DPOS 共识算法API接口实现

DPOS/dpos_api.py

@@ -0,0 +1,163 @@
+# Interacting with the Dexter's blockchain with multiple nodes using HTTP requests
+
+from flask import Flask, jsonify, request
+
+from blockChain import Blockchain
+
+# Initialise our node with identifier and instantiate the Blockchain class
+app = Flask(__name__)
+blockchain = Blockchain()
+
+
+# API endpoint to mine a block, it is an HTTP GET request
+@app.route('/mine', methods=['GET'])
+# Method to mine a block
+def mine():
+    # To ensure that only delegates elected by voting can mine a new block
+    current_port = "localhost:" + str(port)
+    if current_port in blockchain.delegates:
+        
+        # To ensure that a new block is mined only if there are atleast 2 transactions
+        if len(blockchain.unverified_transactions) >= 2:
+            last_block = blockchain.last_block
+            previous_hash = blockchain.hash(last_block)
+            block = blockchain.new_block(previous_hash)
+            
+            response = {
+                'message': "New block mined!",
+                'index': block['index'],
+                'transactions': block['transactions'],
+                'previous_hash': block['previous_hash']
+            }
+            print(len(blockchain.unverified_transactions))
+            return jsonify(response), 200
+        
+        else:
+            response = {
+                'message': 'Not enough transactions to mine a new block and add to chain!'
+            }
+            print(len(blockchain.unverified_transactions))
+            return jsonify(response), 400
+    else:
+        response = {
+            'message': 'You are not authorised to mine block! Only delegates can mine.'
+        }
+        return jsonify(response), 400
+
+
+# Endpoint for a new transaction
+@app.route('/transactions/new', methods=['POST'])
+def new_transaction():
+    values = request.get_json()
+    
+    required = ['Customer name', 'Item name', 'Total billing amount']
+    if not all(k in values for k in required):
+        return 'Missing values! Please enter customer name, item name and billing amount.', 400
+    
+    index = blockchain.new_transaction(values['Customer name'], values['Item name'], values['Total billing amount'])
+    
+    response = {
+        'message': f'Transaction will be added to block {index}'
+    }
+    return jsonify(response), 201
+
+
+# Endpoint for viewing the blockchain
+@app.route('/chain', methods=['GET'])
+def full_chain():
+    response = {
+        'chain': blockchain.chain,
+        'length': len(blockchain.chain)
+    }
+    return jsonify(response), 200
+
+
+# Endpoint for adding HTTP address of new nodes along with their stakes in the network.
+@app.route('/nodes/add', methods=['POST'])
+def add_nodes():
+    values = request.get_json()
+    required = ['nodes', 'stake']
+    
+    if not all(k in values for k in required):
+        return 'Error', 400
+    
+    blockchain.add_node(values['nodes'], values['stake'])
+    
+    response = {
+        'message': 'New nodes are added!',
+        'total_nodes': list(blockchain.nodes)
+    }
+    print(blockchain.nodes)
+    return jsonify(response), 201
+
+
+# Endpoint to start the voting process
+@app.route('/voting', methods=['GET'])
+def voting():
+    if port == 5000:
+        show_votes = blockchain.add_vote()
+        
+        response = {
+            'message': 'The voting results are as follows:',
+            'nodes': blockchain.voteNodespool
+        }
+        
+        return jsonify(response), 200
+    
+    else:
+        response = {
+            'message': 'You are not authorized to conduct the election process!'
+        }
+        return jsonify(response), 400
+
+
+# Endpoint to view the list of all three elected delegate nodes
+@app.route('/delegates/show', methods=['GET'])
+def delegates():
+    show_delegates = blockchain.selection()
+    
+    response = {
+        'message': 'The 3 delegate nodes selected for block mining are:',
+        'node_delegates': blockchain.delegates
+    }
+    return jsonify(response), 200
+
+
+# Endpoint to synchronise the list of elected delegates with all other nodes in the network
+@app.route('/delegates/sync', methods=['GET'])
+def sync_delegates():
+    sync_delegates = blockchain.sync()
+    
+    response = {
+        'message': 'The delegate nodes are:',
+        'node_delegates': blockchain.delegates
+    }
+    return jsonify(response), 200
+
+
+# Endpoint to resolve and replace current chain with the longest validated one,achieving consensus
+@app.route('/chain/resolve', methods=['GET'])
+def consensus():
+    replaced = blockchain.resolve_chain()
+    
+    if replaced:
+        response = {
+            'message': 'Our chain was replaced',
+            'new_chain': blockchain.chain
+        }
+    else:
+        response = {
+            'message': 'Our chain is authoritative',
+            'chain': blockchain.chain
+        }
+    return jsonify(response), 200
+
+
+if __name__ == '__main__':
+    from argparse import ArgumentParser
+    
+    parser = ArgumentParser()
+    parser.add_argument('-p', '--port', default=5000, type=int, help='Listening on port')
+    args = parser.parse_args()
+    port = args.port
+    app.run(host='0.0.0.0', port=port)