47 lines
1.3 KiB
C
47 lines
1.3 KiB
C
#include <flexptp/ptp_raw_msg_circbuf.h>
|
|
|
|
void ptp_circ_buf_init(PtpCircBuf * pCircBuf, RawPtpMessage * pMsgPool, uint8_t n)
|
|
{
|
|
pCircBuf->msgs = pMsgPool;
|
|
pCircBuf->totalSize = n;
|
|
pCircBuf->freeBufs = n;
|
|
pCircBuf->lastReceived = 0;
|
|
pCircBuf->allocPending = -1;
|
|
}
|
|
|
|
// allocate packet (CALL ONLY IF THERE IS SPACE AVAILABLE!)
|
|
RawPtpMessage *ptp_circ_buf_alloc(PtpCircBuf * pCircBuf)
|
|
{
|
|
if (pCircBuf->freeBufs > 0 && pCircBuf->allocPending == -1) {
|
|
uint8_t current = (pCircBuf->lastReceived + 1) % pCircBuf->totalSize; // allocate a new packet
|
|
pCircBuf->allocPending = current;
|
|
return &(pCircBuf->msgs[current]);
|
|
} else {
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
int ptp_circ_buf_commit(PtpCircBuf * pCircBuf)
|
|
{
|
|
if (pCircBuf->allocPending != -1) {
|
|
pCircBuf->lastReceived = pCircBuf->allocPending; // advance last index
|
|
pCircBuf->freeBufs--; // decrease amount of free buffers
|
|
pCircBuf->allocPending = -1; // turn off allocation pending flag
|
|
return pCircBuf->lastReceived;
|
|
} else {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
void ptp_circ_buf_free(PtpCircBuf * pCircBuf)
|
|
{
|
|
if (pCircBuf->freeBufs < pCircBuf->totalSize) {
|
|
pCircBuf->freeBufs++;
|
|
}
|
|
}
|
|
|
|
RawPtpMessage *ptp_circ_buf_get(PtpCircBuf * pCircBuf, uint8_t idx)
|
|
{
|
|
return &(pCircBuf->msgs[idx]);
|
|
}
|