Implement v2 client GET functionality

api/clients/codecs/mock/BlobCodec.go

@@ -0,0 +1,68 @@
+package mock
+
+import mock "github.com/stretchr/testify/mock"
+
+// BlobCodec is an autogenerated mock type for the BlobCodec type
+type BlobCodec struct {
+	mock.Mock
+}
+
+// DecodeBlob provides a mock function with given fields: encodedData
+func (_m *BlobCodec) DecodeBlob(encodedData []byte) ([]byte, error) {
+	ret := _m.Called(encodedData)
+
+	if len(ret) == 0 {
+		panic("no return value specified for DecodeBlob")
+	}
+
+	var r0 []byte
+	var r1 error
+	if rf, ok := ret.Get(0).(func([]byte) ([]byte, error)); ok {
+		return rf(encodedData)
+	}
+	if rf, ok := ret.Get(0).(func([]byte) []byte); ok {
+		r0 = rf(encodedData)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).([]byte)
+		}
+	}
+
+	if rf, ok := ret.Get(1).(func([]byte) error); ok {
+		r1 = rf(encodedData)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
+// EncodeBlob provides a mock function with given fields: rawData
+func (_m *BlobCodec) EncodeBlob(rawData []byte) ([]byte, error) {
+	ret := _m.Called(rawData)
+
+	if len(ret) == 0 {
+		panic("no return value specified for EncodeBlob")
+	}
+
+	var r0 []byte
+	var r1 error
+	if rf, ok := ret.Get(0).(func([]byte) ([]byte, error)); ok {
+		return rf(rawData)
+	}
+	if rf, ok := ret.Get(0).(func([]byte) []byte); ok {
+		r0 = rf(rawData)
+	} else {
+		if ret.Get(0) != nil {
+			r0 = ret.Get(0).([]byte)
+		}
+	}
+
+	if rf, ok := ret.Get(1).(func([]byte) error); ok {
+		r1 = rf(rawData)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}

api/clients/eigenda_client_v2.go

@@ -0,0 +1,142 @@
+package clients
+
+import (
+	"context"
+	"fmt"
+	"github.com/Layr-Labs/eigenda/api/clients/codecs"
+	corev2 "github.com/Layr-Labs/eigenda/core/v2"
+	"github.com/Layr-Labs/eigensdk-go/logging"
+	"github.com/hashicorp/go-multierror"
+	"math/rand"
+)
+
+// EigenDAClientV2 provides the ability to get blobs from the relay subsystem, and to send new blobs to the disperser.
+type EigenDAClientV2 interface {
+	// GetBlob iteratively attempts to retrieve a given blob with key blobKey from the relays listed in the blobCertificate.
+	GetBlob(ctx context.Context, blobKey corev2.BlobKey, blobCertificate corev2.BlobCertificate) ([]byte, error)
+	GetCodec() codecs.BlobCodec
+	Close() error
+}
+
+type eigenDAClientV2 struct {
+	clientConfig EigenDAClientConfig
+	log          logging.Logger
+	relayClient  RelayClient
+	codec        codecs.BlobCodec
+}
+
+var _ EigenDAClientV2 = &eigenDAClientV2{}
+
+// BuildEigenDAClientV2 builds an EigenDAClientV2 from config structs.
+func BuildEigenDAClientV2(
+	log logging.Logger,
+	clientConfig EigenDAClientConfig,
+	relayClientConfig RelayClientConfig) (EigenDAClientV2, error) {
+
+	err := clientConfig.CheckAndSetDefaults()
+	if err != nil {
+		return nil, err
+	}
+
+	relayClient, err := NewRelayClient(&relayClientConfig, log)
+
+	lowLevelCodec, err := codecs.BlobEncodingVersionToCodec(clientConfig.PutBlobEncodingVersion)
+	if err != nil {
+		return nil, fmt.Errorf("create low level codec: %w", err)
+	}
+	var codec codecs.BlobCodec
+	if clientConfig.DisablePointVerificationMode {
+		codec = codecs.NewNoIFFTCodec(lowLevelCodec)
+	} else {
+		codec = codecs.NewIFFTCodec(lowLevelCodec)
+	}
+
+	return NewEigenDAClientV2(log, clientConfig, relayClient, codec)
+}
+
+// NewEigenDAClientV2 assembles an EigenDAClientV2 from subcomponents that have already been constructed and initialized.
+func NewEigenDAClientV2(
+	log logging.Logger,
+	clientConfig EigenDAClientConfig,
+	relayClient RelayClient,
+	codec codecs.BlobCodec) (EigenDAClientV2, error) {
+
+	return &eigenDAClientV2{
+		clientConfig: clientConfig,
+		log:          log,
+		relayClient:  relayClient,
+		codec:        codec,
+	}, nil
+}
+
+// GetBlob iteratively attempts to retrieve a given blob with key blobKey from the relays listed in the blobCertificate.
+//
+// The relays are attempted in random order.
+//
+// The returned blob is decoded.
+func (c *eigenDAClientV2) GetBlob(ctx context.Context, blobKey corev2.BlobKey, blobCertificate corev2.BlobCertificate) ([]byte, error) {
+	// create a randomized array of indices, so that it isn't always the first relay in the list which gets hit
+	random := rand.New(rand.NewSource(rand.Int63()))
+	relayKeyCount := len(blobCertificate.RelayKeys)
+	var indices []int
+	for i := 0; i < relayKeyCount; i++ {
+		indices = append(indices, i)
+	}
+	random.Shuffle(len(indices), func(i int, j int) {
+		indices[i], indices[j] = indices[j], indices[i]
+	})
+
+	// TODO (litt3): consider creating a utility which can deprioritize relays that fail to respond (or respond maliciously)
+
+	// iterate over relays in random order, until we are able to get the blob from someone
+	for _, val := range indices {
+		relayKey := blobCertificate.RelayKeys[val]
+
+		data, err := c.relayClient.GetBlob(ctx, relayKey, blobKey)
+
+		// if GetBlob returned an error, try calling a different relay
+		if err != nil {
+			// TODO: should this log type be downgraded to debug to avoid log spam? I'm not sure how frequent retrieval
+			//  from a relay will fail in practice (?)
+			c.log.Info("blob couldn't be retrieved from relay", "blobKey", blobKey, "relayKey", relayKey)
+			continue
+		}
+
+		// An honest relay should never send an empty blob
+		if len(data) == 0 {
+			c.log.Warn("blob received from relay had length 0", "blobKey", blobKey, "relayKey", relayKey)
+			continue
+		}
+
+		// An honest relay should never send a blob which cannot be decoded
+		decodedData, err := c.codec.DecodeBlob(data)
+		if err != nil {
+			c.log.Warn("error decoding blob", "blobKey", blobKey, "relayKey", relayKey)
+			continue
+		}
+
+		return decodedData, nil
+	}
+
+	return nil, fmt.Errorf("unable to retrieve blob from any relay")
+}
+
+func (c *eigenDAClientV2) GetCodec() codecs.BlobCodec {
+	return c.codec
+}
+
+func (c *eigenDAClientV2) Close() error {
+	var errList *multierror.Error
+
+	// TODO: this is using a multierror, since there will be more subcomponents requiring closing after adding PUT functionality
+	relayClientErr := c.relayClient.Close()
+	if relayClientErr != nil {
+		errList = multierror.Append(errList, relayClientErr)
+	}
+
+	if errList != nil {
+		return errList.ErrorOrNil()
+	}
+
+	return nil
+}