From 043a178bf25ac93528ce39ff52f387bb5b68fde3 Mon Sep 17 00:00:00 2001
From: Ian Shim <100327837+ian-shim@users.noreply.github.com>
Date: Wed, 18 Dec 2024 09:33:03 -0800
Subject: [PATCH] Add `AlreadyExists` error from disperser (#1026)

---
 api/errors.go                                  |  4 ++++
 disperser/apiserver/disperse_blob_v2.go        | 15 +++++++++++++++
 disperser/apiserver/server_v2_test.go          |  8 ++++++++
 disperser/common/v2/blobstore/s3_blob_store.go |  8 +++++++-
 4 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/api/errors.go b/api/errors.go
index 42632da105..de026f1655 100644
--- a/api/errors.go
+++ b/api/errors.go
@@ -62,6 +62,10 @@ func NewErrorCanceled(msg string) error {
 	return newErrorGRPC(codes.Canceled, msg)
 }
 
+func NewErrorAlreadyExists(msg string) error {
+	return newErrorGRPC(codes.AlreadyExists, msg)
+}
+
 // ErrorFailover is returned by the disperser-client and eigenda-client to signify
 // that eigenda is temporarily unavailable, and suggest to the caller
 // (most likely some rollup batcher via the eigenda-proxy) to failover
diff --git a/disperser/apiserver/disperse_blob_v2.go b/disperser/apiserver/disperse_blob_v2.go
index bffb62ad1b..c53c1bc66e 100644
--- a/disperser/apiserver/disperse_blob_v2.go
+++ b/disperser/apiserver/disperse_blob_v2.go
@@ -2,12 +2,14 @@ package apiserver
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"time"
 
 	"github.com/Layr-Labs/eigenda/api"
 	pb "github.com/Layr-Labs/eigenda/api/grpc/disperser/v2"
 	corev2 "github.com/Layr-Labs/eigenda/core/v2"
+	"github.com/Layr-Labs/eigenda/disperser/common"
 	dispv2 "github.com/Layr-Labs/eigenda/disperser/common/v2"
 	"github.com/Layr-Labs/eigenda/encoding"
 	"github.com/Layr-Labs/eigenda/encoding/rs"
@@ -60,6 +62,11 @@ func (s *DispersalServerV2) StoreBlob(ctx context.Context, data []byte, blobHead
 	}
 
 	if err := s.blobStore.StoreBlob(ctx, blobKey, data); err != nil {
+		s.logger.Warn("failed to store blob", "err", err, "blobKey", blobKey.Hex())
+		if errors.Is(err, common.ErrAlreadyExists) {
+			return corev2.BlobKey{}, api.NewErrorAlreadyExists(fmt.Sprintf("blob already exists: %s", blobKey.Hex()))
+		}
+
 		return corev2.BlobKey{}, api.NewErrorInternal(fmt.Sprintf("failed to store blob: %v", err))
 	}
 
@@ -73,6 +80,14 @@ func (s *DispersalServerV2) StoreBlob(ctx context.Context, data []byte, blobHead
 		UpdatedAt:   uint64(requestedAt.UnixNano()),
 	}
 	err = s.blobMetadataStore.PutBlobMetadata(ctx, blobMetadata)
+	if err != nil {
+		s.logger.Warn("failed to store blob metadata", "err", err, "blobKey", blobKey.Hex())
+		if errors.Is(err, common.ErrAlreadyExists) {
+			return corev2.BlobKey{}, api.NewErrorAlreadyExists(fmt.Sprintf("blob metadata already exists: %s", blobKey.Hex()))
+		}
+
+		return corev2.BlobKey{}, api.NewErrorInternal(fmt.Sprintf("failed to store blob metadata: %v", err))
+	}
 	return blobKey, err
 }
 
diff --git a/disperser/apiserver/server_v2_test.go b/disperser/apiserver/server_v2_test.go
index a5decc958b..c26260ec66 100644
--- a/disperser/apiserver/server_v2_test.go
+++ b/disperser/apiserver/server_v2_test.go
@@ -106,6 +106,14 @@ func TestV2DisperseBlob(t *testing.T) {
 	assert.Greater(t, blobMetadata.Expiry, uint64(now.Unix()))
 	assert.Greater(t, blobMetadata.RequestedAt, uint64(now.UnixNano()))
 	assert.Equal(t, blobMetadata.RequestedAt, blobMetadata.UpdatedAt)
+
+	// Try dispersing the same blob
+	reply, err = c.DispersalServerV2.DisperseBlob(ctx, &pbv2.DisperseBlobRequest{
+		Data:       data,
+		BlobHeader: blobHeaderProto,
+	})
+	assert.Nil(t, reply)
+	assert.ErrorContains(t, err, "blob already exists")
 }
 
 func TestV2DisperseBlobRequestValidation(t *testing.T) {
diff --git a/disperser/common/v2/blobstore/s3_blob_store.go b/disperser/common/v2/blobstore/s3_blob_store.go
index 5bcfbf1176..433af0a765 100644
--- a/disperser/common/v2/blobstore/s3_blob_store.go
+++ b/disperser/common/v2/blobstore/s3_blob_store.go
@@ -26,7 +26,13 @@ func NewBlobStore(s3BucketName string, s3Client s3.Client, logger logging.Logger
 
 // StoreBlob adds a blob to the blob store
 func (b *BlobStore) StoreBlob(ctx context.Context, key corev2.BlobKey, data []byte) error {
-	err := b.s3Client.UploadObject(ctx, b.bucketName, s3.ScopedBlobKey(key), data)
+	_, err := b.s3Client.HeadObject(ctx, b.bucketName, s3.ScopedBlobKey(key))
+	if err == nil {
+		b.logger.Warnf("blob already exists in bucket %s: %s", b.bucketName, key)
+		return common.ErrAlreadyExists
+	}
+
+	err = b.s3Client.UploadObject(ctx, b.bucketName, s3.ScopedBlobKey(key), data)
 	if err != nil {
 		b.logger.Errorf("failed to upload blob in bucket %s: %v", b.bucketName, err)
 		return err