fifo.cpp

00001 #include "fifo.h"
00002 
00003 fifo::fifo()
00004 {
00005     this->head = 0;
00006     this->tail = 0;
00007 }
00008 uint32_t fifo::available()
00009 {
00010     return (FIFO_SIZE + this->head - this->tail) % FIFO_SIZE;
00011 }
00012 uint32_t fifo::free()
00013 {
00014     return (FIFO_SIZE - 1 - available());
00015 }
00016 uint8_t fifo::put(FIFO_TYPE data)
00017 {
00018     uint32_t next;
00019 
00020     // check if FIFO has room
00021     next = (this->head + 1) % FIFO_SIZE;
00022     if (next == this->tail)
00023     {
00024         // full
00025         return 1;
00026     }
00027 
00028     this->buffer[this->head] = data;
00029     this->head = next;
00030 
00031     return 0;
00032 }
00033 uint8_t fifo::get(FIFO_TYPE* data)
00034 {
00035     uint32_t next;
00036 
00037     // check if FIFO has data
00038     if (this->head == this->tail)
00039     {
00040         return 1; // FIFO empty
00041     }
00042 
00043     next = (this->tail + 1) % FIFO_SIZE;
00044 
00045     *data = this->buffer[this->tail];
00046     this->tail = next;
00047 
00048     return 0;
00049 }