Block & Transaction broadcast

[sukrawidhyawan]

Description

Implement Observer Pattern (for now used core services to & from p2p service). Add SendBlock & SendTransaction in p2pCommunication service to receive or send block & transaction to each peer

Breakdown

• Add observerpackage
• Add SendBlock & SendTransaction in p2pCommunication service
• Add BlockPushed listener : Call when has new block pushed ( and will send to peers)
• Add BlockReceived listener : Call when received block from another peer
• Add TransactionAdded listener: Call when new transaction inserted in mempool
• Add TransactionReceived listener: Call when received new transaction from another peer
• Add unit test

Reference Issue

Closes #69 #70

Step to Test (optional)

• Test Block Broadcast :
  • Delete all file with extention .db in ./resource path
  • Open 2 separate terminal tabs
  • Run go run main.go -config-postfix 2 in first tab terminal
  • Then run go run main.go in second terminal
  • Compare data block beetween zoobc_2.db with zoobc.db . (zoobc_2.db act as receiver and zoobc.db act as block creator and send block to listed peer)

• Test Transaction Broadcast :
  • Open 3 separate terminal tabs
  • Run go run main.go -config-postfix 2 in first tab terminal
  • Then run go run main.go in second terminal
  • Then run client.go in ./api/client/PostTransaction path in third terminal
  • When run client.go new transaction will save mempol in zoobc.db and broadcast to the listed peer
  • Compare data mempol beetween zoobc_2.db with zoobc.db .

[andy-shi88]

Neat! 👍 , added some comment answering the block signature verification todo comment and some typo in constant

[astaphobia]

waiting for test files

[sukrawidhyawan]

Please Review zoobc-schema/pull/28