xmlio.c

libxml,在UNIX/LINUX下非常重要的一个库,为XML相关应用提供方便.目前上载的是最新版本,若要取得最新版本,请参考里面的readme.

    if (in->raw) {
        xmlBufferFree(in->raw);
	in->raw = NULL;
    }
    if (in->encoder != NULL) {
        xmlCharEncCloseFunc(in->encoder);
    }
    if (in->closecallback != NULL) {
	in->closecallback(in->context);
    }
    if (in->buffer != NULL) {
        xmlBufferFree(in->buffer);
	in->buffer = NULL;
    }

    xmlFree(in);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlOutputBufferClose:
 * @out:  a buffered output
 *
 * flushes and close the output I/O channel
 * and free up all the associated resources
 *
 * Returns the number of byte written or -1 in case of error.
 */
int
xmlOutputBufferClose(xmlOutputBufferPtr out)
{
    int written;
    int err_rc = 0;

    if (out == NULL)
        return (-1);
    if (out->writecallback != NULL)
        xmlOutputBufferFlush(out);
    if (out->closecallback != NULL) {
        err_rc = out->closecallback(out->context);
    }
    written = out->written;
    if (out->conv) {
        xmlBufferFree(out->conv);
        out->conv = NULL;
    }
    if (out->encoder != NULL) {
        xmlCharEncCloseFunc(out->encoder);
    }
    if (out->buffer != NULL) {
        xmlBufferFree(out->buffer);
        out->buffer = NULL;
    }

    if (out->error)
        err_rc = -1;
    xmlFree(out);
    return ((err_rc == 0) ? written : err_rc);
}
#endif /* LIBXML_OUTPUT_ENABLED */

xmlParserInputBufferPtr
__xmlParserInputBufferCreateFilename(const char *URI, xmlCharEncoding enc) {
    xmlParserInputBufferPtr ret;
    int i = 0;
    void *context = NULL;

    if (xmlInputCallbackInitialized == 0)
	xmlRegisterDefaultInputCallbacks();

    if (URI == NULL) return(NULL);

    /*
     * Try to find one of the input accept method accepting that scheme
     * Go in reverse to give precedence to user defined handlers.
     */
    if (context == NULL) {
	for (i = xmlInputCallbackNr - 1;i >= 0;i--) {
	    if ((xmlInputCallbackTable[i].matchcallback != NULL) &&
		(xmlInputCallbackTable[i].matchcallback(URI) != 0)) {
		context = xmlInputCallbackTable[i].opencallback(URI);
		if (context != NULL) {
		    break;
		}
	    }
	}
    }
    if (context == NULL) {
	return(NULL);
    }

    /*
     * Allocate the Input buffer front-end.
     */
    ret = xmlAllocParserInputBuffer(enc);
    if (ret != NULL) {
	ret->context = context;
	ret->readcallback = xmlInputCallbackTable[i].readcallback;
	ret->closecallback = xmlInputCallbackTable[i].closecallback;
#ifdef HAVE_ZLIB_H
	if ((xmlInputCallbackTable[i].opencallback == xmlGzfileOpen) &&
		(strcmp(URI, "-") != 0)) {
	    if (((z_stream *)context)->avail_in > 4) {
	        char *cptr, buff4[4];
		cptr = (char *) ((z_stream *)context)->next_in;
		if (gzread(context, buff4, 4) == 4) {
		    if (strncmp(buff4, cptr, 4) == 0)
		        ret->compressed = 0;
		    else
		        ret->compressed = 1;
		    gzrewind(context);
		}
	    }
	}
#endif
    }
    else
      xmlInputCallbackTable[i].closecallback (context);

    return(ret);
}

/**
 * xmlParserInputBufferCreateFilename:
 * @URI:  a C string containing the URI or filename
 * @enc:  the charset encoding if known
 *
 * Create a buffered parser input for the progressive parsing of a file
 * If filename is "-' then we use stdin as the input.
 * Automatic support for ZLIB/Compress compressed document is provided
 * by default if found at compile-time.
 * Do an encoding check if enc == XML_CHAR_ENCODING_NONE
 *
 * Returns the new parser input or NULL
 */
xmlParserInputBufferPtr
xmlParserInputBufferCreateFilename(const char *URI, xmlCharEncoding enc) {
    if ((xmlParserInputBufferCreateFilenameValue)) {
		return xmlParserInputBufferCreateFilenameValue(URI, enc);
	}
	return __xmlParserInputBufferCreateFilename(URI, enc);
}

#ifdef LIBXML_OUTPUT_ENABLED
xmlOutputBufferPtr
__xmlOutputBufferCreateFilename(const char *URI,
                              xmlCharEncodingHandlerPtr encoder,
                              int compression ATTRIBUTE_UNUSED) {
    xmlOutputBufferPtr ret;
    xmlURIPtr puri;
    int i = 0;
    void *context = NULL;
    char *unescaped = NULL;
#ifdef HAVE_ZLIB_H
    int is_file_uri = 1;
#endif

    if (xmlOutputCallbackInitialized == 0)
	xmlRegisterDefaultOutputCallbacks();

    if (URI == NULL) return(NULL);

    puri = xmlParseURI(URI);
    if (puri != NULL) {
        if ((puri->scheme != NULL) &&
	    (!xmlStrEqual(BAD_CAST puri->scheme, BAD_CAST "file")))
#ifdef HAVE_ZLIB_H
	    is_file_uri = 0;
#endif
	/*
	 * try to limit the damages of the URI unescaping code.
	 */
	if (puri->scheme != NULL)
	    unescaped = xmlURIUnescapeString(URI, 0, NULL);
	xmlFreeURI(puri);
    }

    /*
     * Try to find one of the output accept method accepting that scheme
     * Go in reverse to give precedence to user defined handlers.
     * try with an unescaped version of the URI
     */
    if (unescaped != NULL) {
#ifdef HAVE_ZLIB_H
	if ((compression > 0) && (compression <= 9) && (is_file_uri == 1)) {
	    context = xmlGzfileOpenW(unescaped, compression);
	    if (context != NULL) {
		ret = xmlAllocOutputBuffer(encoder);
		if (ret != NULL) {
		    ret->context = context;
		    ret->writecallback = xmlGzfileWrite;
		    ret->closecallback = xmlGzfileClose;
		}
		xmlFree(unescaped);
		return(ret);
	    }
	}
#endif
	for (i = xmlOutputCallbackNr - 1;i >= 0;i--) {
	    if ((xmlOutputCallbackTable[i].matchcallback != NULL) &&
		(xmlOutputCallbackTable[i].matchcallback(unescaped) != 0)) {
#if defined(LIBXML_HTTP_ENABLED) && defined(HAVE_ZLIB_H)
		/*  Need to pass compression parameter into HTTP open calls  */
		if (xmlOutputCallbackTable[i].matchcallback == xmlIOHTTPMatch)
		    context = xmlIOHTTPOpenW(unescaped, compression);
		else
#endif
		    context = xmlOutputCallbackTable[i].opencallback(unescaped);
		if (context != NULL)
		    break;
	    }
	}
	xmlFree(unescaped);
    }

    /*
     * If this failed try with a non-escaped URI this may be a strange
     * filename
     */
    if (context == NULL) {
#ifdef HAVE_ZLIB_H
	if ((compression > 0) && (compression <= 9) && (is_file_uri == 1)) {
	    context = xmlGzfileOpenW(URI, compression);
	    if (context != NULL) {
		ret = xmlAllocOutputBuffer(encoder);
		if (ret != NULL) {
		    ret->context = context;
		    ret->writecallback = xmlGzfileWrite;
		    ret->closecallback = xmlGzfileClose;
		}
		return(ret);
	    }
	}
#endif
	for (i = xmlOutputCallbackNr - 1;i >= 0;i--) {
	    if ((xmlOutputCallbackTable[i].matchcallback != NULL) &&
		(xmlOutputCallbackTable[i].matchcallback(URI) != 0)) {
#if defined(LIBXML_HTTP_ENABLED) && defined(HAVE_ZLIB_H)
		/*  Need to pass compression parameter into HTTP open calls  */
		if (xmlOutputCallbackTable[i].matchcallback == xmlIOHTTPMatch)
		    context = xmlIOHTTPOpenW(URI, compression);
		else
#endif
		    context = xmlOutputCallbackTable[i].opencallback(URI);
		if (context != NULL)
		    break;
	    }
	}
    }

    if (context == NULL) {
	return(NULL);
    }

    /*
     * Allocate the Output buffer front-end.
     */
    ret = xmlAllocOutputBuffer(encoder);
    if (ret != NULL) {
	ret->context = context;
	ret->writecallback = xmlOutputCallbackTable[i].writecallback;
	ret->closecallback = xmlOutputCallbackTable[i].closecallback;
    }
    return(ret);
}

/**
 * xmlOutputBufferCreateFilename:
 * @URI:  a C string containing the URI or filename
 * @encoder:  the encoding converter or NULL
 * @compression:  the compression ration (0 none, 9 max).
 *
 * Create a buffered  output for the progressive saving of a file
 * If filename is "-' then we use stdout as the output.
 * Automatic support for ZLIB/Compress compressed document is provided
 * by default if found at compile-time.
 * TODO: currently if compression is set, the library only support
 *       writing to a local file.
 *
 * Returns the new output or NULL
 */
xmlOutputBufferPtr
xmlOutputBufferCreateFilename(const char *URI,
                              xmlCharEncodingHandlerPtr encoder,
                              int compression ATTRIBUTE_UNUSED) {
    if ((xmlOutputBufferCreateFilenameValue)) {
		return xmlOutputBufferCreateFilenameValue(URI, encoder, compression);
	}
	return __xmlOutputBufferCreateFilename(URI, encoder, compression);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlParserInputBufferCreateFile:
 * @file:  a FILE* 
 * @enc:  the charset encoding if known
 *
 * Create a buffered parser input for the progressive parsing of a FILE *
 * buffered C I/O
 *
 * Returns the new parser input or NULL
 */
xmlParserInputBufferPtr
xmlParserInputBufferCreateFile(FILE *file, xmlCharEncoding enc) {
    xmlParserInputBufferPtr ret;

    if (xmlInputCallbackInitialized == 0)
	xmlRegisterDefaultInputCallbacks();

    if (file == NULL) return(NULL);

    ret = xmlAllocParserInputBuffer(enc);
    if (ret != NULL) {
        ret->context = file;
	ret->readcallback = xmlFileRead;
	ret->closecallback = xmlFileFlush;
    }

    return(ret);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlOutputBufferCreateFile:
 * @file:  a FILE* 
 * @encoder:  the encoding converter or NULL
 *
 * Create a buffered output for the progressive saving to a FILE *
 * buffered C I/O
 *
 * Returns the new parser output or NULL
 */
xmlOutputBufferPtr
xmlOutputBufferCreateFile(FILE *file, xmlCharEncodingHandlerPtr encoder) {
    xmlOutputBufferPtr ret;

    if (xmlOutputCallbackInitialized == 0)
	xmlRegisterDefaultOutputCallbacks();

    if (file == NULL) return(NULL);

    ret = xmlAllocOutputBuffer(encoder);
    if (ret != NULL) {
        ret->context = file;
	ret->writecallback = xmlFileWrite;
	ret->closecallback = xmlFileFlush;
    }

    return(ret);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlParserInputBufferCreateFd:
 * @fd:  a file descriptor number
 * @enc:  the charset encoding if known
 *
 * Create a buffered parser input for the progressive parsing for the input
 * from a file descriptor
 *
 * Returns the new parser input or NULL
 */
xmlParserInputBufferPtr
xmlParserInputBufferCreateFd(int fd, xmlCharEncoding enc) {
    xmlParserInputBufferPtr ret;

    if (fd < 0) return(NULL);

    ret = xmlAllocParserInputBuffer(enc);
    if (ret != NULL) {
        ret->context = (void *) (long) fd;
	ret->readcallback = xmlFdRead;
	ret->closecallback = xmlFdClose;
    }

    return(ret);
}

/**
 * xmlParserInputBufferCreateMem:
 * @mem:  the memory input
 * @size:  the length of the memory block
 * @enc:  the charset encoding if known
 *
 * Create a buffered parser input for the progressive parsing for the input
 * from a memory area.
 *
 * Returns the new parser input or NULL
 */
xmlParserInputBufferPtr
xmlParserInputBufferCreateMem(const char *mem, int size, xmlCharEncoding enc) {
    xmlParserInputBufferPtr ret;
    int errcode;

    if (size <= 0) return(NULL);
    if (mem == NULL) return(NULL);

    ret = xmlAllocParserInputBuffer(enc);
    if (ret != NULL) {
        ret->context = (void *) mem;
	ret->readcallback = (xmlInputReadCallback) xmlNop;
	ret->closecallback = NULL;
	errcode = xmlBufferAdd(ret->buffer, (const xmlChar *) mem, size);
	if (errcode != 0) {
	    xmlFree(ret);
	    return(NULL);
	}
    }

    return(ret);
}

/**
 * xmlParserInputBufferCreateStatic:
 * @mem:  the memory input
 * @size:  the length of the memory block
 * @enc:  the charset encoding if known
 *
 * Create a buffered parser input for the progressive parsing for the input
 * from an immutable memory area. This will not copy the memory area to
 * the buffer, but the memory is expected to be available until the end of
 * the parsing, this is useful for example when using mmap'ed file.
 *
 * Returns the new parser input or NULL
 */
xmlParserInputBufferPtr
xmlParserInputBufferCreateStatic(const char *mem, int size,
                                 xmlCharEncoding enc) {
    xmlParserInputBufferPtr ret;

    if (size <= 0) return(NULL);
    if (mem == NULL) return(NULL);

    ret = (xmlParserInputBufferPtr) xmlMalloc(sizeof(xmlParserInputBuffer));
    if (ret == NULL) {
	xmlIOErrMemory("creating input buffer");
	return(NULL);
    }
    memset(ret, 0, (size_t) sizeof(xmlParserInputBuffer));
    ret->buffer = xmlBufferCreateStatic((void *)mem, (size_t) size);
    if (ret->buffer == NULL) {
        xmlFree(ret);
	return(NULL);
    }
    ret->encoder = xmlGetCharEncodingHandler(enc);
    if (ret->encoder != NULL)
        ret->raw = xmlBufferCreateSize(2 * xmlDefaultBufferSize);
    else
        ret->raw = NULL;
    ret->compressed = -1;
    ret->context = (void *) mem;
    ret->readcallback = NULL;
    ret->closecallback = NULL;

    return(ret);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlOutputBufferCreateFd:
 * @fd:  a file descriptor number
 * @encoder:  the encoding converter or NULL
 *
 * Create a buffered output for the progressive saving 
 * to a file descriptor
 *
 * Returns the new parser output or NULL
 */
xmlOutputBufferPtr
xmlOutputBufferCreateFd(int fd, xmlCharEncodingHandlerPtr encoder) {
    xmlOutputBufferPtr ret;

    if (fd < 0) return(NULL);

    ret = xmlAllocOutputBuffer(encoder);
    if (ret != NULL) {
        ret->context = (void *) (long) fd;
	ret->writecallback = xmlFdWrite;
	ret->closecallback = NULL;
    }

    return(ret);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlParserInputBufferCreateIO:
 * @ioread:  an I/O read function
 * @ioclose:  an I/O close function
 * @ioctx:  an I/O handler
 * @enc:  the charset encoding if known
 *
 * Create a buffered parser input for the progressive parsing for the input
 * from an I/O handler
 *
 * Returns the new parser input or NULL
 */
xmlParserInputBufferPtr
xmlParserInputBufferCreateIO(xmlInputReadCallback   ioread,
	 xmlInputCloseCallback  ioclose, void *ioctx, xmlCharEncoding enc) {
    xmlParserInputBufferPtr ret;

    if (ioread == NULL) return(NULL);

    ret = xmlAllocParserInputBuffer(enc);
    if (ret != NULL) {
        ret->context = (void *) ioctx;
	ret->readcallback = ioread;
	ret->closecallback = ioclose;
    }

    return(ret);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlOutputBufferCreateIO:
 * @iowrite:  an I/O write function
 * @ioclose:  an I/O close function
 * @ioctx:  an I/O handler
 * @encoder:  the charset encoding i