nanohttp.c.svn-base

这是一个用于解析xml文件的类库。使用这个类库

/**
 * xmlNanoHTTPOpenRedir:
 * @URL:  The URL to load
 * @contentType:  if available the Content-Type information will be
 *                returned at that location
 * @redir: if available the redirected URL will be returned
 *
 * This function try to open a connection to the indicated resource
 * via HTTP GET.
 *
 * Returns NULL in case of failure, otherwise a request handler.
 *     The contentType, if provided must be freed by the caller
 */

void*
xmlNanoHTTPOpenRedir(const char *URL, char **contentType, char **redir) {
    if (contentType != NULL) *contentType = NULL;
    if (redir != NULL) *redir = NULL;
    return(xmlNanoHTTPMethodRedir(URL, NULL, NULL, contentType, redir, NULL,0));
}

/**
 * xmlNanoHTTPRead:
 * @ctx:  the HTTP context
 * @dest:  a buffer
 * @len:  the buffer length
 *
 * This function tries to read @len bytes from the existing HTTP connection
 * and saves them in @dest. This is a blocking call.
 *
 * Returns the number of byte read. 0 is an indication of an end of connection.
 *         -1 indicates a parameter error.
 */
int
xmlNanoHTTPRead(void *ctx, void *dest, int len) {
    xmlNanoHTTPCtxtPtr ctxt = (xmlNanoHTTPCtxtPtr) ctx;

    if (ctx == NULL) return(-1);
    if (dest == NULL) return(-1);
    if (len <= 0) return(0);

    while (ctxt->inptr - ctxt->inrptr < len) {
        if (xmlNanoHTTPRecv(ctxt) <= 0) break;
    }
    if (ctxt->inptr - ctxt->inrptr < len)
        len = ctxt->inptr - ctxt->inrptr;
    memcpy(dest, ctxt->inrptr, len);
    ctxt->inrptr += len;
    return(len);
}

/**
 * xmlNanoHTTPClose:
 * @ctx:  the HTTP context
 *
 * This function closes an HTTP context, it ends up the connection and
 * free all data related to it.
 */
void
xmlNanoHTTPClose(void *ctx) {
    xmlNanoHTTPCtxtPtr ctxt = (xmlNanoHTTPCtxtPtr) ctx;

    if (ctx == NULL) return;

    xmlNanoHTTPFreeCtxt(ctxt);
}

/**
 * xmlNanoHTTPMethodRedir:
 * @URL:  The URL to load
 * @method:  the HTTP method to use
 * @input:  the input string if any
 * @contentType:  the Content-Type information IN and OUT
 * @redir:  the redirected URL OUT
 * @headers:  the extra headers
 * @ilen:  input length
 *
 * This function try to open a connection to the indicated resource
 * via HTTP using the given @method, adding the given extra headers
 * and the input buffer for the request content.
 *
 * Returns NULL in case of failure, otherwise a request handler.
 *     The contentType, or redir, if provided must be freed by the caller
 */

void*
xmlNanoHTTPMethodRedir(const char *URL, const char *method, const char *input,
                  char **contentType, char **redir,
		  const char *headers, int ilen ) {
    xmlNanoHTTPCtxtPtr ctxt;
    char *bp, *p;
    int blen, ret;
    int head;
    int nbRedirects = 0;
    char *redirURL = NULL;
#ifdef DEBUG_HTTP
    int xmt_bytes;
#endif
    
    if (URL == NULL) return(NULL);
    if (method == NULL) method = "GET";
    xmlNanoHTTPInit();

retry:
    if (redirURL == NULL)
	ctxt = xmlNanoHTTPNewCtxt(URL);
    else {
	ctxt = xmlNanoHTTPNewCtxt(redirURL);
	ctxt->location = xmlMemStrdup(redirURL);
    }

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

    if ((ctxt->protocol == NULL) || (strcmp(ctxt->protocol, "http"))) {
	__xmlIOErr(XML_FROM_HTTP, XML_HTTP_URL_SYNTAX, "Not a valid HTTP URI");
        xmlNanoHTTPFreeCtxt(ctxt);
	if (redirURL != NULL) xmlFree(redirURL);
        return(NULL);
    }
    if (ctxt->hostname == NULL) {
	__xmlIOErr(XML_FROM_HTTP, XML_HTTP_UNKNOWN_HOST,
	           "Failed to identify host in URI");
        xmlNanoHTTPFreeCtxt(ctxt);
	if (redirURL != NULL) xmlFree(redirURL);
        return(NULL);
    }
    if (proxy) {
	blen = strlen(ctxt->hostname) * 2 + 16;
	ret = xmlNanoHTTPConnectHost(proxy, proxyPort);
    }
    else {
	blen = strlen(ctxt->hostname);
	ret = xmlNanoHTTPConnectHost(ctxt->hostname, ctxt->port);
    }
    if (ret < 0) {
        xmlNanoHTTPFreeCtxt(ctxt);
	if (redirURL != NULL) xmlFree(redirURL);
        return(NULL);
    }
    ctxt->fd = ret;

    if (input == NULL)
	ilen = 0;
    else
	blen += 36;

    if (headers != NULL)
	blen += strlen(headers) + 2;
    if (contentType && *contentType)
	blen += strlen(*contentType) + 16;
    blen += strlen(method) + strlen(ctxt->path) + 24;
    bp = (char*)xmlMallocAtomic(blen);
    if ( bp == NULL ) {
        xmlNanoHTTPFreeCtxt( ctxt );
	xmlHTTPErrMemory("allocating header buffer");
	return ( NULL );
    }

    p = bp;

    if (proxy) {
	if (ctxt->port != 80) {
	    p += snprintf( p, blen - (p - bp), "%s http://%s:%d%s", 
			method, ctxt->hostname,
		 	ctxt->port, ctxt->path );
	}
	else 
	    p += snprintf( p, blen - (p - bp), "%s http://%s%s", method,
	    		ctxt->hostname, ctxt->path);
    }
    else
	p += snprintf( p, blen - (p - bp), "%s %s", method, ctxt->path);

    p += snprintf( p, blen - (p - bp), " HTTP/1.0\r\nHost: %s\r\n", 
		    ctxt->hostname);

    if (contentType != NULL && *contentType) 
	p += snprintf(p, blen - (p - bp), "Content-Type: %s\r\n", *contentType);

    if (headers != NULL)
	p += snprintf( p, blen - (p - bp), "%s", headers );

    if (input != NULL)
	snprintf(p, blen - (p - bp), "Content-Length: %d\r\n\r\n", ilen );
    else
	snprintf(p, blen - (p - bp), "\r\n");

#ifdef DEBUG_HTTP
    xmlGenericError(xmlGenericErrorContext,
	    "-> %s%s", proxy? "(Proxy) " : "", bp);
    if ((blen -= strlen(bp)+1) < 0)
	xmlGenericError(xmlGenericErrorContext,
		"ERROR: overflowed buffer by %d bytes\n", -blen);
#endif
    ctxt->outptr = ctxt->out = bp;
    ctxt->state = XML_NANO_HTTP_WRITE;
    blen = strlen( ctxt->out );
#ifdef DEBUG_HTTP
    xmt_bytes = xmlNanoHTTPSend(ctxt, ctxt->out, blen );
    if ( xmt_bytes != blen )
        xmlGenericError( xmlGenericErrorContext,
			"xmlNanoHTTPMethodRedir:  Only %d of %d %s %s\n",
			xmt_bytes, blen,
			"bytes of HTTP headers sent to host",
			ctxt->hostname );
#else
    xmlNanoHTTPSend(ctxt, ctxt->out, blen );
#endif

    if ( input != NULL ) {
#ifdef DEBUG_HTTP
        xmt_bytes = xmlNanoHTTPSend( ctxt, input, ilen );

	if ( xmt_bytes != ilen )
	    xmlGenericError( xmlGenericErrorContext,
	    		"xmlNanoHTTPMethodRedir:  Only %d of %d %s %s\n",
			xmt_bytes, ilen,
			"bytes of HTTP content sent to host",
			ctxt->hostname );
#else
	xmlNanoHTTPSend( ctxt, input, ilen );
#endif
    }

    ctxt->state = XML_NANO_HTTP_READ;
    head = 1;

    while ((p = xmlNanoHTTPReadLine(ctxt)) != NULL) {
        if (head && (*p == 0)) {
	    head = 0;
	    ctxt->content = ctxt->inrptr;
	    xmlFree(p);
	    break;
	}
	xmlNanoHTTPScanAnswer(ctxt, p);

#ifdef DEBUG_HTTP
	xmlGenericError(xmlGenericErrorContext, "<- %s\n", p);
#endif
        xmlFree(p);
    }

    if ((ctxt->location != NULL) && (ctxt->returnValue >= 300) &&
        (ctxt->returnValue < 400)) {
#ifdef DEBUG_HTTP
	xmlGenericError(xmlGenericErrorContext,
		"\nRedirect to: %s\n", ctxt->location);
#endif
	while ( xmlNanoHTTPRecv(ctxt) > 0 ) ;
        if (nbRedirects < XML_NANO_HTTP_MAX_REDIR) {
	    nbRedirects++;
	    if (redirURL != NULL)
		xmlFree(redirURL);
	    redirURL = xmlMemStrdup(ctxt->location);
	    xmlNanoHTTPFreeCtxt(ctxt);
	    goto retry;
	}
	xmlNanoHTTPFreeCtxt(ctxt);
	if (redirURL != NULL) xmlFree(redirURL);
#ifdef DEBUG_HTTP
	xmlGenericError(xmlGenericErrorContext,
		"xmlNanoHTTPMethodRedir: Too many redirects, aborting ...\n");
#endif
	return(NULL);
    }

    if (contentType != NULL) {
	if (ctxt->contentType != NULL)
	    *contentType = xmlMemStrdup(ctxt->contentType);
	else
	    *contentType = NULL;
    }

    if ((redir != NULL) && (redirURL != NULL)) {
	*redir = redirURL;
    } else {
	if (redirURL != NULL)
	    xmlFree(redirURL);
	if (redir != NULL)
	    *redir = NULL;
    }

#ifdef DEBUG_HTTP
    if (ctxt->contentType != NULL)
	xmlGenericError(xmlGenericErrorContext,
		"\nCode %d, content-type '%s'\n\n",
	       ctxt->returnValue, ctxt->contentType);
    else
	xmlGenericError(xmlGenericErrorContext,
		"\nCode %d, no content-type\n\n",
	       ctxt->returnValue);
#endif

    return((void *) ctxt);
}

/**
 * xmlNanoHTTPMethod:
 * @URL:  The URL to load
 * @method:  the HTTP method to use
 * @input:  the input string if any
 * @contentType:  the Content-Type information IN and OUT
 * @headers:  the extra headers
 * @ilen:  input length
 *
 * This function try to open a connection to the indicated resource
 * via HTTP using the given @method, adding the given extra headers
 * and the input buffer for the request content.
 *
 * Returns NULL in case of failure, otherwise a request handler.
 *     The contentType, if provided must be freed by the caller
 */

void*
xmlNanoHTTPMethod(const char *URL, const char *method, const char *input,
                  char **contentType, const char *headers, int ilen) {
    return(xmlNanoHTTPMethodRedir(URL, method, input, contentType,
		                  NULL, headers, ilen));
}

/**
 * xmlNanoHTTPFetch:
 * @URL:  The URL to load
 * @filename:  the filename where the content should be saved
 * @contentType:  if available the Content-Type information will be
 *                returned at that location
 *
 * This function try to fetch the indicated resource via HTTP GET
 * and save it's content in the file.
 *
 * Returns -1 in case of failure, 0 incase of success. The contentType,
 *     if provided must be freed by the caller
 */
int
xmlNanoHTTPFetch(const char *URL, const char *filename, char **contentType) {
    void *ctxt = NULL;
    char *buf = NULL;
    int fd;
    int len;
    
    ctxt = xmlNanoHTTPOpen(URL, contentType);
    if (ctxt == NULL) return(-1);

    if (!strcmp(filename, "-")) 
        fd = 0;
    else {
        fd = open(filename, O_CREAT | O_WRONLY, 00644);
	if (fd < 0) {
	    xmlNanoHTTPClose(ctxt);
	    if ((contentType != NULL) && (*contentType != NULL)) {
	        xmlFree(*contentType);
		*contentType = NULL;
	    }
	    return(-1);
	}
    }

    xmlNanoHTTPFetchContent( ctxt, &buf, &len );
    if ( len > 0 ) {
	write(fd, buf, len);
    }

    xmlNanoHTTPClose(ctxt);
    close(fd);
    return(0);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlNanoHTTPSave:
 * @ctxt:  the HTTP context
 * @filename:  the filename where the content should be saved
 *
 * This function saves the output of the HTTP transaction to a file
 * It closes and free the context at the end
 *
 * Returns -1 in case of failure, 0 incase of success.
 */
int
xmlNanoHTTPSave(void *ctxt, const char *filename) {
    char *buf = NULL;
    int fd;
    int len;
    
    if (ctxt == NULL) return(-1);

    if (!strcmp(filename, "-")) 
        fd = 0;
    else {
        fd = open(filename, O_CREAT | O_WRONLY);
	if (fd < 0) {
	    xmlNanoHTTPClose(ctxt);
	    return(-1);
	}
    }

    xmlNanoHTTPFetchContent( ctxt, &buf, &len );
    if ( len > 0 ) {
	write(fd, buf, len);
    }

    xmlNanoHTTPClose(ctxt);
    close(fd);
    return(0);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlNanoHTTPReturnCode:
 * @ctx:  the HTTP context
 *
 * Get the latest HTTP return code received
 *
 * Returns the HTTP return code for the request.
 */
int
xmlNanoHTTPReturnCode(void *ctx) {
    xmlNanoHTTPCtxtPtr ctxt = (xmlNanoHTTPCtxtPtr) ctx;

    if (ctxt == NULL) return(-1);

    return(ctxt->returnValue);
}

/**
 * xmlNanoHTTPAuthHeader:
 * @ctx:  the HTTP context
 *
 * Get the authentication header of an HTTP context
 *
 * Returns the stashed value of the WWW-Authenticate or Proxy-Authenticate
 * header.
 */
const char *
xmlNanoHTTPAuthHeader(void *ctx) {
    xmlNanoHTTPCtxtPtr ctxt = (xmlNanoHTTPCtxtPtr) ctx;

    if (ctxt == NULL) return(NULL);

    return(ctxt->authHeader);
}

/**
 * xmlNanoHTTPContentLength:
 * @ctx:  the HTTP context
 *
 * Provides the specified content length from the HTTP header.
 *
 * Return the specified content length from the HTTP header.  Note that
 * a value of -1 indicates that the content length element was not included in
 * the response header.
 */
int
xmlNanoHTTPContentLength( void * ctx ) {
    xmlNanoHTTPCtxtPtr	ctxt = (xmlNanoHTTPCtxtPtr)ctx;

    return ( ( ctxt == NULL ) ? -1 : ctxt->ContentLength );
}

/**
 * xmlNanoHTTPRedir:
 * @ctx:  the HTTP context
 *
 * Provides the specified redirection URL if available from the HTTP header.
 *
 * Return the specified redirection URL or NULL if not redirected.
 */
const char *
xmlNanoHTTPRedir( void * ctx ) {
    xmlNanoHTTPCtxtPtr	ctxt = (xmlNanoHTTPCtxtPtr)ctx;

    return ( ( ctxt == NULL ) ? NULL : ctxt->location );
}

/**
 * xmlNanoHTTPEncoding:
 * @ctx:  the HTTP context
 *
 * Provides the specified encoding if specified in the HTTP headers.
 *
 * Return the specified encoding or NULL if not available
 */
const char *
xmlNanoHTTPEncoding( void * ctx ) {
    xmlNanoHTTPCtxtPtr	ctxt = (xmlNanoHTTPCtxtPtr)ctx;

    return ( ( ctxt == NULL ) ? NULL : ctxt->encoding );
}

/**
 * xmlNanoHTTPMimeType:
 * @ctx:  the HTTP context
 *
 * Provides the specified Mime-Type if specified in the HTTP headers.
 *
 * Return the specified Mime-Type or NULL if not available
 */
const char *
xmlNanoHTTPMimeType( void * ctx ) {
    xmlNanoHTTPCtxtPtr	ctxt = (xmlNanoHTTPCtxtPtr)ctx;

    return ( ( ctxt == NULL ) ? NULL : ctxt->mimeType );
}

/**
 * xmlNanoHTTPFetchContent:
 * @ctx:  the HTTP context
 * @ptr:  pointer to set to the content buffer.
 * @len:  integer pointer to hold the length of the content
 *
 * Check if all the content was read
 *
 * Returns 0 if all the content was read and available, returns
 * -1 if received content length was less than specified or an error 
 * occurred.
 */
int
xmlNanoHTTPFetchContent( void * ctx, char ** ptr, int * len ) {
    xmlNanoHTTPCtxtPtr	ctxt = (xmlNanoHTTPCtxtPtr)ctx;

    int			rc = 0;
    int			cur_lgth;
    int			rcvd_lgth;
    int			dummy_int;
    char *		dummy_ptr = NULL;

    /*  Dummy up return input parameters if not provided  */

    if ( len == NULL )
        len = &dummy_int;

    if ( ptr == NULL )
        ptr = &dummy_ptr;

    /*  But can't work without the context pointer  */

    if ( ( ctxt == NULL ) || ( ctxt->content == NULL ) ) {
        *len = 0;
	*ptr = NULL;
	return ( -1 );
    }

    rcvd_lgth = ctxt->inptr - ctxt->content;

    while ( (cur_lgth = xmlNanoHTTPRecv( ctxt )) > 0 ) {

	rcvd_lgth += cur_lgth;
	if ( (ctxt->ContentLength > 0) && (rcvd_lgth >= ctxt->ContentLength) )
	    break;
    }

    *ptr = ctxt->content;
    *len = rcvd_lgth;

    if ( ( ctxt->ContentLength > 0 ) && ( rcvd_lgth < ctxt->ContentLength ) )
        rc = -1;
    else if ( rcvd_lgth == 0 )
	rc = -1;

    return ( rc );
}

#ifdef STANDALONE
int main(int argc, char **argv) {
    char *contentType = NULL;

    if (argv[1] != NULL) {
	if (argv[2] != NULL) 
	    xmlNanoHTTPFetch(argv[1], argv[2], &contentType);
        else
	    xmlNanoHTTPFetch(argv[1], "-", &contentType);
	if (contentType != NULL) xmlFree(contentType);
    } else {
        xmlGenericError(xmlGenericErrorContext,
		"%s: minimal HTTP GET implementation\n", argv[0]);
        xmlGenericError(xmlGenericErrorContext,
		"\tusage %s [ URL [ filename ] ]\n", argv[0]);
    }
    xmlNanoHTTPCleanup();
    xmlMemoryDump();
    return(0);
}
#endif /* STANDALONE */
#else /* !LIBXML_HTTP_ENABLED */
#ifdef STANDALONE
#include <stdio.h>
int main(int argc, char **argv) {
    xmlGenericError(xmlGenericErrorContext,
	    "%s : HTTP support not compiled in\n", argv[0]);
    return(0);
}
#endif /* STANDALONE */
#endif /* LIBXML_HTTP_ENABLED */