dcc/tools/readsig/readsig.cpp

/* Quick program to read the output from makedsig */

#include <stdio.h>
#include <io.h>
#include <stdlib.h>
#include <memory.h>
#include <string.h>
#include "perfhlib.h"

/* statics */
byte buf[100];
int	numKeys;			/* Number of hash table entries (keys) */
int numVert;			/* Number of vertices in the graph (also size of g[]) */
int PatLen;				/* Size of the keys (pattern length) */
int SymLen;				/* Max size of the symbols, including null */
FILE *f;				/* File being read */

static	word	*T1base, *T2base;	/* Pointers to start of T1, T2 */
static	word	*g;					/* g[] */

/* prototypes */
void grab(int n);
word readFileShort(void);
void cleanup(void);

static bool bDispAll = FALSE;

void
main(int argc, char *argv[])
{
	word w, len;
	int h, i, j;
	long filePos;

	if (argc <= 1)
	{
		printf("Usage: readsig [-a] <SigFilename>\n");
		printf("-a for all symbols (else just duplicates)\n");
		exit(1);
	}

	i = 1;

	if (strcmp(argv[i], "-a") == 0)
	{
		i++;
		bDispAll = TRUE;
	}
	if ((f = fopen(argv[i], "rb")) == NULL)
	{
		printf("Cannot open %s\n", argv[i]);
		exit(2);
	}

	/* Read the parameters */
	grab(4);
	if (memcmp("dccs", buf, 4) != 0)
	{
		printf("Not a dccs file!\n");
		exit(3);
	}
	numKeys = readFileShort();
	numVert = readFileShort();
	PatLen = readFileShort();
	SymLen = readFileShort();

	/* Initialise the perfhlib stuff. Also allocates T1, T2, g, etc */
	hashParams(						/* Set the parameters for the hash table */
		numKeys,					/* The number of symbols */
		PatLen,						/* The length of the pattern to be hashed */
		256,						/* The character set of the pattern (0-FF) */
		0,							/* Minimum pattern character value */
		numVert);					/* Specifies C, the sparseness of the graph.
										See Czech, Havas and Majewski for details
									*/

	T1base	= readT1();
	T2base	= readT2();
	g		= readG();

	/* Read T1 and T2 tables */
	grab(2);
	if (memcmp("T1", buf, 2) != 0)
	{
		printf("Expected 'T1'\n");
		exit(3);
	}
	len = PatLen * 256 * sizeof(word);
	w = readFileShort();
	if (w != len)
	{
		printf("Problem with size of T1: file %d, calc %d\n", w, len);
		exit(4);
	}
	if (fread(T1base, 1, len, f) != len)
	{
		printf("Could not read T1\n");
		exit(5);
	}

	grab(2);
	if (memcmp("T2", buf, 2) != 0)
	{
		printf("Expected 'T2'\n");
		exit(3);
	}
	w = readFileShort();
	if (w != len)
	{
		printf("Problem with size of T2: file %d, calc %d\n", w, len);
		exit(4);
	}
	if (fread(T2base, 1, len, f) != len)
	{
		printf("Could not read T2\n");
		exit(5);
	}

	/* Now read the function g[] */
	grab(2);
	if (memcmp("gg", buf, 2) != 0)
	{
		printf("Expected 'gg'\n");
		exit(3);
	}
	len = numVert * sizeof(word);
	w = readFileShort();
	if (w != len)
	{
		printf("Problem with size of g[]: file %d, calc %d\n", w, len);
		exit(4);
	}
	if (fread(g, 1, len, f) != len)
	{
		printf("Could not read T2\n");
		exit(5);
	}


	/* This is now the hash table */
	grab(2);
	if (memcmp("ht", buf, 2) != 0)
	{
		printf("Expected 'ht'\n");
		exit(3);
	}
	w = readFileShort();
	if (w != numKeys * (SymLen + PatLen + sizeof(word)))
	{
		printf("Problem with size of hash table: file %d, calc %d\n", w, len);
		exit(6);
	}

	if (bDispAll)
	{
		fseek(f, 0, SEEK_CUR);		/* Needed due to bug in MS fread()! */
		filePos = _lseek(fileno(f), 0, SEEK_CUR);
		for (i=0; i < numKeys; i++)
		{
			grab(SymLen + PatLen);

			printf("%16s ", buf);
			for (j=0; j < PatLen; j++)
			{
				printf("%02X", buf[SymLen+j]);
				if ((j%4) == 3) printf(" ");
			}
			printf("\n");
		}
		printf("\n\n\n");
		fseek(f, filePos, SEEK_SET);
	}

	for (i=0; i < numKeys; i++)
	{
		grab(SymLen + PatLen);

		h = hash(&buf[SymLen]);
		if (h != i)
		{
			printf("Symbol %16s (index %3d) hashed to %d\n",
				buf, i, h);
		}
	}

	printf("Done!\n");
	fclose(f);

}


void
cleanup(void)
{
	/* Free the storage for variable sized tables etc */
	if (T1base)	free(T1base);
	if (T2base)	free(T2base);
	if (g) free(g);
}

void grab(int n)
{
	if (fread(buf, 1, n, f) != (size_t)n)
	{
		printf("Could not read\n");
		exit(11);
	}
}

word
readFileShort(void)
{
	byte b1, b2;

	if (fread(&b1, 1, 1, f) != 1)
	{
		printf("Could not read\n");
		exit(11);
	}
	if (fread(&b2, 1, 1, f) != 1)
	{
		printf("Could not read\n");
		exit(11);
	}
	return (b2 << 8) + b1;
}

/* Following two functions not needed unless creating tables */

void getKey(int i, byte **keys)
{
}

/* Display key i */
void
dispKey(int i)
{
}