@fluidframework/common-utils Package
Packages > @fluidframework/common-utils
Classes
| Class | Description |
|---|---|
| BaseTelemetryNullLogger | Null logger It can be used in places where logger instance is required, but events should be not send over. |
| BatchManager | Manages a queue of work to be batch processed at next javascript turn of execution |
| Buffer | Declare the subset of Buffer functionality we want to make available instead of exposing the entirely of Node's typings. This should match the public interface of the browser implementation, so any changes made in one should be made in both. |
| Deferred | A deferred creates a promise and the ability to resolve or reject it |
| EventForwarder | Base class used for forwarding events from a source EventEmitter. This can be useful when all arbitrary listeners need to be removed, but the primary source needs to stay intact. |
| Heap | Ordered Heap data structure implementation |
| Lazy | Helper class for lazy initialized values. Ensures the value is only generated once, and remain immutable |
| LazyPromise | A lazy evaluated promise. The execute function is delayed until the promise is used, e.g. await, then, catch ... The execute function is only called once. All calls are then proxied to the promise returned by the execute method. |
| PromiseCache | A specialized cache for async work, allowing you to safely cache the promised result of some async work without fear of running it multiple times or losing track of errors. |
| PromiseTimer | This class is a wrapper over setTimeout and clearTimeout which makes it simpler to keep track of recurring timeouts with the same handlers and timeouts, while also providing a promise that resolves when it times out. |
| RangeTracker | Helper class that keeps track of the relation between two ranges in a 1:N fashion. Primary is continuous and always maps to a single value in secondary above the base value. The range defines an increasing step function.Used by deli to keep track of the branch map |
| RateLimiter | A rate limiter to make sure that a client can only request help for one task within a time window. |
| TelemetryNullLogger | Null logger It can be used in places where logger instance is required, but events should be not send over. |
| Timer | This class is a thin wrapper over setTimeout and clearTimeout which makes it simpler to keep track of recurring timeouts with the same or similar handlers and timeouts. |
| Trace | Helper class for tracing performance of events Time measurements are in milliseconds as a floating point with a decimal |
| TypedEventEmitter | Event Emitter helper class the supports emitting typed events |
Functions
| Function | Description |
|---|---|
| assertNotRejected(promise) | Helper function that asserts that the given promise only resolves |
| doIfNotDisposed(disposable, f) | |
| gitHashFile(file) | Create a github hash (Github hashes the string with blob and size) Must be called under secure context for browsers |
| hashFile(file) | Hash a file. Consistent within a session, but should not be persisted and is not consistent with git. Must be called under secure context for browsers |
| safelyParseJSON(json) | Wrapper for JSON.parse to translate all exception to return undefined |
| Uint8ArrayToString(arr, encoding) | Converts a Uint8Array to a string of the provided encoding Useful when the array might be an IsoBuffer |
| unreachableCase(_, message) | This function can be used to assert at compile time that a given value has type never. One common usage is in the default case of a switch block, to ensure that all cases are explicitly handled. |
Interfaces
| Interface | Description |
|---|---|
| IComparer | Interface for a comparere |
| IHeapNode | Interface to a node in Heap |
| IPromiseTimer | Timer which offers a promise that fulfills when the timer completes. |
| IPromiseTimerResult | |
| IRange | A range in the RangeTracker |
| IRangeTrackerSnapshot | A serialized version of the RangeTracker |
| ITimer | |
| ITraceEvent | Event in a performance trace including time elapsed. |
| PromiseCacheOptions | Options for configuring the PromiseCache |
Variables
| Variable | Description |
|---|---|
| fromBase64ToUtf8 | |
| fromUtf8ToBase64 | |
| IsoBuffer | |
| NumberComparer | A comparer for numbers |
| toUtf8 | Convenience function to convert unknown encoding to utf8 that avoids buffer copies/encode ops when no conversion is needed |
Type Aliases
| Type Alias | Description |
|---|---|
| EventEmitterEventType | |
| IsoBuffer | |
| PromiseCacheExpiry | Three supported expiry policies: - indefinite: entries don't expire and must be explicitly removed - absolute: entries expire after the given duration in MS, even if accessed multiple times in the mean time - sliding: entries expire after the given duration in MS of inactivity (i.e. get resets the clock) |
| TypedEventTransform |
Functions
assertNotRejected
Helper function that asserts that the given promise only resolves
Signature:
export declare function assertNotRejected<T>(promise: Promise<T>): Promise<T>;
Parameters
| Parameter | Type | Description |
|---|---|---|
| promise | Promise |
Returns:
Promise<T>
doIfNotDisposed
Signature:
export declare function doIfNotDisposed<T>(disposable: IDisposable, f: (...args: any[]) => T): (...args: any[]) => T;
Parameters
| Parameter | Type | Description |
|---|---|---|
| disposable | IDisposable | |
| f | (...args: any[]) => T |
Returns:
(…args: any[]) => T
gitHashFile
Create a github hash (Github hashes the string with blob and size) Must be called under secure context for browsers
Signature:
export declare function gitHashFile(file: IsoBuffer): Promise<string>;
Parameters
| Parameter | Type | Description |
|---|---|---|
| file | IsoBuffer | The contents of the file in a buffer |
Returns:
Promise<string>
The sha1 hash of the content of the buffer with the blob prefix and size
hashFile
Hash a file. Consistent within a session, but should not be persisted and is not consistent with git. Must be called under secure context for browsers
Signature:
export declare function hashFile(file: IsoBuffer): Promise<string>;
Parameters
| Parameter | Type | Description |
|---|---|---|
| file | IsoBuffer | The contents of the file in a buffer |
Returns:
Promise<string>
The hash of the content of the buffer
safelyParseJSON
Wrapper for JSON.parse to translate all exception to return undefined
Signature:
export declare function safelyParseJSON(json: string): any;
Parameters
| Parameter | Type | Description |
|---|---|---|
| json | string | the JSON string to parse |
Returns:
any
the result JSON.parse is successful, undefined if exception happens
Uint8ArrayToString
Converts a Uint8Array to a string of the provided encoding Useful when the array might be an IsoBuffer
Signature:
export declare function Uint8ArrayToString(arr: Uint8Array, encoding?: string): string;
Parameters
| Parameter | Type | Description |
|---|---|---|
| arr | Uint8Array | The array to convert |
| encoding | string | Optional target encoding; only "utf8" and "base64" are supported, with "utf8" being default |
Returns:
string
The converted string
unreachableCase
This function can be used to assert at compile time that a given value has type never. One common usage is in the default case of a switch block, to ensure that all cases are explicitly handled.
Signature:
export declare function unreachableCase(_: never, message?: string): never;
Parameters
| Parameter | Type | Description |
|---|---|---|
| _ | never | |
| message | string |
Returns:
never
Variables
fromBase64ToUtf8
Signature:
fromBase64ToUtf8: (input: string) => string
fromUtf8ToBase64
Signature:
fromUtf8ToBase64: (input: string) => string
IsoBuffer
Signature:
IsoBuffer: typeof Buffer
NumberComparer
A comparer for numbers
Signature:
NumberComparer: IComparer<number>
toUtf8
Convenience function to convert unknown encoding to utf8 that avoids buffer copies/encode ops when no conversion is needed
Signature:
toUtf8: (input: string, encoding: string) => string
Type Aliases
EventEmitterEventType
Signature:
export declare type EventEmitterEventType = EventEmitter extends {
on(event: infer E, listener: any): any;
} ? E : never;
IsoBuffer
Signature:
export declare type IsoBuffer = Buffer;
PromiseCacheExpiry
Three supported expiry policies: - indefinite: entries don’t expire and must be explicitly removed - absolute: entries expire after the given duration in MS, even if accessed multiple times in the mean time - sliding: entries expire after the given duration in MS of inactivity (i.e. get resets the clock)
Signature:
export declare type PromiseCacheExpiry = {
policy: "indefinite";
} | {
policy: "absolute" | "sliding";
durationMs: number;
};
TypedEventTransform
Signature:
export declare type TypedEventTransform<TThis, TEvent extends IEvent> = TransformedEvent<TThis, "newListener" | "removeListener", Parameters<(event: string, listener: (...args: any[]) => void) => void>> & IEventTransformer<TThis, TEvent> & TransformedEvent<TThis, EventEmitterEventType, any[]>;