go-ethereum/lib/event.js
2015-02-03 16:16:38 +01:00

136 lines
4.0 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 event.js
* @authors:
* Marek Kotewicz <marek@ethdev.com>
* @date 2014
*/
var abi = require('./abi');
var utils = require('./utils');
/// filter inputs array && returns only indexed (or not) inputs
/// @param inputs array
/// @param bool if result should be an array of indexed params on not
/// @returns array of (not?) indexed params
var filterInputs = function (inputs, indexed) {
return inputs.filter(function (current) {
return current.indexed === indexed;
});
};
var inputWithName = function (inputs, name) {
var index = utils.findIndex(inputs, function (input) {
return input.name === name;
});
if (index === -1) {
console.error('indexed param with name ' + name + ' not found');
return undefined;
}
return inputs[index];
};
var indexedParamsToTopics = function (event, indexed) {
// sort keys?
return Object.keys(indexed).map(function (key) {
var inputs = [inputWithName(filterInputs(event.inputs, true), key)];
var value = indexed[key];
if (value instanceof Array) {
return value.map(function (v) {
return abi.formatInput(inputs, [v]);
});
}
return abi.formatInput(inputs, [value]);
});
};
var inputParser = function (address, signature, event) {
// valid options are 'earliest', 'latest', 'offset' and 'max', as defined for 'eth.watch'
return function (indexed, options) {
var o = options || {};
o.address = address;
o.topic = [];
o.topic.push(signature);
if (indexed) {
o.topic = o.topic.concat(indexedParamsToTopics(event, indexed));
}
return o;
};
};
var getArgumentsObject = function (inputs, indexed, notIndexed) {
var indexedCopy = indexed.slice();
var notIndexedCopy = notIndexed.slice();
return inputs.reduce(function (acc, current) {
var value;
if (current.indexed)
value = indexed.splice(0, 1)[0];
else
value = notIndexed.splice(0, 1)[0];
acc[current.name] = value;
return acc;
}, {});
};
var outputParser = function (event) {
return function (output) {
var result = {
event: utils.extractDisplayName(event.name),
number: output.number,
args: {}
};
if (!output.topic) {
return result;
}
var indexedOutputs = filterInputs(event.inputs, true);
var indexedData = "0x" + output.topic.slice(1, output.topic.length).map(function (topic) { return topic.slice(2); }).join("");
var indexedRes = abi.formatOutput(indexedOutputs, indexedData);
var notIndexedOutputs = filterInputs(event.inputs, false);
var notIndexedRes = abi.formatOutput(notIndexedOutputs, output.data);
result.args = getArgumentsObject(event.inputs, indexedRes, notIndexedRes);
return result;
};
};
var getMatchingEvent = function (events, payload) {
for (var i = 0; i < events.length; i++) {
var signature = abi.eventSignatureFromAscii(events[i].name);
if (signature === payload.topic[0]) {
return events[i];
}
}
return undefined;
};
module.exports = {
inputParser: inputParser,
outputParser: outputParser,
getMatchingEvent: getMatchingEvent
};