Chapter 780: TimestampQueryPool

Core Idea

Abstract base class of a timestamp query pool.

currentQueryIndex : number: How many queries allocated so far.
frames : Array.<number>: Stores all timestamp frames.
isDisposed : boolean: Whether the pool has been disposed or not.
lastValue : number: The total frame duration until the next update.
maxQueries : number: Maximum number of queries this pool can hold.
pendingResolve : boolean | Promise.<number>: This property is used to avoid multiple concurrent resolve operations. The WebGL backend uses it as a boolean flag. In context of WebGPU, i…
queryOffsets : Map.<string, number>: Tracks offsets for different contexts.
timestamps : Map.<string, number>: Stores the latest timestamp for each render context.
trackTimestamp : boolean: Whether to track timestamps or not.

Constructor

Signature
`new TimestampQueryPool( maxQueries : number ) (abstract)`

Properties

Property	Description
`.currentQueryIndex : number`	How many queries allocated so far.
`.frames : Array.<number>`	Stores all timestamp frames.
`.isDisposed : boolean`	Whether the pool has been disposed or not.
`.lastValue : number`	The total frame duration until the next update.
`.maxQueries : number`	Maximum number of queries this pool can hold.
`.pendingResolve : boolean	Promise.<number>`
`.queryOffsets : Map.<string, number>`	Tracks offsets for different contexts.
`.timestamps : Map.<string, number>`	Stores the latest timestamp for each render context.
`.trackTimestamp : boolean`	Whether to track timestamps or not.

Methods

Method	Description
`.allocateQueriesForContext( uid : string, frameId : number ) : number (abstract)`	Allocate queries for a specific uid.
`.dispose() (abstract)`	Dispose of the query pool.
`.getTimestamp( uid : string ) : number`	Returns the timestamp for a given render context.
`.getTimestampFrames() : Array.<number>`	Returns all timestamp frames.
`.hasTimestampQuery( uid : string ) : boolean`	Returns whether a timestamp is available for a given render context.
`.resolveQueriesAsync() : Promise.<number>	number (async, abstract)`

Most relevant properties: currentQueryIndex, frames, isDisposed, lastValue.
Key methods: allocateQueriesForContext, dispose, getTimestamp, getTimestampFrames.