feat(ws): release generic WebSocket client and server v0.31.0-preview

ws/rpc/config.go

@@ -0,0 +1,67 @@
+// Package rpc implements an optional, versioned JSON protocol over ws sessions.
+// Both endpoints may issue calls and events. It does not provide durable delivery.
+package rpc
+
+import (
+	"context"
+	"errors"
+	"time"
+)
+
+const Subprotocol = "go-omni.rpc.v1"
+
+var (
+	ErrClosed       = errors.New("rpc: closed")
+	ErrNotConnected = errors.New("rpc: not connected")
+	ErrBusy         = errors.New("rpc: capacity reached")
+	ErrProtocol     = errors.New("rpc: invalid protocol message")
+)
+
+// Config bounds allocations, concurrency, and the lifetime of incoming work.
+// Zero fields select defaults. A canceled handler must return before Wait succeeds.
+type Config struct {
+	MaxMessageBytes int           `json:"maxMessageBytes"`
+	MaxPending      int           `json:"maxPending"`
+	MaxConcurrent   int           `json:"maxConcurrent"`
+	CallTimeout     time.Duration `json:"callTimeout"`
+	WriteTimeout    time.Duration `json:"writeTimeout"`
+	// OnEventError observes local notification failures; they have no reply on
+	// the wire. This callback runs within the handler completion barrier.
+	OnEventError func(context.Context, error) `json:"-"`
+}
+
+func DefaultConfig() Config {
+	return Config{MaxMessageBytes: 1 << 20, MaxPending: 128, MaxConcurrent: 32, CallTimeout: 30 * time.Second, WriteTimeout: 5 * time.Second}
+}
+func (c Config) Validate() error { _, err := normalize(c); return err }
+func normalize(c Config) (Config, error) {
+	if c.MaxMessageBytes < 0 || c.MaxMessageBytes > 16<<20 || c.MaxPending < 0 || c.MaxPending > 65536 || c.MaxConcurrent < 0 || c.MaxConcurrent > 4096 || c.CallTimeout < 0 || c.CallTimeout > 24*time.Hour || c.WriteTimeout < 0 || c.WriteTimeout > time.Minute {
+		return c, errors.New("rpc: configuration exceeds supported bounds")
+	}
+	d := DefaultConfig()
+	if c.MaxMessageBytes == 0 {
+		c.MaxMessageBytes = d.MaxMessageBytes
+	}
+	if c.MaxPending == 0 {
+		c.MaxPending = d.MaxPending
+	}
+	if c.MaxConcurrent == 0 {
+		c.MaxConcurrent = d.MaxConcurrent
+	}
+	if c.CallTimeout == 0 {
+		c.CallTimeout = d.CallTimeout
+	}
+	if c.WriteTimeout == 0 {
+		c.WriteTimeout = d.WriteTimeout
+	}
+	return c, nil
+}
+
+// Error is an explicitly public error. Only this type's code/message may be
+// sent to the other endpoint; all other handler errors become INTERNAL.
+type Error struct {
+	Code    string `json:"code"`
+	Message string `json:"message"`
+}
+
+func (e *Error) Error() string { return "rpc: " + e.Code }