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| Rev | Author | Line No. | Line |
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| 1339 | cejka | 1 | /* |
| 2 | * Copyright (C) 2006 Josef Cejka |
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| 3 | * All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * |
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| 9 | * - Redistributions of source code must retain the above copyright |
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| 10 | * notice, this list of conditions and the following disclaimer. |
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| 11 | * - Redistributions in binary form must reproduce the above copyright |
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| 12 | * notice, this list of conditions and the following disclaimer in the |
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| 13 | * documentation and/or other materials provided with the distribution. |
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| 14 | * - The name of the author may not be used to endorse or promote products |
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| 15 | * derived from this software without specific prior written permission. |
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| 16 | * |
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 27 | */ |
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| 28 | |||
| 29 | #include <key_buffer.h> |
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| 1476 | cejka | 30 | #include <futex.h> |
| 1339 | cejka | 31 | |
| 1476 | cejka | 32 | atomic_t keybuffer_futex = FUTEX_INITIALIZER; |
| 33 | |||
| 1344 | cejka | 34 | /** Clear key buffer. |
| 35 | */ |
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| 1451 | cejka | 36 | void keybuffer_free(keybuffer_t *keybuffer) |
| 1339 | cejka | 37 | { |
| 1476 | cejka | 38 | futex_down(&keybuffer_futex); |
| 39 | keybuffer->head = 0; |
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| 40 | keybuffer->tail = 0; |
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| 1451 | cejka | 41 | keybuffer->items = 0; |
| 1476 | cejka | 42 | futex_up(&keybuffer_futex); |
| 1339 | cejka | 43 | } |
| 44 | |||
| 1344 | cejka | 45 | /** Key buffer initialization. |
| 46 | * |
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| 47 | */ |
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| 1451 | cejka | 48 | void keybuffer_init(keybuffer_t *keybuffer) |
| 1339 | cejka | 49 | { |
| 1451 | cejka | 50 | keybuffer_free(keybuffer); |
| 1339 | cejka | 51 | } |
| 52 | |||
| 1344 | cejka | 53 | /** Get free space in buffer. |
| 54 | * This function is useful for processing some scancodes that are translated |
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| 55 | * to more than one character. |
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| 1339 | cejka | 56 | * @return empty buffer space |
| 57 | */ |
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| 1451 | cejka | 58 | int keybuffer_available(keybuffer_t *keybuffer) |
| 1339 | cejka | 59 | { |
| 1451 | cejka | 60 | return KEYBUFFER_SIZE - keybuffer->items; |
| 1339 | cejka | 61 | } |
| 62 | |||
| 1344 | cejka | 63 | /** |
| 64 | * @return nonzero, if buffer is not empty. |
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| 65 | */ |
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| 1451 | cejka | 66 | int keybuffer_empty(keybuffer_t *keybuffer) |
| 1344 | cejka | 67 | { |
| 1451 | cejka | 68 | return (keybuffer->items == 0); |
| 1344 | cejka | 69 | } |
| 70 | |||
| 71 | /** Push key to key buffer. |
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| 72 | * If buffer is full, character is ignored. |
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| 73 | * @param key code of stored key |
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| 74 | */ |
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| 1451 | cejka | 75 | void keybuffer_push(keybuffer_t *keybuffer, char key) |
| 1339 | cejka | 76 | { |
| 1476 | cejka | 77 | futex_down(&keybuffer_futex); |
| 1451 | cejka | 78 | if (keybuffer->items < KEYBUFFER_SIZE) { |
| 1476 | cejka | 79 | keybuffer->fifo[keybuffer->tail] = key; |
| 80 | keybuffer->tail = (keybuffer->tail + 1) % KEYBUFFER_SIZE; |
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| 1451 | cejka | 81 | keybuffer->items++; |
| 1339 | cejka | 82 | } |
| 1476 | cejka | 83 | futex_up(&keybuffer_futex); |
| 1339 | cejka | 84 | } |
| 85 | |||
| 86 | /** Pop character from buffer. |
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| 1344 | cejka | 87 | * @param c pointer to space where to store character from buffer. |
| 1339 | cejka | 88 | * @return zero on empty buffer, nonzero else |
| 89 | */ |
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| 1451 | cejka | 90 | int keybuffer_pop(keybuffer_t *keybuffer, char *c) |
| 1339 | cejka | 91 | { |
| 1476 | cejka | 92 | futex_down(&keybuffer_futex); |
| 1451 | cejka | 93 | if (keybuffer->items > 0) { |
| 94 | keybuffer->items--; |
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| 1476 | cejka | 95 | *c = keybuffer->fifo[keybuffer->head]; |
| 96 | keybuffer->head = (keybuffer->head + 1) % KEYBUFFER_SIZE; |
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| 97 | futex_up(&keybuffer_futex); |
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| 1339 | cejka | 98 | return 1; |
| 99 | } |
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| 1476 | cejka | 100 | futex_up(&keybuffer_futex); |
| 1339 | cejka | 101 | return 0; |
| 102 | } |
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| 103 | |||
| 104 |