flocore-node/lib/services/timestamp/index.js
Chris Kleeschulte 6fc170f7da wip
2017-05-22 15:45:16 -04:00

147 lines
3.4 KiB
JavaScript

'use strict';
var Encoding = require('./encoding');
var BaseService = require('../../service');
var inherits = require('util').inherits;
var LRU = require('lru-cache');
var utils = require('../../../lib/utils');
function TimestampService(options) {
BaseService.call(this, options);
this.currentBlock = null;
this.currentTimestamp = null;
this._cache = LRU(50);
var genesis = self.node.services.block.genesis;
this._cache.set(genesis.hash, genesis.__height);
}
inherits(TimestampService, BaseService);
TimestampService.dependencies = [ 'db' ];
TimestampService.prototype.start = function(callback) {
var self = this;
this.db = this.node.services.db;
this.node.services.db.getPrefix(this.name, function(err, prefix) {
if(err) {
return callback(err);
}
self.prefix = prefix;
self.encoding = new Encoding(self.prefix);
callback();
});
self.counter = 0;
};
TimestampService.prototype.stop = function(callback) {
setImmediate(callback);
};
TimestampService.prototype._processBlockHandlerQueue = function(block) {
var self = this;
var blockTime = block.header.timestamp;
var prevHash = utils.reverseBufferToString(block.header.prevHash);
var prev = self._cache.get(prevHash);
if (prev && !prev.prevHash) {
if (blockTime <= prev.time) {
blockTime++;
}
self._cache.del(prevHash);
self._cache.set(block.hash, { time: blockTime });
return [{ hash: block.hash, time: blockTime }];
}
self._cache.set(block.hash, { time: blockTime, prevHash: prevHash });
var additionalBlocks = [];
var dependentHash = block.hash;
self._cache.rforEach(function(value, key) {
if (dependentHash === value.prevHash) {
additionalBlocks.push({ hash: key, time: value.time });
dependentHash = value.prevHash;
self._cache.del(key);
}
});
return additionalBlocks;
};
TimestampService.prototype.blockHandler = function(block, connectBlock, callback) {
var self = this;
var action = connectBlock ? 'put' : 'del';
var queue = self._processBlockHandlerQueue(block);
var operations = [];
if (!queue.length < 1) {
return callback(null, []);
}
operations = operations.concat([
{
type: action,
key: self.encoding.encodeTimestampBlockKey(timestamp),
value: self.encoding.encodeTimestampBlockValue(block.header.hash)
},
{
type: action,
key: self.encoding.encodeBlockTimestampKey(block.header.hash),
value: self.encoding.encodeBlockTimestampValue(timestamp)
}
]);
callback(null, operations);
};
TimestampService.prototype.getBlockHeights = function(timestamps, callback) {
var self = this;
timestamps.sort();
timestamps = timestamps.map(function(timestamp) {
return timestamp >= MAINNET_BITCOIN_GENESIS_TIME ? timestamp : MAINNET_BITCOIN_GENESIS_TIME;
});
var start = self.encoding.encodeTimestampBlockKey(timestamps[0]);
var end = self.encoding.encodeTimestampBlockKey(timestamps[1]);
var stream = self.db.createReadStream({
gte: start,
lte: end
});
var hashes = [];
var hashTuple = [];
var streamErr = null;
stream.on('data', function(data) {
hashes.push(self.encoding.decodeTimestampBlockValue(data.value));
});
stream.on('error', function(err) {
streamErr = err;
});
stream.on('end', function() {
if (!streamErr && hashes.length > 1) {
hashTuple = [ hashes[0], hashes[hashes.length - 1] ];
}
callback(streamErr, hashTuple);
});
};
module.exports = TimestampService;