encoding.c

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 *     -2 if the transcoding fails (for *in is not valid utf8 string or
 *        the result of transformation can't fit into the encoding we want), or
 */
int
xmlCharEncFirstLine(xmlCharEncodingHandler *handler, xmlBufferPtr out,
                 xmlBufferPtr in) {
    int ret = -2;
    int written;
    int toconv;

    if (handler == NULL) return(-1);
    if (out == NULL) return(-1);
    if (in == NULL) return(-1);

    written = out->size - out->use;
    toconv = in->use;
    if (toconv * 2 >= written) {
        xmlBufferGrow(out, toconv);
	written = out->size - out->use - 1;
    }

    /*
     * echo '<?xml version="1.0" encoding="UCS4"?>' | wc -c => 38
     * 45 chars should be sufficient to reach the end of the encoding
     * declaration without going too far inside the document content.
     */
    written = 45;

    if (handler->input != NULL) {
	ret = handler->input(&out->content[out->use], &written,
	                     in->content, &toconv);
	xmlBufferShrink(in, toconv);
	out->use += written;
	out->content[out->use] = 0;
    }
#ifdef LIBXML_ICONV_ENABLED
    else if (handler->iconv_in != NULL) {
	ret = xmlIconvWrapper(handler->iconv_in, &out->content[out->use],
	                      &written, in->content, &toconv);
	xmlBufferShrink(in, toconv);
	out->use += written;
	out->content[out->use] = 0;
	if (ret == -1) ret = -3;
    }
#endif /* LIBXML_ICONV_ENABLED */
#ifdef DEBUG_ENCODING
    switch (ret) {
        case 0:
	    xmlGenericError(xmlGenericErrorContext,
		    "converted %d bytes to %d bytes of input\n",
	            toconv, written);
	    break;
        case -1:
	    xmlGenericError(xmlGenericErrorContext,"converted %d bytes to %d bytes of input, %d left\n",
	            toconv, written, in->use);
	    break;
        case -2:
	    xmlGenericError(xmlGenericErrorContext,
		    "input conversion failed due to input error\n");
	    break;
        case -3:
	    xmlGenericError(xmlGenericErrorContext,"converted %d bytes to %d bytes of input, %d left\n",
	            toconv, written, in->use);
	    break;
	default:
	    xmlGenericError(xmlGenericErrorContext,"Unknown input conversion failed %d\n", ret);
    }
#endif /* DEBUG_ENCODING */
    /*
     * Ignore when input buffer is not on a boundary
     */
    if (ret == -3) ret = 0;
    if (ret == -1) ret = 0;
    return(ret);
}

/**
 * xmlCharEncInFunc:
 * @handler:	char encoding transformation data structure
 * @out:  an xmlBuffer for the output.
 * @in:  an xmlBuffer for the input
 *     
 * Generic front-end for the encoding handler input function
 *     
 * Returns the number of byte written if success, or 
 *     -1 general error
 *     -2 if the transcoding fails (for *in is not valid utf8 string or
 *        the result of transformation can't fit into the encoding we want), or
 */
int
xmlCharEncInFunc(xmlCharEncodingHandler * handler, xmlBufferPtr out,
                 xmlBufferPtr in)
{
    int ret = -2;
    int written;
    int toconv;

    if (handler == NULL)
        return (-1);
    if (out == NULL)
        return (-1);
    if (in == NULL)
        return (-1);

    toconv = in->use;
    if (toconv == 0)
        return (0);
    written = out->size - out->use;
    if (toconv * 2 >= written) {
        xmlBufferGrow(out, out->size + toconv * 2);
        written = out->size - out->use - 1;
    }
    if (handler->input != NULL) {
        ret = handler->input(&out->content[out->use], &written,
                             in->content, &toconv);
        xmlBufferShrink(in, toconv);
        out->use += written;
        out->content[out->use] = 0;
    }
#ifdef LIBXML_ICONV_ENABLED
    else if (handler->iconv_in != NULL) {
        ret = xmlIconvWrapper(handler->iconv_in, &out->content[out->use],
                              &written, in->content, &toconv);
        xmlBufferShrink(in, toconv);
        out->use += written;
        out->content[out->use] = 0;
        if (ret == -1)
            ret = -3;
    }
#endif /* LIBXML_ICONV_ENABLED */
    switch (ret) {
        case 0:
#ifdef DEBUG_ENCODING
            xmlGenericError(xmlGenericErrorContext,
                            "converted %d bytes to %d bytes of input\n",
                            toconv, written);
#endif
            break;
        case -1:
#ifdef DEBUG_ENCODING
            xmlGenericError(xmlGenericErrorContext,
                         "converted %d bytes to %d bytes of input, %d left\n",
                            toconv, written, in->use);
#endif
            break;
        case -3:
#ifdef DEBUG_ENCODING
            xmlGenericError(xmlGenericErrorContext,
                        "converted %d bytes to %d bytes of input, %d left\n",
                            toconv, written, in->use);
#endif
            break;
        case -2:
            xmlGenericError(xmlGenericErrorContext,
                            "input conversion failed due to input error\n");
            xmlGenericError(xmlGenericErrorContext,
                            "Bytes: 0x%02X 0x%02X 0x%02X 0x%02X\n",
                            in->content[0], in->content[1],
                            in->content[2], in->content[3]);
    }
    /*
     * Ignore when input buffer is not on a boundary
     */
    if (ret == -3)
        ret = 0;
    return (written);
}

/**
 * xmlCharEncOutFunc:
 * @handler:	char enconding transformation data structure
 * @out:  an xmlBuffer for the output.
 * @in:  an xmlBuffer for the input
 *     
 * Generic front-end for the encoding handler output function
 * a first call with @in == NULL has to be made firs to initiate the 
 * output in case of non-stateless encoding needing to initiate their
 * state or the output (like the BOM in UTF16).
 * In case of UTF8 sequence conversion errors for the given encoder,
 * the content will be automatically remapped to a CharRef sequence.
 *     
 * Returns the number of byte written if success, or 
 *     -1 general error
 *     -2 if the transcoding fails (for *in is not valid utf8 string or
 *        the result of transformation can't fit into the encoding we want), or
 */
int
xmlCharEncOutFunc(xmlCharEncodingHandler *handler, xmlBufferPtr out,
                  xmlBufferPtr in) {
    int ret = -2;
    int written;
    int writtentot = 0;
    int toconv;
    int output = 0;

    if (handler == NULL) return(-1);
    if (out == NULL) return(-1);

retry:
    
    written = out->size - out->use;

    if (written > 0)
	written--; /* Gennady: count '/0' */

    /*
     * First specific handling of in = NULL, i.e. the initialization call
     */
    if (in == NULL) {
        toconv = 0;
	if (handler->output != NULL) {
	    ret = handler->output(&out->content[out->use], &written,
				  NULL, &toconv);
	    if (ret >= 0) { /* Gennady: check return value */
		out->use += written;
		out->content[out->use] = 0;
	    }
	}
#ifdef LIBXML_ICONV_ENABLED
	else if (handler->iconv_out != NULL) {
	    ret = xmlIconvWrapper(handler->iconv_out, &out->content[out->use],
				  &written, NULL, &toconv);
	    out->use += written;
	    out->content[out->use] = 0;
	}
#endif /* LIBXML_ICONV_ENABLED */
#ifdef DEBUG_ENCODING
	xmlGenericError(xmlGenericErrorContext,
		"initialized encoder\n");
#endif
        return(0);
    }

    /*
     * Conversion itself.
     */
    toconv = in->use;
    if (toconv == 0)
	return(0);
    if (toconv * 2 >= written) {
        xmlBufferGrow(out, toconv * 2);
	written = out->size - out->use - 1;
    }
    if (handler->output != NULL) {
	ret = handler->output(&out->content[out->use], &written,
	                      in->content, &toconv);
	xmlBufferShrink(in, toconv);
	out->use += written;
	writtentot += written;
	out->content[out->use] = 0;
    }
#ifdef LIBXML_ICONV_ENABLED
    else if (handler->iconv_out != NULL) {
	ret = xmlIconvWrapper(handler->iconv_out, &out->content[out->use],
	                      &written, in->content, &toconv);
	xmlBufferShrink(in, toconv);
	out->use += written;
	writtentot += written;
	out->content[out->use] = 0;
	if (ret == -1) {
	    if (written > 0) {
		/*
		 * Can be a limitation of iconv
		 */
		goto retry;
	    }
	    ret = -3;
	}
    }
#endif /* LIBXML_ICONV_ENABLED */
    else {
	xmlGenericError(xmlGenericErrorContext,
		"xmlCharEncOutFunc: no output function !\n");
	return(-1);
    }

    if (ret >= 0) output += ret;

    /*
     * Attempt to handle error cases
     */
    switch (ret) {
        case 0:
#ifdef DEBUG_ENCODING
	    xmlGenericError(xmlGenericErrorContext,
		    "converted %d bytes to %d bytes of output\n",
	            toconv, written);
#endif
	    break;
        case -1:
#ifdef DEBUG_ENCODING
	    xmlGenericError(xmlGenericErrorContext,
		    "output conversion failed by lack of space\n");
#endif
	    break;
        case -3:
#ifdef DEBUG_ENCODING
	    xmlGenericError(xmlGenericErrorContext,"converted %d bytes to %d bytes of output %d left\n",
	            toconv, written, in->use);
#endif
	    break;
        case -2: {
	    int len = in->use;
	    const xmlChar *utf = (const xmlChar *) in->content;
	    int cur;

	    cur = xmlGetUTF8Char(utf, &len);
	    if (cur > 0) {
		xmlChar charref[20];

#ifdef DEBUG_ENCODING
		xmlGenericError(xmlGenericErrorContext,
			"handling output conversion error\n");
		xmlGenericError(xmlGenericErrorContext,
			"Bytes: 0x%02X 0x%02X 0x%02X 0x%02X\n",
			in->content[0], in->content[1],
			in->content[2], in->content[3]);
#endif
		/*
		 * Removes the UTF8 sequence, and replace it by a charref
		 * and continue the transcoding phase, hoping the error
		 * did not mangle the encoder state.
		 */
		snprintf((char *) charref, sizeof(charref), "&#%d;", cur);
		xmlBufferShrink(in, len);
		xmlBufferAddHead(in, charref, -1);

		goto retry;
	    } else {
		xmlGenericError(xmlGenericErrorContext,
			"output conversion failed due to conv error\n");
		xmlGenericError(xmlGenericErrorContext,
			"Bytes: 0x%02X 0x%02X 0x%02X 0x%02X\n",
			in->content[0], in->content[1],
			in->content[2], in->content[3]);
		in->content[0] = ' ';
	    }
	    break;
	}
    }
    return(ret);
}

/**
 * xmlCharEncCloseFunc:
 * @handler:	char enconding transformation data structure
 *     
 * Generic front-end for encoding handler close function
 *
 * Returns 0 if success, or -1 in case of error
 */
int
xmlCharEncCloseFunc(xmlCharEncodingHandler *handler) {
    int ret = 0;
    if (handler == NULL) return(-1);
    if (handler->name == NULL) return(-1);
#ifdef LIBXML_ICONV_ENABLED
    /*
     * Iconv handlers can be used only once, free the whole block.
     * and the associated icon resources.
     */
    if ((handler->iconv_out != NULL) || (handler->iconv_in != NULL)) {
	if (handler->name != NULL)
	    xmlFree(handler->name);
	handler->name = NULL;
	if (handler->iconv_out != NULL) {
	    if (iconv_close(handler->iconv_out))
		ret = -1;
	    handler->iconv_out = NULL;
	}
	if (handler->iconv_in != NULL) {
	    if (iconv_close(handler->iconv_in))
		ret = -1;
	    handler->iconv_in = NULL;
	}
	xmlFree(handler);
    }
#endif /* LIBXML_ICONV_ENABLED */
#ifdef DEBUG_ENCODING
    if (ret)
        xmlGenericError(xmlGenericErrorContext,
		"failed to close the encoding handler\n");
    else
        xmlGenericError(xmlGenericErrorContext,
		"closed the encoding handler\n");
#endif

    return(ret);
}

/**
 * xmlByteConsumed:
 * @ctxt: an XML parser context
 *
 * This function provides the current index of the parser relative
 * to the start of the current entity. This function is computed in
 * bytes from the beginning starting at zero and finishing at the
 * size in byte of the file if parsing a file. The function is
 * of constant cost if the input is UTF-8 but can be costly if run
 * on non-UTF-8 input.
 *
 * Returns the index in bytes from the beginning of the entity or -1
 *         in case the index could not be computed.
 */
long
xmlByteConsumed(xmlParserCtxtPtr ctxt) {
    xmlParserInputPtr in;
    
    if (ctxt == NULL) return(-1);
    in = ctxt->input;
    if (in == NULL)  return(-1);
    if ((in->buf != NULL) && (in->buf->encoder != NULL)) {
        unsigned int unused = 0;
	xmlCharEncodingHandler * handler = in->buf->encoder;
        /*
	 * Encoding conversion, compute the number of unused original
	 * bytes from the input not consumed and substract that from
	 * the raw consumed value, this is not a cheap operation
	 */
        if (in->end - in->cur > 0) {
	    unsigned char convbuf[32000];
	    const unsigned char *cur = (const unsigned char *)in->cur;
	    int toconv = in->end - in->cur, written = 32000;

	    int ret;

	    if (handler->output != NULL) {
	        do {
		    toconv = in->end - cur;
		    written = 32000;
		    ret = handler->output(&co