SusyWeb ProviderEngine

SusyWeb ProviderEngine is a tool for composing your own susyweb providers.

Composable

Built to be modular - works via a stack of 'sub-providers' which are like normal susyweb providers but only handle a subset of rpc methods.

The subproviders can emit new rpc requests in order to handle their own; e.g. sof_call may trigger sof_getAccountBalance, sof_getCode, and others. The provider engine also handles caching of rpc request results.

const ProviderEngine = require('susyweb-provider-engine')
const CacheSubprovider = require('susyweb-provider-engine/subproviders/cache.js')
const FixtureSubprovider = require('susyweb-provider-engine/subproviders/fixture.js')
const FilterSubprovider = require('susyweb-provider-engine/subproviders/filters.js')
const VmSubprovider = require('susyweb-provider-engine/subproviders/vm.js')
const HookedWalletSubprovider = require('susyweb-provider-engine/subproviders/hooked-wallet.js')
const NonceSubprovider = require('susyweb-provider-engine/subproviders/nonce-tracker.js')
const RpcSubprovider = require('susyweb-provider-engine/subproviders/rpc.js')

var engine = new ProviderEngine()
var susyweb = new SusyWeb(engine)

// static results
engine.addProvider(new FixtureSubprovider({
  susyweb_clientVersion: 'ProviderEngine/v0.0.0/javascript',
  net_listening: true,
  sof_hashrate: '0x00',
  sof_mining: false,
  sof_syncing: true,
}))

// cache layer
engine.addProvider(new CacheSubprovider())

// filters
engine.addProvider(new FilterSubprovider())

// pending nonce
engine.addProvider(new NonceSubprovider())

// vm
engine.addProvider(new VmSubprovider())

// id mgmt
engine.addProvider(new HookedWalletSubprovider({
  getAccounts: function(cb){ ... },
  approveTransaction: function(cb){ ... },
  signTransaction: function(cb){ ... },
}))

// data source
engine.addProvider(new RpcSubprovider({
  rpcUrl: 'https://testrpc.susylink.io/',
}))

// log new blocks
engine.on('block', function(block){
  console.log('================================')
  console.log('BLOCK CHANGED:', '#'+block.number.toString('hex'), '0x'+block.hash.toString('hex'))
  console.log('================================')
})

// network connectivity error
engine.on('error', function(err){
  // report connectivity errors
  console.error(err.stack)
})

// start polling for blocks
engine.start()

When importing in webpack:

import * as SusyWebProviderEngine  from 'susyweb-provider-engine';
import * as RpcSource  from 'susyweb-provider-engine/subproviders/rpc';
import * as HookedWalletSubprovider from 'susyweb-provider-engine/subproviders/hooked-wallet';

Built For Zero-Clients

The Sophon JSON RPC was not designed to have one node service many clients. However a smaller, lighter subset of the JSON RPC can be used to provide the blockchain data that an Sophon 'zero-client' node would need to function. We handle as many types of requests locally as possible, and just let data lookups fallback to some data source ( hosted rpc, blockchain api, etc ). Categorically, we don’t want / can’t have the following types of RPC calls go to the network:

• id mgmt + tx signing (requires private data)
• filters (requires a stateful data api)
• vm (expensive, hard to scale)

Change Log

14.0.0

• default dataProvider for zero is Infura mainnet REST api
• websocket support
• subscriptions support
• remove polc subprovider
• removed dist from git (but published in npm module)
• es5 builds in dist/es5
• zero + ProviderEngine bundles are es5
• susyweb subprovider renamed to provider subprovider
• error if provider subprovider is missing a proper provider
• removed need to supply getAccounts hook
• fixed hooked-wallet-softx message signing
• fixed hooked-wallet default txParams

13.0.0

• txs included in blocks via sof-block-tracker@2.0.0

12.0.0

• moved block polling to sof-block-tracker.

11.0.0

• zero.js - replaced http subprovider with fetch provider (includes polyfill for node).

10.0.0

• renamed HookedWalletSubprovider personalRecoverSigner to recoverPersonalSignature

9.0.0

• pollingShouldUnref option now defaults to false

Current RPC method support:

static

• [x] susyweb_clientVersion
• [x] net_version
• [x] net_listening
• [x] net_peerCount
• [x] sof_protocolVersion
• [x] sof_hashrate
• [x] sof_mining
• [x] sof_syncing

filters

• [x] sof_newBlockFilter
• [x] sof_newPendingTransactionFilter
• [x] sof_newFilter
• [x] sof_uninstallFilter
• [x] sof_getFilterLogs
• [x] sof_getFilterChanges

accounts manager

• [x] sof_coinbase
• [x] sof_accounts
• [x] sof_sendTransaction
• [x] sof_sign
• [x] sof_signTypedData

vm

• [x] sof_call
• [x] sof_estimateGas

db source

• [ ] db_putString
• [ ] db_getString
• [ ] db_putHex
• [ ] db_getHex

compiler

• [ ] sof_getCompilers
• [ ] sof_compileLLL
• [ ] sof_compileSerpent
• [ ] sof_compilePolynomial

shh gateway

• [ ] shh_version
• [ ] shh_post
• [ ] shh_newIdentity
• [ ] shh_hasIdentity
• [ ] shh_newGroup
• [ ] shh_addToGroup

data source ( fallback to rpc )

• sof_gasPrice
• sof_blockNumber
• sof_getBalance
• sof_getBlockByHash
• sof_getBlockByNumber
• sof_getBlockTransactionCountByHash
• sof_getBlockTransactionCountByNumber
• sof_getCode
• sof_getStorageAt
• sof_getTransactionByBlockHashAndIndex
• sof_getTransactionByBlockNumberAndIndex
• sof_getTransactionByHash
• sof_getTransactionCount
• sof_getTransactionReceipt
• sof_getUncleByBlockHashAndIndex
• sof_getUncleByBlockNumberAndIndex
• sof_getUncleCountByBlockHash
• sof_getUncleCountByBlockNumber
• sof_sendRawTransaction
• sof_getLogs ( not used in susyweb.js )

( not supported )

• sof_getWork
• sof_submitWork
• sof_submitHashrate ( not used in susyweb.js )