Bandaid for failing erasure coding (#855)

codex/erasure/asyncbackend.nim

@@ -114,15 +114,29 @@ proc proxySpawnEncodeTask(
   args: EncodeTaskArgs,
   data: ref seq[seq[byte]]
 ): Flowvar[EncodeTaskResult] =
-  tp.spawn encodeTask(args, data[])
+  # FIXME Uncomment the code below after addressing an issue:
+  # https://github.com/codex-storage/nim-codex/issues/854
+
+  # tp.spawn encodeTask(args, data[])
+
+  let fv = EncodeTaskResult.newFlowVar
+  fv.readyWith(encodeTask(args, data[]))
+  return fv
 
 proc proxySpawnDecodeTask(
   tp: Taskpool,
   args: DecodeTaskArgs,
   data: ref seq[seq[byte]],
   parity: ref seq[seq[byte]]
 ): Flowvar[DecodeTaskResult] =
-  tp.spawn decodeTask(args, data[], parity[])
+  # FIXME Uncomment the code below after addressing an issue:
+  # https://github.com/codex-storage/nim-codex/issues/854
+
+  # tp.spawn decodeTask(args, data[], parity[])
+
+  let fv = DecodeTaskResult.newFlowVar
+  fv.readyWith(decodeTask(args, data[], parity[]))
+  return fv
 
 proc awaitResult[T](signal: ThreadSignalPtr, handle: Flowvar[T]): Future[?!T] {.async.} =
   await wait(signal)

tests/codex/testerasure.nim

@@ -252,3 +252,22 @@ suite "Erasure encode/decode":
       decoded.treeCid == manifest.treeCid
       decoded.treeCid == verifiable.originalTreeCid
       decoded.blocksCount == verifiable.originalBlocksCount
+
+  for i in 1..5:
+    test "Should encode/decode using various parameters " & $i & "/5":
+      let
+        blockSize   = rng.sample(@[1, 2, 4, 8, 16, 32, 64].mapIt(it.KiBs))
+        datasetSize = 1.MiBs
+        ecK         = 10.Natural
+        ecM         = 10.Natural
+
+      let
+        chunker = RandomChunker.new(rng, size = datasetSize, chunkSize = blockSize)
+        manifest = await storeDataGetManifest(store, chunker)
+        encoded = (await erasure.encode(manifest, ecK, ecM)).tryGet()
+        decoded = (await erasure.decode(encoded)).tryGet()
+
+      check:
+        decoded.treeCid == manifest.treeCid
+        decoded.treeCid == encoded.originalTreeCid
+        decoded.blocksCount == encoded.originalBlocksCount