Update tx-example.py and blocks-query.py

example/python/batch-example.py

@@ -10,6 +10,11 @@
 
 """)
 
+import sys
+
+if sys.version_info[0] < 3:
+    raise Exception('Python 3 or a more recent version is required.')
+
 from irohalib import Iroha, IrohaGrpc
 from irohalib import IrohaCrypto as ic
 

example/python/blocks-query.py

@@ -1,45 +1,45 @@
-import sys
-sys.path.insert(0, 'build/shared_model/bindings')
-import iroha
+#
+# Copyright Soramitsu Co., Ltd. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
 
-import endpoint_pb2_grpc
-import queries_pb2
-import grpc
-import time
+import sys
 
+if sys.version_info[0] < 3:
+    raise Exception('Python 3 or a more recent version is required.')
 
-blocks_query_builder = iroha.ModelBlocksQueryBuilder()
-crypto = iroha.ModelCrypto()
+from irohalib import IrohaCrypto
+from irohalib import Iroha, IrohaGrpc
 
-admin_priv = open("../[email protected]", "r").read()
-admin_pub = open("../[email protected]", "r").read()
-key_pair = crypto.convertFromExisting(admin_pub, admin_priv)
 
-creator = "admin@test"
-current_time = int(round(time.time() * 1000)) - 10**5
+admin_private_key = open('../[email protected]').read()
+iroha = Iroha('admin@test')
+net = IrohaGrpc()
 
-def get_blocks():
-    query = blocks_query_builder.creatorAccountId(creator)\
-    .createdTime(current_time)\
-    .queryCounter(1) \
-    .build()
 
-    query_blob = iroha.ModelProtoBlocksQuery(query).signAndAddSignature(key_pair).finish().blob()
-    proto_query = queries_pb2.BlocksQuery()
+def trace(func):
+    """
+    A decorator for tracing methods' begin/end execution points
+    """
+    def tracer(*args, **kwargs):
+        name = func.__name__
+        print('\tEntering "{}"'.format(name))
+        result = func(*args, **kwargs)
+        print('\tLeaving "{}"'.format(name))
+        return result
+    return tracer
 
-    if sys.version_info[0] == 2:
-        tmp = ''.join(map(chr, query_blob))
-    else:
-        tmp = bytes(query_blob)
 
-    proto_query.ParseFromString(tmp)
-
-    channel = grpc.insecure_channel('127.0.0.1:50051')
-    query_stub = endpoint_pb2_grpc.QueryServiceStub(channel)
-    query_response = query_stub.FetchCommits(proto_query)
+@trace
+def get_blocks():
+    """
+    Subscribe to blocks stream from the network
+    :return:
+    """
+    query = iroha.blocks_query()
+    IrohaCrypto.sign_query(query, admin_private_key)
+    for block in net.send_blocks_stream_query(query):
+        print('The next block arrived:', block)
 
-    for block in query_response:
-        print("block:")
-        print(block)
 
 get_blocks()

example/python/irohalib.py

@@ -44,7 +44,13 @@ def hash(proto_with_payload):
         :proto_with_payload: proto transaction or query
         :return: bytes representation of hash
         """
-        bytes = proto_with_payload.payload.SerializeToString()
+        obj = None
+        if hasattr(proto_with_payload, 'payload'):
+            obj = getattr(proto_with_payload, 'payload')
+        elif hasattr(proto_with_payload, 'meta'):
+            obj = getattr(proto_with_payload, 'meta')
+
+        bytes = obj.SerializeToString()
         hash = hashlib.sha3_256(bytes).digest()
         return hash
 
@@ -211,6 +217,28 @@ def query(self, name, counter=1, creator_account=None, created_time=None, **kwar
             internal_query.CopyFrom(message)
         return query_wrapper
 
+    def blocks_query(self, counter=1, creator_account=None, created_time=None):
+        """
+        Creates a protobuf query for a blocks stream
+        :param counter: query counter, should be incremented for each new query
+        :param creator_account: account id of query creator
+        :param created_time: query creation timestamp in milliseconds
+        :return: a proto blocks query
+        """
+        if not created_time:
+            created_time = self.now()
+        if not creator_account:
+            creator_account = self.creator_account
+
+        meta = queries_pb2.QueryPayloadMeta()
+        meta.created_time = created_time
+        meta.creator_account_id = creator_account
+        meta.query_counter = counter
+
+        query_wrapper = queries_pb2.BlocksQuery()
+        query_wrapper.meta.CopyFrom(meta)
+        return query_wrapper
+
     @staticmethod
     def batch(*transactions, atomic=True):
         """
@@ -284,6 +312,17 @@ def send_query(self, query):
         response = self._query_service_stub.Find(query)
         return response
 
+    def send_blocks_stream_query(self, query):
+        """
+        Send a query for blocks stream to Iroha
+        :param query: protobuf BlocksQuery
+        :return: an iterable over a stream of blocks
+        :raise: grpc.RpcError with .code() available in case of any error
+        """
+        response = self._query_service_stub.FetchCommits(query)
+        for block in response:
+            yield block
+
     def tx_status(self, transaction):
         """
         Request a status of a transaction