feat: wip

Author: alanshaw

retrieval/client/connection.go

@@ -0,0 +1,70 @@
+package client
+
+import (
+	"context"
+	"crypto/sha256"
+	"fmt"
+	"hash"
+
+	"github.com/storacha/go-ucanto/client"
+	"github.com/storacha/go-ucanto/core/invocation"
+	"github.com/storacha/go-ucanto/core/message"
+	"github.com/storacha/go-ucanto/transport"
+	"github.com/storacha/go-ucanto/transport/headercar"
+	"github.com/storacha/go-ucanto/ucan"
+)
+
+func NewConnection(id ucan.Principal, channel transport.Channel) (*Connection, error) {
+	hasher := sha256.New
+	codec := headercar.NewOutboundCodec()
+	return &Connection{id, codec, channel, hasher}, nil
+}
+
+type Connection struct {
+	id      ucan.Principal
+	codec   transport.OutboundCodec
+	channel transport.Channel
+	hasher  func() hash.Hash
+}
+
+var _ client.Connection = (*Connection)(nil)
+
+func (c *Connection) ID() ucan.Principal {
+	return c.id
+}
+
+func (c *Connection) Codec() transport.OutboundCodec {
+	return c.codec
+}
+
+func (c *Connection) Channel() transport.Channel {
+	return c.channel
+}
+
+func (c *Connection) Hasher() hash.Hash {
+	return c.hasher()
+}
+
+func Execute(ctx context.Context, invocations []invocation.Invocation, conn client.Connection) (client.ExecutionResponse, error) {
+	input, err := message.Build(invocations, nil)
+	if err != nil {
+		return nil, fmt.Errorf("building message: %w", err)
+	}
+
+	req, err := conn.Codec().Encode(input)
+	if err != nil {
+		return nil, fmt.Errorf("encoding message: %w", err)
+	}
+
+	res, err := conn.Channel().Request(ctx, req)
+	if err != nil {
+		return nil, fmt.Errorf("sending message: %w", err)
+	}
+
+	output, err := conn.Codec().Decode(res)
+	if err != nil {
+		return nil, fmt.Errorf("decoding message: %w", err)
+	}
+
+	return client.ExecutionResponse(output), nil
+}

transport/headercar/codec.go

@@ -37,7 +37,7 @@ func (oc *OutboundCodec) Decode(res transport.HTTPResponse) (message.AgentMessag
 
 var _ transport.OutboundCodec = (*OutboundCodec)(nil)
 
-func NewOutboundCodec(opts ...OutboundOption) transport.OutboundCodec {
+func NewOutboundCodec(opts ...OutboundOption) *OutboundCodec {
 	cfg := outboundConfig{}
 	for _, option := range opts {
 		option(&cfg)