fix: gateway/blocks-backend: GetBlock should not perform IPLD decoding (#845)

* gateway/blocks-backend: GetBlock should not perform IPLD decoding #673

Author: gsergey418

CHANGELOG.md

@@ -43,6 +43,7 @@ The following emojis are used to highlight certain changes:
 
 - Fix memory leaks due to not cleaning up wantlists [#829](https://github.com/ipfs/boxo/pull/829), [#833](https://github.com/ipfs/boxo/pull/833)
 - `ipns`: Improved interop with legacy clients by restoring support for `[]byte` CID in `Value` field. `Value()` will convert it to a valid `path.Path`. Empty `Value()` will produce `NoopPath` (`/ipfs/bafkqaaa`) to avoid breaking existing code that expects a valid record to always produce a valid content path. [#830](https://github.com/ipfs/boxo/pull/830)
+- `gateway/blocks-backend`: Removed IPLD decoding in GetBlock funciton in gateway's BlocksBackend. Now it's querying the blockService directly instead of dagService. [#845](https://github.com/ipfs/boxo/pull/845)
 
 
 ## [v0.27.3]

gateway/backend_blocks.go

@@ -211,12 +211,25 @@ func (bb *BlocksBackend) GetAll(ctx context.Context, path path.ImmutablePath) (C
 }
 
 func (bb *BlocksBackend) GetBlock(ctx context.Context, path path.ImmutablePath) (ContentPathMetadata, files.File, error) {
-	md, nd, err := bb.getNode(ctx, path)
+	roots, lastSeg, remainder, err := bb.getPathRoots(ctx, path)
+	if err != nil {
+		return ContentPathMetadata{}, nil, err
+	}
+
+	md := ContentPathMetadata{
+		PathSegmentRoots:     roots,
+		LastSegment:          lastSeg,
+		LastSegmentRemainder: remainder,
+	}
+
+	lastRoot := lastSeg.RootCid()
+
+	b, err := bb.blockService.GetBlock(ctx, lastRoot)
 	if err != nil {
 		return md, nil, err
 	}
 
-	return md, files.NewBytesFile(nd.RawData()), nil
+	return md, files.NewBytesFile(b.RawData()), nil
 }
 
 func (bb *BlocksBackend) Head(ctx context.Context, path path.ImmutablePath) (ContentPathMetadata, *HeadResponse, error) {