Fixed MetadataV14 block author retrieval #138

polkascan · Oct 14, 2021 · 1cadcbe · 1cadcbe
1 parent 4be05f0
commit 1cadcbe
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Showing 4 changed files with 39 additions and 16 deletions.
diff --git a/requirements.txt b/requirements.txt
@@ -6,7 +6,7 @@ requests>=2.21.0,<3
 xxhash>=1.3.0,<3
 pytest>=4.4.0
 
-scalecodec>=1.0.6,<2
+scalecodec>=1.0.9,<2
 py-sr25519-bindings~=0.1.2
 py-ed25519-bindings~=0.1.2
 py-bip39-bindings~=0.1.6
diff --git a/setup.py b/setup.py
@@ -182,7 +182,7 @@
         'idna>=2.1.0,<4',
         'requests>=2.21.0,<3',
         'xxhash>=1.3.0,<3',
-        'scalecodec>=1.0.6,<2',
+        'scalecodec>=1.0.9,<2',
         'py-sr25519-bindings~=0.1.2',
         'py-ed25519-bindings~=0.1.2',
         'py-bip39-bindings~=0.1.6'

diff --git a/substrateinterface/base.py b/substrateinterface/base.py
@@ -2206,10 +2206,12 @@ def __get_block_handler(self, block_hash: str, ignore_decoding_errors: bool = Fa
         except BlockNotFound:
             return None
 
-        def decode_block(block_data):
+        def decode_block(block_data, block_data_hash=None):
 
             if block_data:
-                block_data['header']['hash'] = block_hash
+                if block_data_hash:
+                    block_data['header']['hash'] = block_data_hash
+
                 block_data['header']['number'] = int(block_data['header']['number'], 16)
 
                 extrinsic_cls = self.runtime_config.get_decoder_class('Extrinsic')
@@ -2245,16 +2247,37 @@ def decode_block(block_data):
 
                         if include_author and 'PreRuntime' in log_digest.value:
 
-                            if log_digest.value['PreRuntime']['engine'] == 'BABE':
-                                validator_set = self.query("Session", "Validators", block_hash=block_hash)
-                                rank_validator = log_digest.value['PreRuntime']['data']['authority_index']
+                            if self.implements_scaleinfo():
+                                if log_digest.value['PreRuntime'][0] == f"0x{b'BABE'.hex()}":
+                                    babe_predigest = self.runtime_config.create_scale_object(
+                                        type_string='RawBabePreDigest',
+                                        data=ScaleBytes(log_digest.value['PreRuntime'][1])
+                                    )
+
+                                    babe_predigest.decode()
+
+                                    validator_set = self.query("Session", "Validators", block_hash=block_hash)
+                                    rank_validator = babe_predigest[1].value['authority_index']
+
+                                    block_author = validator_set[rank_validator]
+                                    block_data['author'] = block_author.value
 
-                                block_author = validator_set.elements[rank_validator]
-                                block_data['author'] = block_author.value
+                                else:
+                                    raise NotImplementedError(
+                                        f"Cannot extract author for engine {log_digest.value['PreRuntime'][0]}"
+                                    )
                             else:
-                                raise NotImplementedError(
-                                    f"Cannot extract author for engine {log_digest.value['PreRuntime']['engine']}"
-                                )
+
+                                if log_digest.value['PreRuntime']['engine'] == 'BABE':
+                                    validator_set = self.query("Session", "Validators", block_hash=block_hash)
+                                    rank_validator = log_digest.value['PreRuntime']['data']['authority_index']
+
+                                    block_author = validator_set.elements[rank_validator]
+                                    block_data['author'] = block_author.value
+                                else:
+                                    raise NotImplementedError(
+                                        f"Cannot extract author for engine {log_digest.value['PreRuntime']['engine']}"
+                                    )
 
                     except Exception:
                         if not ignore_decoding_errors:
@@ -2287,11 +2310,11 @@ def result_handler(message, update_nr, subscription_id):
 
             if header_only:
                 response = self.rpc_request('chain_getHeader', [block_hash])
-                return decode_block({'header': response['result']})
+                return decode_block({'header': response['result']}, block_data_hash=block_hash)
 
             else:
                 response = self.rpc_request('chain_getBlock', [block_hash])
-                return decode_block(response['result']['block'])
+                return decode_block(response['result']['block'], block_data_hash=block_hash)
 
     def get_block(self, block_hash: str = None, block_number: int = None, ignore_decoding_errors: bool = False,
                   include_author: bool = False, finalized_only: bool = False):

diff --git a/test/test_block.py b/test/test_block.py
@@ -248,11 +248,11 @@ def test_include_author(self):
     def test_subscribe_block_headers(self):
 
         def subscription_handler(obj, update_nr, subscription_id):
-            return f"callback: '{obj['header']['hash']}"
+            return f"callback: {obj['header']['number']}"
 
         result = self.substrate.subscribe_block_headers(subscription_handler)
 
-        self.assertEqual(f"callback: '0xec828914eca09331dad704404479e2899a971a9b5948345dc40abca4ac818f93", result)
+        self.assertEqual(f"callback: 103", result)
 
     def test_check_requirements(self):
         self.assertRaises(ValueError, self.substrate.get_block,