td512.h

//  td512.h
//  high-speed lossless tiny data compression of 1 to 512 bytes
//
//  Created by L. Stevan Leonard on 10/31/21.
//  Copyright © 2021-2022 L. Stevan Leonard. All rights reserved.
/*
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.
 
 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
 
 You should have received a copy of the GNU General Public License
 along with this program. If not, see <https://www.gnu.org/licenses/>.
 */
// Notes for version 2.1.1:
/*
 1. In td512.c, for 128 and more values, text and extended string modes
    are called for checked data. For other data, and for any remaining values
    from calls for 128 or more values, td64 is called.
    A minimum of 16 characters are compressed.
 2. In tdString.c, extended string mode was modified to stop on the 65th
    unique value. This value is the last value output and the number
    of values at that point is returned.
 3. In main.c, after decompression, the input file is verified against
    the decompressed output file.
*/
// Notes for version 2.1.2:
/*
 1. In tdString.c, make the definition of string length and associated
    number of bits based on number of input values. For <= 64 values,
    length is 9 and bits are 3. For > 64 values, length is 17 and
    bits are 4. Longer strings are likely to be found in larger data sets.
 */
// Notes for version 2.1.3:
/*
 1. In td512.c, modified checktd64 to use the output of td64 call when possible.
 2. In td64.c, changed decodeAdaptiveTextMode to use arrays of bit positions and bits taken to maximize execution speed.
 */
// Notes for version 2.1.4:
/*
 1. In tdstring.c, extended string mode, continue processing after 64 unique values encountered for up to 64 additional non-unique values that are output as if they are unique values but are not indexed for string matching. The initial 64 unique values continue to be used. This improves compression for files with larger numbers of unique values, and reduces compression for some other files. The net result is better average compression.
 */
// Notes for version 2.1.5:
/*
 1. In tdstring.c, implemented 64-bit output of encoded values to improve compression speed.
 */
// Notes for version 2.1.6:
/*
 1. In td512.c, modified checkTextMode to return a code that causes use of extended string mode and improves compression speed. Also added ' (quote) to the text chars array.
 2. In td512.c, modified checktd64 (name change from checkSingleValueMode) to return a code for expected random data to be processed as a failing block of 64 bytes in the same way that td64 would handle this block.
 3. In td64.c, modified decodeAdaptiveTextMode to read one byte ahead to improve speed of processing dtbmPeekBits. This change can require one byte read beyond length of input array.
 */
// Notes for version 2.1.7:
/*
 1. In main.c, changed benchmarking to have max of 2000 external loops under timer with remaining loops run inside timer.
 2. In td64.c, decodeAdaptiveTextMode, made dtbmThisVal internal to function rather than static global. Added a read-ahead byte so that peaking at bits does not require an extra read. The read-ahead means main loop must stop three values early to avoid reading beyond end of input values, and those three values must be processed without read-ahead.
 3. In td64.c, decodeStringMode, made dsmThisVal internal to function rather than static global.
 */
// Notes for version 2.1.8:
/*
 1. In tdString.c, moved the inline functions for bit output to td64_internal.h where they can also be used by functions in td64.c.
 2. In td64.c, implemented bit output improvements for encode AdaptiveTextMode and encodeStringMode.
 */
#ifndef td512_h
#define td512_h

#include "td64.h"
#include "tdString.h"
#include <unistd.h>

#define TD512_VERSION "v2.1.7"
#define MIN_VALUES_EXTENDED_MODE 128
#define MIN_UNIQUES_SINGLE_VALUE_MODE_CHECK 14
#define MIN_VALUES_TO_COMPRESS 16
//#define TD512_TEST_MODE // enable this macro to generate statistics

extern const uint32_t predefinedBitTextChars[256];

int32_t td512(const unsigned char *inVals, unsigned char *outVals, const uint32_t nValues);
int32_t td512d(const unsigned char *inVals, unsigned char *outVals, uint32_t *totalBytesProcessed);

#endif /* td512_h */