Files
Thesis_Code/vsr/client.c
T
2026-02-19 15:27:47 +01:00

274 lines
8.4 KiB
C

#if defined(MAIN_SIMULATION) || defined(MAIN_TEST)
#define QUAKEY_ENABLE_MOCKS
#endif
#include <quakey.h>
#include <stdint.h>
#include <assert.h>
#include <lib/file_system.h>
#include "node.h"
#include "client.h"
//#define CLIENT_TRACE(fmt, ...) {}
#define CLIENT_TRACE(fmt, ...) fprintf(stderr, "CLIENT: " fmt "\n", ##__VA_ARGS__);
// Format time as seconds with 3 decimal places for trace output
#define TIME_FMT "%.3fs"
#define TIME_VAL(t) ((double)(t) / 1000000000.0)
static int leader_idx(ClientState *state)
{
return state->view_number % state->num_servers;
}
static int
process_message(ClientState *state,
int conn_idx, uint8_t type, ByteView msg)
{
(void) conn_idx;
if (!state->pending)
return -1;
if (type != MESSAGE_TYPE_REPLY)
return -1;
ReplyMessage reply_message;
if (msg.len != sizeof(ReplyMessage))
return -1;
memcpy(&reply_message, msg.ptr, sizeof(reply_message));
{
Time now = get_current_time();
CLIENT_TRACE("[" TIME_FMT "] received REPLY (rejected=%s)",
TIME_VAL(now),
reply_message.rejected ? "true" : "false");
}
state->pending = false;
return 0;
}
int client_init(void *state_, int argc, char **argv,
void **ctxs, struct pollfd *pdata, int pcap, int *pnum,
int *timeout)
{
ClientState *state = state_;
state->num_servers = 0;
for (int i = 1; i < argc; i++) {
if (!strcmp(argv[i], "--server")) {
i++;
if (i == argc) {
fprintf(stderr, "Option --server missing value. Usage is --server <addr>:<port>\n");
return -1;
}
if (state->num_servers == NODE_LIMIT) {
fprintf(stderr, "Node limit of %d reached\n", NODE_LIMIT);
return -1;
}
// TODO: Check address is not duplicated
if (parse_addr_arg(argv[i], &state->server_addrs[state->num_servers++]) < 0) {
fprintf(stderr, "Malformed <addr>:<port> pair for --server option\n");
return -1;
}
} else {
printf("Ignoring option '%s'\n", argv[i]);
}
}
// Now sort the addresses
addr_sort(state->server_addrs, state->num_servers);
if (tcp_context_init(&state->tcp) < 0) {
fprintf(stderr, "Client :: Couldn't setup TCP context\n");
return -1;
}
state->pending = false;
state->view_number = 0;
state->request_id = 0;
// Load or generate a persistent client_id from disk.
// This ensures the client_id survives process restarts.
{
string path = S("client_id");
Handle fd;
bool loaded = false;
if (file_exists(path)) {
if (file_open(path, &fd) == 0) {
file_set_offset(fd, 0);
uint64_t saved_id;
if (file_read_exact(fd, (char*)&saved_id, sizeof(saved_id)) == (int)sizeof(saved_id)) {
state->client_id = saved_id;
loaded = true;
}
file_close(fd);
}
}
if (!loaded) {
Time now = get_current_time();
state->client_id = (uint64_t)now;
if (file_open(path, &fd) == 0) {
file_set_offset(fd, 0);
file_write_exact(fd, (char*)&state->client_id, sizeof(state->client_id));
file_sync(fd);
file_close(fd);
}
}
}
// Connect to all known servers
for (int i = 0; i < state->num_servers; i++) {
if (tcp_connect(&state->tcp, state->server_addrs[i], i, NULL) < 0) {
fprintf(stderr, "Client :: Couldn't connect to server %d\n", i);
tcp_context_free(&state->tcp);
return -1;
}
}
{
Time now = get_current_time();
CLIENT_TRACE("[" TIME_FMT "] initialized: num_servers=%d, leader_idx=%d",
TIME_VAL(now), state->num_servers, leader_idx(state));
}
*timeout = 0;
if (pcap < TCP_POLL_CAPACITY) {
fprintf(stderr, "Client :: Not enough poll() capacity (got %d, needed %d)\n", pcap, TCP_POLL_CAPACITY);
return -1;
}
*pnum = tcp_register_events(&state->tcp, ctxs, pdata);
return 0;
}
int client_tick(void *state_, void **ctxs,
struct pollfd *pdata, int pcap, int *pnum, int *timeout)
{
ClientState *state = state_;
Event events[TCP_EVENT_CAPACITY];
int num_events = tcp_translate_events(&state->tcp, events, ctxs, pdata, *pnum);
for (int i = 0; i < num_events; i++) {
if (events[i].type == EVENT_DISCONNECT) {
int conn_idx = events[i].conn_idx;
int tag = tcp_get_tag(&state->tcp, conn_idx);
if (tag == leader_idx(state) && state->pending) {
Time now = get_current_time();
CLIENT_TRACE("[" TIME_FMT "] lost connection to leader (node %d), resetting pending request",
TIME_VAL(now), leader_idx(state));
state->pending = false;
}
tcp_close(&state->tcp, conn_idx);
continue;
}
if (events[i].type != EVENT_MESSAGE)
continue;
int conn_idx = events[i].conn_idx;
for (;;) {
ByteView msg;
uint16_t msg_type;
int ret = tcp_next_message(&state->tcp, conn_idx, &msg, &msg_type);
if (ret == 0)
break;
if (ret < 0) {
tcp_close(&state->tcp, conn_idx);
break;
}
ret = process_message(state, conn_idx, msg_type, msg);
if (ret < 0) {
tcp_close(&state->tcp, conn_idx);
break;
}
tcp_consume_message(&state->tcp, conn_idx);
}
}
Time now = get_current_time();
// If we've been waiting too long for a response, give up and
// try the next server (the current leader may have crashed and
// a view change may have happened)
if (state->pending) {
Time request_deadline = state->request_time + PRIMARY_DEATH_TIMEOUT_SEC * 1000000000ULL;
if (request_deadline <= now) {
CLIENT_TRACE("[" TIME_FMT "] request to leader (node %d, view=%lu) timed out, trying next server",
TIME_VAL(now), leader_idx(state),
(unsigned long)state->view_number);
state->view_number++;
state->pending = false;
}
}
if (!state->pending) {
int conn_idx = tcp_index_from_tag(&state->tcp, leader_idx(state));
if (conn_idx < 0) {
// Leader connection not available, try reconnecting
{
CLIENT_TRACE("[" TIME_FMT "] leader (node %d) not connected, reconnecting",
TIME_VAL(now), leader_idx(state));
}
tcp_connect(&state->tcp, state->server_addrs[leader_idx(state)], leader_idx(state), NULL);
} else {
// Now start a new operation
state->request_id++;
RequestMessage request_message = {
.base = {
.version = MESSAGE_VERSION,
.type = MESSAGE_TYPE_REQUEST,
.length = sizeof(RequestMessage),
},
.oper = OPERATION_A,
.client_id = state->client_id,
.request_id = state->request_id,
};
ByteQueue *output = tcp_output_buffer(&state->tcp, conn_idx);
assert(output);
byte_queue_write(output, &request_message, request_message.base.length);
{
CLIENT_TRACE("[" TIME_FMT "] sent REQUEST to leader (node %d, view=%lu, client_id=%lu, req_id=%lu)",
TIME_VAL(now), leader_idx(state),
(unsigned long)state->view_number,
(unsigned long)state->client_id,
(unsigned long)state->request_id);
}
state->pending = true;
state->request_time = now;
}
}
// Set timeout based on pending request deadline
Time deadline = INVALID_TIME;
if (state->pending) {
nearest_deadline(&deadline, state->request_time + PRIMARY_DEATH_TIMEOUT_SEC * 1000000000ULL);
}
*timeout = deadline_to_timeout(deadline, now);
if (pcap < TCP_POLL_CAPACITY)
return -1;
*pnum = tcp_register_events(&state->tcp, ctxs, pdata);
return 0;
}
int client_free(void *state_)
{
ClientState *state = state_;
tcp_context_free(&state->tcp);
return 0;
}