fcoin/migrate/ensure-tip-index.js
Christopher Jeffrey 5d5bcee9fa
refactor: cleanup.
2017-01-06 10:24:39 -08:00

159 lines
3.5 KiB
JavaScript

var assert = require('assert');
var encoding = require('../lib/utils/encoding');
var co = require('../lib/utils/co');
var BufferWriter = require('../lib/utils/writer');
var BufferReader = require('../lib/utils/reader');
var crypto = require('../lib/crypto/crypto');
var util = require('../lib/utils/util');
var LDB = require('../lib/db/ldb');
var BN = require('bn.js');
var DUMMY = new Buffer([0]);
var file = process.argv[2];
var db, batch;
assert(typeof file === 'string', 'Please pass in a database path.');
file = file.replace(/\.ldb\/?$/, '');
db = LDB({
location: file,
db: 'leveldb',
compression: true,
cacheSize: 32 << 20,
createIfMissing: false,
bufferKeys: true
});
var checkVersion = co(function* checkVersion() {
var data, ver;
console.log('Checking version.');
data = yield db.get('V');
if (!data)
return;
ver = data.readUInt32LE(0, true);
if (ver !== 1)
throw Error('DB is version ' + ver + '.');
});
function entryFromRaw(data) {
var p = new BufferReader(data, true);
var hash = crypto.hash256(p.readBytes(80));
var entry = {};
p.seek(-80);
entry.hash = hash.toString('hex');
entry.version = p.readU32(); // Technically signed
entry.prevBlock = p.readHash('hex');
entry.merkleRoot = p.readHash('hex');
entry.ts = p.readU32();
entry.bits = p.readU32();
entry.nonce = p.readU32();
entry.height = p.readU32();
entry.chainwork = new BN(p.readBytes(32), 'le');
return entry;
}
function getEntries() {
return db.values({
gte: pair('e', encoding.ZERO_HASH),
lte: pair('e', encoding.MAX_HASH),
parse: entryFromRaw
});
}
var getTip = co(function* getTip(entry) {
var state = yield db.get('R');
assert(state);
var tip = state.toString('hex', 0, 32);
var data = yield db.get(pair('e', tip));
assert(data);
return entryFromRaw(data);
});
var isMainChain = co(function* isMainChain(entry, tip) {
if (entry.hash === tip)
return true;
if (yield db.get(pair('n', entry.hash)))
return true;
return false;
});
// And this insane function is why we should
// be indexing tips in the first place!
var indexTips = co(function* indexTips() {
var entries = yield getEntries();
var tip = yield getTip();
var tips = [];
var orphans = [];
var prevs = {};
var i, orphan, entry, main;
for (i = 0; i < entries.length; i++) {
entry = entries[i];
main = yield isMainChain(entry, tip.hash);
if (!main) {
orphans.push(entry);
prevs[entry.prevBlock] = true;
}
}
for (i = 0; i < orphans.length; i++) {
orphan = orphans[i];
if (!prevs[orphan.hash])
tips.push(orphan.hash);
}
tips.push(tip.hash);
for (i = 0; i < tips.length; i++) {
tip = tips[i];
console.log('Indexing chain tip: %s.', util.revHex(tip));
batch.put(pair('p', tip), DUMMY);
}
});
function write(data, str, off) {
if (Buffer.isBuffer(str))
return str.copy(data, off);
data.write(str, off, 'hex');
}
function pair(prefix, hash) {
var key = new Buffer(33);
if (typeof prefix === 'string')
prefix = prefix.charCodeAt(0);
key[0] = prefix;
write(key, hash, 1);
return key;
}
function ipair(prefix, num) {
var key = new Buffer(5);
if (typeof prefix === 'string')
prefix = prefix.charCodeAt(0);
key[0] = prefix;
key.writeUInt32BE(num, 1, true);
return key;
}
co.spawn(function* () {
yield db.open();
console.log('Opened %s.', file);
batch = db.batch();
yield checkVersion();
yield indexTips();
yield batch.write();
}).then(function() {
console.log('Migration complete.');
process.exit(0);
});