config.go RawHistoryFolder

1package brokeripc
2
3import (
4	"time"
5
6	"github.com/bnema/vev/internal/adapters/brokerwire"
7	"github.com/bnema/vev/internal/protocol"
8)
9
10// Bounds. Every limit below is mandatory: no listener, session, or stream
11// grows an unbounded queue, and every default is small enough that a stalled
12// peer is refused rather than absorbed.
13const (
14	// DefaultMaxClients bounds concurrent accepted client connections on one
15	// listener. A listener acquires one slot before accepting, so the bound is
16	// enforced before a socket is admitted rather than after.
17	DefaultMaxClients = 64
18)
19
20// Config bounds one endpoint. The zero value is valid and selects every
21// default; a negative or zero explicit bound is replaced by its default.
22type Config struct {
23	// MaxClients bounds concurrent accepted client connections.
24	MaxClients int
25	// HandshakeTimeout bounds one accepted connection's broker preamble, broker
26	// admission, and the wait for its Register. The client dialer also bounds
27	// its whole setup (Unix dial, preamble, Register send, and wait for
28	// Registered) with it. On the server the registration phase shares the same
29	// accept-time budget as the preamble and admission: a peer that completes
30	// the preamble and admission but never sends Register is settled when that
31	// deadline elapses, so it cannot hold a core client lease or a listener slot
32	// indefinitely. It is deliberately separate from the session handshake
33	// budget that runs inside a logical stream.
34	HandshakeTimeout time.Duration
35	// MaxPendingOperations bounds mutating operations this side is waiting for
36	// on one connection. It never exceeds the brokerwire per-connection bound.
37	MaxPendingOperations int
38	// PassiveSubscribe marks every snapshot subscription of a client
39	// connection as a read-only reader: it receives publications but never
40	// counts as observation demand, so a CLI read never triggers a probe.
41	PassiveSubscribe bool
42	Build            string
43	OnRetire         func()
44}
45
46// withDefaults fills every unset bound with its package default.
47func (c Config) withDefaults() Config {
48	if c.Build == "" {
49		c.Build = defaultBuildIdentity()
50	}
51	if c.MaxClients <= 0 {
52		c.MaxClients = DefaultMaxClients
53	}
54	if c.HandshakeTimeout <= 0 {
55		c.HandshakeTimeout = protocol.HandshakeTimeout
56	}
57	if c.MaxPendingOperations <= 0 {
58		c.MaxPendingOperations = brokerwire.MaxPendingOperations
59	}
60	return c
61}
62
63// validate refuses a configuration whose explicit bounds cannot be honored.
64// The zero value is always valid because withDefaults has already been applied.
65func (c Config) validate() error {
66	if c.MaxClients <= 0 || c.HandshakeTimeout <= 0 {
67		return ErrConfig
68	}
69	if c.MaxPendingOperations <= 0 || c.MaxPendingOperations > brokerwire.MaxPendingOperations {
70		return ErrConfig
71	}
72	return nil
73}