1

/*

     2

  This file is part of Beremiz, a Integrated Development Environment for

     3

  programming IEC 61131-3 automates supporting plcopen standard and CanFestival.

     4

     5

  See COPYING.runtime

     6

     7

  Copyright (C) 2018: Sergey Surkov <surkov.sv@summatechnology.ru>

     8

  Copyright (C) 2018: Andrey Skvortsov <andrej.skvortzov@gmail.com>

     9

    10

*/

    11

    12

#ifndef HAVE_RETAIN

    13

#include <stdio.h>

    14

#include <stdint.h>

    15

#include <unistd.h>

    16

#include "iec_types.h"

    17

    18

int GetRetainSize(void);

    19

    20

/* Retain buffer.  */

    21

FILE *retain_buffer;

    22

const char rb_file[] = "retain_buffer_file";

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const char rb_file_bckp[] = "retain_buffer_file.bak";

    24

    25

/* Retain header struct.  */

    26

struct retain_info_t {

    27

    uint32_t retain_size;

    28

    uint32_t hash_size;

    29

    uint8_t *hash;

    30

    uint32_t header_offset;

    31

    uint32_t header_crc;

    32

};

    33

    34

/* Init retain info structure.  */

    35

struct retain_info_t retain_info;

    36

    37

/* CRC lookup table and initial state.  */

    38

static const uint32_t crc32_table[256] = {

    39

    0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,

    40

        0xE963A535, 0x9E6495A3,

    41

    0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD,

    42

        0xE7B82D07, 0x90BF1D91,

    43

    0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB,

    44

        0xF4D4B551, 0x83D385C7,

    45

    0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,

    46

        0xFA0F3D63, 0x8D080DF5,

    47

    0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447,

    48

        0xD20D85FD, 0xA50AB56B,

    49

    0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75,

    50

        0xDCD60DCF, 0xABD13D59,

    51

    0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423,

    52

        0xCFBA9599, 0xB8BDA50F,

    53

    0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11,

    54

        0xC1611DAB, 0xB6662D3D,

    55

    0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F,

    56

        0x9FBFE4A5, 0xE8B8D433,

    57

    0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,

    58

        0x91646C97, 0xE6635C01,

    59

    0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B,

    60

        0x8208F4C1, 0xF50FC457,

    61

    0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49,

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        0x8CD37CF3, 0xFBD44C65,

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    0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7,

    64

        0xA4D1C46D, 0xD3D6F4FB,

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    0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5,

    66

        0xAA0A4C5F, 0xDD0D7CC9,

    67

    0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3,

    68

        0xB966D409, 0xCE61E49F,

    69

    0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81,

    70

        0xB7BD5C3B, 0xC0BA6CAD,

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    0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF,

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        0x04DB2615, 0x73DC1683,

    73

    0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D,

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        0x0A00AE27, 0x7D079EB1,

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    0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,

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        0x196C3671, 0x6E6B06E7,

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    0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9,

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        0x17B7BE43, 0x60B08ED5,

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    0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767,

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        0x3FB506DD, 0x48B2364B,

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    0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55,

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        0x316E8EEF, 0x4669BE79,

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    0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703,

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        0x220216B9, 0x5505262F,

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    0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31,

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        0x2CD99E8B, 0x5BDEAE1D,

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    0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F,

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        0x72076785, 0x05005713,

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    0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D,

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        0x7CDCEFB7, 0x0BDBDF21,

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    0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B,

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        0x6FB077E1, 0x18B74777,

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    0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69,

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        0x616BFFD3, 0x166CCF45,

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    0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7,

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        0x4969474D, 0x3E6E77DB,

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    0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5,

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        0x47B2CF7F, 0x30B5FFE9,

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    0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693,

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        0x54DE5729, 0x23D967BF,

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    0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1,

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        0x5A05DF1B, 0x2D02EF8D,

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};

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uint32_t retain_crc;

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   107

/* Calculate CRC32 for len bytes from pointer buf with init starting value.  */

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uint32_t GenerateCRC32Sum(const void *buf, unsigned int len, uint32_t init)

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{

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    uint32_t crc = ~init;

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    unsigned char *current = (unsigned char *)buf;

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    while (len--)

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        crc = crc32_table[(crc ^ *current++) & 0xFF] ^ (crc >> 8);

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    return ~crc;

   115

}

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/* Calc CRC32 for retain file byte by byte.  */

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int CheckFileCRC(FILE * file_buffer)

   119

{

   120

    /* Set the magic constant for one-pass CRC calc according to ZIP CRC32.  */

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    const uint32_t magic_number = 0x2144df1c;

   122

   123

    /* CRC initial state.  */

   124

    uint32_t calc_crc32 = 0;

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    char data_block = 0;

   126

   127

    while (!feof(file_buffer)) {

   128

        if (fread(&data_block, sizeof(data_block), 1, file_buffer))

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            calc_crc32 =

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                GenerateCRC32Sum(&data_block, sizeof(char), calc_crc32);

   131

    }

   132

   133

    /* Compare crc result with a magic number.  */

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    return (calc_crc32 == magic_number) ? 1 : 0;

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}

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/* Compare current hash with hash from file byte by byte.  */

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int CheckFilehash(void)

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{

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    int k, ret;

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    int offset = sizeof(retain_info.retain_size);

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    rewind(retain_buffer);

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    fseek(retain_buffer, offset, SEEK_SET);

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    uint32_t size;

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    ret = fread(&size, sizeof(size), 1, retain_buffer);

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    if (size != retain_info.hash_size)

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        return 0;

   150

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    for (k = 0; k < retain_info.hash_size; k++) {

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        uint8_t file_digit;

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        ret = fread(&file_digit, sizeof(char), 1, retain_buffer);

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        if (file_digit != *(retain_info.hash + k))

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            return 0;

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    }

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    return 1;

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}

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void InitRetain(void)

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{

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    int i;

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    /* Get retain size in bytes */

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    retain_info.retain_size = GetRetainSize();

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    /* Hash stored in retain file as array of char in hex digits

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       (that's why we divide strlen in two).  */

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    retain_info.hash_size = PLC_ID ? strlen(PLC_ID) / 2 : 0;

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    //retain_info.hash_size = 0;

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    retain_info.hash = malloc(retain_info.hash_size);

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    /* Transform hash string into byte sequence.  */

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    for (i = 0; i < retain_info.hash_size; i++) {

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        int byte = 0;

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        sscanf((PLC_ID + i * 2), "%02X", &byte);

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        retain_info.hash[i] = byte;

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    }

   180

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    /* Calc header offset.  */

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    retain_info.header_offset = sizeof(retain_info.retain_size) +

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        sizeof(retain_info.hash_size) + retain_info.hash_size;

   184

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    /*  Set header CRC initial state.  */

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    retain_info.header_crc = 0;

   187

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    /* Calc crc for header.  */

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    retain_info.header_crc = GenerateCRC32Sum(&retain_info.retain_size,

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                                              sizeof(retain_info.retain_size),

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                                              retain_info.header_crc);

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    retain_info.header_crc = GenerateCRC32Sum(&retain_info.hash_size,

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                                              sizeof(retain_info.hash_size),

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                                              retain_info.header_crc);

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    retain_info.header_crc = GenerateCRC32Sum(retain_info.hash,

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                                              retain_info.hash_size,

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                                              retain_info.header_crc);

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}

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void CleanupRetain(void)

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{

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    /* Free hash memory.  */

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    free(retain_info.hash);

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}

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int CheckRetainFile(const char *file)

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{

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    retain_buffer = fopen(file, "rb");

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    if (retain_buffer) {

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        /* Check CRC32 and hash.  */

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        if (CheckFileCRC(retain_buffer))

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            if (CheckFilehash())

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                return 1;

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        fclose(retain_buffer);

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        retain_buffer = NULL;

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    }

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    return 0;

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}

   221

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int CheckRetainBuffer(void)

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{

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    retain_buffer = NULL;

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    if (!retain_info.retain_size)

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        return 1;

   227

   228

    /* Check latest retain file.  */

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    if (CheckRetainFile(rb_file))

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        return 1;

   231

   232

    /* Check if we have backup.  */

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    if (CheckRetainFile(rb_file_bckp))

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        return 1;

   235

   236

    /* We don't have any valid retain buffer - nothing to remind.  */

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    return 0;

   238

}

   239

   240

#ifndef FILE_RETAIN_SAVE_PERIOD_S

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#define FILE_RETAIN_SAVE_PERIOD_S 1.0

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#endif

   243

   244

static double CalcDiffSeconds(IEC_TIME * t1, IEC_TIME * t2)

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{

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    IEC_TIME dt = {

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        t1->tv_sec - t2->tv_sec,

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        t1->tv_nsec - t2->tv_nsec

   249

    };

   250

   251

    if ((dt.tv_nsec < -1000000000) || ((dt.tv_sec > 0) && (dt.tv_nsec < 0))) {

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        dt.tv_sec--;

   253

        dt.tv_nsec += 1000000000;

   254

    }

   255

    if ((dt.tv_nsec > +1000000000) || ((dt.tv_sec < 0) && (dt.tv_nsec > 0))) {

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        dt.tv_sec++;

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        dt.tv_nsec -= 1000000000;

   258

    }

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    return dt.tv_sec + 1e-9 * dt.tv_nsec;

   260

}

   261

   262

int RetainSaveNeeded(void)

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{

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    int ret = 0;

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    static IEC_TIME last_save;

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    IEC_TIME now;

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    double diff_s;

   268

   269

    /* no retain */

   270

    if (!retain_info.retain_size)

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        return 0;

   272

   273

    /* periodic retain flush to avoid high I/O load */

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    PLC_GetTime(&now);

   275

   276

    diff_s = CalcDiffSeconds(&now, &last_save);

   277

   278

    if ((diff_s > FILE_RETAIN_SAVE_PERIOD_S) || ForceSaveRetainReq()) {

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        ret = 1;

   280

        last_save = now;

   281

    }

   282

    return ret;

   283

}

   284

   285

void ValidateRetainBuffer(void)

   286

{

   287

    if (!retain_buffer)

   288

        return;

   289

   290

    /* Add retain data CRC to the end of buffer file.  */

   291

    fseek(retain_buffer, 0, SEEK_END);

   292

    fwrite(&retain_crc, sizeof(uint32_t), 1, retain_buffer);

   293

   294

    /* Sync file buffer and close file.  */

   295

#ifdef __WIN32

   296

    fflush(retain_buffer);

   297

#else

   298

    fsync(fileno(retain_buffer));

   299

#endif

   300

   301

    fclose(retain_buffer);

   302

    retain_buffer = NULL;

   303

}

   304

   305

void InValidateRetainBuffer(void)

   306

{

   307

    if (!RetainSaveNeeded())

   308

        return;

   309

   310

    /* Rename old retain file into *.bak if it exists.  */

   311

    rename(rb_file, rb_file_bckp);

   312

   313

    /* Set file CRC initial value.  */

   314

    retain_crc = retain_info.header_crc;

   315

   316

    /* Create new retain file.  */

   317

    retain_buffer = fopen(rb_file, "wb+");

   318

    if (!retain_buffer) {

   319

        fprintf(stderr, "Failed to create retain file : %s\n", rb_file);

   320

        return;

   321

    }

   322

   323

    /* Write header to the new file.  */

   324

    fwrite(&retain_info.retain_size,

   325

           sizeof(retain_info.retain_size), 1, retain_buffer);

   326

    fwrite(&retain_info.hash_size,

   327

           sizeof(retain_info.hash_size), 1, retain_buffer);

   328

    fwrite(retain_info.hash,

   329

           sizeof(char), retain_info.hash_size, retain_buffer);

   330

}

   331

   332

void Retain(unsigned int offset, unsigned int count, void *p)

   333

{

   334

    if (!retain_buffer)

   335

        return;

   336

   337

    /* Generate CRC 32 for each data block.  */

   338

    retain_crc = GenerateCRC32Sum(p, count, retain_crc);

   339

   340

    /* Save current var in file.  */

   341

    fseek(retain_buffer, retain_info.header_offset + offset, SEEK_SET);

   342

    fwrite(p, count, 1, retain_buffer);

   343

}

   344

   345

void Remind(unsigned int offset, unsigned int count, void *p)

   346

{

   347

    int ret;

   348

    /* Remind variable from file.  */

   349

    fseek(retain_buffer, retain_info.header_offset + offset, SEEK_SET);

   350

    ret = fread((void *)p, count, 1, retain_buffer);

   351

}

   352

#endif                          // !HAVE_RETAIN