diff options
Even more documentation for various controllers and libs.
Diffstat (limited to 'app/scripts/controllers/recent-blocks.js')
-rw-r--r-- | app/scripts/controllers/recent-blocks.js | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/app/scripts/controllers/recent-blocks.js b/app/scripts/controllers/recent-blocks.js index 4ae3810eb..ddcaa7220 100644 --- a/app/scripts/controllers/recent-blocks.js +++ b/app/scripts/controllers/recent-blocks.js @@ -5,6 +5,23 @@ const EthQuery = require('eth-query') class RecentBlocksController { + /** + * Controller responsible for storing, updating and managing the recent history of blocks. Blocks are back filled + * upon the controller's construction and then the list is updated when the given block tracker gets a 'block' event + * (indicating that there is a new block to process). + * + * @typedef {Object} RecentBlocksController + * @param {object} opts Contains objects necessary for tracking blocks and querying the blockchain + * @param {BlockTracker} opts.blockTracker Contains objects necessary for tracking blocks and querying the blockchain + * @param {BlockTracker} opts.provider The provider used to create a new EthQuery instance. + * @property {BlockTracker} blockTracker Points to the passed BlockTracker. On RecentBlocksController construction, + * listens for 'block' events so that new blocks can be processed and added to storage. + * @property {EthQuery} ethQuery Points to the EthQuery instance created with the passed provider + * @property {number} historyLength The maximum length of blocks to track + * @property {object} store Stores the recentBlocks + * @property {array} store.recentBlocks Contains all recent blocks, up to a total that is equal to this.historyLength + * + */ constructor (opts = {}) { const { blockTracker, provider } = opts this.blockTracker = blockTracker @@ -20,12 +37,23 @@ class RecentBlocksController { this.backfill() } + /** + * Sets store.recentBlocks to an empty array + * + */ resetState () { this.store.updateState({ recentBlocks: [], }) } + /** + * Receives a new block and modifies it with this.mapTransactionsToPrices. Then adds that block to the recentBlocks + * array in storage. If the recentBlocks array contains the maximum number of blocks, the oldest block is removed. + * + * @param {object} newBlock The new block to modify and add to the recentBlocks array + * + */ processBlock (newBlock) { const block = this.mapTransactionsToPrices(newBlock) @@ -39,6 +67,15 @@ class RecentBlocksController { this.store.updateState(state) } + /** + * Receives a new block and modifies it with this.mapTransactionsToPrices. Adds that block to the recentBlocks + * array in storage, but only if the recentBlocks array contains fewer than the maximum permitted. + * + * Unlike this.processBlock, backfillBlock adds the modified new block to the beginning of the recent block array. + * + * @param {object} newBlock The new block to modify and add to the beginning of the recentBlocks array + * + */ backfillBlock (newBlock) { const block = this.mapTransactionsToPrices(newBlock) @@ -51,6 +88,14 @@ class RecentBlocksController { this.store.updateState(state) } + /** + * Receives a block and gets the gasPrice of each of its transactions. These gas prices are added to the block at a + * new property, and the block's transactions are removed. + * + * @param {object} newBlock The block to modify. It's transaction array will be replaced by a gasPrices array. + * @returns {object} The modified block. + * + */ mapTransactionsToPrices (newBlock) { const block = extend(newBlock, { gasPrices: newBlock.transactions.map((tx) => { @@ -61,6 +106,16 @@ class RecentBlocksController { return block } + /** + * On this.blockTracker's first 'block' event after this RecentBlocksController's instantiation, the store.recentBlocks + * array is populated with this.historyLength number of blocks. The block number of the this.blockTracker's first + * 'block' event is used to iteratively generate all the numbers of the previous blocks, which are obtained by querying + * the blockchain. These blocks are backfilled so that the recentBlocks array is ordered from oldest to newest. + * + * Each iteration over the block numbers is delayed by 100 milliseconds. + * + * @returns {Promise<void>} Promises undefined + */ async backfill() { this.blockTracker.once('block', async (block) => { let blockNum = block.number @@ -89,12 +144,25 @@ class RecentBlocksController { }) } + /** + * A helper for this.backfill. Provides an easy way to ensure a 100 millisecond delay using await + * + * @returns {Promise<void>} Promises undefined + * + */ async wait () { return new Promise((resolve) => { setTimeout(resolve, 100) }) } + /** + * Uses EthQuery to get a block that has a given block number. + * + * @param {number} number The number of the block to get + * @returns {Promise<object>} Promises A block with the passed number + * + */ async getBlockByNumber (number) { const bn = new BN(number) return new Promise((resolve, reject) => { |