| /* |
| Copyright (C) 1999 Lars Knoll (knoll@mpi-hd.mpg.de) |
| Copyright (C) 2003-2017 Apple Inc. All rights reserved. |
| Copyright (C) 2005, 2006, 2007 Alexey Proskuryakov (ap@nypop.com) |
| |
| This library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Library General Public |
| License as published by the Free Software Foundation; either |
| version 2 of the License, or (at your option) any later version. |
| |
| This library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Library General Public License for more details. |
| |
| You should have received a copy of the GNU Library General Public License |
| along with this library; see the file COPYING.LIB. If not, write to |
| the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| Boston, MA 02110-1301, USA. |
| */ |
| |
| |
| #include "config.h" |
| #include "TextResourceDecoder.h" |
| |
| #include "HTMLMetaCharsetParser.h" |
| #include "HTMLNames.h" |
| #include "MIMETypeRegistry.h" |
| #include "TextCodec.h" |
| #include "TextEncoding.h" |
| #include "TextEncodingDetector.h" |
| #include "TextEncodingRegistry.h" |
| #include <wtf/ASCIICType.h> |
| |
| |
| namespace WebCore { |
| |
| using namespace HTMLNames; |
| |
| static inline bool bytesEqual(const char* p, char b0, char b1) |
| { |
| return p[0] == b0 && p[1] == b1; |
| } |
| |
| static inline bool bytesEqual(const char* p, char b0, char b1, char b2, char b3, char b4) |
| { |
| return p[0] == b0 && p[1] == b1 && p[2] == b2 && p[3] == b3 && p[4] == b4; |
| } |
| |
| static inline bool bytesEqual(const char* p, char b0, char b1, char b2, char b3, char b4, char b5) |
| { |
| return p[0] == b0 && p[1] == b1 && p[2] == b2 && p[3] == b3 && p[4] == b4 && p[5] == b5; |
| } |
| |
| static inline bool bytesEqual(const char* p, char b0, char b1, char b2, char b3, char b4, char b5, char b6, char b7) |
| { |
| return p[0] == b0 && p[1] == b1 && p[2] == b2 && p[3] == b3 && p[4] == b4 && p[5] == b5 && p[6] == b6 && p[7] == b7; |
| } |
| |
| static inline bool bytesEqual(const char* p, char b0, char b1, char b2, char b3, char b4, char b5, char b6, char b7, char b8, char b9) |
| { |
| return p[0] == b0 && p[1] == b1 && p[2] == b2 && p[3] == b3 && p[4] == b4 && p[5] == b5 && p[6] == b6 && p[7] == b7 && p[8] == b8 && p[9] == b9; |
| } |
| |
| // You might think we should put these find functions elsewhere, perhaps with the |
| // similar functions that operate on UChar, but arguably only the decoder has |
| // a reason to process strings of char rather than UChar. |
| |
| static int find(const char* subject, size_t subjectLength, const char* target) |
| { |
| size_t targetLength = strlen(target); |
| if (targetLength > subjectLength) |
| return -1; |
| for (size_t i = 0; i <= subjectLength - targetLength; ++i) { |
| bool match = true; |
| for (size_t j = 0; j < targetLength; ++j) { |
| if (subject[i + j] != target[j]) { |
| match = false; |
| break; |
| } |
| } |
| if (match) |
| return i; |
| } |
| return -1; |
| } |
| |
| static TextEncoding findTextEncoding(const char* encodingName, int length) |
| { |
| Vector<char, 64> buffer(length + 1); |
| memcpy(buffer.data(), encodingName, length); |
| buffer[length] = '\0'; |
| return buffer.data(); |
| } |
| |
| class KanjiCode { |
| public: |
| enum Type { ASCII, JIS, EUC, SJIS, UTF16, UTF8 }; |
| static enum Type judge(const char* str, int length); |
| static const int ESC = 0x1b; |
| static const unsigned char sjisMap[256]; |
| static int ISkanji(int code) |
| { |
| if (code >= 0x100) |
| return 0; |
| return sjisMap[code & 0xff] & 1; |
| } |
| static int ISkana(int code) |
| { |
| if (code >= 0x100) |
| return 0; |
| return sjisMap[code & 0xff] & 2; |
| } |
| }; |
| |
| const unsigned char KanjiCode::sjisMap[256] = { |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, |
| 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
| 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
| 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, |
| 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, |
| 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, |
| 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, |
| 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, |
| 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0 |
| }; |
| |
| /* |
| * EUC-JP is |
| * [0xa1 - 0xfe][0xa1 - 0xfe] |
| * 0x8e[0xa1 - 0xfe](SS2) |
| * 0x8f[0xa1 - 0xfe][0xa1 - 0xfe](SS3) |
| * |
| * Shift_Jis is |
| * [0x81 - 0x9f, 0xe0 - 0xef(0xfe?)][0x40 - 0x7e, 0x80 - 0xfc] |
| * |
| * Shift_Jis Hankaku Kana is |
| * [0xa1 - 0xdf] |
| */ |
| |
| /* |
| * KanjiCode::judge() is based on judge_jcode() from jvim |
| * http://hp.vector.co.jp/authors/VA003457/vim/ |
| * |
| * Special Thanks to Kenichi Tsuchida |
| */ |
| |
| enum KanjiCode::Type KanjiCode::judge(const char* str, int size) |
| { |
| enum Type code; |
| int i; |
| int bfr = false; /* Kana Moji */ |
| int bfk = 0; /* EUC Kana */ |
| int sjis = 0; |
| int euc = 0; |
| |
| const unsigned char* ptr = reinterpret_cast<const unsigned char*>(str); |
| |
| code = ASCII; |
| |
| i = 0; |
| while (i < size) { |
| if (ptr[i] == ESC && (size - i >= 3)) { |
| if (bytesEqual(str + i + 1, '$', 'B') |
| || bytesEqual(str + i + 1, '(', 'B') |
| || bytesEqual(str + i + 1, '$', '@') |
| || bytesEqual(str + i + 1, '(', 'J')) { |
| code = JIS; |
| goto breakBreak; |
| } |
| if (bytesEqual(str + i + 1, '(', 'I') || bytesEqual(str + i + 1, ')', 'I')) { |
| code = JIS; |
| i += 3; |
| } else { |
| i++; |
| } |
| bfr = false; |
| bfk = 0; |
| } else { |
| if (ptr[i] < 0x20) { |
| bfr = false; |
| bfk = 0; |
| /* ?? check kudokuten ?? && ?? hiragana ?? */ |
| if ((i >= 2) && (ptr[i - 2] == 0x81) |
| && (0x41 <= ptr[i - 1] && ptr[i - 1] <= 0x49)) { |
| code = SJIS; |
| sjis += 100; /* kudokuten */ |
| } else if ((i >= 2) && (ptr[i - 2] == 0xa1) |
| && (0xa2 <= ptr[i - 1] && ptr[i - 1] <= 0xaa)) { |
| code = EUC; |
| euc += 100; /* kudokuten */ |
| } else if ((i >= 2) && (ptr[i - 2] == 0x82) && (0xa0 <= ptr[i - 1])) { |
| sjis += 40; /* hiragana */ |
| } else if ((i >= 2) && (ptr[i - 2] == 0xa4) && (0xa0 <= ptr[i - 1])) { |
| euc += 40; /* hiragana */ |
| } |
| } else { |
| /* ?? check hiragana or katana ?? */ |
| if ((size - i > 1) && (ptr[i] == 0x82) && (0xa0 <= ptr[i + 1])) { |
| sjis++; /* hiragana */ |
| } else if ((size - i > 1) && (ptr[i] == 0x83) |
| && (0x40 <= ptr[i + 1] && ptr[i + 1] <= 0x9f)) { |
| sjis++; /* katakana */ |
| } else if ((size - i > 1) && (ptr[i] == 0xa4) && (0xa0 <= ptr[i + 1])) { |
| euc++; /* hiragana */ |
| } else if ((size - i > 1) && (ptr[i] == 0xa5) && (0xa0 <= ptr[i + 1])) { |
| euc++; /* katakana */ |
| } |
| if (bfr) { |
| if ((i >= 1) && (0x40 <= ptr[i] && ptr[i] <= 0xa0) && ISkanji(ptr[i - 1])) { |
| code = SJIS; |
| goto breakBreak; |
| } else if ((i >= 1) && (0x81 <= ptr[i - 1] && ptr[i - 1] <= 0x9f) && ((0x40 <= ptr[i] && ptr[i] < 0x7e) || (0x7e < ptr[i] && ptr[i] <= 0xfc))) { |
| code = SJIS; |
| goto breakBreak; |
| } else if ((i >= 1) && (0xfd <= ptr[i] && ptr[i] <= 0xfe) && (0xa1 <= ptr[i - 1] && ptr[i - 1] <= 0xfe)) { |
| code = EUC; |
| goto breakBreak; |
| } else if ((i >= 1) && (0xfd <= ptr[i - 1] && ptr[i - 1] <= 0xfe) && (0xa1 <= ptr[i] && ptr[i] <= 0xfe)) { |
| code = EUC; |
| goto breakBreak; |
| } else if ((i >= 1) && (ptr[i] < 0xa0 || 0xdf < ptr[i]) && (0x8e == ptr[i - 1])) { |
| code = SJIS; |
| goto breakBreak; |
| } else if (ptr[i] <= 0x7f) { |
| code = SJIS; |
| goto breakBreak; |
| } else { |
| if (0xa1 <= ptr[i] && ptr[i] <= 0xa6) { |
| euc++; /* sjis hankaku kana kigo */ |
| } else if (0xa1 <= ptr[i] && ptr[i] <= 0xdf) { |
| ; /* sjis hankaku kana */ |
| } else if (0xa1 <= ptr[i] && ptr[i] <= 0xfe) { |
| euc++; |
| } else if (0x8e == ptr[i]) { |
| euc++; |
| } else if (0x20 <= ptr[i] && ptr[i] <= 0x7f) { |
| sjis++; |
| } |
| bfr = false; |
| bfk = 0; |
| } |
| } else if (0x8e == ptr[i]) { |
| if (size - i <= 1) { |
| ; |
| } else if (0xa1 <= ptr[i + 1] && ptr[i + 1] <= 0xdf) { |
| /* EUC KANA or SJIS KANJI */ |
| if (bfk == 1) { |
| euc += 100; |
| } |
| bfk++; |
| i++; |
| } else { |
| /* SJIS only */ |
| code = SJIS; |
| goto breakBreak; |
| } |
| } else if (0x81 <= ptr[i] && ptr[i] <= 0x9f) { |
| /* SJIS only */ |
| code = SJIS; |
| if ((size - i >= 1) |
| && ((0x40 <= ptr[i + 1] && ptr[i + 1] <= 0x7e) |
| || (0x80 <= ptr[i + 1] && ptr[i + 1] <= 0xfc))) { |
| goto breakBreak; |
| } |
| } else if (0xfd <= ptr[i] && ptr[i] <= 0xfe) { |
| /* EUC only */ |
| code = EUC; |
| if ((size - i >= 1) |
| && (0xa1 <= ptr[i + 1] && ptr[i + 1] <= 0xfe)) { |
| goto breakBreak; |
| } |
| } else if (ptr[i] <= 0x7f) { |
| ; |
| } else { |
| bfr = true; |
| bfk = 0; |
| } |
| } |
| i++; |
| } |
| } |
| if (code == ASCII) { |
| if (sjis > euc) { |
| code = SJIS; |
| } else if (sjis < euc) { |
| code = EUC; |
| } |
| } |
| breakBreak: |
| return (code); |
| } |
| |
| TextResourceDecoder::ContentType TextResourceDecoder::determineContentType(const String& mimeType) |
| { |
| if (equalLettersIgnoringASCIICase(mimeType, "text/css")) |
| return CSS; |
| if (equalLettersIgnoringASCIICase(mimeType, "text/html")) |
| return HTML; |
| if (MIMETypeRegistry::isXMLMIMEType(mimeType)) |
| return XML; |
| return PlainText; |
| } |
| |
| const TextEncoding& TextResourceDecoder::defaultEncoding(ContentType contentType, const TextEncoding& specifiedDefaultEncoding) |
| { |
| // Despite 8.5 "Text/xml with Omitted Charset" of RFC 3023, we assume UTF-8 instead of US-ASCII |
| // for text/xml. This matches Firefox. |
| if (contentType == XML) |
| return UTF8Encoding(); |
| if (!specifiedDefaultEncoding.isValid()) |
| return Latin1Encoding(); |
| return specifiedDefaultEncoding; |
| } |
| |
| inline TextResourceDecoder::TextResourceDecoder(const String& mimeType, const TextEncoding& specifiedDefaultEncoding, bool usesEncodingDetector) |
| : m_contentType(determineContentType(mimeType)) |
| , m_encoding(defaultEncoding(m_contentType, specifiedDefaultEncoding)) |
| , m_usesEncodingDetector(usesEncodingDetector) |
| { |
| } |
| |
| Ref<TextResourceDecoder> TextResourceDecoder::create(const String& mimeType, const TextEncoding& defaultEncoding, bool usesEncodingDetector) |
| { |
| return adoptRef(*new TextResourceDecoder(mimeType, defaultEncoding, usesEncodingDetector)); |
| } |
| |
| TextResourceDecoder::~TextResourceDecoder() = default; |
| |
| void TextResourceDecoder::setEncoding(const TextEncoding& encoding, EncodingSource source) |
| { |
| // In case the encoding didn't exist, we keep the old one (helps some sites specifying invalid encodings). |
| if (!encoding.isValid()) |
| return; |
| |
| // When encoding comes from meta tag (i.e. it cannot be XML files sent via XHR), |
| // treat x-user-defined as windows-1252 (bug 18270) |
| if (source == EncodingFromMetaTag && equalLettersIgnoringASCIICase(encoding.name(), "x-user-defined")) |
| m_encoding = "windows-1252"; |
| else if (source == EncodingFromMetaTag || source == EncodingFromXMLHeader || source == EncodingFromCSSCharset) |
| m_encoding = encoding.closestByteBasedEquivalent(); |
| else |
| m_encoding = encoding; |
| |
| m_codec = nullptr; |
| m_source = source; |
| } |
| |
| bool TextResourceDecoder::hasEqualEncodingForCharset(const String& charset) const |
| { |
| return defaultEncoding(m_contentType, charset) == m_encoding; |
| } |
| |
| // Returns the position of the encoding string. |
| static int findXMLEncoding(const char* str, int len, int& encodingLength) |
| { |
| int pos = find(str, len, "encoding"); |
| if (pos == -1) |
| return -1; |
| pos += 8; |
| |
| // Skip spaces and stray control characters. |
| while (pos < len && str[pos] <= ' ') |
| ++pos; |
| |
| // Skip equals sign. |
| if (pos >= len || str[pos] != '=') |
| return -1; |
| ++pos; |
| |
| // Skip spaces and stray control characters. |
| while (pos < len && str[pos] <= ' ') |
| ++pos; |
| |
| // Skip quotation mark. |
| if (pos >= len) |
| return - 1; |
| char quoteMark = str[pos]; |
| if (quoteMark != '"' && quoteMark != '\'') |
| return -1; |
| ++pos; |
| |
| // Find the trailing quotation mark. |
| int end = pos; |
| while (end < len && str[end] != quoteMark) |
| ++end; |
| if (end >= len) |
| return -1; |
| |
| encodingLength = end - pos; |
| return pos; |
| } |
| |
| size_t TextResourceDecoder::checkForBOM(const char* data, size_t len) |
| { |
| // Check for UTF-16 or UTF-8 BOM mark at the beginning, which is a sure sign of a Unicode encoding. |
| // We let it override even a user-chosen encoding. |
| const size_t maximumBOMLength = 3; |
| |
| ASSERT(!m_checkedForBOM); |
| |
| size_t lengthOfBOM = 0; |
| |
| size_t bufferLength = m_buffer.size(); |
| |
| size_t buf1Len = bufferLength; |
| size_t buf2Len = len; |
| const unsigned char* buf1 = reinterpret_cast<const unsigned char*>(m_buffer.data()); |
| const unsigned char* buf2 = reinterpret_cast<const unsigned char*>(data); |
| unsigned char c1 = buf1Len ? (static_cast<void>(--buf1Len), *buf1++) : buf2Len ? (static_cast<void>(--buf2Len), *buf2++) : 0; |
| unsigned char c2 = buf1Len ? (static_cast<void>(--buf1Len), *buf1++) : buf2Len ? (static_cast<void>(--buf2Len), *buf2++) : 0; |
| unsigned char c3 = buf1Len ? (static_cast<void>(--buf1Len), *buf1++) : buf2Len ? (static_cast<void>(--buf2Len), *buf2++) : 0; |
| |
| // Check for the BOM. |
| if (c1 == 0xFF && c2 == 0xFE) { |
| ASSERT(UTF16LittleEndianEncoding().isValid()); |
| setEncoding(UTF16LittleEndianEncoding(), AutoDetectedEncoding); |
| lengthOfBOM = 2; |
| } else if (c1 == 0xFE && c2 == 0xFF) { |
| ASSERT(UTF16BigEndianEncoding().isValid()); |
| setEncoding(UTF16BigEndianEncoding(), AutoDetectedEncoding); |
| lengthOfBOM = 2; |
| } else if (c1 == 0xEF && c2 == 0xBB && c3 == 0xBF) { |
| ASSERT(UTF8Encoding().isValid()); |
| setEncoding(UTF8Encoding(), AutoDetectedEncoding); |
| lengthOfBOM = 3; |
| } |
| |
| if (lengthOfBOM || bufferLength + len >= maximumBOMLength) |
| m_checkedForBOM = true; |
| |
| ASSERT(lengthOfBOM <= maximumBOMLength); |
| return lengthOfBOM; |
| } |
| |
| bool TextResourceDecoder::checkForCSSCharset(const char* data, size_t len, bool& movedDataToBuffer) |
| { |
| if (m_source != DefaultEncoding && m_source != EncodingFromParentFrame) { |
| m_checkedForCSSCharset = true; |
| return true; |
| } |
| |
| size_t oldSize = m_buffer.size(); |
| m_buffer.grow(oldSize + len); |
| memcpy(m_buffer.data() + oldSize, data, len); |
| |
| movedDataToBuffer = true; |
| |
| if (m_buffer.size() <= 13) // strlen('@charset "x";') == 13 |
| return false; |
| |
| const char* dataStart = m_buffer.data(); |
| const char* dataEnd = dataStart + m_buffer.size(); |
| |
| if (bytesEqual(dataStart, '@', 'c', 'h', 'a', 'r', 's', 'e', 't', ' ', '"')) { |
| dataStart += 10; |
| const char* pos = dataStart; |
| |
| while (pos < dataEnd && *pos != '"') |
| ++pos; |
| if (pos == dataEnd) |
| return false; |
| |
| int encodingNameLength = pos - dataStart; |
| |
| ++pos; |
| if (pos == dataEnd) |
| return false; |
| |
| if (*pos == ';') |
| setEncoding(findTextEncoding(dataStart, encodingNameLength), EncodingFromCSSCharset); |
| } |
| |
| m_checkedForCSSCharset = true; |
| return true; |
| } |
| |
| bool TextResourceDecoder::checkForHeadCharset(const char* data, size_t len, bool& movedDataToBuffer) |
| { |
| if (m_source != DefaultEncoding && m_source != EncodingFromParentFrame) { |
| m_checkedForHeadCharset = true; |
| return true; |
| } |
| |
| // This is not completely efficient, since the function might go |
| // through the HTML head several times. |
| |
| size_t oldSize = m_buffer.size(); |
| m_buffer.grow(oldSize + len); |
| memcpy(m_buffer.data() + oldSize, data, len); |
| |
| movedDataToBuffer = true; |
| |
| // Continue with checking for an HTML meta tag if we were already doing so. |
| if (m_charsetParser) |
| return checkForMetaCharset(data, len); |
| |
| const char* ptr = m_buffer.data(); |
| const char* pEnd = ptr + m_buffer.size(); |
| |
| // Is there enough data available to check for XML declaration? |
| if (m_buffer.size() < 8) |
| return false; |
| |
| // Handle XML declaration, which can have encoding in it. This encoding is honored even for HTML documents. |
| // It is an error for an XML declaration not to be at the start of an XML document, and it is ignored in HTML documents in such case. |
| if (bytesEqual(ptr, '<', '?', 'x', 'm', 'l')) { |
| const char* xmlDeclarationEnd = ptr; |
| while (xmlDeclarationEnd != pEnd && *xmlDeclarationEnd != '>') |
| ++xmlDeclarationEnd; |
| if (xmlDeclarationEnd == pEnd) |
| return false; |
| // No need for +1, because we have an extra "?" to lose at the end of XML declaration. |
| int len = 0; |
| int pos = findXMLEncoding(ptr, xmlDeclarationEnd - ptr, len); |
| if (pos != -1) |
| setEncoding(findTextEncoding(ptr + pos, len), EncodingFromXMLHeader); |
| // continue looking for a charset - it may be specified in an HTTP-Equiv meta |
| } else if (bytesEqual(ptr, '<', 0, '?', 0, 'x', 0)) { |
| setEncoding(UTF16LittleEndianEncoding(), AutoDetectedEncoding); |
| return true; |
| } else if (bytesEqual(ptr, 0, '<', 0, '?', 0, 'x')) { |
| setEncoding(UTF16BigEndianEncoding(), AutoDetectedEncoding); |
| return true; |
| } |
| |
| // The HTTP-EQUIV meta has no effect on XHTML. |
| if (m_contentType == XML) |
| return true; |
| |
| m_charsetParser = makeUnique<HTMLMetaCharsetParser>(); |
| return checkForMetaCharset(data, len); |
| } |
| |
| bool TextResourceDecoder::checkForMetaCharset(const char* data, size_t length) |
| { |
| if (!m_charsetParser->checkForMetaCharset(data, length)) |
| return false; |
| |
| setEncoding(m_charsetParser->encoding(), EncodingFromMetaTag); |
| m_charsetParser = nullptr; |
| m_checkedForHeadCharset = true; |
| return true; |
| } |
| |
| void TextResourceDecoder::detectJapaneseEncoding(const char* data, size_t len) |
| { |
| switch (KanjiCode::judge(data, len)) { |
| case KanjiCode::JIS: |
| setEncoding("ISO-2022-JP", AutoDetectedEncoding); |
| break; |
| case KanjiCode::EUC: |
| setEncoding("EUC-JP", AutoDetectedEncoding); |
| break; |
| case KanjiCode::SJIS: |
| setEncoding("Shift_JIS", AutoDetectedEncoding); |
| break; |
| case KanjiCode::ASCII: |
| case KanjiCode::UTF16: |
| case KanjiCode::UTF8: |
| break; |
| } |
| } |
| |
| // We use the encoding detector in two cases: |
| // 1. Encoding detector is turned ON and no other encoding source is |
| // available (that is, it's DefaultEncoding). |
| // 2. Encoding detector is turned ON and the encoding is set to |
| // the encoding of the parent frame, which is also auto-detected. |
| // Note that condition #2 is NOT satisfied unless parent-child frame |
| // relationship is compliant to the same-origin policy. If they're from |
| // different domains, |m_source| would not be set to EncodingFromParentFrame |
| // in the first place. |
| bool TextResourceDecoder::shouldAutoDetect() const |
| { |
| return m_usesEncodingDetector |
| && (m_source == DefaultEncoding || (m_source == EncodingFromParentFrame && m_parentFrameAutoDetectedEncoding)); |
| } |
| |
| String TextResourceDecoder::decode(const char* data, size_t length) |
| { |
| size_t lengthOfBOM = 0; |
| if (!m_checkedForBOM) |
| lengthOfBOM = checkForBOM(data, length); |
| |
| bool movedDataToBuffer = false; |
| |
| if (m_contentType == CSS && !m_checkedForCSSCharset) |
| if (!checkForCSSCharset(data, length, movedDataToBuffer)) |
| return emptyString(); |
| |
| if ((m_contentType == HTML || m_contentType == XML) && !m_checkedForHeadCharset) // HTML and XML |
| if (!checkForHeadCharset(data, length, movedDataToBuffer)) |
| return emptyString(); |
| |
| // FIXME: It is wrong to change the encoding downstream after we have already done some decoding. |
| if (shouldAutoDetect()) { |
| if (m_encoding.isJapanese()) |
| detectJapaneseEncoding(data, length); // FIXME: We should use detectTextEncoding() for all languages. |
| else { |
| TextEncoding detectedEncoding; |
| if (detectTextEncoding(data, length, m_parentFrameAutoDetectedEncoding, &detectedEncoding)) |
| setEncoding(detectedEncoding, AutoDetectedEncoding); |
| } |
| } |
| |
| ASSERT(m_encoding.isValid()); |
| |
| if (!m_codec) |
| m_codec = newTextCodec(m_encoding); |
| |
| if (m_buffer.isEmpty()) |
| return m_codec->decode(data + lengthOfBOM, length - lengthOfBOM, false, m_contentType == XML, m_sawError); |
| |
| if (!movedDataToBuffer) { |
| size_t oldSize = m_buffer.size(); |
| m_buffer.grow(oldSize + length); |
| memcpy(m_buffer.data() + oldSize, data, length); |
| } |
| |
| String result = m_codec->decode(m_buffer.data() + lengthOfBOM, m_buffer.size() - lengthOfBOM, false, m_contentType == XML && !m_useLenientXMLDecoding, m_sawError); |
| m_buffer.clear(); |
| return result; |
| } |
| |
| String TextResourceDecoder::flush() |
| { |
| // If we can not identify the encoding even after a document is completely |
| // loaded, we need to detect the encoding if other conditions for |
| // autodetection is satisfied. |
| if (m_buffer.size() && shouldAutoDetect() |
| && ((!m_checkedForHeadCharset && (m_contentType == HTML || m_contentType == XML)) || (!m_checkedForCSSCharset && (m_contentType == CSS)))) { |
| TextEncoding detectedEncoding; |
| if (detectTextEncoding(m_buffer.data(), m_buffer.size(), m_parentFrameAutoDetectedEncoding, &detectedEncoding)) |
| setEncoding(detectedEncoding, AutoDetectedEncoding); |
| } |
| |
| if (!m_codec) |
| m_codec = newTextCodec(m_encoding); |
| |
| String result = m_codec->decode(m_buffer.data(), m_buffer.size(), true, m_contentType == XML && !m_useLenientXMLDecoding, m_sawError); |
| m_buffer.clear(); |
| m_codec = nullptr; |
| m_checkedForBOM = false; // Skip BOM again when re-decoding. |
| return result; |
| } |
| |
| String TextResourceDecoder::decodeAndFlush(const char* data, size_t length) |
| { |
| String decoded = decode(data, length); |
| return decoded + flush(); |
| } |
| |
| const TextEncoding* TextResourceDecoder::encodingForURLParsing() |
| { |
| // For UTF-{7,16,32}, we want to use UTF-8 for the query part as |
| // we do when submitting a form. A form with GET method |
| // has its contents added to a URL as query params and it makes sense |
| // to be consistent. |
| auto& encoding = m_encoding.encodingForFormSubmissionOrURLParsing(); |
| if (encoding == UTF8Encoding()) |
| return nullptr; |
| return &encoding; |
| } |
| |
| } |
