flocore-node/lib/services/timestamp/index.js
Chris Kleeschulte d9efd7bc02 wip
2017-05-08 21:00:50 -04:00

143 lines
3.5 KiB
JavaScript

'use strict';
var Encoding = require('./encoding');
var BaseService = require('../../service');
var inherits = require('util').inherits;
var MAINNET_BITCOIN_GENESIS_TIME = 1296688602;
function TimestampService(options) {
BaseService.call(this, options);
this.currentBlock = null;
this.currentTimestamp = null;
}
inherits(TimestampService, BaseService);
TimestampService.dependencies = [ 'db' ];
TimestampService.prototype.start = function(callback) {
var self = this;
this.store = this.node.services.db.store;
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();
});
};
TimestampService.prototype.stop = function(callback) {
setImmediate(callback);
};
TimestampService.prototype.blockHandler = function(block, connectBlock, callback) {
var self = this;
var action = 'put';
if (!connectBlock) {
action = 'del';
}
var operations = [];
function getLastTimestamp(next) {
if(block.__height === 0) {
return next(null, (block.header.timestamp - 1));
}
self.getTimestamp(block.toObject().header.prevHash, next);
}
getLastTimestamp(function(err, lastTimestamp) {
if(err) {
return callback(err);
}
var timestamp = block.header.timestamp;
if(timestamp <= lastTimestamp) {
timestamp = lastTimestamp + 1;
}
self.currentBlock = block.hash;
self.currentTimestamp = timestamp;
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.getTimestamp = function(hash, callback) {
var self = this;
if (hash === self.currentBlock) {
return setImmediate(function() {
callback(null, self.currentTimestamp);
});
}
var key = self.encoding.encodeBlockTimestampKey(hash);
self.store.get(key, function(err, buffer) {
if(err) {
return callback(err);
}
return callback(null, self.encoding.decodeBlockTimestampValue(buffer));
});
};
TimestampService.prototype.getBlockHeights = function(timestamps, callback) {
var self = this;
timestamps.sort();
//due to a bug in the encoding routines, thers is a minimum timestamp that
//can be searched for, which is 1296688602 (the bitcoin mainnet genesis block
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.store.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;