Implements getting treeCID from slot

codex/proof/slotblocks.nim

@@ -2,15 +2,29 @@ import std/bitops
 import std/sugar
 
 import pkg/chronos
+import pkg/chronicles
 import pkg/libp2p
 import pkg/questionable
 import pkg/questionable/results
 
 import ../contracts/requests
 import ../stores/blockstore
+import ../manifest
 
 proc getTreeCidForSlot*(slot: Slot, blockstore: BlockStore): Future[?!Cid] {.async.} =
-  raiseAssert("a")
+  without manifestBlockCid =? Cid.init(slot.request.content.cid).mapFailure, err:
+    error "Unable to init CID from slot.content.cid"
+    return failure err
+
+  without manifestBlock =? await blockstore.getBlock(manifestBlockCid), err:
+    error "Failed to fetch manifest block", cid = manifestBlockCid
+    return failure err
+
+  without manifest =? Manifest.decode(manifestBlock):
+    error "Unable to decode manifest"
+    return failure("Unable to decode manifest")
+
+  return success(manifest.treeCid)
 
 proc getSlotBlock*(slot: Slot, blockstore: BlockStore, treeCid: Cid, slotBlockIndex: int): Future[?!Block] {.async.} =
   raiseAssert("a")

tests/codex/proof/testslotblocks.nim

@@ -41,6 +41,8 @@ asyncchecksuite "Test slotblocks":
       treeCid = Cid.example,
       blockSize = 1.MiBs,
       datasetSize = 100.MiBs)
+
+  var
     manifestBlock = bt.Block.new(manifest.encode().tryGet(), codec = DagPBCodec).tryGet()
     slot = Slot(
       request: StorageRequest(
@@ -67,7 +69,8 @@ asyncchecksuite "Test slotblocks":
   #       break
   #     slotBlocks.add(bt.Block.new(chunk).tryGet())
 
-  # setup:
+  setup:
+    discard await localStore.putBlock(manifestBlock)
   #   await createSlotBlocks()
 
   test "Can get tree root for slot":
@@ -75,3 +78,29 @@ asyncchecksuite "Test slotblocks":
 
     check:
       cid == manifest.treeCid
+
+  test "Can fail to get tree root for invalid cid":
+    slot.request.content.cid = "invalid"
+    let cid = (await getTreeCidForSlot(slot, localStore))
+
+    check:
+      cid.isErr
+
+  test "Can fail to get tree root when manifest block not found":
+    let
+      emptyStore = CacheStore.new()
+      cid = (await getTreeCidForSlot(slot, emptyStore))
+
+    check:
+      cid.isErr
+
+  test "Can fail to get tree root when manifest fails to decode":
+    manifestBlock.data = @[]
+
+    let cid = (await getTreeCidForSlot(slot, localStore))
+
+    check:
+      cid.isErr
+
+
+