Beispiel #1
0
void cproxy_del_front_cache_key_ascii(downstream *d,
                                      char *command) {
    cb_assert(d);
    cb_assert(d->ptd);
    cb_assert(d->ptd->proxy);

    if (d->ptd->behavior_pool.base.front_cache_lifespan == 0) {
        return;
    }

    if (mcache_started(&d->ptd->proxy->front_cache)) {
        char *spc = strchr(command, ' ');
        if (spc != NULL) {
            char *key = spc + 1;
            int   key_len = skey_len(key);

            cproxy_front_cache_delete(d->ptd, key, key_len);
        }
    }
}
/* Forward an upstream command that came with item data,
 * like set/add/replace/etc.
 */
bool cproxy_forward_a2a_item_downstream(downstream *d, short cmd,
                                        item *it, conn *uc) {
    assert(d != NULL);
    assert(d->ptd != NULL);
    assert(d->ptd->proxy != NULL);
    assert(d->downstream_conns != NULL);
    assert(it != NULL);
    assert(uc != NULL);
    assert(uc->next == NULL);

    // Assuming we're already connected to downstream.
    //

    conn *c = cproxy_find_downstream_conn(d, ITEM_key(it), it->nkey, NULL);
    if (c != NULL) {

        if (cproxy_prep_conn_for_write(c)) {
            assert(c->state == conn_pause);

            char *verb = nread_text(cmd);
            assert(verb != NULL);

            char *str_flags   = ITEM_suffix(it);
            char *str_length  = strchr(str_flags + 1, ' ');
            int   len_flags   = str_length - str_flags;
            int   len_length  = it->nsuffix - len_flags - 2;
            char *str_exptime = add_conn_suffix(c);
            char *str_cas     = (cmd == NREAD_CAS ? add_conn_suffix(c) : NULL);

            if (str_flags != NULL &&
                str_length != NULL &&
                len_flags > 1 &&
                len_length > 1 &&
                str_exptime != NULL &&
                (cmd != NREAD_CAS ||
                 str_cas != NULL)) {
                sprintf(str_exptime, " %u", it->exptime);

                if (str_cas != NULL) {
                    sprintf(str_cas, " %llu",
                            (unsigned long long) ITEM_get_cas(it));
                }

                if (add_iov(c, verb, strlen(verb)) == 0 &&
                    add_iov(c, ITEM_key(it), it->nkey) == 0 &&
                    add_iov(c, str_flags, len_flags) == 0 &&
                    add_iov(c, str_exptime, strlen(str_exptime)) == 0 &&
                    add_iov(c, str_length, len_length) == 0 &&
                    (str_cas == NULL ||
                     add_iov(c, str_cas, strlen(str_cas)) == 0) &&
                    (uc->noreply == false ||
                     add_iov(c, " noreply", 8) == 0) &&
                    add_iov(c, ITEM_data(it) - 2, it->nbytes + 2) == 0) {
                    conn_set_state(c, conn_mwrite);
                    c->write_and_go = conn_new_cmd;

                    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);

                            // During a synchronous (with-reply) SET,
                            // handle fire-&-forget SET optimization.
                            //
                            if (cmd == NREAD_SET &&
                                cproxy_optimize_set_ascii(d, uc,
                                                          ITEM_key(it),
                                                          it->nkey)) {
                                d->ptd->stats.stats.tot_optimize_sets++;
                            }
                        } else {
                            c->write_and_go = conn_pause;

                            cproxy_front_cache_delete(d->ptd,
                                                      ITEM_key(it), it->nkey);
                        }

                        return true;
                    }
                }

                d->ptd->stats.stats.err_oom++;
                cproxy_close_conn(c);
            } else {
                // TODO: Handle this weird error case.
            }
        } else {
            d->ptd->stats.stats.err_downstream_write_prep++;
            cproxy_close_conn(c);
        }

        if (settings.verbose > 1) {
            moxi_log_write("Proxy item write out of memory");
        }
    }

    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) {
    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 != (protocol_binary_command) -1);
    assert(d->multiget == NULL);
    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);
    }

    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.
    //
    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)) {
            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;
}