stream.c

/**
 * @file
 *
 * @brief
 *
 * @copyright BSD License (see LICENSE.md or https://www.libelektra.org)
 */

#include "xmltool.h"

#ifdef HAVE_KDBCONFIG_H
#include "kdbconfig.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#include "kdbtools.h"
#include <kdbinternal.h>


/**
 * @brief Methods to output, generate and toXML Keys and Keysets.
 *
 * Here are some functions that are in a separate library because they
 * depend on non-basic libraries as libxml. Link against kdbtools library if your
 * program won't be installed in /bin, or is not essential in early boot
 * stages.
 *
 * It is also possible to have a dynamic linkage, see the
 * sourcecode from kdb-tool or testing framework how to achieve
 * that.
 *
 * Output prints keys line per line, meant to be read by humans.
 * - keyOutput()
 * - ksOutput()
 *
 * toXML prints keys and keysets as XML, meant to be used
 * as exchange format.
 * - keyToStream()
 * - ksToStream()
 *
 * To use them:
 * @code
#include <kdbtools.h>
 * @endcode
 *
 *
 */


/*********************************************
 *    Textual XML methods                    *
 *********************************************/


/**
 * Prints an XML representation of the key.
 *
 * String generated is of the form:
 * @verbatim
	<key name="system:/sw/xorg/Monitor/Monitor0/Name"
		type="string" uid="root" gid="root" mode="0600">

		<value>Samsung TFT panel</value>
		<comment>My monitor</comment>
	</key>@endverbatim



 * @verbatim
	<key parent="system:/sw/xorg/Monitor/Monitor0" basename="Name"
		type="string" uid="root" gid="root" mode="0600">

		<value>Samsung TFT panel</value>
		<comment>My monitor</comment>
	</key>@endverbatim
 *
 * @param key the key object to work with
 * @param stream where to write output: a file or stdout
 * @param options Some #KDBStream ORed:
 * - @p KDBStream::KDB_O_NUMBERS \n
 *   Do not convert UID and GID into user and group names
 * - @p KDBStream::KDB_O_CONDENSED \n
 *   Less human readable, more condensed output
 * - @p KDBStream::KDB_O_FULLNAME \n
 *   The @p user keys are exported with their full names (including
 *   user domains)
 *
 * @see ksToStream()
 * @return number of bytes written to output
 */
ssize_t keyToStream (const Key * key, FILE * stream, KDBStream options)
{
	return keyToStreamBasename (key, stream, 0, 0, options);
}


/**
 * Same as keyToStream() but tries to strip @p parentSize bytes from
 * @p key name if it matches @p parent .
 *
 * Taking the example from keyToStream(), if @p parent is
 * @c "system:/sw/xorg", the generated string is of the form:
 * @verbatim
	<key basename="Monitor/Monitor0/Name"
		type="string" uid="root" gid="root" mode="0600">

		<value>Samsung TFT panel</value>
		<comment>My monitor</comment>
	</key>@endverbatim
 *
 * It useful to produce more human readable XML output of a key when
 * it is being represented in a context that defines the parent key name.
 * For example:
 *
 * @verbatim
	<keyset parent="user:/sw">
		<key basename="kdbedit"..../>
		<key basename="phototools"..../>
		<key basename="myapp"..../>
	</keyset>@endverbatim
 *
 * In the above example, each @p @<key@> entry was generated by a call to
 * keyToStreamBasename() having @c "user:/sw" as @p parent .
 *
 * This method is used when ksToStream() is called with
 * KDBOption::KDB_O_HIER option.
 *
 * @param key the key object to work with
 * @param stream the FILE where to send the stream
 * @param parentSize the maximum size of @p parent that will be used.
 *        If 0, the entire @p parent will be used.
 * @param parent the string (or part of it, defined by @p parentSize ) that
 *        will be used to strip from the key name.
 * @param options Some #KDBStream ORed:
 * - @p KDBStream::KDB_O_NUMBERS \n
 *   Do not convert UID and GID into user and group names
 * - @p KDBStream::KDB_O_CONDENSED \n
 *   Less human readable, more condensed output
 * - @p KDBStream::KDB_O_FULLNAME \n
 *   The @p user keys are exported with their full names (including
 *   user domains)
 *
 * @return number of bytes written to output
 */
ssize_t keyToStreamBasename (const Key * key, FILE * stream, const char * parent, const size_t parentSize, KDBStream options)
{
	ssize_t written = 0;

	/* Write key name */
	if (parent)
	{
		/* some logic to see if we should print only the relative basename */
		int found;
		size_t skip = parentSize ? parentSize : elektraStrLen (parent) - 1;

		found = memcmp (parent, key->key, skip);
		if (found == 0)
		{
			while (*(key->key + skip) == KDB_PATH_SEPARATOR)
				++skip;

			if (*(key->key + skip) != 0) /* we don't want a null basename */
				written += fprintf (stream, "<key basename=\"%s\"", key->key + skip);
		}
	}

	if (written == 0)
	{ /* no "<key basename=..." was written so far */
		if (options & KDB_O_FULLNAME)
		{
			char buffer[KDB_MAX_PATH_LENGTH];
			keyGetName (key, buffer, sizeof (buffer));
			written += fprintf (stream, "<key name=\"%s\"", buffer);
		}
		else
			written += fprintf (stream, "<key name=\"%s\"", key->key);
	}

	if (!key->data.v && !keyComment (key))
	{ /* no data AND no comment */
		written += fprintf (stream, "/>");
		if (!(options & KDB_O_CONDENSED)) written += fprintf (stream, "\n\n");

		return written; /* end of <key/> */
	}
	else
	{
		if (key->data.v)
		{
			if ((key->dataSize <= 16) && keyIsString (key) && /*TODO: is this for string?*/
			    !strchr (key->data.c, '\n'))
			{

				/* we'll use a "value" attribute instead of a <value> node,
				   for readability, so the cut size will be 16, which is
				   the maximum size of an IPv4 address */

				if (options & KDB_O_CONDENSED)
					written += fprintf (stream, " ");
				else
					written += fprintf (stream, "\n\t");

				written += fprintf (stream, "value=\"%s\"", key->data.c);

				if (keyComment (key))
					written += fprintf (stream, ">\n");
				else
				{
					written += fprintf (stream, "/>");
					if (!(options & KDB_O_CONDENSED)) written += fprintf (stream, "\n");

					return written;
				}
			}
			else
			{ /* value is bigger than 16 bytes: deserves own <value> */
				written += fprintf (stream, ">");
				if (!(options & KDB_O_CONDENSED)) written += fprintf (stream, "\n\n     ");

				written += fprintf (stream, "<value>");
				if (keyIsString (key))
				{ /*TODO: is this for string?*/
					written += fprintf (stream, "<![CDATA[");
					fflush (stream);
					/* must chop ending \\0 */
					written += fwrite (key->data.v, sizeof (char), key->dataSize - 1, stream);
					written += fprintf (stream, "]]>");
				}
				else
				{
					/* TODO Binary values
					char *encoded=elektraMalloc(3*key->dataSize);
					size_t encodedSize;

					written+=fprintf(stream,"\n");
					encodedSize=kdbbEncode(key->data.c,key->dataSize,encoded);
					fflush(stream);
					written+=fwrite(encoded,sizeof(char),encodedSize,stream);
					elektraFree (encoded);
					written+=fprintf(stream,"\n");
					*/
				}
				/* fflush(stream); */
				written += fprintf (stream, "</value>");
			}
		}
		else
		{ /* we have no data */
			if (keyComment (key))
			{
				written += fprintf (stream, ">");
				if (!(options & KDB_O_CONDENSED)) written += fprintf (stream, "\n");
			}
			else
			{
				written += fprintf (stream, "/>");
				if (!(options & KDB_O_CONDENSED)) written += fprintf (stream, "\n\n");

				return written;
			}
		}
	}

	if (!(options & KDB_O_CONDENSED))
	{
		written += fprintf (stream, "\n");
		if (keyComment (key)) written += fprintf (stream, "     ");
	}

	if (keyComment (key))
	{
		written += fprintf (stream, "<comment><![CDATA[%s]]></comment>", keyComment (key));
		if (!(options & KDB_O_CONDENSED)) written += fprintf (stream, "\n");
	}

	written += fprintf (stream, "</key>");

	if (!(options & KDB_O_CONDENSED)) written += fprintf (stream, "\n\n");

	return written;
}

/**
 * Writes to @p stream an XML version of the @p ks object.
 *
 * String generated is of the form:
 * @verbatim
<keyset>
<key name=...>...</key>
<key name=...>...</key>
<key name=...>...</key>

</keyset>
 * @endverbatim
 *
 * or if KDB_O_HIER is used, the form will be:
 * @verbatim
<keyset parent="user:/smallest/parent/name">

<key basename=...>...</key>
<key name=...>...</key> <!-- a key thats not under this keyset's parent -->
<key basename=...>...</key>

</keyset>
 * @endverbatim
 *
 * KDB_O_HEADER will additionally generate a header like:
 * @verbatim
<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated by Elektra API. Total of n keys. -->
<keyset xmlns="https://www.libelektra.org"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="https://www.libelektra.org elektra.xsd">
 * @endverbatim
 *
 * @param ks the KeySet to serialise
 * @param stream where to write output: a file or stdout
 * @param options accepted #KDBStream ORed:
 * - @p KDBStream::KDB_O_NUMBERS \n
 *   Do not convert UID and GID into user and group names.
 * - @p KDBStream::KDB_O_FULLNAME \n
 *   The @c user keys are exported with their full names (including
 *   user domains)
 * - @p KDBStream::KDB_O_CONDENSED \n
 *   Less human readable, more condensed output.
 * - @p KDBStream::KDB_O_XMLHEADERS \n
 *   Exclude the correct XML headers in the output. If not used, the
 *   &lt;?xml?&gt; and schema info inside the &lt;keyset&gt; object will not be generated.
 * - @p KDBStream::KDB_O_HIER \n
 *   Will generate a &lt;keyset&gt; node containing a @c parent attribute, and
 *   &lt;key&gt; nodes with a @c basename relative to that @c parent. The @c parent
 *   is calculated by taking the smallest key name in the keyset, so it is a
 *   good idea to have only related keys on the keyset. Otherwise, a valid
 *   consistent XML document still will be generated with regular absolute
 *   @c name attribute for the &lt;key&gt; nodes, due to a
 *   clever keyToStreamBasename() implementation.
 *
 * @see keyToStream()
 * @see commandList() for usage example
 * @return number of bytes written to output, or -1 if some error occurs
 * @param ks The keyset to output
 * @param stream the file pointer where to send the stream
 * @param options see above text
 */
ssize_t ksToStream (const KeySet * ks, FILE * stream, KDBStream options)
{
	size_t written = 0;
	Key * key = 0;
	KeySet * cks = ksDup (ks);

	if (options & KDB_O_HEADER)
	{
		written += fprintf (stream, "<?xml version=\"1.0\" encoding=\"%s\"?>", "UTF-8");
		if (~options & KDB_O_CONDENSED)
			written += fprintf (stream, "\n<!-- Generated by Elektra API. Total of %d keys. -->\n", (int) cks->size);
		if (~options & KDB_O_CONDENSED)
			written += fprintf (stream,
					    "<keyset xmlns=\"https://www.libelektra.org\"\n"
					    "\txmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"\n"
					    "\txsi:schemaLocation=\"https://www.libelektra.org elektra.xsd\"\n");
		else
			written += fprintf (stream,
					    "<keyset xmlns=\"https://www.libelektra.org\""
					    " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""
					    " xsi:schemaLocation=\"https://www.libelektra.org elektra.xsd\"");
	}
	else
		written += fprintf (stream, "<keyset");

	if (options & KDB_O_HIER)
	{
		char commonParent[KDB_MAX_PATH_LENGTH];

		ksGetCommonParentName (cks, commonParent, sizeof (commonParent));

		if (commonParent[0])
		{
			written += fprintf (stream, "        parent=\"%s\">\n", commonParent);

			for (elektraCursor it = 0; it < ksGetSize (cks); ++it)
			{
				key = ksAtCursor (cks, it);
				written += keyToStreamBasename (key, stream, commonParent, 0, options);
			}
		}
		else
		{
			written += fprintf (stream, ">\n");

			for (elektraCursor it = 0; it < ksGetSize (cks); ++it)
			{
				key = ksAtCursor (cks, it);
				written += keyToStream (key, stream, options);
			}
		}
	}
	else
	{ /* No KDB_O_HIER*/
		written += fprintf (stream, ">\n");

		for (elektraCursor it = 0; it < ksGetSize (cks); ++it)
		{
			key = ksAtCursor (cks, it);
			written += keyToStream (key, stream, options);
		}
	}

	written += fprintf (stream, "</keyset>\n");
	ksDel (cks);
	return written;
}

/**
 * Output every information of a single key depending on options.
 *
 * The format is not very strict and only intend to be read
 * by human eyes for debugging purposes. Don't rely on the
 * format in your applications.
 *
 * @param k the key object to work with
 * @param stream the file pointer where to send the stream
 * @param options see text above
 * @see ksOutput()
 * @retval 1 on success
 * @retval -1 on allocation errors
 * @ingroup stream
 */
int keyOutput (const Key * k, FILE * stream, KDBStream options)
{
	size_t s, c, n;

	n = keyGetNameSize (k);
	if (n > 1)
	{
		char * nam = (char *) elektraMalloc (n);
		if (nam == NULL) return -1;
		keyGetName (k, nam, n);

		fprintf (stream, "Name[%d]: %s : ", (int) n, nam);

		elektraFree (nam);
	}

	s = keyGetValueSize (k);
	if (options & KEY_VALUE && s > 1)
	{
		char * str = (char *) elektraMalloc (s);
		if (str == NULL) return -1;
		if (keyIsBinary (k))
		{
			/*
			char * bin;
			bin = (char*) elektraMalloc (s*3+1);
			keyGetBinary(k, str, s);
			kdbbEncode (str, s, bin);
			elektraFree (bin);
			*/
			keyGetBinary (k, str, s);
			fprintf (stream, "Binary[%d]: %s : ", (int) s, str);
		}
		else
		{
			keyGetString (k, str, s);
			fprintf (stream, "String[%d]: %s : ", (int) s, str);
		}

		elektraFree (str);
	}

	c = keyGetCommentSize (k);
	if (options & KEY_META && c > 1)
	{
		char * com = (char *) elektraMalloc (c);
		if (com == NULL) return -1;
		keyGetComment (k, com, c);

		fprintf (stream, "Comment[%d]: %s : ", (int) c, com);

		elektraFree (com);
	}


	if (options & KDB_O_SHOWMETA) fprintf (stream, " : ");

	if (options & KDB_O_SHOWFLAGS)
	{
		if (!(options & KDB_O_SHOWMETA)) fprintf (stream, " ");
		fprintf (stream, "Flags: ");
		if (keyIsBinary (k)) fprintf (stream, "b");
		if (keyIsString (k)) fprintf (stream, "s");
		if (keyNeedSync (k)) fprintf (stream, "s");
	}

	fprintf (stream, "\n");
	return 1;
}


/**
 * Output all information of a keyset.
 *
 * The format is not very strict and only intend to be read
 * by human eyes for debugging purposes. Don't rely on the
 * format in your applications.
 *
 * Keys are printed line per line with keyOutput().
 *
 * The same options as keyOutput() are taken and passed
 * to them.
 *
 * Additional KDB_O_HEADER will print the number of keys
 * as first line.
 *
 * @param ks the keyset to work with
 * @param stream the file pointer where to send the stream
 * @param options
 * @see keyOutput()
 * @retval 1 on success
 * @retval -1 on allocation errors
 * @ingroup stream
 */
int ksOutput (const KeySet * ks, FILE * stream, KDBStream options)
{
	Key * key;
	KeySet * cks = ksDup (ks);
	size_t size = 0;

	if (KDB_O_HEADER & options)
	{
		fprintf (stream, "Output keyset of size %d\n", (int) ksGetSize (cks));
	}

	for (elektraCursor it = 0; it < ksGetSize (cks); ++it)
	{
		key = ksAtCursor (cks, it);
		if (options & KDB_O_SHOWINDICES) fprintf (stream, "[%d] ", (int) size);
		keyOutput (key, stream, options);
		size++;
	}

	ksDel (cks);
	return 1;
}