fx_fault_tolerant_calculate_checksum.c
| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /*************************************************************************** | ||
| 2 | * Copyright (c) 2024 Microsoft Corporation | ||
| 3 | * Copyright (c) 2026-present Eclipse ThreadX contributors | ||
| 4 | * | ||
| 5 | * This program and the accompanying materials are made available under the | ||
| 6 | * terms of the MIT License which is available at | ||
| 7 | * https://opensource.org/licenses/MIT. | ||
| 8 | * | ||
| 9 | * SPDX-License-Identifier: MIT | ||
| 10 | **************************************************************************/ | ||
| 11 | |||
| 12 | |||
| 13 | /**************************************************************************/ | ||
| 14 | /**************************************************************************/ | ||
| 15 | /** */ | ||
| 16 | /** FileX Component */ | ||
| 17 | /** */ | ||
| 18 | /** Fault Tolerant */ | ||
| 19 | /** */ | ||
| 20 | /**************************************************************************/ | ||
| 21 | /**************************************************************************/ | ||
| 22 | |||
| 23 | #define FX_SOURCE_CODE | ||
| 24 | |||
| 25 | #include "fx_api.h" | ||
| 26 | #include "fx_fault_tolerant.h" | ||
| 27 | #include "fx_utility.h" | ||
| 28 | |||
| 29 | |||
| 30 | #ifdef FX_ENABLE_FAULT_TOLERANT | ||
| 31 | /**************************************************************************/ | ||
| 32 | /* */ | ||
| 33 | /* FUNCTION RELEASE */ | ||
| 34 | /* */ | ||
| 35 | /* _fx_fault_tolerant_calculate_checksum PORTABLE C */ | ||
| 36 | /* 6.1 */ | ||
| 37 | /* AUTHOR */ | ||
| 38 | /* */ | ||
| 39 | /* William E. Lamie, Microsoft Corporation */ | ||
| 40 | /* */ | ||
| 41 | /* DESCRIPTION */ | ||
| 42 | /* */ | ||
| 43 | /* This function calculates checksum for consecutive data. The size */ | ||
| 44 | /* of the log file is required to be 4-byte aligned. Therefore this */ | ||
| 45 | /* checksum routine is able to perform 4-byte access. */ | ||
| 46 | /* */ | ||
| 47 | /* INPUT */ | ||
| 48 | /* */ | ||
| 49 | /* data Pointer to data */ | ||
| 50 | /* len Data length */ | ||
| 51 | /* */ | ||
| 52 | /* OUTPUT */ | ||
| 53 | /* */ | ||
| 54 | /* Computed checksum value */ | ||
| 55 | /* */ | ||
| 56 | /* CALLS */ | ||
| 57 | /* */ | ||
| 58 | /* _fx_utility_32_unsigned_read Read a UINT from memory */ | ||
| 59 | /* */ | ||
| 60 | /* CALLED BY */ | ||
| 61 | /* */ | ||
| 62 | /* _fx_fault_tolerant_enable */ | ||
| 63 | /* _fx_fault_tolerant_cleanup_FAT_chain */ | ||
| 64 | /* _fx_fault_tolerant_reset_log_file */ | ||
| 65 | /* _fx_fault_tolerant_set_FAT_chain */ | ||
| 66 | /* _fx_fault_tolerant_transaction_end */ | ||
| 67 | /* */ | ||
| 68 | /**************************************************************************/ | ||
| 69 | 493759346 | USHORT _fx_fault_tolerant_calculate_checksum(UCHAR *data, UINT len) | |
| 70 | { | ||
| 71 | 493759346 | ULONG checksum = 0; | |
| 72 | ULONG long_value; | ||
| 73 | |||
| 74 |
2/2✓ Branch 5 → 3 taken 3163272621 times.
✓ Branch 5 → 6 taken 493759346 times.
|
3657031967 | while (len >= 4) |
| 75 | { | ||
| 76 | |||
| 77 | /* Read first long value. */ | ||
| 78 | 3163272621 | long_value = _fx_utility_32_unsigned_read(data); | |
| 79 | |||
| 80 | /* Calculate checksum. */ | ||
| 81 | 3163272621 | checksum += (long_value >> 16) + (long_value & 0xFFFF); | |
| 82 | |||
| 83 | /* Decrease length. */ | ||
| 84 | 3163272621 | len -= sizeof(ULONG); | |
| 85 | 3163272621 | data += sizeof(ULONG); | |
| 86 | } | ||
| 87 | |||
| 88 | /* Trim high 16 bits of checksum. */ | ||
| 89 | 493759346 | checksum = (checksum & 0xFFFF) + (checksum >> 16); | |
| 90 | 493759346 | checksum = (checksum & 0xFFFF) + (checksum >> 16); | |
| 91 | |||
| 92 | 493759346 | return((USHORT)((~checksum) & 0xFFFF)); | |
| 93 | } | ||
| 94 | #endif /* FX_ENABLE_FAULT_TOLERANT */ | ||
| 95 | |||
| 96 |