eris-db

erisdb-js (Alpha)

This is a JavaScript API for communicating with a ErisDB server.

Installation

Prerequisites

• Git
• Monax Eris version 0.12
• Node.js version 6 or higher

You can check the installed version of Node.js with the command:

$ node --version

If your distribution of Linux has a version older than 6 then you can update it using NodeSource's distribution.

To Install

$ npm install eris-db

Usage

If you created an ErisDB server using the Eris CLI tool, you can find out its IP address using the following command:

$ eris chains inspect <name of ErisDB server> NetworkSettings.IPAddress

The main class is ErisDB. A standard ErisDB instance is created like this:

var edbFactory = require('eris-db');
 
var edb = edbFactory.createInstance("http://<IP address>:1337/rpc");

The parameters for createInstance is the server URL as a string. The client-type is chosen based on the URL scheme. As of now, the supported schemes are: http and ws (websockets). No additional configuration is needed.

API Reference

There are bindings for all the RPC methods. All functions are on the form function(param1, param2, ... , callback), where the callback is a function on the form function(error,data) (it is documented under the name methodCallback). The data object is the same as you would get by calling the corresponding RPC method directly.

This is the over-all structure of the library. The unsafe flag means a private key is either sent or received, so should be used with care (dev only).

NOTE: There will be links to the proper jsdoc and integration with erisindustries.com. For now, the components point to the actual code files and methods points to the web-API method in question.

ErisDB

Component Name	Accessor
Accounts	ErisDB.accounts()
Blockchain	ErisDB.blockchain()
Consensus	ErisDB.consensus()
Events	ErisDB.events()
NameReg	ErisDB.namereg()
Network	ErisDB.network()
Transactions	ErisDB.txs()

Components

Accounts

The accounts object has methods for getting account and account-storage data.

Method	RPC method	Notes
Accounts.getAccounts	erisdb.getAccounts
Accounts.getAccount	erisdb.getAccount
Accounts.getStorage	erisdb.getStorage
Accounts.getStorageAt	erisdb.getStorageAt
Accounts.genPrivAccount	erisdb.genPrivAccount	unsafe

BlockChain

The accounts object has methods for getting blockchain-related data, such as a list of blocks, or individual blocks, or the hash of the genesis block.

Method	RPC method	Notes
BlockChain.getInfo	erisdb.getBlockchainInfo
BlockChain.getChainId	erisdb.getChainId
BlockChain.getGenesisHash	erisdb.getGenesisHash
BlockChain.getLatestBlockHeight	erisdb.getLatestBlockHeight
BlockChain.getLatestBlock	erisdb.getLatestBlock
BlockChain.getBlocks	erisdb.getBlocks
BlockChain.getBlock	erisdb.getBlock

Consensus

The consensus object has methods for getting consensus-related data.

Method	RPC method	Notes
Consensus.getState	erisdb.getConsensusState
Consensus.getValidators	erisdb.getValidators

Events

The tendermint client will generate and fire off events when important things happen, like when a new block has been committed, or someone is transacting to an account. It is possible to subscribe to these events. These are the methods for subscribing, un-subscribing and polling.

Method	RPC method	Notes
Events.subscribe	erisdb.eventSubscribe
Events.unsubscribe	erisdb.eventUnsubscribe
Events.poll	erisdb.eventPoll

Helpers

The helper functions makes it easier to manage subscriptions. Normally you'd be using these functions rather then managing the subscriptions yourself.

Helper functions always contain two callback functions - a createCallback(error, data) and an eventCallback(error, data).

The createCallback data is an EventSub object, that can be used to do things like getting the event ID, the subscriber ID, and to stop the subscription.

The eventCallback data is the event object. This object is different depending on the event type. In the case of NewBlock it will be a block, the consensus events is a transaction object, etc. More info can be found in the api doc.

Method	Arguments
Events.subAccountInput	account address <string>
Events.subAccountOutput	account address <string>
Events.subAccountReceive	account address <string>
Events.subLogEvent	account address <string>
Events.subSolidityEvent	account address <string>
Events.subNewBlocks	-
Events.subForks	-
Events.subBonds	-
Events.subUnbonds	-
Events.subRebonds	-
Events.subDupeouts	-

subSolidityEvent and subLogEvent are two different names for the same type of subscription (log events).

NameReg

The NameReg object has methods for accessing the name registry.

Method	RPC method	Notes
NameReg.getEntry	erisdb.getNameRegEntry
NameReg.getEntries	erisdb.getNameRegEntries

Network

The accounts object has methods for getting network-related data, such as a list of all peers. It could also have been named "node".

Client Version may be a bit misplaced

Method	RPC method	Notes
Network.getInfo	erisdb.getNetworkInfo
Network.getClientVersion	erisdb.getClientVersion
Network.getMoniker	erisdb.getMoniker
Network.isListening	erisdb.isListening
Network.getListeners	erisdb.getListeners
Network.getPeers	erisdb.getPeers
Network.getPeer	erisdb.getPeer

Transactions

A transaction is the equivalence of a database write operation. They can be done in two ways. There's the "dev" way, which is to call transact and pass along the target address (if any), data, gas, and a private key used for signing. It is very similar to the old Ethereum way of transacting, except Tendermint does not keep accounts in the client, so a private key needs to be sent along. This means the server should either run on the same machine as the tendermint client, or in the same, private network.

Transacting via broadcastTx will be the standard way of doing things if you want the key to remain on the users machine. This requires a browser plugin for doing the actual signing, which we will add later. For now, you should stick to the transact method.

To get a private key for testing/developing, you can run tendermint gen_account if you have it installed. You can also run tools/pa_generator.js if you have a local node running. It will take the url as command line argument at some point...

Calls

Calls provide read-only access to the smart contracts. It is used mostly to get data out of a contract-accounts storage by using the contracts accessor methods, but can be used to call any method that does not change any data in any account. A trivial example would be a contract function that takes two numbers as input, adds them, and then simply returns the sum.

There are two types of calls. Call takes a data string and an account address and calls the code in that account (if any) using the provided data as input. This is the standard method for read-only operations.

CallCode works the same except you don't provide an account address but the actual compiled code instead. It's a dev tool for accessing the VM directly. "Code-execution as a service".

Method	RPC method	Notes
Transactions.broadcastTx	erisdb.broadcastTx	see below
Transactions.getUnconfirmedTxs	erisdb.getUnconfirmedTxs
Transactions.call	erisdb.call
Transactions.callCode	erisdb.callCode
Transactions.transact	erisdb.transact	unsafe
Transactions.transactAndHold	erisdb.transactAndHold	unsafe
Transactions.transactNameReg	erisdb.transactNameReg	unsafe

broadcastTx is useless until we add a client-side signing solution.

Documentation

Generate documentation using the command npm run doc.

Testing

To test the library against pre-recorded vectors:

npm test

To test the library against Eris DB while recording vectors:

TEST=record npm test

To test Eris DB against pre-recorded vectors without exercising the library:

TEST=server npm test

Debugging

Debugging information will display on stderr if the library is run with NODE_DEBUG=eris in the environment.

Copyright

Copyright 2015 Monax

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.