/*
*   $Id: sort.c 498 2007-02-17 22:43:15Z dhiebert $
*
*   Copyright (c) 1996-2002, Darren Hiebert
*
*   This source code is released for free distribution under the terms of the
*   GNU General Public License.
*
*   This module contains functions to sort the tag entries.
*/

/*
*   INCLUDE FILES
*/
#include "general.h"  /* must always come first */

#if defined (HAVE_STDLIB_H)
# include <stdlib.h>  /* to declare malloc () */
#endif
#include <string.h>
#include <stdio.h>

#include "debug.h"
#include "entry.h"
#include "options.h"
#include "read.h"
#include "routines.h"
#include "sort.h"

/*
*   FUNCTION DEFINITIONS
*/

extern void catFile (const char *const name)
{
	FILE *const fp = fopen (name, "r");

	if (fp != NULL)
	{
		int c;
		while ((c = getc (fp)) != EOF)
			CTAGSPUTCHAR (c);
		fflush (CTAGSSTDOUT);
		fclose (fp);
	}
}

#ifdef EXTERNAL_SORT

#ifdef NON_CONST_PUTENV_PROTOTYPE
# define PE_CONST
#else
# define PE_CONST const
#endif

extern void externalSortTags (const boolean toStdout)
{
	const char *const sortNormalCommand = "sort -u -o";
	const char *const sortFoldedCommand = "sort -u -f -o";
	const char *sortCommand =
		Option.sorted == SO_FOLDSORTED ? sortFoldedCommand : sortNormalCommand;
	PE_CONST char *const sortOrder1 = "LC_COLLATE=C";
	PE_CONST char *const sortOrder2 = "LC_ALL=C";
	const size_t length = 4 + strlen (sortOrder1) + strlen (sortOrder2) +
			strlen (sortCommand) + (2 * strlen (tagFileName ()));
	char *const cmd = (char *) malloc (length + 1);
	int ret = -1;

	if (cmd != NULL)
	{
		/*  Ensure ASCII value sort order.
		 */
#ifdef HAVE_SETENV
		setenv ("LC_COLLATE", "C", 1);
		setenv ("LC_ALL", "C", 1);
		sprintf (cmd, "%s %s %s", sortCommand, tagFileName (), tagFileName ());
#else
# ifdef HAVE_PUTENV
		putenv (sortOrder1);
		putenv (sortOrder2);
		sprintf (cmd, "%s %s %s", sortCommand, tagFileName (), tagFileName ());
# else
		sprintf (cmd, "%s %s %s %s %s", sortOrder1, sortOrder2, sortCommand,
				tagFileName (), tagFileName ());
# endif
#endif
		verbose ("system (\"%s\")\n", cmd);
		ret = system (cmd);
		free (cmd);

	}
	if (ret != 0)
		error (FATAL | PERROR, "cannot sort tag file");
	else if (toStdout)
		catFile (tagFileName ());
}

#else

/*
 *  These functions provide a basic internal sort. No great memory
 *  optimization is performed (e.g. recursive subdivided sorts),
 *  so have lots of memory if you have large tag files.
 */

static void failedSort (FILE *const fp, const char* msg)
{
	const char* const cannotSort = "cannot sort tag file";
	if (fp != NULL)
		fclose (fp);
	if (msg == NULL)
		error (FATAL | PERROR, cannotSort);
	else
		error (FATAL, "%s: %s", msg, cannotSort);
}

static int compareTagsFolded(const void *const one, const void *const two)
{
	const char *const line1 = *(const char* const*) one;
	const char *const line2 = *(const char* const*) two;

	return struppercmp (line1, line2);
}

static int compareTags (const void *const one, const void *const two)
{
	const char *const line1 = *(const char* const*) one;
	const char *const line2 = *(const char* const*) two;

	return strcmp (line1, line2);
}

static void writeSortedTags (
		char **const table, const size_t numTags, const boolean toStdout)
{
	FILE *fp;
	size_t i;

	/*  Write the sorted lines back into the tag file.
	 */
	if (toStdout)
		fp = CTAGSSTDOUT;
	else
	{
		fp = fopen (tagFileName (), "w");
		if (fp == NULL)
			failedSort (fp, NULL);
	}
	for (i = 0 ; i < numTags ; ++i)
	{
		/*  Here we filter out identical tag *lines* (including search
		 *  pattern) if this is not an xref file.
		 */
		if (i == 0  ||  Option.xref  ||  strcmp (table [i], table [i-1]) != 0)
			if (fputs (table [i], fp) == EOF)
				failedSort (fp, NULL);
	}
	if (toStdout)
		fflush (fp);
	else
		fclose (fp);
}

extern void internalSortTags (const boolean toStdout)
{
	vString *vLine = vStringNew ();
	FILE *fp = NULL;
	const char *line;
	size_t i;
	int (*cmpFunc)(const void *, const void *);

	/*  Allocate a table of line pointers to be sorted.
	 */
	size_t numTags = TagFile.numTags.added + TagFile.numTags.prev;
	const size_t tableSize = numTags * sizeof (char *);
	char **const table = (char **) malloc (tableSize);  /* line pointers */
	DebugStatement ( size_t mallocSize = tableSize; )  /* cumulative total */


	cmpFunc = Option.sorted == SO_FOLDSORTED ? compareTagsFolded : compareTags;
	if (table == NULL)
		failedSort (fp, "out of memory");

	/*  Open the tag file and place its lines into allocated buffers.
	 */
	fp = fopen (tagFileName (), "r");
	if (fp == NULL)
		failedSort (fp, NULL);
	for (i = 0  ;  i < numTags  &&  ! feof (fp)  ;  )
	{
		line = readLine (vLine, fp);
		if (line == NULL)
		{
			if (! feof (fp))
				failedSort (fp, NULL);
			break;
		}
		else if (*line == '\0'  ||  strcmp (line, "\n") == 0)
			;  /* ignore blank lines */
		else
		{
			const size_t stringSize = strlen (line) + 1;

			table [i] = (char *) malloc (stringSize);
			if (table [i] == NULL)
				failedSort (fp, "out of memory");
			DebugStatement ( mallocSize += stringSize; )
			strcpy (table [i], line);
			++i;
		}
	}
	numTags = i;
	fclose (fp);
	vStringDelete (vLine);

	/*  Sort the lines.
	 */
	qsort (table, numTags, sizeof (*table), cmpFunc);

	writeSortedTags (table, numTags, toStdout);

	PrintStatus (("sort memory: %ld bytes\n", (long) mallocSize));
	for (i = 0 ; i < numTags ; ++i)
		free (table [i]);
	free (table);
}

#endif

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