From 81a6eb13bc7731593e78db6d259cd2b1b43aad4c Mon Sep 17 00:00:00 2001
From: Dmitriy Ryajov <dryajov@gmail.com>
Date: Thu, 26 Oct 2023 09:11:50 -0600
Subject: [PATCH] wip

---
 codex/merkletree/backend.nim              |  0
 codex/merkletree/backends/dsbackend.nim   | 28 +++++++++++++++++++++++
 codex/merkletree/backends/merklestore.nim | 17 ++++++++++++++
 codex/merkletree/merkletree.nim           |  5 ++--
 codex/namespaces.nim                      |  3 +++
 5 files changed, 51 insertions(+), 2 deletions(-)
 create mode 100644 codex/merkletree/backend.nim
 create mode 100644 codex/merkletree/backends/dsbackend.nim
 create mode 100644 codex/merkletree/backends/merklestore.nim

diff --git a/codex/merkletree/backend.nim b/codex/merkletree/backend.nim
new file mode 100644
index 00000000..e69de29b
diff --git a/codex/merkletree/backends/dsbackend.nim b/codex/merkletree/backends/dsbackend.nim
new file mode 100644
index 00000000..6db98bbf
--- /dev/null
+++ b/codex/merkletree/backends/dsbackend.nim
@@ -0,0 +1,28 @@
+## Nim-Codex
+## Copyright (c) 2023 Status Research & Development GmbH
+## Licensed under either of
+##  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
+##  * MIT license ([LICENSE-MIT](LICENSE-MIT))
+## at your option.
+## This file may not be copied, modified, or distributed except according to
+## those terms.
+
+import ./merklestore
+import pkg/datastore
+import ../../namespaces
+
+type
+  DataStoreBackend* = ref object of MerkleStore
+    store*: Datastore
+
+method put*(
+  self: DataStoreBackend,
+  index, level: Natural,
+  hash: seq[byte]): Future[?!void] {.async.} =
+  success await self.store.put(index, hash)
+
+method get*(self: DataStoreBackend, index, level: Natural): Future[!?seq[byte]] =
+  raiseAssert("Not implemented!")
+
+func new*(_: type DataStoreBackend, store: Datastore): DataStoreBackend =
+  DataStoreBackend(store: store)
diff --git a/codex/merkletree/backends/merklestore.nim b/codex/merkletree/backends/merklestore.nim
new file mode 100644
index 00000000..eea9a5f0
--- /dev/null
+++ b/codex/merkletree/backends/merklestore.nim
@@ -0,0 +1,17 @@
+## Nim-Codex
+## Copyright (c) 2023 Status Research & Development GmbH
+## Licensed under either of
+##  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
+##  * MIT license ([LICENSE-MIT](LICENSE-MIT))
+## at your option.
+## This file may not be copied, modified, or distributed except according to
+## those terms.
+
+type
+  MerkleStore* = ref object of RootObj
+
+method put*(self: MerkleStore, index, level: Natural, hash: seq[byte]): Future[?!void] =
+  raiseAssert("Not implemented!")
+
+method get*(self: MerkleStore, index, level: Natural): Future[!?seq[byte]] =
+  raiseAssert("Not implemented!")
diff --git a/codex/merkletree/merkletree.nim b/codex/merkletree/merkletree.nim
index 5c96de6f..c67d5bd8 100644
--- a/codex/merkletree/merkletree.nim
+++ b/codex/merkletree/merkletree.nim
@@ -26,14 +26,14 @@ logScope:
   topics = "codex merkletree"
 
 type
-  MerkleTree* = object
+  MerkleTree* = ref object of RootObj
     mcodec: MultiCodec              # multicodec of the hash function
     height: Natural                 # current height of the tree (levels - 1)
     levels: Natural                 # number of levels in the tree (height + 1)
     leafs: Natural                  # total number of leafs, if odd the last leaf will be hashed twice
+    length: Natural                 # corrected to even number of leafs in the tree
     size: Natural                   # total number of nodes in the tree (corrected for odd leafs)
     leafsIter: AsyncIter[seq[byte]] # leafs iterator of the tree
-    nodesIter: AsyncIter[seq[byte]] # nodes iterator of the tree
 
   MerkleProof* = object
     mcodec: MultiCodec
@@ -135,6 +135,7 @@ func init*(
     self = MerkleTree(
       mcodec: mcodec,
       leafs: leafs,
+      length: length,
       size: size,
       height: height,
       levels: height - 1,
diff --git a/codex/namespaces.nim b/codex/namespaces.nim
index 42f5684a..761ac71a 100644
--- a/codex/namespaces.nim
+++ b/codex/namespaces.nim
@@ -14,6 +14,9 @@ const
   CodexBlockTotalNamespace* = CodexMetaNamespace & "/total"   # number of blocks in the repo
   CodexBlocksNamespace* = CodexRepoNamespace & "/blocks"      # blocks namespace
   CodexManifestNamespace* = CodexRepoNamespace & "/manifests" # manifest namespace
+  CodexMerkleTreeNamespace* = CodexRepoNamespace & "/trees"   # merkle tree namespace
+  CodexMerkleTreeHeader* =                                    # merkle tree header
+    CodexMerkleTreeNamespace & "/header"
   CodexBlocksTtlNamespace* =                                  # Cid TTL
     CodexMetaNamespace & "/ttl"
   CodexBlockProofNamespace* =                                  # Cid and Proof