f-stack/app/redis-6.2.6/tests/unit/obuf-limits.tcl

start_server {tags {"obuf-limits"}} {
    test {Client output buffer hard limit is enforced} {
        r config set client-output-buffer-limit {pubsub 100000 0 0}
        set rd1 [redis_deferring_client]

        $rd1 subscribe foo
        set reply [$rd1 read]
        assert {$reply eq "subscribe foo 1"}

        set omem 0
        while 1 {
            r publish foo bar
            set clients [split [r client list] "\r\n"]
            set c [split [lindex $clients 1] " "]
            if {![regexp {omem=([0-9]+)} $c - omem]} break
            if {$omem > 200000} break
        }
        assert {$omem >= 70000 && $omem < 200000}
        $rd1 close
    }
    
    foreach {soft_limit_time wait_for_timeout} {3 yes
                                                4 no } {
        if $wait_for_timeout {
            set test_name "Client output buffer soft limit is enforced if time is overreached"
        } else {
            set test_name "Client output buffer soft limit is not enforced too early and is enforced when no traffic"
        }

        test $test_name {
            r config set client-output-buffer-limit "pubsub 0 100000 $soft_limit_time"
            set soft_limit_time [expr $soft_limit_time*1000]
            set rd1 [redis_deferring_client]

            $rd1 client setname test_client
            set reply [$rd1 read]
            assert {$reply eq "OK"}

            $rd1 subscribe foo
            set reply [$rd1 read]
            assert {$reply eq "subscribe foo 1"}

            set omem 0
            set start_time 0
            set time_elapsed 0
            set last_under_limit_time [clock milliseconds]
            while 1 {
                r publish foo [string repeat "x" 1000]
                set clients [split [r client list] "\r\n"]
                set c [lsearch -inline $clients *name=test_client*]
                if {$start_time != 0} {
                    set time_elapsed [expr {[clock milliseconds]-$start_time}]
                    # Make sure test isn't taking too long
                    assert {$time_elapsed <= [expr $soft_limit_time+3000]}
                }
                if {$wait_for_timeout && $c == ""} {
                    # Make sure we're disconnected when we reach the soft limit
                    assert {$omem >= 100000 && $time_elapsed >= $soft_limit_time}
                    break
                } else {
                    assert {[regexp {omem=([0-9]+)} $c - omem]}
                }
                if {$omem > 100000} {
                    if {$start_time == 0} {set start_time $last_under_limit_time}
                    if {!$wait_for_timeout && $time_elapsed >= [expr $soft_limit_time-1000]} break
                    # Slow down loop when omem has reached the limit.
                    after 10
                } else {
                    # if the OS socket buffers swallowed what we previously filled, reset the start timer.
                    set start_time 0
                    set last_under_limit_time [clock milliseconds]
                }
            }

            if {!$wait_for_timeout} {
                # After we completely stopped the traffic, wait for soft limit to time out
                set timeout [expr {$soft_limit_time+1500 - ([clock milliseconds]-$start_time)}]
                wait_for_condition [expr $timeout/10] 10 {
                    [lsearch [split [r client list] "\r\n"] *name=test_client*] == -1
                } else {
                    fail "Soft limit timed out but client still connected"
                }
            }

            $rd1 close
        }
    }

    test {No response for single command if client output buffer hard limit is enforced} {
        r config set client-output-buffer-limit {normal 100000 0 0}
        # Total size of all items must be more than 100k
        set item [string repeat "x" 1000]
        for {set i 0} {$i < 150} {incr i} {
            r lpush mylist $item
        }
        set orig_mem [s used_memory]
        # Set client name and get all items
        set rd [redis_deferring_client]
        $rd client setname mybiglist
        assert {[$rd read] eq "OK"}
        $rd lrange mylist 0 -1
        $rd flush
        after 100

        # Before we read reply, redis will close this client.
        set clients [r client list]
        assert_no_match "*name=mybiglist*" $clients
        set cur_mem [s used_memory]
        # 10k just is a deviation threshold
        assert {$cur_mem < 10000 + $orig_mem}

        # Read nothing
        set fd [$rd channel]
        assert_equal {} [read $fd]
    }

    # Note: This test assumes that what's written with one write, will be read by redis in one read.
    # this assumption is wrong, but seem to work empirically (for now)
    test {No response for multi commands in pipeline if client output buffer limit is enforced} {
        r config set client-output-buffer-limit {normal 100000 0 0}
        set value [string repeat "x" 10000]
        r set bigkey $value
        set rd1 [redis_deferring_client]
        set rd2 [redis_deferring_client]
        $rd2 client setname multicommands
        assert_equal "OK" [$rd2 read]

        # Let redis sleep 1s firstly
        $rd1 debug sleep 1
        $rd1 flush
        after 100

        # Create a pipeline of commands that will be processed in one socket read.
        # It is important to use one write, in TLS mode independant writes seem
        # to wait for response from the server.
        # Total size should be less than OS socket buffer, redis can
        # execute all commands in this pipeline when it wakes up.
        set buf ""
        for {set i 0} {$i < 15} {incr i} {
            append buf "set $i $i\r\n"
            append buf "get $i\r\n"
            append buf "del $i\r\n"
            # One bigkey is 10k, total response size must be more than 100k
            append buf "get bigkey\r\n"
        }
        $rd2 write $buf
        $rd2 flush
        after 100

        # Reds must wake up if it can send reply
        assert_equal "PONG" [r ping]
        set clients [r client list]
        assert_no_match "*name=multicommands*" $clients
        set fd [$rd2 channel]
        assert_equal {} [read $fd]
    }

    test {Execute transactions completely even if client output buffer limit is enforced} {
        r config set client-output-buffer-limit {normal 100000 0 0}
        # Total size of all items must be more than 100k
        set item [string repeat "x" 1000]
        for {set i 0} {$i < 150} {incr i} {
            r lpush mylist2 $item
        }

        # Output buffer limit is enforced during executing transaction
        r client setname transactionclient
        r set k1 v1
        r multi
        r set k2 v2
        r get k2
        r lrange mylist2 0 -1
        r set k3 v3
        r del k1
        catch {[r exec]} e
        assert_match "*I/O error*" $e
        reconnect
        set clients [r client list]
        assert_no_match "*name=transactionclient*" $clients

        # Transactions should be executed completely
        assert_equal {} [r get k1]
        assert_equal "v2" [r get k2]
        assert_equal "v3" [r get k3]
    }
}