80 lines
1.8 KiB
C
80 lines
1.8 KiB
C
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#ifndef CORRECT_REED_SOLOMON
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#define CORRECT_REED_SOLOMON
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#include <string.h>
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//#include <stdlib.h>
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//#include <stdio.h>
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#include <stdbool.h>
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#include <time.h>
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#include <stdint.h>
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#include "correct.h"
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#include "portable.h"
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#include "os_mem_api.h"
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#include "iot_module_api.h"
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// an element in GF(2^8)
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typedef uint8_t field_element_t;
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// a power of the primitive element alpha
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typedef uint8_t field_logarithm_t;
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// give us some bits of headroom to do arithmetic
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// variables of this type aren't really in any proper space
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typedef uint16_t field_operation_t;
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// generated by find_poly
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typedef struct {
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const field_element_t *exp;
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const field_logarithm_t *log;
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} field_t;
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typedef struct {
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field_element_t *coeff;
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uint16_t order;
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} polynomial_t;
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struct correct_reed_solomon {
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size_t block_length;
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size_t message_length;
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size_t min_distance;
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field_logarithm_t first_consecutive_root;
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field_logarithm_t generator_root_gap;
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field_t field;
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polynomial_t generator;
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field_element_t *generator_roots;
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field_logarithm_t **generator_root_exp;
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polynomial_t encoded_polynomial;
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polynomial_t encoded_remainder;
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field_element_t *syndromes;
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field_element_t *modified_syndromes;
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polynomial_t received_polynomial;
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polynomial_t error_locator;
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polynomial_t error_locator_log;
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polynomial_t erasure_locator;
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field_element_t *error_roots;
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field_element_t *error_vals;
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field_logarithm_t *error_locations;
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field_logarithm_t **element_exp;
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// scratch
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// (do no allocations at steady state)
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// used during find_error_locator
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polynomial_t last_error_locator;
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// used during error value search
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polynomial_t error_evaluator;
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polynomial_t error_locator_derivative;
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polynomial_t init_from_roots_scratch[2];
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bool has_init_decode;
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};
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#endif
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