xmlsave.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.

/*
 * xmlsave.c: Implemetation of the document serializer
 *
 * See Copyright for the status of this software.
 *
 * [e-mail]
 */

#define IN_LIBXML
#include "libxml.h"

#include <string.h>
#include <libxml/xmlmemory.h>
#include <libxml/parserInternals.h>
#include <libxml/tree.h>
#include <libxml/xmlsave.h>

#define MAX_INDENT 60

#include <libxml/HTMLtree.h>

/************************************************************************
 *									*
 *			XHTML detection					*
 *									*
 ************************************************************************/
#define XHTML_STRICT_PUBLIC_ID BAD_CAST \
   "-//W3C//DTD XHTML 1.0 Strict//EN"
#define XHTML_STRICT_SYSTEM_ID BAD_CAST \
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"
#define XHTML_FRAME_PUBLIC_ID BAD_CAST \
   "-//W3C//DTD XHTML 1.0 Frameset//EN"
#define XHTML_FRAME_SYSTEM_ID BAD_CAST \
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd"
#define XHTML_TRANS_PUBLIC_ID BAD_CAST \
   "-//W3C//DTD XHTML 1.0 Transitional//EN"
#define XHTML_TRANS_SYSTEM_ID BAD_CAST \
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"

#define XHTML_NS_NAME BAD_CAST "http://www.w3.org/1999/xhtml"
/**
 * xmlIsXHTML:
 * @systemID:  the system identifier
 * @publicID:  the public identifier
 *
 * Try to find if the document correspond to an XHTML DTD
 *
 * Returns 1 if true, 0 if not and -1 in case of error
 */
int
xmlIsXHTML(const xmlChar *systemID, const xmlChar *publicID) {
    if ((systemID == NULL) && (publicID == NULL))
	return(-1);
    if (publicID != NULL) {
	if (xmlStrEqual(publicID, XHTML_STRICT_PUBLIC_ID)) return(1);
	if (xmlStrEqual(publicID, XHTML_FRAME_PUBLIC_ID)) return(1);
	if (xmlStrEqual(publicID, XHTML_TRANS_PUBLIC_ID)) return(1);
    }
    if (systemID != NULL) {
	if (xmlStrEqual(systemID, XHTML_STRICT_SYSTEM_ID)) return(1);
	if (xmlStrEqual(systemID, XHTML_FRAME_SYSTEM_ID)) return(1);
	if (xmlStrEqual(systemID, XHTML_TRANS_SYSTEM_ID)) return(1);
    }
    return(0);
}

#ifdef LIBXML_OUTPUT_ENABLED

#define TODO 								\
    xmlGenericError(xmlGenericErrorContext,				\
	    "Unimplemented block at %s:%d\n",				\
            __FILE__, __LINE__);

struct _xmlSaveCtxt {
    void *_private;
    int type;
    int fd;
    const xmlChar *filename;
    const xmlChar *encoding;
    xmlCharEncodingHandlerPtr handler;
    xmlOutputBufferPtr buf;
    xmlDocPtr doc;
    int options;
    int level;
    int format;
    char indent[MAX_INDENT + 1];	/* array for indenting output */
    int indent_nr;
    int indent_size;
    xmlCharEncodingOutputFunc escape;	/* used for element content */
    xmlCharEncodingOutputFunc escapeAttr;/* used for attribute content */
};

/************************************************************************
 *									*
 * 			Output error handlers				*
 *									*
 ************************************************************************/
/**
 * xmlSaveErrMemory:
 * @extra:  extra informations
 *
 * Handle an out of memory condition
 */
static void
xmlSaveErrMemory(const char *extra)
{
    __xmlSimpleError(XML_FROM_OUTPUT, XML_ERR_NO_MEMORY, NULL, NULL, extra);
}

/**
 * xmlSaveErr:
 * @code:  the error number
 * @node:  the location of the error.
 * @extra:  extra informations
 *
 * Handle an out of memory condition
 */
static void
xmlSaveErr(int code, xmlNodePtr node, const char *extra)
{
    const char *msg = NULL;

    switch(code) {
        case XML_SAVE_NOT_UTF8:
	    msg = "string is not in UTF-8";
	    break;
	case XML_SAVE_CHAR_INVALID:
	    msg = "invalid character value";
	    break;
	case XML_SAVE_UNKNOWN_ENCODING:
	    msg = "unknown encoding %s";
	    break;
	case XML_SAVE_NO_DOCTYPE:
	    msg = "document has no DOCTYPE";
	    break;
	default:
	    msg = "unexpected error number";
    }
    __xmlSimpleError(XML_FROM_OUTPUT, code, node, msg, extra);
}

/************************************************************************
 *									*
 *			Special escaping routines			*
 *									*
 ************************************************************************/
static unsigned char *
xmlSerializeHexCharRef(unsigned char *out, int val) {
    unsigned char *ptr;

    *out++ = '&';
    *out++ = '#';
    *out++ = 'x';
    if (val < 0x10) ptr = out;
    else if (val < 0x100) ptr = out + 1;
    else if (val < 0x1000) ptr = out + 2;
    else if (val < 0x10000) ptr = out + 3;
    else if (val < 0x100000) ptr = out + 4;
    else ptr = out + 5;
    out = ptr + 1;
    while (val > 0) {
	switch (val & 0xF) {
	    case 0: *ptr-- = '0'; break;
	    case 1: *ptr-- = '1'; break;
	    case 2: *ptr-- = '2'; break;
	    case 3: *ptr-- = '3'; break;
	    case 4: *ptr-- = '4'; break;
	    case 5: *ptr-- = '5'; break;
	    case 6: *ptr-- = '6'; break;
	    case 7: *ptr-- = '7'; break;
	    case 8: *ptr-- = '8'; break;
	    case 9: *ptr-- = '9'; break;
	    case 0xA: *ptr-- = 'A'; break;
	    case 0xB: *ptr-- = 'B'; break;
	    case 0xC: *ptr-- = 'C'; break;
	    case 0xD: *ptr-- = 'D'; break;
	    case 0xE: *ptr-- = 'E'; break;
	    case 0xF: *ptr-- = 'F'; break;
	    default: *ptr-- = '0'; break;
	}
	val >>= 4;
    }
    *out++ = ';';
    *out = 0;
    return(out);
}

/**
 * xmlEscapeEntities:
 * @out:  a pointer to an array of bytes to store the result
 * @outlen:  the length of @out
 * @in:  a pointer to an array of unescaped UTF-8 bytes
 * @inlen:  the length of @in
 *
 * Take a block of UTF-8 chars in and escape them. Used when there is no
 * encoding specified.
 *
 * Returns 0 if success, or -1 otherwise
 * The value of @inlen after return is the number of octets consumed
 *     if the return value is positive, else unpredictable.
 * The value of @outlen after return is the number of octets consumed.
 */
static int
xmlEscapeEntities(unsigned char* out, int *outlen,
                 const xmlChar* in, int *inlen) {
    unsigned char* outstart = out;
    const unsigned char* base = in;
    unsigned char* outend = out + *outlen;
    const unsigned char* inend;
    int val;

    inend = in + (*inlen);
    
    while ((in < inend) && (out < outend)) {
    	if (*in == '<') {
	    if (outend - out < 4) break;
	    *out++ = '&';
	    *out++ = 'l';
	    *out++ = 't';
	    *out++ = ';';
	    in++;
	    continue;
	} else if (*in == '>') {
	    if (outend - out < 4) break;
	    *out++ = '&';
	    *out++ = 'g';
	    *out++ = 't';
	    *out++ = ';';
	    in++;
	    continue;
	} else if (*in == '&') {
	    if (outend - out < 5) break;
	    *out++ = '&';
	    *out++ = 'a';
	    *out++ = 'm';
	    *out++ = 'p';
	    *out++ = ';';
	    in++;
	    continue;
	} else if (((*in >= 0x20) && (*in < 0x80)) ||
	           (*in == '\n') || (*in == '\t')) {
	    /*
	     * default case, just copy !
	     */
	    *out++ = *in++;
	    continue;
	} else if (*in >= 0x80) {
	    /*
	     * We assume we have UTF-8 input.
	     */
	    if (outend - out < 10) break;

	    if (*in < 0xC0) {
		xmlSaveErr(XML_SAVE_NOT_UTF8, NULL, NULL);
		in++;
		goto error;
	    } else if (*in < 0xE0) {
		if (inend - in < 2) break;
		val = (in[0]) & 0x1F;
		val <<= 6;
		val |= (in[1]) & 0x3F;
		in += 2;
	    } else if (*in < 0xF0) {
		if (inend - in < 3) break;
		val = (in[0]) & 0x0F;
		val <<= 6;
		val |= (in[1]) & 0x3F;
		val <<= 6;
		val |= (in[2]) & 0x3F;
		in += 3;
	    } else if (*in < 0xF8) {
		if (inend - in < 4) break;
		val = (in[0]) & 0x07;
		val <<= 6;
		val |= (in[1]) & 0x3F;
		val <<= 6;
		val |= (in[2]) & 0x3F;
		val <<= 6;
		val |= (in[3]) & 0x3F;
		in += 4;
	    } else {
		xmlSaveErr(XML_SAVE_CHAR_INVALID, NULL, NULL);
		in++;
		goto error;
	    }
	    if (!IS_CHAR(val)) {
		xmlSaveErr(XML_SAVE_CHAR_INVALID, NULL, NULL);
		in++;
		goto error;
	    }

	    /*
	     * We could do multiple things here. Just save as a char ref
	     */
	    out = xmlSerializeHexCharRef(out, val);
	} else if (IS_BYTE_CHAR(*in)) {
	    if (outend - out < 6) break;
	    out = xmlSerializeHexCharRef(out, *in++);
	} else {
	    xmlGenericError(xmlGenericErrorContext,
		"xmlEscapeEntities : char out of range\n");
	    in++;
	    goto error;
	}
    }
    *outlen = out - outstart;
    *inlen = in - base;
    return(0);
error:
    *outlen = out - outstart;
    *inlen = in - base;
    return(-1);
}

/************************************************************************
 *									*
 *			Allocation and deallocation			*
 *									*
 ************************************************************************/
/**
 * xmlSaveCtxtInit:
 * @ctxt: the saving context
 *
 * Initialize a saving context
 */
static void
xmlSaveCtxtInit(xmlSaveCtxtPtr ctxt)
{
    int i;
    int len;

    if (ctxt == NULL) return;
    if ((ctxt->encoding == NULL) && (ctxt->escape == NULL))
        ctxt->escape = xmlEscapeEntities;
    len = xmlStrlen((xmlChar *)xmlTreeIndentString);
    if ((xmlTreeIndentString == NULL) || (len == 0)) {
        memset(&ctxt->indent[0], 0, MAX_INDENT + 1);
    } else {
	ctxt->indent_size = len;
	ctxt->indent_nr = MAX_INDENT / ctxt->indent_size;
	for (i = 0;i < ctxt->indent_nr;i++)
	    memcpy(&ctxt->indent[i * ctxt->indent_size], xmlTreeIndentString,
		   ctxt->indent_size);
        ctxt->indent[ctxt->indent_nr * ctxt->indent_size] = 0;
    }
}

/**
 * xmlFreeSaveCtxt:
 *
 * Free a saving context, destroying the ouptut in any remaining buffer
 */
static void
xmlFreeSaveCtxt(xmlSaveCtxtPtr ctxt)
{
    if (ctxt == NULL) return;
    if (ctxt->encoding != NULL)
        xmlFree((char *) ctxt->encoding);
    if (ctxt->buf != NULL)
        xmlOutputBufferClose(ctxt->buf);
    xmlFree(ctxt);
}

/**
 * xmlNewSaveCtxt:
 *
 * Create a new saving context
 *
 * Returns the new structure or NULL in case of error
 */
static xmlSaveCtxtPtr
xmlNewSaveCtxt(const char *encoding, int options)
{
    xmlSaveCtxtPtr ret;

    ret = (xmlSaveCtxtPtr) xmlMalloc(sizeof(xmlSaveCtxt));
    if (ret == NULL) {
	xmlSaveErrMemory("creating saving context");
	return ( NULL );
    }
    memset(ret, 0, sizeof(xmlSaveCtxt));

    /*
     * Use the options
     */
    ret->options = options;
    if (options & XML_SAVE_FORMAT)
        ret->format = 1;

    if (encoding != NULL) {
        ret->handler = xmlFindCharEncodingHandler(encoding);
	if (ret->handler == NULL) {
	    xmlSaveErr(XML_SAVE_UNKNOWN_ENCODING, NULL, encoding);
            xmlFreeSaveCtxt(ret);
	    return(NULL);
	}
        ret->encoding = xmlStrdup((const xmlChar *)encoding);
	ret->escape = xmlEscapeEntities;
    }
    xmlSaveCtxtInit(ret);

    return(ret);
}

/************************************************************************
 *									*
 *   		Dumping XML tree content to a simple buffer		*
 *									*
 ************************************************************************/
/**
 * xmlAttrSerializeContent:
 * @buf:  the XML buffer output
 * @doc:  the document
 * @attr:  the attribute pointer
 *
 * Serialize the attribute in the buffer
 */
static void
xmlAttrSerializeContent(xmlOutputBufferPtr buf, xmlAttrPtr attr)
{
    xmlNodePtr children;

    children = attr->children;
    while (children != NULL) {
        switch (children->type) {
            case XML_TEXT_NODE:
	        xmlAttrSerializeTxtContent(buf->buffer, attr->doc,
		                           attr, children->content);
		break;
            case XML_ENTITY_REF_NODE:
                xmlBufferAdd(buf->buffer, BAD_CAST "&", 1);
                xmlBufferAdd(buf->buffer, children->name,
                             xmlStrlen(children->name));
                xmlBufferAdd(buf->buffer, BAD_CAST ";", 1);
                break;
            default:
                /* should not happen unless we have a badly built tree */
                break;
        }
        children = children->next;
    }
}

/************************************************************************
 *									*
 *   		Dumping XML tree content to an I/O output buffer	*
 *									*