encoding.h

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/* Copyright (C) 2015-2017 Chris Piker <chris-piker@uiowa.edu>
 *
 * This file is part of libdas2, the Core Das2 C Library.
 * 
 * Libdas2 is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License version 2.1 as published
 * by the Free Software Foundation.
 *
 * Libdas2 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 Lesser General Public License for
 * more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 2.1 along with libdas2; if not, see <http://www.gnu.org/licenses/>. 
 */


#ifndef _das_encoding_h_
#define _das_encoding_h_

#include <das2/util.h>
#include <das2/units.h>
#include <das2/buffer.h>

#ifdef __cplusplus
extern "C" {
#endif

double getDas2Fill(void);

int isDas2Fill( double value );


/* Most Significant byte First (big-endian) IEEE-754 reals */
#define DAS2DT_BE_REAL 0x0001

/* Most Significant byte last (little-endian) IEEE-754 reals */
#define DAS2DT_LE_REAL 0x0002

#ifdef HOST_IS_LSB_FIRST
#define DAS2DT_HOST_REAL 0x0002
#else
#define DAS2DT_HOST_REAL 0x0001
#endif

/* A real number formatted in some number of characters.
 * Conventionally there are a whitespace characters to improve readability,
 * but this is not required.  The formatted number should be parsable by 
 * scanf in C, readf in IDL, or Double.parseDouble in java.
 */
#define DAS2DT_ASCII 0x0003

/* A date-time formatted as an ASCII ISO-8601 string.
 * Actually any time that is parseable by the parsetime routine will work
 * Generally if a human can read it, it's parseable. For example, 
 * YYYY-MM-DDThh:mm:ss.mmmZ.
 */
#define DAS2DT_TIME 0x0004

/* Most Significant byte First (big-endian) signed integers */
#define DAS2DT_BE_INT 0x0005

/* Most Significant byte last (little-endian) signed integers */
#define DAS2DT_LE_INT 0x0006

/* Most Significant byte First (big-endian) un-signed integers */
#define DAS2DT_BE_UINT 0x0007

/* Most Significant byte last (little-endian) un-signed integers */
#define DAS2DT_LE_UINT 0x0008

#define DASENC_FMT_LEN  64
#define DASENC_TYPE_LEN 48


typedef struct das_encoding{
   unsigned int nCat;
   
   unsigned int nWidth;
   
   char sFmt[DASENC_FMT_LEN];
   
   char sType[DASENC_TYPE_LEN];
   
} DasEncoding;

DasEncoding* new_DasEncoding(int nCat, int nWidth, const char* sFmt);

DasEncoding* new_DasEncoding_str(const char* sType);


DasEncoding* DasEnc_copy(DasEncoding* pThis);


bool DasEnc_equals(const DasEncoding* pOne, const DasEncoding* pTwo);

void DasEnc_setAsciiFormat(DasEncoding* pThis, const char* sValFmt, 
                           int nFmtWidth);


void DasEnc_setTimeFormat(DasEncoding* pThis, const char* sTimeFmt, 
                           int nFmtWidth);


/* More explicit indication of a big-endian 8-byte number */
#define DAS2DT_BE_REAL_8 0x0801

/* little-endian (least significant byte first) 8-byte real */
#define DAS2DT_LE_REAL_8 0x0802

/* 8-byte real number, in host byte order */
#ifdef HOST_IS_LSB_FIRST
#define DAS2DT_DOUBLE 0x0802
#else
#define DAS2DT_DOUBLE 0x0801
#endif

/* More explicit indication of a big-endian 4-byte number */
#define DAS2DT_BE_REAL_4 0x0401

/* little-endian (least significant byte first) 4-byte real */
#define DAS2DT_LE_REAL_4 0x0402


#ifdef HOST_IS_LSB_FIRST
#define DAS2DT_FLOAT 0x0402
#else
#define DAS2DT_FLOAT 0x0401
#endif

/* Legacy specific width encoding */
#define DAS2DT_ASCII_10 0x0A03
#define DAS2DT_ASCII_24 0x1804 
#define DAS2DT_ASCII_14 0x0E04

#define DAS2DT_TIME_25 0x1904   
#define DAS2DT_TIME_28 0x1c04   


unsigned int DasEnc_hash(const DasEncoding* pThis);


DasErrCode DasEnc_toStr(DasEncoding* pThis, char* sType, size_t nLen);


DasErrCode DasEnc_write(DasEncoding* pThis, DasBuf* pBuf, double value,
                       das_units units);


/*  (Not Implemented)
 * Encode and write a value to a buffer.
 * 
 * Similar to DasEnc_write except this version outputs to a DasBuf object.
 * 
 * @param pThis the DasEncoding object to handle the translation
 * @param pBuf the buffer to receive the encoded bytes
 * @param value the numeric value to write
 * @param units Handles scaling and offset of values if needed.
 * 
 * @returns 0 on success, a positive error code on failure.
 * @memberof DasEncoding
 */
/* ErrorCode DasEnc_encode(
   DasEncoding* pThis, DasBuf* pBuf, double value, UnitType units
); */

DasErrCode DasEnc_read(
   const DasEncoding* pThis, DasBuf* pBuf, das_units units, double* pOut
);

#ifdef __cplusplus
}
#endif

#endif /* _das_encoding_h_ */