fcoin/migrate/ensure-tip-index.js
2018-03-29 21:56:48 -07:00

147 lines
3.2 KiB
JavaScript

'use strict';
const assert = require('assert');
const BDB = require('bdb');
const encoding = require('bufio/lib/encoding');
const BufferReader = require('bufio/lib/reader');
const hash256 = require('bcrypto/lib/hash256');
const BN = require('bcrypto/lib/bn');
const DUMMY = Buffer.from([0]);
let file = process.argv[2];
let batch;
assert(typeof file === 'string', 'Please pass in a database path.');
file = file.replace(/\.ldb\/?$/, '');
const db = new BDB({
location: file,
db: 'leveldb',
compression: true,
cacheSize: 32 << 20,
createIfMissing: false,
bufferKeys: true
});
async function checkVersion() {
console.log('Checking version.');
const data = await db.get('V');
if (!data)
return;
const ver = data.readUInt32LE(0, true);
if (ver !== 1)
throw Error(`DB is version ${ver}.`);
}
function entryFromRaw(data) {
const p = new BufferReader(data, true);
const hash = hash256.digest(p.readBytes(80));
const 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.time = 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
});
}
async function getTip(entry) {
const state = await db.get('R');
assert(state);
const tip = state.toString('hex', 0, 32);
const data = await db.get(pair('e', tip));
assert(data);
return entryFromRaw(data);
}
async function isMainChain(entry, tip) {
if (entry.hash === tip)
return true;
if (await 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!
async function indexTips() {
const entries = await getEntries();
const tip = await getTip();
const tips = [];
const orphans = [];
const prevs = {};
for (let i = 0; i < entries.length; i++) {
const entry = entries[i];
const main = await isMainChain(entry, tip.hash);
if (!main) {
orphans.push(entry);
prevs[entry.prevBlock] = true;
}
}
for (let i = 0; i < orphans.length; i++) {
const orphan = orphans[i];
if (!prevs[orphan.hash])
tips.push(orphan.hash);
}
tips.push(tip.hash);
for (let i = 0; i < tips.length; i++) {
const tip = tips[i];
console.log('Indexing chain tip: %s.', encoding.revHex(tip));
batch.put(pair('p', tip), DUMMY);
}
}
function write(data, str, off) {
if (Buffer.isBuffer(str))
return str.copy(data, off);
return data.write(str, off, 'hex');
}
function pair(prefix, hash) {
const key = Buffer.allocUnsafe(33);
if (typeof prefix === 'string')
prefix = prefix.charCodeAt(0);
key[0] = prefix;
write(key, hash, 1);
return key;
}
(async () => {
await db.open();
console.log('Opened %s.', file);
batch = db.batch();
await checkVersion();
await indexTips();
await batch.write();
})().then(() => {
console.log('Migration complete.');
process.exit(0);
});