go-pulse/lib/providermanager.js

120 lines
3.7 KiB
JavaScript

/*
This file is part of ethereum.js.
ethereum.js is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
ethereum.js 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with ethereum.js. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file providermanager.js
* @authors:
* Jeffrey Wilcke <jeff@ethdev.com>
* Marek Kotewicz <marek@ethdev.com>
* Marian Oancea <marian@ethdev.com>
* Gav Wood <g@ethdev.com>
* @date 2014
*/
var web3 = require('./web3');
var jsonrpc = require('./jsonrpc');
/**
* Provider manager object prototype
* It's responsible for passing messages to providers
* If no provider is set it's responsible for queuing requests
* It's also responsible for polling the ethereum node for incoming messages
* Default poll timeout is 12 seconds
* If we are running ethereum.js inside ethereum browser, there are backend based tools responsible for polling,
* and provider manager polling mechanism is not used
*/
var ProviderManager = function() {
this.polls = [];
this.provider = undefined;
var self = this;
var poll = function () {
if (self.provider) {
var pollsBatch = self.polls.map(function (data) {
return data.data;
});
var payload = jsonrpc.toBatchPayload(pollsBatch);
var results = self.provider.send(payload);
self.polls.forEach(function (data, index) {
var result = results[index];
if (!jsonrpc.isValidResponse(result)) {
console.log(result);
return;
}
result = result.result;
// dont call the callback if result is not an array, or empty one
if (!(result instanceof Array) || result.length === 0) {
return;
}
data.callback(result);
});
}
setTimeout(poll, 1000);
};
poll();
};
/// sends outgoing requests
/// @params data - an object with at least 'method' property
ProviderManager.prototype.send = function(data) {
var payload = jsonrpc.toPayload(data.method, data.params);
if (this.provider === undefined) {
console.error('provider is not set');
return null;
}
var result = this.provider.send(payload);
if (!jsonrpc.isValidResponse(result)) {
console.log(result);
return null;
}
return result.result;
};
/// setups provider, which will be used for sending messages
ProviderManager.prototype.set = function(provider) {
this.provider = provider;
};
/// this method is only used, when we do not have native qt bindings and have to do polling on our own
/// should be callled, on start watching for eth/shh changes
ProviderManager.prototype.startPolling = function (data, pollId, callback) {
this.polls.push({data: data, id: pollId, callback: callback});
};
/// should be called to stop polling for certain watch changes
ProviderManager.prototype.stopPolling = function (pollId) {
for (var i = this.polls.length; i--;) {
var poll = this.polls[i];
if (poll.id === pollId) {
this.polls.splice(i, 1);
}
}
};
module.exports = ProviderManager;