feat: add independent platform modules and multi-provider storage

resilience/http.go

@@ -0,0 +1,67 @@
+package resilience
+
+import (
+	"errors"
+	"io"
+	"net/http"
+)
+
+// Transport isolates one logical upstream. Create separate Breakers for
+// different dependencies. Slots remain occupied until body Close/EOF.
+type Transport struct {
+	Base    http.RoundTripper
+	Breaker *Breaker
+}
+
+func (t Transport) RoundTrip(r *http.Request) (*http.Response, error) {
+	if t.Breaker == nil {
+		return nil, errors.New("resilience: breaker required")
+	}
+	done, err := t.Breaker.Acquire(r.Context())
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if v := recover(); v != nil {
+			done(false)
+			panic(v)
+		}
+	}()
+	base := t.Base
+	if base == nil {
+		base = http.DefaultTransport
+	}
+	response, err := base.RoundTrip(r)
+	if err != nil {
+		done(!t.Breaker.config.IsFailure(err))
+		if response != nil && response.Body != nil {
+			response.Body.Close()
+		}
+		return nil, err
+	}
+	if response == nil || response.Body == nil {
+		done(false)
+		return nil, errors.New("resilience: invalid transport response")
+	}
+	response.Body = &breakerBody{ReadCloser: response.Body, done: done, success: response.StatusCode < 500}
+	return response, nil
+}
+
+type breakerBody struct {
+	io.ReadCloser
+	done    func(bool)
+	success bool
+}
+
+func (b *breakerBody) Read(p []byte) (int, error) {
+	n, err := b.ReadCloser.Read(p)
+	if err != nil {
+		b.done(b.success && err == io.EOF)
+	}
+	return n, err
+}
+func (b *breakerBody) Close() error {
+	err := b.ReadCloser.Close()
+	b.done(b.success && err == nil)
+	return err
+}