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/*
Copyright (C) 1999 Lars Knoll (knoll@mpi-hd.mpg.de)
Copyright (C) 2006 Alexey Proskuryakov (ap@nypop.com)
Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
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.
*/
#ifndef TextResourceDecoder_h
#define TextResourceDecoder_h
#include "core/CoreExport.h"
#include "wtf/PtrUtil.h"
#include "wtf/text/TextEncoding.h"
#include <memory>
namespace blink {
class HTMLMetaCharsetParser;
class CORE_EXPORT TextResourceDecoder {
USING_FAST_MALLOC(TextResourceDecoder);
WTF_MAKE_NONCOPYABLE(TextResourceDecoder);
public:
enum EncodingSource {
DefaultEncoding,
AutoDetectedEncoding,
EncodingFromContentSniffing,
EncodingFromXMLHeader,
EncodingFromMetaTag,
EncodingFromCSSCharset,
EncodingFromHTTPHeader,
EncodingFromParentFrame
};
static std::unique_ptr<TextResourceDecoder> create(
const String& mimeType,
const WTF::TextEncoding& defaultEncoding = WTF::TextEncoding()) {
return WTF::wrapUnique(new TextResourceDecoder(
mimeType, defaultEncoding, UseContentAndBOMBasedDetection, String()));
}
static std::unique_ptr<TextResourceDecoder> createWithAutoDetection(
const String& mimeType,
const WTF::TextEncoding& defaultEncoding,
const String& url) {
return WTF::wrapUnique(new TextResourceDecoder(mimeType, defaultEncoding,
UseAllAutoDetection, url));
}
// Corresponds to utf-8 decode in Encoding spec:
// https://encoding.spec.whatwg.org/#utf-8-decode.
static std::unique_ptr<TextResourceDecoder> createAlwaysUseUTF8ForText() {
return WTF::wrapUnique(new TextResourceDecoder(
"plain/text", UTF8Encoding(), AlwaysUseUTF8ForText, String()));
}
~TextResourceDecoder();
void setEncoding(const WTF::TextEncoding&, EncodingSource);
const WTF::TextEncoding& encoding() const { return m_encoding; }
bool encodingWasDetectedHeuristically() const {
return m_source == AutoDetectedEncoding ||
m_source == EncodingFromContentSniffing;
}
String decode(const char* data, size_t length);
String flush();
void setHintEncoding(const WTF::TextEncoding& encoding) {
m_hintEncoding = encoding.name();
}
void useLenientXMLDecoding() { m_useLenientXMLDecoding = true; }
bool sawError() const { return m_sawError; }
size_t checkForBOM(const char*, size_t);
protected:
// TextResourceDecoder does three kind of encoding detection:
// 1. By BOM,
// 2. By Content if |m_contentType| is not |PlainTextContext|
// (e.g. <meta> tag for HTML), and
// 3. By detectTextEncoding().
enum EncodingDetectionOption {
// Use 1. + 2. + 3.
UseAllAutoDetection,
// Use 1. + 2.
UseContentAndBOMBasedDetection,
// Use None of them.
// |m_contentType| must be |PlainTextContent| and
// |m_encoding| must be UTF8Encoding.
// This doesn't change encoding based on BOMs, but still processes
// utf-8 BOMs so that utf-8 BOMs don't appear in the decoded result.
AlwaysUseUTF8ForText
};
TextResourceDecoder(const String& mimeType,
const WTF::TextEncoding& defaultEncoding,
EncodingDetectionOption,
const String& url);
private:
enum ContentType {
PlainTextContent,
HTMLContent,
XMLContent,
CSSContent
}; // PlainText only checks for BOM.
static ContentType determineContentType(const String& mimeType);
static const WTF::TextEncoding& defaultEncoding(
ContentType,
const WTF::TextEncoding& defaultEncoding);
bool checkForCSSCharset(const char*, size_t, bool& movedDataToBuffer);
bool checkForXMLCharset(const char*, size_t, bool& movedDataToBuffer);
void checkForMetaCharset(const char*, size_t);
bool shouldAutoDetect() const;
ContentType m_contentType;
WTF::TextEncoding m_encoding;
std::unique_ptr<TextCodec> m_codec;
EncodingSource m_source;
const char* m_hintEncoding;
const CString m_hintUrl;
Vector<char> m_buffer;
char m_hintLanguage[3];
bool m_checkedForBOM;
bool m_checkedForCSSCharset;
bool m_checkedForXMLCharset;
bool m_checkedForMetaCharset;
bool m_useLenientXMLDecoding; // Don't stop on XML decoding errors.
bool m_sawError;
EncodingDetectionOption m_encodingDetectionOption;
std::unique_ptr<HTMLMetaCharsetParser> m_charsetParser;
};
} // namespace blink
#endif
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