Function xmlBufferAddHead

ThirdParty/libxml2/vtklibxml2/tree.c:7581–7629

* xmlBufferAddHead: * @buf: the buffer * @str: the #xmlChar string * @len: the number of #xmlChar to add * * Add a string range to the beginning of an XML buffer. * if len == -1, the length of @str is recomputed. * * Returns 0 successful, a positive error code number otherwise * and -1 in case of internal or API error. */

 *         and -1 in case of internal or API error.
 */
int
xmlBufferAddHead(xmlBufferPtr buf, const xmlChar *str, int len) {
    unsigned int needSize;

    if (buf == NULL)
        return(-1);
    if (str == NULL) {
	return -1;
    }
    if (len < -1) {
	return -1;
    }
    if (len == 0) return 0;

    if (len < 0)
        len = xmlStrlen(str);

    if (len <= 0) return -1;

    if ((buf->alloc == XML_BUFFER_ALLOC_IO) && (buf->contentIO != NULL)) {
        size_t start_buf = buf->content - buf->contentIO;

	if (start_buf > (unsigned int) len) {
	    /*
	     * We can add it in the space previously shrunk
	     */
	    buf->content -= len;
            memmove(&buf->content[0], str, len);
	    buf->use += len;
	    buf->size += len;
            buf->content[buf->use] = 0;
	    return(0);
	}
    }
    /* Note that both buf->size and buf->use can be zero here. */
    if ((unsigned) len >= buf->size - buf->use) {
        if ((unsigned) len >= UINT_MAX - buf->use)
            return(-1);
        needSize = buf->use + len + 1;
        if (!xmlBufferResize(buf, needSize))
            return(-1);
    }

    memmove(&buf->content[len], &buf->content[0], buf->use);
    memmove(&buf->content[0], str, len);
    buf->use += len;
    buf->content[buf->use] = 0;
    return 0;
}

/**
 * xmlBufferCat: