v0.3.3 pipeline rate limiter added

src/internal/config/ratelimit.go

@@ -0,0 +1,52 @@
+// FILE: src/internal/config/ratelimit.go
+package config
+
+import (
+	"fmt"
+	"strings"
+)
+
+// RateLimitPolicy defines the action to take when a rate limit is exceeded.
+type RateLimitPolicy int
+
+const (
+	// PolicyPass allows all logs through, effectively disabling the limiter.
+	PolicyPass RateLimitPolicy = iota
+	// PolicyDrop drops logs that exceed the rate limit.
+	PolicyDrop
+)
+
+// RateLimitConfig defines the configuration for pipeline-level rate limiting.
+type RateLimitConfig struct {
+	// Rate is the number of log entries allowed per second. Default: 0 (disabled).
+	Rate float64 `toml:"rate"`
+	// Burst is the maximum number of log entries that can be sent in a short burst. Defaults to the Rate.
+	Burst float64 `toml:"burst"`
+	// Policy defines the action to take when the limit is exceeded. "pass" or "drop".
+	Policy string `toml:"policy"`
+}
+
+func validateRateLimit(pipelineName string, cfg *RateLimitConfig) error {
+	if cfg == nil {
+		return nil
+	}
+
+	if cfg.Rate < 0 {
+		return fmt.Errorf("pipeline '%s': rate limit rate cannot be negative", pipelineName)
+	}
+
+	if cfg.Burst < 0 {
+		return fmt.Errorf("pipeline '%s': rate limit burst cannot be negative", pipelineName)
+	}
+
+	// Validate policy
+	switch strings.ToLower(cfg.Policy) {
+	case "", "pass", "drop":
+		// Valid policies
+	default:
+		return fmt.Errorf("pipeline '%s': invalid rate limit policy '%s' (must be 'pass' or 'drop')",
+			pipelineName, cfg.Policy)
+	}
+
+	return nil
+}