeLimit = text->b; 100 text->chunkLength = text->b; 101 text->nativeIndexingLimit = text->chunkLength; 102 int64_t offset = nativeIndex - text->chunkNativeStart; 103 // Ensure chunk offset is well defined if computed offset exceeds int32_t range or chunk length. 104 ASSERT(offset < std::numeric_limits<int32_t>::max()); 105 text->chunkOffset = std::min(offset < std::numeric_limits<int32_t>::max() ? static_cast<int32_t>(offset) : 0, text->chunkLength); 106} 107 108static void textUTF16ContextAwareSwitchToPriorContext(UText* text, int64_t nativeIndex, int64_t nativeLength, UBool forward) 109{ 110 ASSERT(!text->chunkContents || text->chunkContents == text->p); 111 text->chunkContents = static_cast<const UChar*>(text->q); 112 textUTF16ContextAwareMoveInPriorContext(text, nativeIndex, nativeLength, forward); 113} 114 115static UText* uTextUTF16ContextAwareClone(UText* destination, const UText* source, UBool deep, UErrorCode* status) 116{ 117 return uTextCloneImpl(destination, source, deep, status); 118} 119 120static inline int64_t uTextUTF16ContextAwareNativeLength(UText* text) 121{ 122 return text->a + text->b; 123} 124 125static UBool uTextUTF16ContextAwareAccess(UText* text, int64_t nativeIndex, UBool forward) 126{ 127 if (!text->context) 128 return FALSE; 129 int64_t nativeLength = uTextUTF16ContextAwareNativeLength(text); 130 UBool isAccessible; 131 if (uTextAccessInChunkOrOutOfRange(text, nativeIndex, nativeLength, forward, isAccessible)) 132 return isAccessible; 133 nativeIndex = uTextAccessPinIndex(nativeIndex, nativeLength); 134 UTextProviderContext currentContext = textUTF16ContextAwareGetCurrentContext(text); 135 UTextProviderContext newContext = uTextProviderContext(text, nativeIndex, forward); 136 ASSERT(newContext != UTextProviderContext::NoContext); 137 if (newContext == currentContext) { 138 if (currentContext == UTextProviderContext::PrimaryContext) 139 textUTF16ContextAwareMoveInPrimaryContext(text, nativeIndex, nativeLength, forward); 140 else 141 textUTF16ContextAwareMoveInPriorContext(text, nativeIndex, nativeLength, forward); 142 } else if (newContext == UTextProviderContext::PrimaryContext) 143 textUTF16ContextAwareSwitchToPrimaryContext(text, nativeIndex, nativeLength, forward); 144 else { 145 ASSERT(newContext == UTextProviderContext::PriorContext); 146 textUTF16ContextAwareSwitchToPriorContext(text, nativeIndex, nativeLength, forward); 147 } 148 return TRUE; 149} 150 151static int32_t uTextUTF16ContextAwareExtract(UText*, int64_t, int64_t, UChar*, int32_t, UErrorCode* errorCode) 152{ 153 // In the present context, this text provider is used only with ICU functions 154 // that do not perform an extract operation. 155 ASSERT_NOT_REACHED(); 156 *errorCode = U_UNSUPPORTED_ERROR; 157 return 0; 158} 159 160static void uTextUTF16ContextAwareClose(UText* text) 161{ 162 text->context = nullptr; 163} 164 165UText* openUTF16ContextAwareUTextProvider(UText* text, const UChar* string, unsigned length, const UChar* priorContext, int priorContextLength, UErrorCode* status) 166{ 167 if (U_FAILURE(*status)) 168 return 0; 169 if (!string || length > static_cast<unsigned>(std::numeric_limits<int32_t>::max())) { 170 *status = U_ILLEGAL_ARGUMENT_ERROR; 171 return 0; 172 } 173 text = utext_setup(text, 0, status); 174 if (U_FAILURE(*status)) { 175 ASSERT(!text); 176 return 0; 177 } 178 179 initializeContextAwareUTextProvider(text, &textUTF16ContextAwareFuncs, string, length, priorContext, priorContextLength); 180 return text; 181} 182 183} // namespace WebCore 184