jochen
cc7fb99f29
Read verbs now run in the serving process, where a panic would end every call; refused logins are nobody's reconnect loop (review of hq issue 327).
50 lines
1.8 KiB
Go
50 lines
1.8 KiB
Go
package main
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import (
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"flag"
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"fmt"
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"io"
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"os"
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"sync/atomic"
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"github.com/novox/mesh-controller/internal/broker"
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)
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// The serving controller's own connection, lent to whatever it does for a moment (novox/hq issue 327).
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//
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// Every place that needed the bus for a moment dialled it: a verb's own process, and in the serving
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// controller a watchdog tick reading whether the build seat paused, a walk's step reading readiness, a
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// queue read. Each paid a connection, a TLS handshake and a login on the control node, and hundreds an
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// hour hid in the server's connection total the one thing it would show: a client reconnecting in a loop.
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// The serving controller is on the bus already; what it does is done on that connection.
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// servingBus is the serving controller's connection, set when it starts serving; nil in every other
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// process, which dials its own.
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var servingBus atomic.Pointer[broker.JetStream]
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// aBus is a connection for something done for a moment: the serving controller's own, lent — so its
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// Close closes nothing — when this process is it, and otherwise one dialled for it, named for this
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// process (broker.ConnectionName), which its Close closes.
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func aBus() (*broker.JetStream, error) {
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if serving := servingBus.Load(); serving != nil {
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return broker.Borrow(serving), nil
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}
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address, err := broker.BusAddress()
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if err != nil {
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return nil, err
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}
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js, err := broker.Dial(address)
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if err != nil {
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return nil, fmt.Errorf("cannot reach the bus: %w", err)
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}
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return js, nil
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}
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// usageTo sends a command's flag errors and usage to where its answer goes when that is not this process's
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// output: a verb answered in the serving controller says them in its answer, not in the controller's log.
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func usageTo(set *flag.FlagSet, w io.Writer) {
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if w != os.Stdout {
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set.SetOutput(w)
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}
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}
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