Add Segregated Witness support for Emercoin (#835)

electrumx/lib/coins.py

@@ -522,7 +522,7 @@ class Emercoin(Coin):
     VALUE_PER_COIN = 1000000
     RPC_PORT = 6662
 
-    DESERIALIZER = lib_tx.DeserializerTxTimeAuxPow
+    DESERIALIZER = lib_tx.DeserializerEmercoin
 
     PEERS = []
 

electrumx/lib/tx.py

@@ -386,6 +386,65 @@ class DeserializerTxTime(Deserializer):
         )
 
 
+class TxTimeSegWit(namedtuple(
+        "Tx", "version time marker flag inputs outputs witness locktime")):
+    '''Class representing a SegWit transaction with time.'''
+
+
+class DeserializerTxTimeSegWit(DeserializerTxTime):
+    def _read_witness(self, fields):
+        read_witness_field = self._read_witness_field
+        return [read_witness_field() for _ in range(fields)]
+
+    def _read_witness_field(self):
+        read_varbytes = self._read_varbytes
+        return [read_varbytes() for _ in range(self._read_varint())]
+
+    def _read_tx_parts(self):
+        '''Return a (deserialized TX, tx_hash, vsize) tuple.'''
+        start = self.cursor
+        marker = self.binary[self.cursor + 8]
+        if marker:
+            tx = super().read_tx()
+            tx_hash = self.TX_HASH_FN(self.binary[start:self.cursor])
+            return tx, tx_hash, self.binary_length
+
+        version = self._read_le_int32()
+        time = self._read_le_uint32()
+        orig_ser = self.binary[start:self.cursor]
+
+        marker = self._read_byte()
+        flag = self._read_byte()
+
+        start = self.cursor
+        inputs = self._read_inputs()
+        outputs = self._read_outputs()
+        orig_ser += self.binary[start:self.cursor]
+
+        base_size = self.cursor - start
+        witness = self._read_witness(len(inputs))
+
+        start = self.cursor
+        locktime = self._read_le_uint32()
+        orig_ser += self.binary[start:self.cursor]
+        vsize = (3 * base_size + self.binary_length) // 4
+
+        return TxTimeSegWit(
+            version, time, marker, flag, inputs, outputs, witness, locktime),\
+            self.TX_HASH_FN(orig_ser), vsize
+
+    def read_tx(self):
+        return self._read_tx_parts()[0]
+
+    def read_tx_and_hash(self):
+        tx, tx_hash, vsize = self._read_tx_parts()
+        return tx, tx_hash
+
+    def read_tx_and_vsize(self):
+        tx, tx_hash, vsize = self._read_tx_parts()
+        return tx, vsize
+
+
 class TxTrezarcoin(
         namedtuple("Tx", "version time inputs outputs locktime txcomment")):
     '''Class representing transaction that has a time and txcomment field.'''
@@ -454,7 +513,7 @@ class DeserializerReddcoin(Deserializer):
         return TxTime(version, time, inputs, outputs, locktime)
 
 
-class DeserializerTxTimeAuxPow(DeserializerTxTime):
+class DeserializerEmercoin(DeserializerTxTimeSegWit):
     VERSION_AUXPOW = (1 << 8)
 
     def is_merged_block(self):

tests/blocks/emercoin_mainnet_357826.json

@@ -0,0 +1,15 @@
+{
+  "hash": "3547b7602c258ecbcc41add2a88ae7a17ba4ba652738665f2d251721f5ef5c10",
+  "size": 529,
+  "height": 357826,
+  "merkleroot": "e3006f819f8d63d775fb9768c79459020af2476378038582ae84b161a0ba0acc",
+  "tx": [
+    "9a5459ab695dc33350fe8cda07e0e7d0785a8ffd15ab15ce24e71b7c29032ac0",
+    "478e827fd064766f3ffd4a48d66436d3f5b4067d8f23eb61138e9d79b2b44c0e"
+  ],
+  "time": 1559191908,
+  "nonce": 0,
+  "bits": "1c0bd7cd",
+  "previousblockhash": "7a6ca59966f6c64c63e3a7368e69d802bcce24bb4e52f4913e38440ec4511599",
+  "block": "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"
+}