Implement a packet queue (incl. tests)
This commit is contained in:
parent
402e36dda5
commit
2348cd0c88
81
impl/src/layer2/packet_queue.c
Normal file
81
impl/src/layer2/packet_queue.c
Normal file
|
@ -0,0 +1,81 @@
|
|||
#include <stdlib.h>
|
||||
|
||||
#include "packet_queue.h"
|
||||
|
||||
void packet_queue_init(packet_queue_t *q)
|
||||
{
|
||||
q->write_idx = 0;
|
||||
q->read_idx = 0;
|
||||
}
|
||||
|
||||
|
||||
void packet_queue_destroy(packet_queue_t *q)
|
||||
{
|
||||
packet_queue_delete(q, packet_queue_get_used_space(q));
|
||||
}
|
||||
|
||||
|
||||
bool packet_queue_can_add_packet(const packet_queue_t *q)
|
||||
{
|
||||
return packet_queue_get_free_space(q) != 0;
|
||||
}
|
||||
|
||||
|
||||
bool packet_queue_add(packet_queue_t *q, const layer2_packet_header_t *header, uint8_t *data, size_t data_len)
|
||||
{
|
||||
size_t next_idx = (q->write_idx + 1) % PACKET_QUEUE_SIZE;
|
||||
|
||||
if(next_idx == q->read_idx) {
|
||||
return false;
|
||||
}
|
||||
|
||||
q->entries[q->write_idx].header = *header;
|
||||
q->entries[q->write_idx].data = data;
|
||||
q->entries[q->write_idx].data_len = data_len;
|
||||
|
||||
q->write_idx = next_idx;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
|
||||
const packet_queue_entry_t* packet_queue_get(const packet_queue_t *q, size_t index)
|
||||
{
|
||||
if(index >= packet_queue_get_used_space(q)) {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
size_t internal_index = (q->read_idx + index) % PACKET_QUEUE_SIZE;
|
||||
|
||||
return &q->entries[internal_index];
|
||||
}
|
||||
|
||||
|
||||
void packet_queue_delete(packet_queue_t *q, size_t count)
|
||||
{
|
||||
for(size_t i = 0; i < count; i++) {
|
||||
if(q->read_idx == q->write_idx) {
|
||||
// stop early if there are no entries left to delete
|
||||
break;
|
||||
}
|
||||
|
||||
packet_queue_entry_t *entry = &q->entries[q->read_idx];
|
||||
|
||||
free(entry->data);
|
||||
entry->data_len = 0;
|
||||
|
||||
q->read_idx++;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
size_t packet_queue_get_free_space(const packet_queue_t *q)
|
||||
{
|
||||
return (q->read_idx + PACKET_QUEUE_SIZE - 1 - q->write_idx) % PACKET_QUEUE_SIZE;
|
||||
}
|
||||
|
||||
|
||||
size_t packet_queue_get_used_space(const packet_queue_t *q)
|
||||
{
|
||||
return (q->write_idx + PACKET_QUEUE_SIZE - q->read_idx) % PACKET_QUEUE_SIZE;
|
||||
}
|
75
impl/src/layer2/packet_queue.h
Normal file
75
impl/src/layer2/packet_queue.h
Normal file
|
@ -0,0 +1,75 @@
|
|||
#ifndef PACKET_QUEUE_H
|
||||
#define PACKET_QUEUE_H
|
||||
|
||||
#include "packet_structs.h"
|
||||
|
||||
#define PACKET_QUEUE_SIZE 16
|
||||
|
||||
typedef struct packet_queue_entry_s {
|
||||
layer2_packet_header_t header;
|
||||
uint8_t *data;
|
||||
size_t data_len;
|
||||
} packet_queue_entry_t;
|
||||
|
||||
typedef struct packet_queue_s {
|
||||
packet_queue_entry_t entries[PACKET_QUEUE_SIZE];
|
||||
|
||||
size_t write_idx; //!< Write index in \ref entries
|
||||
size_t read_idx; //!< Read index in \ref entries
|
||||
} packet_queue_t;
|
||||
|
||||
/*!\brief Initialize a packet queue.
|
||||
* \param q Pointer to the queue struct to initialize.
|
||||
*/
|
||||
void packet_queue_init(packet_queue_t *q);
|
||||
|
||||
/*!\brief Destroy a packet queue and free all memory.
|
||||
* \param q Pointer to the queue struct to destroy.
|
||||
*/
|
||||
void packet_queue_destroy(packet_queue_t *q);
|
||||
|
||||
/*!\brief Check if a packet can be added to the queue.
|
||||
* \param q Pointer to the queue to check.
|
||||
* \returns True if a packet can be added, false if the queue is full.
|
||||
*/
|
||||
bool packet_queue_can_add_packet(const packet_queue_t *q);
|
||||
|
||||
/*!\brief Add a packet to the queue.
|
||||
* \details
|
||||
* This function takes ownership of the given data block which must be
|
||||
* allocated using malloc(). It is free()d when the packet is removed from the
|
||||
* queue.
|
||||
*
|
||||
* \param q Pointer to the queue to append to.
|
||||
* \param header The packet header.
|
||||
* \param data The packet data.
|
||||
* \param data_len Length of the given packet data.
|
||||
* \returns True if the packet was added, false otherwise.
|
||||
*/
|
||||
bool packet_queue_add(packet_queue_t *q, const layer2_packet_header_t *header, uint8_t *data, size_t data_len);
|
||||
|
||||
/*!\brief Get the nth packet in the queue without removing it.
|
||||
*
|
||||
* \param q Pointer to the queue to access.
|
||||
* \param index The index of the packet to retrieve.
|
||||
* \returns A pointer to the entry or NULL if the queue does not have this entry.
|
||||
*/
|
||||
const packet_queue_entry_t* packet_queue_get(const packet_queue_t *q, size_t index);
|
||||
|
||||
/*!\brief Free packets up to the given entry index.
|
||||
*
|
||||
* \param q Pointer to the queue to access.
|
||||
* \param count Number of entries to delete (maximum; stops early if no entries are left).
|
||||
*/
|
||||
void packet_queue_delete(packet_queue_t *q, size_t count);
|
||||
|
||||
/*!\brief Get the number of used slots in the packet queue.
|
||||
*/
|
||||
size_t packet_queue_get_used_space(const packet_queue_t *q);
|
||||
|
||||
|
||||
/*!\brief Get the number of free slots in the packet queue.
|
||||
*/
|
||||
size_t packet_queue_get_free_space(const packet_queue_t *q);
|
||||
|
||||
#endif // PACKET_QUEUE_H
|
|
@ -145,3 +145,16 @@ add_executable(
|
|||
target_link_libraries(
|
||||
test_ham64
|
||||
)
|
||||
|
||||
#------------------------------------
|
||||
|
||||
add_executable(
|
||||
test_packet_queue
|
||||
../src/layer2/packet_queue.c
|
||||
../src/layer2/packet_queue.h
|
||||
test_packet_queue.c
|
||||
)
|
||||
|
||||
target_link_libraries(
|
||||
test_packet_queue
|
||||
)
|
||||
|
|
69
impl/test/test_packet_queue.c
Normal file
69
impl/test/test_packet_queue.c
Normal file
|
@ -0,0 +1,69 @@
|
|||
#include <assert.h>
|
||||
#include <stdbool.h>
|
||||
#include <stdio.h>
|
||||
#include <string.h>
|
||||
#include <stdlib.h>
|
||||
|
||||
#include <layer2/packet_queue.h>
|
||||
|
||||
int main(void)
|
||||
{
|
||||
packet_queue_t queue;
|
||||
|
||||
layer2_packet_header_t header = {0};
|
||||
uint8_t *data;
|
||||
size_t data_len;
|
||||
|
||||
// initialize
|
||||
packet_queue_init(&queue);
|
||||
|
||||
// add a first packet
|
||||
header.tx_seq_nr = 0;
|
||||
data_len = 2;
|
||||
data = malloc(data_len);
|
||||
strncpy((char*)data, "A", data_len);
|
||||
|
||||
assert(packet_queue_add(&queue, &header, data, data_len));
|
||||
|
||||
assert(packet_queue_get_used_space(&queue) == 1);
|
||||
assert(packet_queue_get_free_space(&queue) == PACKET_QUEUE_SIZE-2);
|
||||
|
||||
// add more packets until the queue is / should be full
|
||||
for(size_t i = 0; i < PACKET_QUEUE_SIZE-2; i++) {
|
||||
char s[2];
|
||||
s[0] = 'A' + i + 1;
|
||||
s[1] = 0;
|
||||
|
||||
header.tx_seq_nr = i+1;
|
||||
data_len = 2;
|
||||
data = malloc(data_len);
|
||||
strncpy((char*)data, s, data_len);
|
||||
|
||||
assert(packet_queue_add(&queue, &header, data, data_len));
|
||||
|
||||
assert(packet_queue_get_used_space(&queue) == i+2);
|
||||
assert(packet_queue_get_free_space(&queue) == PACKET_QUEUE_SIZE-3-i);
|
||||
}
|
||||
|
||||
// adding another packet should fail now
|
||||
assert(!packet_queue_add(&queue, &header, data, data_len));
|
||||
|
||||
// delete the first five packets
|
||||
packet_queue_delete(&queue, 5);
|
||||
|
||||
assert(packet_queue_get_free_space(&queue) == 5);
|
||||
|
||||
// now the sequence number of the first packet should be 5
|
||||
const packet_queue_entry_t *entry = packet_queue_get(&queue, 0);
|
||||
|
||||
assert(entry->header.tx_seq_nr == 5);
|
||||
|
||||
// try to access the 10th and 11th packet, which are the last existing and
|
||||
// the first nonexisting packets
|
||||
assert(packet_queue_get(&queue, 9) != NULL);
|
||||
assert(packet_queue_get(&queue, 10) == NULL);
|
||||
|
||||
packet_queue_destroy(&queue);
|
||||
|
||||
printf("Test completed successfully!\n");
|
||||
}
|
Loading…
Reference in a new issue