/* Forward a simple one-liner command downstream.
* For example, get, incr/decr, delete, etc.
* The response, though, might be a simple line or
* multiple VALUE+END lines.
*/
bool cproxy_forward_a2a_simple_downstream(downstream *d,
char *command, conn *uc) {
assert(d != NULL);
assert(d->ptd != NULL);
assert(d->ptd->proxy != NULL);
assert(d->downstream_conns != NULL);
assert(command != NULL);
assert(uc != NULL);
assert(uc->item == NULL);
assert(uc->cmd_curr != -1);
assert(d->multiget == NULL);
assert(d->merger == NULL);
// Handles get and gets.
//
if (uc->cmd_curr == PROTOCOL_BINARY_CMD_GET) {
// Only use front_cache for 'get', not for 'gets'.
//
mcache *front_cache =
(command[3] == ' ') ? &d->ptd->proxy->front_cache : NULL;
return multiget_ascii_downstream(d, uc,
a2a_multiget_start,
a2a_multiget_skey,
a2a_multiget_end,
front_cache);
}
assert(uc->next == NULL);
if (uc->cmd_curr == PROTOCOL_BINARY_CMD_FLUSH)
return cproxy_broadcast_a2a_downstream(d, command, uc,
"OK\r\n");
if (uc->cmd_curr == PROTOCOL_BINARY_CMD_STAT) {
if (strncmp(command + 5, " reset", 6) == 0)
return cproxy_broadcast_a2a_downstream(d, command, uc,
"RESET\r\n");
if (cproxy_broadcast_a2a_downstream(d, command, uc,
"END\r\n")) {
d->merger = genhash_init(512, skeyhash_ops);
return true;
} else {
return false;
}
}
// TODO: Inefficient repeated scan_tokens.
//
int cmd_len = 0;
token_t tokens[MAX_TOKENS];
size_t ntokens = scan_tokens(command, tokens, MAX_TOKENS, &cmd_len);
char *key = tokens[KEY_TOKEN].value;
int key_len = tokens[KEY_TOKEN].length;
if (ntokens <= 1) { // This was checked long ago, while parsing
assert(false); // the upstream conn.
return false;
}
// Assuming we're already connected to downstream.
//
bool self = false;
conn *c = cproxy_find_downstream_conn(d, key, key_len,
&self);
if (c != NULL) {
if (self) {
// TODO: This optimization could be done much earlier,
// even before the upstream conn was assigned
// to a downstream.
//
cproxy_optimize_to_self(d, uc, command);
process_command(uc, command);
return true;
}
if (cproxy_prep_conn_for_write(c)) {
assert(c->state == conn_pause);
out_string(c, command);
if (settings.verbose > 1)
fprintf(stderr, "forwarding to %d, noreply %d\n",
c->sfd, uc->noreply);
if (update_event(c, EV_WRITE | EV_PERSIST)) {
d->downstream_used_start = 1;
d->downstream_used = 1;
if (cproxy_dettach_if_noreply(d, uc) == false) {
cproxy_start_downstream_timeout(d, c);
} else {
c->write_and_go = conn_pause;
// Do mcache_delete() here only during a noreply,
// otherwise for with-reply requests, we could
// be in a race with other clients repopulating
// the front_cache. For with-reply requests, we
// clear the front_cache when we get a success reply.
//
mcache_delete(&d->ptd->proxy->front_cache, key, key_len);
}
return true;
}
if (settings.verbose > 1)
fprintf(stderr, "Couldn't update cproxy write event\n");
d->ptd->stats.stats.err_oom++;
cproxy_close_conn(c);
} else {
d->ptd->stats.stats.err_downstream_write_prep++;
cproxy_close_conn(c);
}
}
return false;
}
/* Forward a simple one-liner command downstream.
* For example, get, incr/decr, delete, etc.
* The response, though, might be a simple line or
* multiple VALUE+END lines.
*/
bool cproxy_forward_a2a_simple_downstream(downstream *d,
char *command, conn *uc) {
cb_assert(d != NULL);
cb_assert(d->ptd != NULL);
cb_assert(d->ptd->proxy != NULL);
cb_assert(d->downstream_conns != NULL);
cb_assert(command != NULL);
cb_assert(uc != NULL);
cb_assert(uc->item == NULL);
cb_assert(uc->cmd_curr != (protocol_binary_command) -1);
cb_assert(d->multiget == NULL);
cb_assert(d->merger == NULL);
/* Handles get and gets. */
if (uc->cmd_curr == PROTOCOL_BINARY_CMD_GETK ||
uc->cmd_curr == PROTOCOL_BINARY_CMD_GETKQ ||
uc->cmd_curr == PROTOCOL_BINARY_CMD_GETL) {
/* Only use front_cache for 'get', not for 'gets'. */
mcache *front_cache =
(command[3] == ' ') ? &d->ptd->proxy->front_cache : NULL;
return multiget_ascii_downstream(d, uc,
a2a_multiget_start,
a2a_multiget_skey,
a2a_multiget_end,
front_cache);
}
cb_assert(uc->next == NULL);
if (uc->cmd_curr == PROTOCOL_BINARY_CMD_FLUSH) {
return cproxy_broadcast_a2a_downstream(d, command, uc,
"OK\r\n");
}
if (uc->cmd_curr == PROTOCOL_BINARY_CMD_STAT) {
if (strncmp(command + 5, " reset", 6) == 0) {
return cproxy_broadcast_a2a_downstream(d, command, uc,
"RESET\r\n");
}
if (cproxy_broadcast_a2a_downstream(d, command, uc,
"END\r\n")) {
d->merger = genhash_init(512, skeyhash_ops);
return true;
} else {
return false;
}
}
/* TODO: Inefficient repeated scan_tokens. */
int cmd_len = 0;
token_t tokens[MAX_TOKENS];
size_t ntokens = scan_tokens(command, tokens, MAX_TOKENS, &cmd_len);
char *key = tokens[KEY_TOKEN].value;
int key_len = tokens[KEY_TOKEN].length;
if (ntokens <= 1) { /* This was checked long ago, while parsing */
cb_assert(false); /* the upstream conn. */
return false;
}
/* Assuming we're already connected to downstream. */
if (!strcmp(command, "version")) {
/* fake key for version command handling */
key = "v";
key_len = 1;
}
conn *c = cproxy_find_downstream_conn(d, key, key_len, NULL);
if (c != NULL) {
if (cproxy_prep_conn_for_write(c)) {
cb_assert(c->state == conn_pause);
out_string(c, command);
if (settings.verbose > 1) {
moxi_log_write("forwarding to %d, noreply %d\n",
c->sfd, uc->noreply);
}
if (update_event(c, EV_WRITE | EV_PERSIST)) {
d->downstream_used_start = 1;
d->downstream_used = 1;
if (cproxy_dettach_if_noreply(d, uc) == false) {
cproxy_start_downstream_timeout(d, c);
} else {
c->write_and_go = conn_pause;
/* Do mcache_delete() here only during a noreply, */
/* otherwise for with-reply requests, we could */
/* be in a race with other clients repopulating */
/* the front_cache. For with-reply requests, we */
/* clear the front_cache when we get a success reply. */
cproxy_front_cache_delete(d->ptd, key, key_len);
}
return true;
}
if (settings.verbose > 1) {
moxi_log_write("Couldn't update cproxy write event\n");
}
d->ptd->stats.stats.err_oom++;
cproxy_close_conn(c);
} else {
d->ptd->stats.stats.err_downstream_write_prep++;
cproxy_close_conn(c);
}
}
return false;
}
