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{"version":3,"file":"promisebuffer.js","sources":["../../src/promisebuffer.ts"],"sourcesContent":["import { SentryError } from './error';\nimport { SyncPromise, rejectedSyncPromise, resolvedSyncPromise } from './syncpromise';\n\nexport interface PromiseBuffer<T> {\n // exposes the internal array so tests can assert on the state of it.\n // XXX: this really should not be public api.\n $: Array<PromiseLike<T>>;\n add(taskProducer: () => PromiseLike<T>): PromiseLike<T>;\n drain(timeout?: number): PromiseLike<boolean>;\n}\n\n/**\n * Creates an new PromiseBuffer object with the specified limit\n * @param limit max number of promises that can be stored in the buffer\n */\nexport function makePromiseBuffer<T>(limit?: number): PromiseBuffer<T> {\n const buffer: Array<PromiseLike<T>> = [];\n\n function isReady(): boolean {\n return limit === undefined || buffer.length < limit;\n }\n\n /**\n * Remove a promise from the queue.\n *\n * @param task Can be any PromiseLike<T>\n * @returns Removed promise.\n */\n function remove(task: PromiseLike<T>): PromiseLike<T> {\n return buffer.splice(buffer.indexOf(task), 1)[0];\n }\n\n /**\n * Add a promise (representing an in-flight action) to the queue, and set it to remove itself on fulfillment.\n *\n * @param taskProducer A function producing any PromiseLike<T>; In previous versions this used to be `task:\n * PromiseLike<T>`, but under that model, Promises were instantly created on the call-site and their executor\n * functions therefore ran immediately. Thus, even if the buffer was full, the action still happened. By\n * requiring the promise to be wrapped in a function, we can defer promise creation until after the buffer\n * limit check.\n * @returns The original promise.\n */\n function add(taskProducer: () => PromiseLike<T>): PromiseLike<T> {\n if (!isReady()) {\n return rejectedSyncPromise(new SentryError('Not adding Promise because buffer limit was reached.'));\n }\n\n // start the task and add its promise to the queue\n const task = taskProducer();\n if (buffer.indexOf(task) === -1) {\n buffer.push(task);\n }\n void task\n .then(() => remove(task))\n // Use `then(null, rejectionHandler)` rather than `catch(rejectionHandler)` so that we can use `PromiseLike`\n // rather than `Promise`. `PromiseLike` doesn't have a `.catch` method, making its polyfill smaller. (ES5 didn't\n // have promises, so TS has to polyfill when down-compiling.)\n .then(null, () =>\n remove(task).then(null, () => {\n // We have to add another catch here because `remove()` starts a new promise chain.\n }),\n );\n return task;\n }\n\n /**\n * Wait for all promises in the queue to resolve or for timeout to expire, whichever comes first.\n *\n * @param timeout The time, in ms, after which to resolve to `false` if the queue is still non-empty. Passing `0` (or\n * not passing anything) will make the promise wait as long as it takes for the queue to drain before resolving to\n * `true`.\n * @returns A promise which will resolve to `true` if the queue is already empty or drains before the timeout, and\n * `false` otherwise\n */\n function drain(timeout?: number): PromiseLike<boolean> {\n return new SyncPromise<boolean>((resolve, reject) => {\n let counter = buffer.length;\n\n if (!counter) {\n return resolve(true);\n }\n\n // wait for `timeout` ms and then resolve to `false` (if not cancelled first)\n const capturedSetTimeout = setTimeout(() => {\n if (timeout && timeout > 0) {\n resolve(false);\n }\n }, timeout);\n\n // if all promises resolve in time, cancel the timer and resolve to `true`\n buffer.forEach(item => {\n void resolvedSyncPromise(item).then(() => {\n if (!--counter) {\n clearTimeout(capturedSetTimeout);\n resolve(true);\n }\n }, reject);\n });\n });\n }\n\n return {\n $: buffer,\n add,\n
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