fix linearstrategy, use verifiableStrategy to select blocks for slots

codex/indexingstrategy.nim

@@ -49,8 +49,8 @@ func getLinearIndicies(
   self.checkIteration(iteration)
 
   let
-    first = self.firstIndex + iteration * (self.step + 1)
-    last = min(first + self.step, self.lastIndex)
+    first = self.firstIndex + iteration * self.step
+    last = min(first + self.step - 1, self.lastIndex)
 
   getIter(first, last, 1)
 
@@ -94,4 +94,4 @@ func init*(
     firstIndex: firstIndex,
     lastIndex: lastIndex,
     iterations: iterations,
-    step: divUp((lastIndex - firstIndex), iterations))
+    step: divUp((lastIndex - firstIndex + 1), iterations))

codex/manifest/manifest.nim

@@ -231,7 +231,7 @@ func new*(
   treeCid: Cid,
   datasetSize: NBytes,
   ecK, ecM: int,
-  strategy: StrategyType): Manifest =
+  strategy = SteppedStrategy): Manifest =
   ## Create an erasure protected dataset from an
   ## unprotected one
   ##
@@ -277,7 +277,7 @@ func new*(
   ecM: int,
   originalTreeCid: Cid,
   originalDatasetSize: NBytes,
-  strategy: StrategyType): Manifest =
+  strategy = SteppedStrategy): Manifest =
 
   Manifest(
     treeCid: treeCid,
@@ -299,7 +299,7 @@ func new*(
   verifyRoot: Cid,
   slotRoots: openArray[Cid],
   cellSize = DefaultCellSize,
-  strategy = SteppedStrategy): ?!Manifest =
+  strategy = LinearStrategy): ?!Manifest =
   ## Create a verifiable dataset from an
   ## protected one
   ##

codex/node.nim

@@ -534,7 +534,9 @@ proc onStore(
     trace "Unable to fetch manifest for cid", cid, err = err.msg
     return failure(err)
 
-  without builder =? Poseidon2Builder.new(self.networkStore, manifest), err:
+  without builder =? Poseidon2Builder.new(
+    self.networkStore, manifest, manifest.verifiableStrategy
+  ), err:
     trace "Unable to create slots builder", err = err.msg
     return failure(err)
 
@@ -559,8 +561,8 @@ proc onStore(
 
     return success()
 
-  without indexer =? manifest.protectedStrategy.init(
-    0, manifest.numSlotBlocks() - 1, manifest.numSlots).catch, err:
+  without indexer =? manifest.verifiableStrategy.init(
+    0, manifest.blocksCount - 1, manifest.numSlots).catch, err:
     trace "Unable to create indexing strategy from protected manifest", err = err.msg
     return failure(err)
 

tests/codex/node/testcontracts.nim

@@ -131,7 +131,7 @@ asyncchecksuite "Test Node - Host contracts":
       return success()
 
     (await onStore(request, 1.u256, onBlocks)).tryGet()
-    check fetchedBytes == 262144
+    check fetchedBytes == 12 * DefaultBlockSize.uint
 
     let indexer = verifiable.protectedStrategy.init(
       0, verifiable.numSlotBlocks() - 1, verifiable.numSlots)

tests/codex/testindexingstrategy.nim

@@ -58,6 +58,14 @@ suite "Indexing strategies":
     expect IndexingWrongIterationsError:
       discard LinearStrategy.init(0, 10, 0)
 
+  test "should split elements evenly when possible":
+    let
+      l = LinearStrategy.init(0, 11, 3)
+    check:
+      toSeq(l.getIndicies(0)) == @[0, 1, 2, 3].mapIt(it)
+      toSeq(l.getIndicies(1)) == @[4, 5, 6, 7].mapIt(it)
+      toSeq(l.getIndicies(2)) == @[8, 9, 10, 11].mapIt(it)
+
   test "linear - oob":
     expect IndexingError:
       discard linear.getIndicies(3)