@satellite-earth/clock v2.0.0

View full documentation at https://docs.satellite.earth/

Usage

const Clock = require('@satellite-earth/clock');
const Web3 = require('web3');

// ...

// Create the clock
const clock = new Clock();

// Get a web3 instance to read blockchain data
const web3 = new Web3(provider);

// Populate the clock with data from blocks in the given range
const await clock.synchronize(web3);

// Now the clock is ready to use

Constructor

1. Array - (optional) Array of objects to initialize block data, each containing sequential block data number, hash, and timestamp

Properties

initialized

clock.initialized

Boolean - If clock has been been initialized (i.e. if it contains record of any blocks)

min

clock.min

Number|null - Earliest synced block number (null if clock is uninitialized)

max

clock.max

Number|null - Latest synced block number (null if clock is uninitialized)

Methods

init

clock.init(blocks);

Initialize clock's internal data structure. Useful for loading saved clock data instead of having to resynchronize with the blockchain.

Parameters

1. Array - Array of objects, each containing sequential block data number, hash, and timestamp

synchronize

await clock.synchronize(earth, { startBlock, toBlock });

Populate clock with block data directly from the blockchain. By default, the clock starts synchronizing from it's last synced position, or the latest block available.

Parameters

1. Core - Earth core instance (used to communicate with blockchain)
2. Object - Options
   • startBlock - Number - Block number of last block to sync
   • toBlock - Number - Block number of first block to sync

Returns

Promise returns Object - New block data

readHash

const block = clock.readHash(hash);
console.log(block); // { hash, number, timestamp }

Lookup a block's number and timestamp by its hash. Return undefined if block not found.

Parameters

1. String - Block hash
2. Number - (optional) Number of blocks between this block and maximum synced block required to return value. Default 0

Returns

Obejct|undefined - Block data

readNumber

const block = clock.readNumber(hash);
console.log(block); // { hash, number, timestamp }

Lookup a block's hash and timestamp by its number. Return undefined if block not found.

Parameters

1. Number - Block number
2. Number - (optional) Number of blocks between this block an maximum synced block required to return value. Default 0

Returns

Obejct|undefined - Block data

compareHash

const delta = clock.compareHash(hashA, hashB);
console.log(delta) // 42

Given two blockhashes, return the difference in their corresponding block's numbers. If either block is not found, return 0. Useful for sorting blocks by time via hash.

Parameters

1. String - Hash of one block
2. String - Hash of other block

Returns

Number - Block number difference

advance

console.log(clock.max); // 10337501
clock.advance({ number, timestamp, hash, parentHash });
console.log(clock.max); // 10337502

Add a block to the clock's internal data structure. Throws an error if parentHash does not match hash of current maximum block.

Parameters

1. Object - Block data must be an object containing number, timestamp, hash, and parentHash

exportBlocks

const blocks = clock.exportBlocks();
console.log(blocks); // [ { number, timestamp, hash }, . . . ]

Get array of block objects. Useful for exporting block data to be cached elsewhere.

Parameters

1. Object - (optional) range to export, e.g { min: 10337500 max: 10339000 } (default all blocks)

Returns

Array - Array of objects containing block data