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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 1515 | - | 1 | /** |
| 2 | * a simple Fifo |
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| 3 | * @file fifo.c |
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| 4 | * @author Pascal Schnurr |
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| 5 | */ |
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| 6 | |||
| 7 | #include "fifo.h" |
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| 8 | |||
| 9 | //-------------------------------------------------------------- |
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| 10 | void fifo_init (fifo_t * fifo, uint8_t * buffer, uint16_t size) |
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| 11 | { |
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| 12 | fifo->size = size; |
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| 13 | fifo->buffer = buffer; |
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| 14 | fifo->head = 0; |
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| 15 | fifo->count = 0; |
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| 16 | } |
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| 17 | |||
| 18 | //-------------------------------------------------------------- |
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| 19 | bool fifo_is_empty (const fifo_t * fifo) |
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| 20 | { |
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| 21 | return (fifo->count == 0); |
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| 22 | } |
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| 23 | |||
| 24 | //-------------------------------------------------------------- |
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| 25 | bool fifo_is_full (const fifo_t * fifo) |
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| 26 | { |
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| 27 | return (fifo->size - fifo->count == 0); |
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| 28 | } |
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| 29 | |||
| 30 | //-------------------------------------------------------------- |
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| 31 | bool fifo_read (fifo_t * fifo, char *data) |
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| 32 | { |
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| 33 | if (fifo_is_empty (fifo)) |
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| 34 | return false; |
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| 35 | |||
| 36 | uint8_t *head = fifo->buffer + fifo->head; |
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| 37 | |||
| 38 | *data = (char) * head; |
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| 39 | |||
| 40 | fifo->head = ( (fifo->head + 1) % fifo->size); |
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| 41 | |||
| 42 | fifo->count--; |
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| 43 | |||
| 44 | return true; |
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| 45 | } |
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| 46 | |||
| 47 | //-------------------------------------------------------------- |
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| 48 | bool fifo_write (fifo_t * fifo, const char data) |
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| 49 | { |
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| 50 | if (fifo_is_full (fifo)) |
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| 51 | return false; |
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| 52 | |||
| 53 | uint8_t *end = fifo->buffer + ( (fifo->head + fifo->count) % fifo->size); |
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| 54 | |||
| 55 | *end = (uint8_t) data; |
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| 56 | |||
| 57 | fifo->count++; |
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| 58 | |||
| 59 | return true; |
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| 60 | } |
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| 61 | |||
| 62 | //-------------------------------------------------------------- |
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| 63 | bool fifo_clear (fifo_t * fifo) |
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| 64 | { |
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| 65 | fifo->count = 0; |
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| 66 | fifo->head = 0; |
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| 67 | return true; |
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| 68 | } |
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| 69 | |||
| 70 | //-------------------------------------------------------------- |
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| 71 | static bool fifo_cmp_pgm_at (fifo_t * fifo, const prog_char * pgm, const uint16_t index) |
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| 72 | { |
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| 73 | uint16_t i; |
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| 74 | uint8_t fifo_byte; |
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| 75 | uint8_t pgm_byte; |
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| 76 | |||
| 77 | for (i = 0; pgm_read_byte (pgm + i) != 0; i++) |
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| 78 | { |
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| 79 | if (fifo->count <= (i + index)) |
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| 80 | return false; |
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| 81 | |||
| 82 | pgm_byte = pgm_read_byte (pgm + i); |
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| 83 | |||
| 84 | fifo_byte = * (fifo->buffer + ( (fifo->head + i + index) % fifo->size)); |
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| 85 | |||
| 86 | if (fifo_byte != pgm_byte) |
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| 87 | return false; |
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| 88 | } |
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| 89 | |||
| 90 | // We found the string, lets move the pointer |
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| 91 | fifo->head = ( (fifo->head + i + index) % fifo->size); |
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| 92 | |||
| 93 | fifo->count -= (i + index); |
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| 94 | |||
| 95 | return true; |
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| 96 | } |
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| 97 | |||
| 98 | //-------------------------------------------------------------- |
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| 99 | bool fifo_cmp_pgm (fifo_t * fifo, const prog_char * pgm) |
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| 100 | { |
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| 101 | return fifo_cmp_pgm_at (fifo, pgm, 0); |
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| 102 | } |
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| 103 | |||
| 104 | //-------------------------------------------------------------- |
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| 105 | bool fifo_strstr_pgm (fifo_t * fifo, const prog_char * pgm) |
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| 106 | { |
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| 107 | for (uint16_t i = 0; i < fifo->count; i++) |
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| 108 | { |
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| 109 | if (fifo_cmp_pgm_at (fifo, pgm, i)) |
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| 110 | return true; |
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| 111 | } |
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| 112 | |||
| 113 | return false; |
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| 114 | } |