xmlwriter.c

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/*
 * xmlwriter.c: XML text writer implementation
 *
 * For license and disclaimer see the license and disclaimer of
 * libxml2.
 *
 * [e-mail]
 */

#define IN_LIBXML
#include <string.h>

#include "libxml.h"
#include <libxml/xmlmemory.h>
#include <libxml/parser.h>
#include <libxml/uri.h>
#include <libxml/HTMLtree.h>

#ifdef LIBXML_WRITER_ENABLED

#include <libxml/xmlwriter.h>

#define B64LINELEN 72
#define B64CRLF "\r\n"

/*
 * Types are kept private
 */
typedef enum {
    XML_TEXTWRITER_NONE = 0,
    XML_TEXTWRITER_NAME,
    XML_TEXTWRITER_ATTRIBUTE,
    XML_TEXTWRITER_TEXT,
    XML_TEXTWRITER_PI,
    XML_TEXTWRITER_PI_TEXT,
    XML_TEXTWRITER_CDATA,
    XML_TEXTWRITER_DTD,
    XML_TEXTWRITER_DTD_TEXT,
    XML_TEXTWRITER_DTD_ELEM,
    XML_TEXTWRITER_DTD_ELEM_TEXT,
    XML_TEXTWRITER_DTD_ATTL,
    XML_TEXTWRITER_DTD_ATTL_TEXT,
    XML_TEXTWRITER_DTD_ENTY,    /* entity */
    XML_TEXTWRITER_DTD_ENTY_TEXT,
    XML_TEXTWRITER_DTD_PENT,    /* parameter entity */
    XML_TEXTWRITER_COMMENT
} xmlTextWriterState;

typedef struct _xmlTextWriterStackEntry xmlTextWriterStackEntry;

struct _xmlTextWriterStackEntry {
    xmlChar *name;
    xmlTextWriterState state;
};

typedef struct _xmlTextWriterNsStackEntry xmlTextWriterNsStackEntry;
struct _xmlTextWriterNsStackEntry {
    xmlChar *prefix;
    xmlChar *uri;
    xmlLinkPtr elem;
};

struct _xmlTextWriter {
    xmlOutputBufferPtr out;     /* output buffer */
    xmlListPtr nodes;           /* element name stack */
    xmlListPtr nsstack;         /* name spaces stack */
    int level;
    int indent;                 /* enable indent */
    int doindent;               /* internal indent flag */
    xmlChar *ichar;             /* indent character */
    char qchar;                 /* character used for quoting attribute values */
    xmlParserCtxtPtr ctxt;
    int no_doc_free;
};

static void xmlFreeTextWriterStackEntry(xmlLinkPtr lk);
static int xmlCmpTextWriterStackEntry(const void *data0,
                                      const void *data1);
static void xmlFreeTextWriterNsStackEntry(xmlLinkPtr lk);
static int xmlCmpTextWriterNsStackEntry(const void *data0,
                                        const void *data1);
static int xmlTextWriterWriteMemCallback(void *context,
                                         const xmlChar * str, int len);
static int xmlTextWriterCloseMemCallback(void *context);
static int xmlTextWriterWriteDocCallback(void *context,
                                         const xmlChar * str, int len);
static int xmlTextWriterCloseDocCallback(void *context);

static xmlChar *xmlTextWriterVSprintf(const char *format, va_list argptr);
static int xmlOutputBufferWriteBase64(xmlOutputBufferPtr out, int len,
                                      const unsigned char *data);
static void xmlTextWriterStartDocumentCallback(void *ctx);
static int xmlTextWriterWriteIndent(xmlTextWriterPtr writer);
static int
  xmlTextWriterHandleStateDependencies(xmlTextWriterPtr writer,
                                       xmlTextWriterStackEntry * p);

/**
 * xmlWriterErrMsg:
 * @ctxt:  a writer context
 * @error:  the error number
 * @msg:  the error message
 *
 * Handle a writer error
 */
static void
xmlWriterErrMsg(xmlTextWriterPtr ctxt, xmlParserErrors error,
               const char *msg)
{
    if (ctxt != NULL) {
	__xmlRaiseError(NULL, NULL, NULL, ctxt->ctxt,
	            NULL, XML_FROM_WRITER, error, XML_ERR_FATAL,
		    NULL, 0, NULL, NULL, NULL, 0, 0, msg);
    } else {
	__xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_WRITER, error,
                    XML_ERR_FATAL, NULL, 0, NULL, NULL, NULL, 0, 0, msg);
    }
}

/**
 * xmlWriterErrMsgInt:
 * @ctxt:  a writer context
 * @error:  the error number
 * @msg:  the error message
 * @val:  an int
 *
 * Handle a writer error
 */
static void
xmlWriterErrMsgInt(xmlTextWriterPtr ctxt, xmlParserErrors error,
               const char *msg, int val)
{
    if (ctxt != NULL) {
	__xmlRaiseError(NULL, NULL, NULL, ctxt->ctxt,
	            NULL, XML_FROM_WRITER, error, XML_ERR_FATAL,
		    NULL, 0, NULL, NULL, NULL, val, 0, msg, val);
    } else {
	__xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_WRITER, error,
                    XML_ERR_FATAL, NULL, 0, NULL, NULL, NULL, val, 0, msg, val);
    }
}

/**
 * xmlNewTextWriter:
 * @out:  an xmlOutputBufferPtr
 *
 * Create a new xmlNewTextWriter structure using an xmlOutputBufferPtr
 * NOTE: the @out parameter will be deallocated when the writer is closed
 *       (if the call succeed.)
 *
 * Returns the new xmlTextWriterPtr or NULL in case of error
 */
xmlTextWriterPtr
xmlNewTextWriter(xmlOutputBufferPtr out)
{
    xmlTextWriterPtr ret;

    ret = (xmlTextWriterPtr) xmlMalloc(sizeof(xmlTextWriter));
    if (ret == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_NO_MEMORY,
                        "xmlNewTextWriter : out of memory!\n");
        return NULL;
    }
    memset(ret, 0, (size_t) sizeof(xmlTextWriter));

    ret->nodes = xmlListCreate((xmlListDeallocator)
                               xmlFreeTextWriterStackEntry,
                               (xmlListDataCompare)
                               xmlCmpTextWriterStackEntry);
    if (ret->nodes == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_NO_MEMORY,
                        "xmlNewTextWriter : out of memory!\n");
        xmlFree(ret);
        return NULL;
    }

    ret->nsstack = xmlListCreate((xmlListDeallocator)
                                 xmlFreeTextWriterNsStackEntry,
                                 (xmlListDataCompare)
                                 xmlCmpTextWriterNsStackEntry);
    if (ret->nsstack == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_NO_MEMORY,
                        "xmlNewTextWriter : out of memory!\n");
        xmlListDelete(ret->nodes);
        xmlFree(ret);
        return NULL;
    }

    ret->out = out;
    ret->ichar = xmlStrdup(BAD_CAST " ");
    ret->qchar = '"';

    if (!ret->ichar) {
        xmlListDelete(ret->nodes);
        xmlListDelete(ret->nsstack);
        xmlFree(ret);
        xmlWriterErrMsg(NULL, XML_ERR_NO_MEMORY,
                        "xmlNewTextWriter : out of memory!\n");
        return NULL;
    }
    ret->no_doc_free = 0;

    return ret;
}

/**
 * xmlNewTextWriterFilename:
 * @uri:  the URI of the resource for the output
 * @compression:  compress the output?
 *
 * Create a new xmlNewTextWriter structure with @uri as output
 *
 * Returns the new xmlTextWriterPtr or NULL in case of error
 */
xmlTextWriterPtr
xmlNewTextWriterFilename(const char *uri, int compression)
{
    xmlTextWriterPtr ret;
    xmlOutputBufferPtr out;

    out = xmlOutputBufferCreateFilename(uri, NULL, compression);
    if (out == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_NO_MEMORY,
                        "xmlNewTextWriterFilename : out of memory!\n");
        return NULL;
    }

    ret = xmlNewTextWriter(out);
    if (ret == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_NO_MEMORY,
                        "xmlNewTextWriterFilename : out of memory!\n");
        xmlOutputBufferClose(out);
        return NULL;
    }

    ret->indent = 0;
    ret->doindent = 0;
    return ret;
}

/**
 * xmlNewTextWriterMemory:
 * @buf:  xmlBufferPtr
 * @compression:  compress the output?
 *
 * Create a new xmlNewTextWriter structure with @buf as output
 * TODO: handle compression
 *
 * Returns the new xmlTextWriterPtr or NULL in case of error
 */
xmlTextWriterPtr
xmlNewTextWriterMemory(xmlBufferPtr buf, int compression ATTRIBUTE_UNUSED)
{
    xmlTextWriterPtr ret;
    xmlOutputBufferPtr out;

/*::todo handle compression */
    out = xmlOutputBufferCreateIO((xmlOutputWriteCallback)
                                  xmlTextWriterWriteMemCallback,
                                  (xmlOutputCloseCallback)
                                  xmlTextWriterCloseMemCallback,
                                  (void *) buf, NULL);
    if (out == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_NO_MEMORY,
                        "xmlNewTextWriterMemory : out of memory!\n");
        return NULL;
    }

    ret = xmlNewTextWriter(out);
    if (ret == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_NO_MEMORY,
                        "xmlNewTextWriterMemory : out of memory!\n");
        xmlOutputBufferClose(out);
        return NULL;
    }

    return ret;
}

/**
 * xmlNewTextWriterPushParser:
 * @ctxt: xmlParserCtxtPtr to hold the new XML document tree
 * @compression:  compress the output?
 *
 * Create a new xmlNewTextWriter structure with @ctxt as output
 * NOTE: the @ctxt context will be freed with the resulting writer
 *       (if the call succeeds).
 * TODO: handle compression
 *
 * Returns the new xmlTextWriterPtr or NULL in case of error
 */
xmlTextWriterPtr
xmlNewTextWriterPushParser(xmlParserCtxtPtr ctxt,
                           int compression ATTRIBUTE_UNUSED)
{
    xmlTextWriterPtr ret;
    xmlOutputBufferPtr out;

    if (ctxt == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_INTERNAL_ERROR,
                        "xmlNewTextWriterPushParser : invalid context!\n");
        return NULL;
    }

    out = xmlOutputBufferCreateIO((xmlOutputWriteCallback)
                                  xmlTextWriterWriteDocCallback,
                                  (xmlOutputCloseCallback)
                                  xmlTextWriterCloseDocCallback,
                                  (void *) ctxt, NULL);
    if (out == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_INTERNAL_ERROR,
                        "xmlNewTextWriterPushParser : error at xmlOutputBufferCreateIO!\n");
        return NULL;
    }

    ret = xmlNewTextWriter(out);
    if (ret == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_INTERNAL_ERROR,
                        "xmlNewTextWriterPushParser : error at xmlNewTextWriter!\n");
        xmlOutputBufferClose(out);
        return NULL;
    }

    ret->ctxt = ctxt;

    return ret;
}

/**
 * xmlNewTextWriterDoc:
 * @doc: address of a xmlDocPtr to hold the new XML document tree
 * @compression:  compress the output?
 *
 * Create a new xmlNewTextWriter structure with @*doc as output
 *
 * Returns the new xmlTextWriterPtr or NULL in case of error
 */
xmlTextWriterPtr
xmlNewTextWriterDoc(xmlDocPtr * doc, int compression)
{
    xmlTextWriterPtr ret;
    xmlSAXHandler saxHandler;
    xmlParserCtxtPtr ctxt;

    memset(&saxHandler, '\0', sizeof(saxHandler));
    xmlSAX2InitDefaultSAXHandler(&saxHandler, 1);
    saxHandler.startDocument = xmlTextWriterStartDocumentCallback;
    saxHandler.startElement = xmlSAX2StartElement;
    saxHandler.endElement = xmlSAX2EndElement;

    ctxt = xmlCreatePushParserCtxt(&saxHandler, NULL, NULL, 0, NULL);
    if (ctxt == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_INTERNAL_ERROR,
                        "xmlNewTextWriterDoc : error at xmlCreatePushParserCtxt!\n");
        return NULL;
    }
    /*
     * For some reason this seems to completely break if node names
     * are interned.
     */
    ctxt->dictNames = 0;

    ctxt->myDoc = xmlNewDoc(BAD_CAST XML_DEFAULT_VERSION);
    if (ctxt->myDoc == NULL) {
        xmlFreeParserCtxt(ctxt);
        xmlWriterErrMsg(NULL, XML_ERR_INTERNAL_ERROR,
                        "xmlNewTextWriterDoc : error at xmlNewDoc!\n");
        return NULL;
    }

    ret = xmlNewTextWriterPushParser(ctxt, compression);
    if (ret == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_INTERNAL_ERROR,
                        "xmlNewTextWriterDoc : error at xmlNewTextWriterPushParser!\n");
        return NULL;
    }

    xmlSetDocCompressMode(ctxt->myDoc, compression);

    if (doc != NULL) {
        *doc = ctxt->myDoc;
	ret->no_doc_free = 1;
    }

    return ret;
}

/**
 * xmlNewTextWriterTree:
 * @doc: xmlDocPtr
 * @node: xmlNodePtr or NULL for doc->children
 * @compression:  compress the output?
 *
 * Create a new xmlNewTextWriter structure with @doc as output
 * starting at @node
 *
 * Returns the new xmlTextWriterPtr or NULL in case of error
 */
xmlTextWriterPtr
xmlNewTextWriterTree(xmlDocPtr doc, xmlNodePtr node, int compression)
{
    xmlTextWriterPtr ret;
    xmlSAXHandler saxHandler;
    xmlParserCtxtPtr ctxt;

    if (doc == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_INTERNAL_ERROR,
                        "xmlNewTextWriterTree : invalid document tree!\n");
        return NULL;
    }

    memset(&saxHandler, '\0', sizeof(saxHandler));
    xmlSAX2InitDefaultSAXHandler(&saxHandler, 1);
    saxHandler.startDocument = xmlTextWriterStartDocumentCallback;
    saxHandler.startElement = xmlSAX2StartElement;
    saxHandler.endElement = xmlSAX2EndElement;

    ctxt = xmlCreatePushParserCtxt(&saxHandler, NULL, NULL, 0, NULL);
    if (ctxt == NULL) {
        xmlWriterErrMsg(NULL, XML_ERR_INTERNAL_ERROR,
                        "xmlNewTextWriterDoc : error at xmlCreatePushParserCtxt!\n");
        return NULL;
    }
    /*
     * For some reason this seems to completely break if node names
     * are interned.
     */
    ctxt->dictNames = 0;

    ret = xmlNewTextWriterPushParser(ctxt, compression);
    if (ret == NULL) {
        xmlFreeParserCtxt(ctxt);
        xmlWriterErrMsg(NULL, XML_ERR_INTERNAL_ERROR,
                        "xmlNewTextWriterDoc : error at xmlNewTextWriterPushParser!\n");
        return NULL;
    }

    ctxt->myDoc = doc;
    ctxt->node = node;
    ret->no_doc_free = 1;

    xmlSetDocCompressMode(doc, compression);

    return ret;
}

/**
 * xmlFreeTextWriter:
 * @writer:  the xmlTextWriterPtr
 *
 * Deallocate all the resources associated to the writer
 */
void
xmlFreeTextWriter(xmlTextWriterPtr writer)
{
    if (writer == NULL)
        return;

    if (writer->out != NULL)
        xmlOutputBufferClose(writer->out);

    if (writer->nodes != NULL)
        xmlListDelete(writer->nodes);

    if (writer->nsstack != NULL)
        xmlListDelete(writer->nsstack);

    if (writer->ctxt != NULL) {
        if ((writer->ctxt->myDoc != NULL) && (writer->no_doc_free == 0)) {
	    xmlFreeDoc(writer->ctxt->myDoc);
	    writer->ctxt->myDoc = NULL;
	}
        xmlFreeParserCtxt(writer->ctxt);
    }

    if (writer->ichar != NULL)
        xmlFree(writer->ichar);
    xmlFree(writer);
}

/**
 * xmlTextWriterStartDocument:
 * @writer:  the xmlTextWriterPtr
 * @version:  the xml version ("1.0") or NULL for default ("1.0")
 * @encoding:  the encoding or NULL for default
 * @standalone: "yes" or "no" or NULL for default
 *
 * Start a new xml document
 *
 * Returns the bytes written (may be 0 because of buffering) or -1 in case of error