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

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#ifndef HAVE_RETAIN

    13

#include <stdio.h>

    14

#include <stdint.h>

    15

#include <unistd.h>

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#include "iec_types.h"

    17

    18

int GetRetainSize(void);

    19

    20

/* Retain buffer.  */

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FILE *retain_buffer;

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const char rb_file[]      = "retain_buffer_file";

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

    24

    25

    26

/* Retain header struct.  */

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struct retain_info_t {

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	uint32_t retain_size;

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	uint32_t hash_size;

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	uint8_t* hash;

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	uint32_t header_offset;

    32

	uint32_t header_crc;

    33

};

    34

    35

/* Init retain info structure.  */

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struct retain_info_t retain_info;

    37

    38

/* CRC lookup table and initial state.  */

    39

static const uint32_t crc32_table[256] = {

    40

	0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3,

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	0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91,

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	0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,

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	0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5,

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	0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B,

    45

	0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,

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	0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,

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	0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D,

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	0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,

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	0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01,

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	0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457,

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	0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,

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	0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB,

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	0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9,

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	0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,

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	0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD,

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	0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683,

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	0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,

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	0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7,

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	0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5,

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	0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,

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	0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79,

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	0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,

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	0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,

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	0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713,

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	0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21,

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	0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,

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	0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45,

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	0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB,

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	0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,

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	0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,

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	0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D,

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};

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uint32_t retain_crc;

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/* 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;

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}

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

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int CheckFileCRC(FILE* file_buffer)

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{

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

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	const uint32_t magic_number = 0x2144df1c;

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	/* CRC initial state.  */

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	uint32_t calc_crc32 = 0;

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	char data_block = 0;

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	while(!feof(file_buffer)){

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

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

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	}

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	/* 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;

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

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	if (size != retain_info.hash_size)

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		return 0;

   118

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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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		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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	}

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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) + \

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		retain_info.hash_size;

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	/*  Set header CRC initial state.  */

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	retain_info.header_crc = 0;

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	/* Calc crc for header.  */

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	retain_info.header_crc = GenerateCRC32Sum(

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		&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(

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		&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(

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		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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}

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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;

   199

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	/* Check latest retain file.  */

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	if (CheckRetainFile(rb_file))

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		return 1;

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	/* Check if we have backup.  */

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	if (CheckRetainFile(rb_file_bckp))

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		return 1;

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

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	return 0;

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}

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#ifndef FILE_RETAIN_SAVE_PERIOD_S

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#define FILE_RETAIN_SAVE_PERIOD_S 1.0

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#endif

   215

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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

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	};

   222

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	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;

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	}

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	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;

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	}

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

   232

}

   233

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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;

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	/* no retain */

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	if (!retain_info.retain_size)

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		return 0;

   245

   246

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

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	PLC_GetTime(&now);

   248

   249

	diff_s = CalcDiffSeconds(&now, &last_save);

   250

   251

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

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		ret = 1;

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		last_save = now;

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	}

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	return ret;

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}

   257

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void ValidateRetainBuffer(void)

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{

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	if (!retain_buffer)

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		return;

   262

   263

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

   264

	fseek(retain_buffer, 0, SEEK_END);

   265

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

   266

   267

	/* Sync file buffer and close file.  */

   268

#ifdef __WIN32

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	fflush(retain_buffer);

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#else

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	fsync(fileno(retain_buffer));

   272

#endif

   273

   274

	fclose(retain_buffer);

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	retain_buffer = NULL;

   276

}

   277

   278

void InValidateRetainBuffer(void)

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{

   280

	if (!RetainSaveNeeded())

   281

		return;

   282

   283

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

   284

	rename(rb_file, rb_file_bckp);

   285

   286

	/* Set file CRC initial value.  */

   287

	retain_crc = retain_info.header_crc;

   288

   289

	/* Create new retain file.  */

   290

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

   291

	if (!retain_buffer) {

   292

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

   293

		return;

   294

	}

   295

   296

	/* Write header to the new file.  */

   297

	fwrite(&retain_info.retain_size,

   298

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

   299

	fwrite(&retain_info.hash_size,

   300

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

   301

	fwrite(retain_info.hash ,

   302

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

   303

}

   304

   305

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

   306

{

   307

	if (!retain_buffer)

   308

		return;

   309

   310

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

   311

	retain_crc = GenerateCRC32Sum(p, count, retain_crc);

   312

   313

	/* Save current var in file.  */

   314

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

   315

	fwrite(p, count, 1, retain_buffer);

   316

}

   317

   318

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

   319

{

   320

	/* Remind variable from file.  */

   321

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

   322

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

   323

}

   324

#endif // !HAVE_RETAIN