Implements building a minitree for block cells

codex/proof/datasampler.nim

@@ -1,9 +1,13 @@
 import ../contracts/requests
 import ../blocktype as bt
+import ../merkletree
 
 import std/bitops
 import std/sugar
 
+import pkg/chronicles
+import pkg/questionable
+import pkg/questionable/results
 import pkg/constantine/math/arithmetic
 import pkg/poseidon2/types
 import pkg/poseidon2
@@ -18,7 +22,7 @@ const
 type
   DSFieldElement* = F
   DSCellIndex* = uint64
-  DSSample* = seq[byte]
+  DSCell* = seq[byte]
 
 
 func extractLowBits*[n: static int](A: BigInt[n], k: int): uint64 =
@@ -73,10 +77,30 @@ proc getCellIndexInBlock*(cellIndex: DSCellIndex, blockSize: uint64): uint64 =
   let numberOfCellsPerBlock = blockSize div CellSize
   return cellIndex mod numberOfCellsPerBlock
 
-proc getSampleFromBlock*(blk: bt.Block, cellIndex: DSCellIndex, blockSize: uint64): DSSample =
+proc getCellFromBlock*(blk: bt.Block, cellIndex: DSCellIndex, blockSize: uint64): DSCell =
   let
     inBlockCellIndex = getCellIndexInBlock(cellIndex, blockSize)
     dataStart = (CellSize * inBlockCellIndex)
     dataEnd = dataStart + CellSize
 
   return blk.data[dataStart ..< dataEnd]
+
+proc getBlockCells*(blk: bt.Block, blockSize: uint64): seq[DSCell] =
+  let numberOfCellsPerBlock = blockSize div CellSize
+  var cells: seq[DSCell]
+  for i in 0..<numberOfCellsPerBlock:
+    cells.add(getCellFromBlock(blk, i, blockSize))
+  return cells
+
+proc getBlockCellMiniTree*(blk: bt.Block, blockSize: uint64): ?!MerkleTree =
+  without var builder =? MerkleTreeBuilder.init(): # TODO tree with poseidon2 as hasher please
+    error "Failed to create merkle tree builder"
+    return failure("Failed to create merkle tree builder")
+
+  let cells = getBlockCells(blk, blockSize)
+  for cell in cells:
+    if builder.addDataBlock(cell).isErr:
+      error "Failed to add cell data to tree"
+      return failure("Failed to add cell data to tree")
+
+  return builder.build()

tests/codex/proof/testdatasampler.nim

@@ -23,6 +23,7 @@ import pkg/codex/clock
 import pkg/codex/utils/asynciter
 import pkg/codex/contracts/requests
 import pkg/codex/contracts
+import pkg/codex/merkletree
 
 import pkg/codex/proof/datasampler
 import pkg/codex/proof/misc
@@ -167,24 +168,52 @@ asyncchecksuite "Test proof datasampler":
       check:
         cellIndexInBlock == expected.uint64
 
-  test "Can get sample from block":
+  test "Can get cell from block":
     let
       blockSize = CellSize * 3
       bytes = newSeqWith(blockSize.int, rand(uint8))
       blk = bt.Block.new(bytes).tryGet()
 
-      sample0 = getSampleFromBlock(blk, 0, blockSize.uint64)
-      sample1 = getSampleFromBlock(blk, 1, blockSize.uint64)
-      sample2 = getSampleFromBlock(blk, 2, blockSize.uint64)
+      sample0 = getCellFromBlock(blk, 0, blockSize.uint64)
+      sample1 = getCellFromBlock(blk, 1, blockSize.uint64)
+      sample2 = getCellFromBlock(blk, 2, blockSize.uint64)
 
     check:
       sample0 == bytes[0..<CellSize]
       sample1 == bytes[CellSize..<(CellSize*2)]
       sample2 == bytes[(CellSize*2)..^1]
 
-    # proc getSampleFromBlock(blk: bt.Block, cellIndex: DSCellIndex, blockSize: uint64): DSSample
+  test "Can convert block into cells":
+    let
+      blockSize = CellSize * 3
+      bytes = newSeqWith(blockSize.int, rand(uint8))
+      blk = bt.Block.new(bytes).tryGet()
 
+      cells = getBlockCells(blk, blockSize)
 
-    # let length = rand(4096)
-  # let bytes = newSeqWith(length, rand(uint8))
-  # bt.Block.new(bytes).tryGet()
+    check:
+      cells.len == 3
+      cells[0] == bytes[0..<CellSize]
+      cells[1] == bytes[CellSize..<(CellSize*2)]
+      cells[2] == bytes[(CellSize*2)..^1]
+
+  test "Can create mini tree for block cells":
+    let
+      blockSize = CellSize * 3
+      bytes = newSeqWith(blockSize.int, rand(uint8))
+      blk = bt.Block.new(bytes).tryGet()
+      cell0Bytes = bytes[0..<CellSize]
+      cell1Bytes = bytes[CellSize..<(CellSize*2)]
+      cell2Bytes = bytes[(CellSize*2)..^1]
+
+      miniTree = getBlockCellMiniTree(blk, blockSize).tryGet()
+
+    let
+      cell0Proof = miniTree.getProof(0).tryGet()
+      cell1Proof = miniTree.getProof(1).tryGet()
+      cell2Proof = miniTree.getProof(2).tryGet()
+
+    check:
+      cell0Proof.verifyDataBlock(cell0Bytes, miniTree.root).tryGet()
+      cell1Proof.verifyDataBlock(cell1Bytes, miniTree.root).tryGet()
+      cell2Proof.verifyDataBlock(cell2Bytes, miniTree.root).tryGet()