metachains

Tool for accessing and dumping metachain data into the Florincoin blockchain.

Installation

You can clone this repository and use its module directly. Alternatively, you can build a package and install it through pip:

python setup.py sdist
sudo pip install dist/metachains-0.4.0.tar.gz

Florincoin installation

Instructions can be found at INSTALL.md.

Florincoin wrapper usage

This module contains a class that can be used to communicate via json-rpc. It must be configured with the json rpc url, username and password:

import metachains
mtc = metachains.Florincoin(
    "http://127.0.0.1:7313",
    "user",
    "pass")

Be sure to use the rpcport, rpcuser and rpcpassword you used in the Florcoin config or install.

Once you do this, you'll have access to the following methods:

mtc.block_count()        # Returns the number of blocks in the chain.

mtc.balance()            # Returns the wallet balance.

mtc.address(account)     # Returns an address for the given account.

mtc.blocks(index, n)     # Generates n blocks in the chain,
                         # starting from index.

mtc.transactions(block)  # Generates all data transactions in a block,
                         # generating pairs (transaction_id, raw_data).

mtc.send_data(raw_data)  # Sends data to the blockchain.

mtc.send_data(raw_data, address, amount)  # Send data to the blockchain via a standard transaction.

Synchronizer usage

You can use metachains.Synchronizer to synchronize data between a blockchain and a local database:

• Synchronizer.scan_database scans the database and uploads its data to the blockchain.
• Synchronizer.scan_blockchain scans the blockchain and uploads its data to the database.

The database object must respond to the following methods:

• data_dump(n) -- This should return a byte array with the data to be uploaded to the blockchain, up to n bytes. When there is nothing more to upload, it should return None.
• data_load(data, txid) -- Notifies the database of new content that has been added to the blockchain, in the given txid transaction.
• last_known_block() -- Returns the block height from where blockchain scanning should begin.

To use Synchronizer, you must first create a Florincoin and a database object:

import metachains

coin = metachains.Florincoin("http://host:port", "username", "password")
database = ...

sync = metachains.Synchronizer(coin, database)

sync.scan_blockchain()  # Downloads new data *from* the blockchain.
sync.scan_database()    # Uploads new data *to* the blockchain.