add prestate.nim

premix/prestate.nim

@@ -0,0 +1,44 @@
+import
+  json, downloader, stint, eth_trie/db, byteutils,
+  ../nimbus/db/[db_chain, storage_types], rlp, eth_common,
+  ../nimbus/p2p/chain, ../nimbus/tracer
+
+proc generatePrestate*(nimbus: JsonNode) =
+  let
+    state  = nimbus["state"]
+    blockNumber  = 49439.u256
+    parentNumber = blockNumber - 1.u256
+    parentBlock  = requestBlock(parentNumber)
+    thisBlock    = requestBlock(blockNumber)
+    headerHash   = rlpHash(thisBlock.header)
+
+  var
+    memoryDB = newMemoryDB()
+    chainDB = newBaseChainDB(memoryDB, false)
+
+  chainDB.setHead(parentBlock.header, true)
+  chainDB.persistTransactions(blockNumber, thisBlock.body.transactions)
+  discard chainDB.persistUncles(thisBlock.body.uncles)
+
+  memoryDB.put(genericHashKey(headerHash).toOpenArray, rlp.encode(thisBlock.header))
+  chainDB.addBlockNumberToHashLookup(thisBlock.header)
+
+  for k, v in state:
+    let key = hexToSeqByte(k)
+    let value = hexToSeqByte(v.getStr())
+    memoryDB.put(key, value)
+
+  let
+    chain = newChain(chainDB)
+    parent = chainDB.getBlockHeader(parentNumber)
+    header = chainDB.getBlockHeader(blockNumber)
+    body = chainDB.getBlockBody(headerHash)
+    headers = @[header]
+    bodies = @[body]
+
+  var metaData = %{
+    "blockNumber": %blockNumber.toHex
+  }
+
+  metaData.dumpMemoryDB(memoryDB)
+  writeFile("block" & $blockNumber & ".json", metaData.pretty())