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Diffstat (limited to 'intl/uconv/nsIUnicodeDecoder.h')
| -rw-r--r-- | intl/uconv/nsIUnicodeDecoder.h | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/intl/uconv/nsIUnicodeDecoder.h b/intl/uconv/nsIUnicodeDecoder.h new file mode 100644 index 000000000..36a46759b --- /dev/null +++ b/intl/uconv/nsIUnicodeDecoder.h @@ -0,0 +1,140 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef nsIUnicodeDecoder_h___ +#define nsIUnicodeDecoder_h___ + +#include "nscore.h" +#include "nsISupports.h" + +// Interface ID for our Unicode Decoder interface +// {25359602-FC70-4d13-A9AB-8086D3827C0D} +//NS_DECLARE_ID(kIUnicodeDecoderIID, +// 0x25359602, 0xfc70, 0x4d13, 0xa9, 0xab, 0x80, 0x86, 0xd3, 0x82, 0x7c, 0xd); + +#define NS_IUNICODEDECODER_IID \ + { 0x25359602, 0xfc70, 0x4d13, \ + { 0xa9, 0xab, 0x80, 0x86, 0xd3, 0x82, 0x7c, 0xd }} + + +#define NS_UNICODEDECODER_CONTRACTID_BASE "@mozilla.org/intl/unicode/decoder;1?charset=" + +/** + * Interface for a Converter from a Charset into Unicode. + * + * @created 23/Nov/1998 + * @author Catalin Rotaru [CATA] + */ +class nsIUnicodeDecoder : public nsISupports +{ +public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_IUNICODEDECODER_IID) + + enum { + kOnError_Recover, // on an error, recover and continue + kOnError_Signal // on an error, stop and signal + }; + + /** + * Converts the data from one Charset to Unicode. + * + * About the byte ordering: + * - For input, if the converter cares (that depends of the charset, for + * example a singlebyte will ignore the byte ordering) it should assume + * network order. If necessary and requested, we can add a method + * SetInputByteOrder() so that the reverse order can be used, too. That + * method would have as default the assumed network order. + * - The output stream is Unicode, having the byte order which is internal + * for the machine on which the converter is running on. + * + * Unless there is not enough output space, this method must consume all the + * available input data! The eventual incomplete final character data will be + * stored internally in the converter and used when the method is called + * again for continuing the conversion. This way, the caller will not have to + * worry about managing incomplete input data by mergeing it with the next + * buffer. + * + * Error conditions: + * If the read value does not belong to this character set, one should + * replace it with the Unicode special 0xFFFD. When an actual input error is + * encountered, like a format error, the converter stop and return error. + * However, we should keep in mind that we need to be lax in decoding. When + * a decoding error is returned to the caller, it is the caller's + * responsibility to advance over the bad byte (unless aSrcLength is -1 in + * which case the caller should call the decoder with 0 offset again) and + * reset the decoder before trying to call the decoder again. + * + * Converter required behavior: + * In this order: when output space is full - return right away. When input + * data is wrong, return input pointer right after the wrong byte. When + * partial input, it will be consumed and cached. All the time input pointer + * will show how much was actually consumed and how much was actually + * written. + * + * @param aSrc [IN] the source data buffer + * @param aSrcLength [IN/OUT] the length of source data buffer; after + * conversion will contain the number of bytes read or + * -1 on error to indicate that the caller should re-push + * the same buffer after resetting the decoder + * @param aDest [OUT] the destination data buffer + * @param aDestLength [IN/OUT] the length of the destination data buffer; + * after conversion will contain the number of Unicode + * characters written + * @return NS_ERROR_UDEC_ILLEGALINPUT if an illegal input sequence + * was encountered and the behavior was set to "signal"; + * the caller must skip over one byte, reset the decoder + * and retry. + * NS_OK_UDEC_MOREOUTPUT if only a partial conversion + * was done; more output space is needed to continue + * NS_OK_UDEC_MOREINPUT if the input ended in the middle + * of an input code unit sequence. If this is the last + * result the caller has at the end of the stream, the + * caller must append one U+FFFD to the output. + * NS_OK if the input ended after a complete input code + * unit sequence. + */ + NS_IMETHOD Convert(const char * aSrc, int32_t * aSrcLength, + char16_t * aDest, int32_t * aDestLength) = 0; + + /** + * Returns a quick estimation of the size of the buffer needed to hold the + * converted data. Remember: this estimation is >= with the actual size of + * the buffer needed. It will be computed for the "worst case" + * + * @param aSrc [IN] the source data buffer + * @param aSrcLength [IN] the length of source data buffer + * @param aDestLength [OUT] the needed size of the destination buffer + * @return NS_EXACT_LENGTH if an exact length was computed + * NS_ERROR_OUT_OF_MEMORY if OOM + * NS_OK is all we have is an approximation + */ + MOZ_MUST_USE NS_IMETHOD GetMaxLength(const char* aSrc, + int32_t aSrcLength, + int32_t* aDestLength) = 0; + + /** + * Resets the charset converter so it may be recycled for a completely + * different and urelated buffer of data. + */ + NS_IMETHOD Reset() = 0; + + /** + * Specify what to do when a character cannot be mapped into unicode + * + * @param aBehavior [IN] the desired behavior + * @see kOnError_Recover + * @see kOnError_Signal + */ + virtual void SetInputErrorBehavior(int32_t aBehavior) = 0; + + /** + * return the UNICODE character for unmapped character + */ + virtual char16_t GetCharacterForUnMapped() = 0; +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(nsIUnicodeDecoder, NS_IUNICODEDECODER_IID) + +#endif /* nsIUnicodeDecoder_h___ */ |