/* Inserts the given KEY, VALUE pair into this server's store
* Returns 0 if successful, else a negative error code. */
int tpcfollower_put(tpcfollower_t *server, char *key, char *value) {
int ret;
if ((ret = tpcfollower_put_check(server, key, value)) < 0)
return ret;
ret = kvstore_put(&server->store, key, value);
return ret;
}
/* Handles an incoming kvrequest REQ, and populates RES as a response. REQ and
* RES both must point to valid kvrequest_t and kvrespont_t structs,
* respectively. Assumes that the request should be handled as a TPC
* message. This should also log enough information in the server's TPC log to
* be able to recreate the current state of the server upon recovering from
* failure. See the spec for details on logic and error messages.
*/
void tpcfollower_handle_tpc(tpcfollower_t *server, kvrequest_t *req, kvresponse_t *res) {
/* TODO: Implement me! */
if (req->type == DELREQ) {
if (server->state != TPC_WAIT) {
server->state = TPC_WAIT;
} else {
res->type = ERROR;
strcpy(res->body, ERRMSG_INVALID_REQUEST);
return;
}
int del_retval = tpcfollower_del_check(server, req->key);
if (del_retval < 0) {
res->type = VOTE;
if (del_retval == ERR_KEYLEN) {
strcpy(res->body, ERRMSG_KEY_LEN);
} else if (del_retval == ERR_NOKEY) {
strcpy(res->body, ERRMSG_NO_KEY);
} else {
strcpy(res->body, ERRMSG_GENERIC_ERROR);
}
} else {
tpclog_log(&server->log, DELREQ, req->key, NULL);
res->type = VOTE;
strcpy(res->body, MSG_COMMIT);
}
} else if (req->type == PUTREQ) {
if (server->state != TPC_WAIT) {
server->state = TPC_WAIT;
} else {
res->type = ERROR;
strcpy(res->body, ERRMSG_INVALID_REQUEST);
return;
}
int put_retval = tpcfollower_put_check(server, req->key, req->val);
if (put_retval < 0) {
res->type = VOTE;
if (put_retval == ERR_KEYLEN) {
strcpy(res->body, ERRMSG_KEY_LEN);
} else if (put_retval == ERR_VALLEN) {
strcpy(res->body, ERRMSG_VAL_LEN);
} else {
strcpy(res->body, ERRMSG_GENERIC_ERROR);
}
} else {
tpclog_log(&server->log, PUTREQ, req->key, req->val);
res->type = VOTE;
strcpy(res->body, MSG_COMMIT);
}
} else if (req->type == COMMIT) {
server->state = TPC_COMMIT;
res->type = ACK;
tpclog_iterate_begin(&server->log);
logentry_t* entry = malloc(sizeof(logentry_t));
while (tpclog_iterate_has_next(&server->log)) {
entry = tpclog_iterate_next(&server->log, entry);
char* log_key = malloc(strlen(entry->data));
if (entry->type == DELREQ) {
strcpy(log_key, entry->data);
tpcfollower_del(server, log_key);
} else if (entry->type == PUTREQ) {
char* log_val = malloc(entry->length - strlen(entry->data));
strcpy(log_key, entry->data);
strcpy(log_val, entry->data + strlen(entry->data) + 1);
tpcfollower_put(server, log_key, log_val);
}
}
tpclog_clear_log(&server->log);
} else if (req->type == ABORT) {
server->state = TPC_ABORT;
res->type = ACK;
tpclog_clear_log(&server->log);
} else if (req->type == GETREQ) {
int get_retval = tpcfollower_get(server, req->key, res->body);
if (get_retval < 0) {
res->type = ERROR;
if (get_retval == ERR_KEYLEN) {
strcpy(res->body, ERRMSG_KEY_LEN);
} else if (get_retval == ERR_NOKEY) {
strcpy(res->body, ERRMSG_NO_KEY);
} else {
strcpy(res->body, ERRMSG_INVALID_REQUEST);
}
} else {
res->type = GETRESP;
}
}
}
