flocore-node/lib/services/utxo/index.js
Chris Kleeschulte d6f1f26469 wip
2017-05-26 07:40:26 -04:00

161 lines
3.7 KiB
JavaScript

'use strict';
var BaseService = require('../../service');
var inherits = require('util').inherits;
var Encoding = require('./encoding');
var LRU = require('lru-cache');
var utils = require('../../utils');
function UtxoService(options) {
BaseService.call(this, options);
this._exclusionIndexes = [];
}
inherits(UtxoService, BaseService);
UtxoService.dependencies = ['db'];
UtxoService.prototype.start = function(callback) {
var self = this;
self.db = this.node.services.db;
self.db.getPrefix(self.name, function(err, prefix) {
if (err) {
return callback(err);
}
self.prefix = prefix;
self.encoding = new Encoding(self.prefix);
callback();
});
};
UtxoService.prototype.stop = function(callback) {
if (callback) {
setImmediate(callback);
}
};
UtxoService.prototype.blockHandler = function(block, connect, callback) {
var self = this;
self._exclusionIndexes.length = 0;
var operations = [];
for(var i = 0; i < block.transactions.length; i++) {
var tx = block.transactions[i];
var inputs = tx.inputs;
var outputs = tx.outputs;
if (!tx.isCoinbase()) {
operations = self._processInputs(tx, inputs, connect).concat(operations);
}
operations = self._processOutputs(tx, outputs, block, connect).concat(operations);
}
callback(null, operations);
};
UtxoService.prototype.getUtxosForAddress = function(address, callback) {
var self = this;
var utxos = [];
var start = self.encoding.encodeUtxoIndexKey(address);
var stream = self.db.createReadStream({
gte: start.slice(0, -36),
lt: Buffer.concat([ start.slice(0, -36), new Buffer('ff', 'hex') ])
});
stream.on('data', function(data) {
var key = self.encoding.decodeUtxoIndexKey(data.key);
var value = self.encoding.decodeUtxoIndexValue(data.value);
utxos.push({
txid: key.txid,
outputIndex: key.outputIndex,
address: address,
height: value.height,
satoshis: value.satoshis,
script: value.scriptBuffer
});
});
stream.on('end', function() {
callback(null, utxos);
});
};
UtxoService.prototype._processInputs = function(tx, inputs, connect) {
var operations = [];
for(var i = 0; i < inputs.length; i++) {
var input = inputs[i];
var key = input.prevHash + input.outputIndex;
if (input.prevTxId === tx.hash) {
this._exlusionIndexes.push(i);
continue;
}
var ops = this._moveOutput(key, connect);
operations = operations.concat(ops);
}
return operations;
};
UtxoService.prototype._processOutputs = function(tx, outputs, block, connect) {
var operations = [];
for(var i = 0; i < outputs.length; i++) {
var output = outputs[i];
var key = tx.hash + i;
if (this._exclusionIndexes.indexOf(i) > -1) {
continue;
}
var action = connect ? 'put' : 'del';
operations = operations.concat(
{ action: action,
key: this._getOperationsKey(key, output),
value: this._getOperationsValue({
height: block.__height,
satoshis: output.satoshis,
script: output.script
})
}
);
}
return operations;
};
UtxoService.prototype._moveOutput = function(key, connect) {
if (connect) {
return { action: 'del', key: key };
}
return { action: 'put', key: key, value: null };
};
UtxoService.prototype._getOperationsKey = function(key, output) {
var address = utils.getAddressStringFromScript(output.script, this.node.network);
return this.encoding.encodeUtxoIndexKey(address, key.slice(0, 64), parseInt(key.slice(64)));
};
UtxoService.prototype._getOperationsValue = function(value) {
return this.encoding.encodeUtxoIndexValue(value.height, value.satoshis, value.script.toBuffer());
};
module.exports = UtxoService;