xmlio.c

xml开源解析代码.版本为libxml2-2.6.29,可支持GB3212.网络消息发送XML时很有用.

 * compiled-in I/O. 
 *
 * Returns the number of input callback registered or -1 in case of error.
 */
int
xmlPopInputCallbacks(void)
{
    if (!xmlInputCallbackInitialized)
        return(-1);

    if (xmlInputCallbackNr <= 0)
        return(-1);
        
    xmlInputCallbackNr--;
    xmlInputCallbackTable[xmlInputCallbackNr].matchcallback = NULL;
    xmlInputCallbackTable[xmlInputCallbackNr].opencallback = NULL;
    xmlInputCallbackTable[xmlInputCallbackNr].readcallback = NULL;
    xmlInputCallbackTable[xmlInputCallbackNr].closecallback = NULL;

    return(xmlInputCallbackNr);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlCleanupOutputCallbacks:
 *
 * clears the entire output callback table. this includes the
 * compiled-in I/O callbacks. 
 */
void
xmlCleanupOutputCallbacks(void)
{
    int i;

    if (!xmlOutputCallbackInitialized)
        return;

    for (i = xmlOutputCallbackNr - 1; i >= 0; i--) {
        xmlOutputCallbackTable[i].matchcallback = NULL;
        xmlOutputCallbackTable[i].opencallback = NULL;
        xmlOutputCallbackTable[i].writecallback = NULL;
        xmlOutputCallbackTable[i].closecallback = NULL;
    }

    xmlOutputCallbackNr = 0;
    xmlOutputCallbackInitialized = 0;
}
#endif /* LIBXML_OUTPUT_ENABLED */

/************************************************************************
 *									*
 *		Standard I/O for file accesses				*
 *									*
 ************************************************************************/

#if defined(_WIN32) || defined (__DJGPP__) && !defined (__CYGWIN__)

/**
 *  xmlWrapOpenUtf8:
 * @path:  the path in utf-8 encoding
 * @mode:  type of access (0 - read, 1 - write)
 *
 * function opens the file specified by @path
 *
 */
static FILE*
xmlWrapOpenUtf8(const char *path,int mode)
{
    FILE *fd = NULL;
    wchar_t *wPath;

    wPath = __xmlIOWin32UTF8ToWChar(path);
    if(wPath)
    {
       fd = _wfopen(wPath, mode ? L"wb" : L"rb");
       xmlFree(wPath);
    }
    /* maybe path in native encoding */
    if(fd == NULL)
       fd = fopen(path, mode ? "wb" : "rb");

    return fd;
}

/**
 *  xmlWrapStatUtf8:
 * @path:  the path in utf-8 encoding
 * @info:  structure that stores results
 *
 * function obtains information about the file or directory
 *
 */
static int
xmlWrapStatUtf8(const char *path,struct stat *info)
{
#ifdef HAVE_STAT
    int retval = -1;
    wchar_t *wPath;

    wPath = __xmlIOWin32UTF8ToWChar(path);
    if (wPath)
    {
       retval = _wstat(wPath,info);
       xmlFree(wPath);
    }
    /* maybe path in native encoding */
    if(retval < 0)
       retval = stat(path,info);
    return retval;
#else
    return -1;
#endif
}

/**
 *  xmlWrapOpenNative:
 * @path:  the path
 * @mode:  type of access (0 - read, 1 - write)
 *
 * function opens the file specified by @path
 *
 */
static FILE*
xmlWrapOpenNative(const char *path,int mode)
{
    return fopen(path,mode ? "wb" : "rb");
}

/**
 *  xmlWrapStatNative:
 * @path:  the path
 * @info:  structure that stores results
 *
 * function obtains information about the file or directory
 *
 */
static int
xmlWrapStatNative(const char *path,struct stat *info)
{
#ifdef HAVE_STAT
    return stat(path,info);
#else
    return -1;
#endif
}

typedef int (* xmlWrapStatFunc) (const char *f, struct stat *s);
static xmlWrapStatFunc xmlWrapStat = xmlWrapStatNative;
typedef FILE* (* xmlWrapOpenFunc)(const char *f,int mode);
static xmlWrapOpenFunc xmlWrapOpen = xmlWrapOpenNative;

/**
 * xmlInitPlatformSpecificIo:
 *
 * Initialize platform specific features.
 */
static void
xmlInitPlatformSpecificIo(void)
{
    static int xmlPlatformIoInitialized = 0;
    OSVERSIONINFO osvi;

    if(xmlPlatformIoInitialized)
      return;

    osvi.dwOSVersionInfoSize = sizeof(osvi);

    if(GetVersionEx(&osvi) && (osvi.dwPlatformId == VER_PLATFORM_WIN32_NT)) {
      xmlWrapStat = xmlWrapStatUtf8;
      xmlWrapOpen = xmlWrapOpenUtf8;
    } else {
      xmlWrapStat = xmlWrapStatNative;
      xmlWrapOpen = xmlWrapOpenNative;
    }

    xmlPlatformIoInitialized = 1;
    return;
}

#endif

/**
 * xmlCheckFilename:
 * @path:  the path to check
 *
 * function checks to see if @path is a valid source
 * (file, socket...) for XML.
 *
 * if stat is not available on the target machine,
 * returns 1.  if stat fails, returns 0 (if calling
 * stat on the filename fails, it can't be right).
 * if stat succeeds and the file is a directory,
 * returns 2.  otherwise returns 1.
 */

int
xmlCheckFilename (const char *path)
{
#ifdef HAVE_STAT
	struct stat stat_buffer;
#endif
	if (path == NULL)
		return(0);

#ifdef HAVE_STAT
#if defined(_WIN32) || defined (__DJGPP__) && !defined (__CYGWIN__)
    if (xmlWrapStat(path, &stat_buffer) == -1)
        return 0;
#else
    if (stat(path, &stat_buffer) == -1)
        return 0;
#endif
#ifdef S_ISDIR
    if (S_ISDIR(stat_buffer.st_mode))
        return 2;
#endif
#endif /* HAVE_STAT */
    return 1;
}

static int
xmlNop(void) {
    return(0);
}

/**
 * xmlFdRead:
 * @context:  the I/O context
 * @buffer:  where to drop data
 * @len:  number of bytes to read
 *
 * Read @len bytes to @buffer from the I/O channel.
 *
 * Returns the number of bytes written
 */
static int
xmlFdRead (void * context, char * buffer, int len) {
    int ret;

    ret = read((int) (long) context, &buffer[0], len);
    if (ret < 0) xmlIOErr(0, "read()");
    return(ret);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlFdWrite:
 * @context:  the I/O context
 * @buffer:  where to get data
 * @len:  number of bytes to write
 *
 * Write @len bytes from @buffer to the I/O channel.
 *
 * Returns the number of bytes written
 */
static int
xmlFdWrite (void * context, const char * buffer, int len) {
    int ret = 0;

    if (len > 0) {
	ret = write((int) (long) context, &buffer[0], len);
	if (ret < 0) xmlIOErr(0, "write()");
    }
    return(ret);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlFdClose:
 * @context:  the I/O context
 *
 * Close an I/O channel
 *
 * Returns 0 in case of success and error code otherwise
 */
static int
xmlFdClose (void * context) {
    int ret;
    ret = close((int) (long) context);
    if (ret < 0) xmlIOErr(0, "close()");
    return(ret);
}

/**
 * xmlFileMatch:
 * @filename:  the URI for matching
 *
 * input from FILE *
 *
 * Returns 1 if matches, 0 otherwise
 */
int
xmlFileMatch (const char *filename ATTRIBUTE_UNUSED) {
    return(1);
}

/**
 * xmlFileOpen_real:
 * @filename:  the URI for matching
 *
 * input from FILE *, supports compressed input
 * if @filename is " " then the standard input is used
 *
 * Returns an I/O context or NULL in case of error
 */
static void *
xmlFileOpen_real (const char *filename) {
    const char *path = NULL;
    FILE *fd;

    if (filename == NULL)
        return(NULL);

    if (!strcmp(filename, "-")) {
	fd = stdin;
	return((void *) fd);
    }

    if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file://localhost/", 17)) {
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[17];
#else
	path = &filename[16];
#endif
    } else if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file:///", 8)) {
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[8];
#else
	path = &filename[7];
#endif
    } else if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file:/", 6)) {
        /* lots of generators seems to lazy to read RFC 1738 */
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[6];
#else
	path = &filename[5];
#endif
    } else 
	path = filename;

    if (path == NULL)
	return(NULL);
    if (!xmlCheckFilename(path))
        return(NULL);

#if defined(_WIN32) || defined (__DJGPP__) && !defined (__CYGWIN__)
    fd = xmlWrapOpen(path, 0);
#else
    fd = fopen(path, "r");
#endif /* WIN32 */
    if (fd == NULL) xmlIOErr(0, path);
    return((void *) fd);
}

/**
 * xmlFileOpen:
 * @filename:  the URI for matching
 *
 * Wrapper around xmlFileOpen_real that try it with an unescaped
 * version of @filename, if this fails fallback to @filename
 *
 * Returns a handler or NULL in case or failure
 */
void *
xmlFileOpen (const char *filename) {
    char *unescaped;
    void *retval;

    retval = xmlFileOpen_real(filename);
    if (retval == NULL) {
	unescaped = xmlURIUnescapeString(filename, 0, NULL);
	if (unescaped != NULL) {
	    retval = xmlFileOpen_real(unescaped);
	    xmlFree(unescaped);
	}
    }

    return retval;
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlFileOpenW:
 * @filename:  the URI for matching
 *
 * output to from FILE *,
 * if @filename is "-" then the standard output is used
 *
 * Returns an I/O context or NULL in case of error
 */
static void *
xmlFileOpenW (const char *filename) {
    const char *path = NULL;
    FILE *fd;

    if (!strcmp(filename, "-")) {
	fd = stdout;
	return((void *) fd);
    }

    if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file://localhost/", 17))
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[17];
#else
	path = &filename[16];
#endif
    else if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file:///", 8)) {
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[8];
#else
	path = &filename[7];
#endif
    } else 
	path = filename;

    if (path == NULL)
	return(NULL);

#if defined(_WIN32) || defined (__DJGPP__) && !defined (__CYGWIN__)
    fd = xmlWrapOpen(path, 1);
#else
  	   fd = fopen(path, "wb");
#endif /* WIN32 */

	 if (fd == NULL) xmlIOErr(0, path);
    return((void *) fd);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlFileRead:
 * @context:  the I/O context
 * @buffer:  where to drop data
 * @len:  number of bytes to write
 *
 * Read @len bytes to @buffer from the I/O channel.
 *
 * Returns the number of bytes written or < 0 in case of failure
 */
int
xmlFileRead (void * context, char * buffer, int len) {
    int ret;
    if ((context == NULL) || (buffer == NULL)) 
        return(-1);
    ret = fread(&buffer[0], 1,  len, (FILE *) context);
    if (ret < 0) xmlIOErr(0, "fread()");
    return(ret);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlFileWrite:
 * @context:  the I/O context
 * @buffer:  where to drop data
 * @len:  number of bytes to write
 *
 * Write @len bytes from @buffer to the I/O channel.
 *
 * Returns the number of bytes written
 */
static int
xmlFileWrite (void * context, const char * buffer, int len) {
    int items;

    if ((context == NULL) || (buffer == NULL)) 
        return(-1);
    items = fwrite(&buffer[0], len, 1, (FILE *) context);
    if ((items == 0) && (ferror((FILE *) context))) {
        xmlIOErr(0, "fwrite()");
	return(-1);
    }
    return(items * len);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlFileClose:
 * @context:  the I/O context
 *
 * Close an I/O channel
 *
 * Returns 0 or -1 in case of error
 */
int
xmlFileClose (void * context) {
    FILE *fil;
    int ret;

    if (context == NULL)
        return(-1);
    fil = (FILE *) context;
    if ((fil == stdout) || (fil == stderr)) {
        ret = fflush(fil);
	if (ret < 0)
	    xmlIOErr(0, "fflush()");
	return(0);
    }
    if (fil == stdin)
	return(0);
    ret = ( fclose((FILE *) context) == EOF ) ? -1 : 0;
    if (ret < 0)
        xmlIOErr(0, "fclose()");
    return(ret);
}

/**
 * xmlFileFlush:
 * @context:  the I/O context
 *
 * Flush an I/O channel
 */
static int
xmlFileFlush (void * context) {
    int ret;

    if (context == NULL)
        return(-1);
    ret = ( fflush((FILE *) context) == EOF ) ? -1 : 0;
    if (ret < 0)
        xmlIOErr(0, "fflush()");
    return(ret);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlBufferWrite:
 * @context:  the xmlBuffer
 * @buffer:  the data to write