cleanup: return NotFound if blob stored w/o chunking

Author: tyler-french

server/remote_cache/chunking/chunking.go

@@ -4,7 +4,6 @@ package chunking
 import (
 	"context"
 	"encoding/hex"
-	"errors"
 	"flag"
 	"fmt"
 	"io"
@@ -293,17 +292,7 @@ func LoadManifest(ctx context.Context, cache interfaces.Cache, blobDigest *repb.
 		if status.IsInternalError(err) {
 			log.CtxInfof(ctx, "Failed to get chunking manifest (blob %s, manifest key %s): %v", blobDigest.GetHash(), acRNProto.GetDigest().GetHash(), err)
 		}
-		err = sanitizeManifestError(err, acRNProto.GetDigest().GetHash(), blobDigest.GetHash())
-		if status.IsNotFoundError(err) {
-			blobRN := digest.NewCASResourceName(blobDigest, instanceName, digestFunction).ToProto()
-			if exists, existsErr := cache.Contains(ctx, blobRN); existsErr != nil {
-				return nil, errors.Join(existsErr, err)
-			} else if exists {
-				return nil, status.UnimplementedErrorf("blob %s exists but was not stored with chunking", blobDigest.GetHash())
-			}
-			return nil, err
-		}
-		return nil, status.InternalErrorf("retrieve chunked manifest from AC: %w", err)
+		return nil, sanitizeManifestError(err, acRNProto.GetDigest().GetHash(), blobDigest.GetHash())
 	}
 
 	ar := &repb.ActionResult{}

server/remote_cache/chunking/chunking_test.go

@@ -183,22 +183,6 @@ func TestStoreAndLoad(t *testing.T) {
 	}
 }
 
-func TestLoadWithoutManifest_BlobExists(t *testing.T) {
-	ctx := context.Background()
-	te := testenv.GetTestEnv(t)
-	ctx, err := prefix.AttachUserPrefixToContext(ctx, te.GetAuthenticator())
-	require.NoError(t, err)
-	cache := te.GetCache()
-
-	blobRN, blobData := testdigest.RandomCASResourceBuf(t, 500)
-	require.NoError(t, cache.Set(ctx, blobRN, blobData))
-
-	_, err = chunking.LoadManifest(ctx, cache, blobRN.GetDigest(), "", repb.DigestFunction_SHA256)
-	require.Error(t, err)
-	require.True(t, status.IsUnimplementedError(err))
-	assert.Contains(t, err.Error(), "exists but was not stored with chunking")
-}
-
 func TestLoadWithoutManifest_BlobMissing(t *testing.T) {
 	ctx := context.Background()
 	te := testenv.GetTestEnv(t)

server/remote_cache/content_addressable_storage_server/content_addressable_storage_server.go

@@ -1219,9 +1219,6 @@ func (s *ContentAddressableStorageServer) SplitBlob(ctx context.Context, req *re
 
 	manifest, err := chunking.LoadManifest(ctx, s.cache, req.GetBlobDigest(), req.GetInstanceName(), req.GetDigestFunction())
 	if err != nil {
-		// TODO(buildbuddy-internal#6426): Unimplemented is returned when the blob
-		// exists but wasn't stored with chunking. In the future, we could return
-		// the blob as a single chunk to better comply with the RE API contract.
 		return nil, err
 	}