diff options
Diffstat (limited to 'protocol/lufa/midi/bytequeue/bytequeue.c')
| -rwxr-xr-x | protocol/lufa/midi/bytequeue/bytequeue.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/protocol/lufa/midi/bytequeue/bytequeue.c b/protocol/lufa/midi/bytequeue/bytequeue.c new file mode 100755 index 000000000..e43495632 --- /dev/null +++ b/protocol/lufa/midi/bytequeue/bytequeue.c | |||
| @@ -0,0 +1,65 @@ | |||
| 1 | //this is a single reader [maybe multiple writer?] byte queue | ||
| 2 | //Copyright 2008 Alex Norman | ||
| 3 | //writen by Alex Norman | ||
| 4 | // | ||
| 5 | //This file is part of avr-bytequeue. | ||
| 6 | // | ||
| 7 | //avr-bytequeue is free software: you can redistribute it and/or modify | ||
| 8 | //it under the terms of the GNU General Public License as published by | ||
| 9 | //the Free Software Foundation, either version 3 of the License, or | ||
| 10 | //(at your option) any later version. | ||
| 11 | // | ||
| 12 | //avr-bytequeue is distributed in the hope that it will be useful, | ||
| 13 | //but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 14 | //MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
| 15 | //GNU General Public License for more details. | ||
| 16 | // | ||
| 17 | //You should have received a copy of the GNU General Public License | ||
| 18 | //along with avr-bytequeue. If not, see <http://www.gnu.org/licenses/>. | ||
| 19 | |||
| 20 | #include "bytequeue.h" | ||
| 21 | #include "interrupt_setting.h" | ||
| 22 | |||
| 23 | void bytequeue_init(byteQueue_t * queue, uint8_t * dataArray, byteQueueIndex_t arrayLen){ | ||
| 24 | queue->length = arrayLen; | ||
| 25 | queue->data = dataArray; | ||
| 26 | queue->start = queue->end = 0; | ||
| 27 | } | ||
| 28 | |||
| 29 | bool bytequeue_enqueue(byteQueue_t * queue, uint8_t item){ | ||
| 30 | interrupt_setting_t setting = store_and_clear_interrupt(); | ||
| 31 | //full | ||
| 32 | if(((queue->end + 1) % queue->length) == queue->start){ | ||
| 33 | restore_interrupt_setting(setting); | ||
| 34 | return false; | ||
| 35 | } else { | ||
| 36 | queue->data[queue->end] = item; | ||
| 37 | queue->end = (queue->end + 1) % queue->length; | ||
| 38 | restore_interrupt_setting(setting); | ||
| 39 | return true; | ||
| 40 | } | ||
| 41 | } | ||
| 42 | |||
| 43 | byteQueueIndex_t bytequeue_length(byteQueue_t * queue){ | ||
| 44 | byteQueueIndex_t len; | ||
| 45 | interrupt_setting_t setting = store_and_clear_interrupt(); | ||
| 46 | if(queue->end >= queue->start) | ||
| 47 | len = queue->end - queue->start; | ||
| 48 | else | ||
| 49 | len = (queue->length - queue->start) + queue->end; | ||
| 50 | restore_interrupt_setting(setting); | ||
| 51 | return len; | ||
| 52 | } | ||
| 53 | |||
| 54 | //we don't need to avoid interrupts if there is only one reader | ||
| 55 | uint8_t bytequeue_get(byteQueue_t * queue, byteQueueIndex_t index){ | ||
| 56 | return queue->data[(queue->start + index) % queue->length]; | ||
| 57 | } | ||
| 58 | |||
| 59 | //we just update the start index to remove elements | ||
| 60 | void bytequeue_remove(byteQueue_t * queue, byteQueueIndex_t numToRemove){ | ||
| 61 | interrupt_setting_t setting = store_and_clear_interrupt(); | ||
| 62 | queue->start = (queue->start + numToRemove) % queue->length; | ||
| 63 | restore_interrupt_setting(setting); | ||
| 64 | } | ||
| 65 | |||
