useMemory

Source: packages/sdk/src/hardware/useMemory.ts

ActivityManager.getMemoryInfo (total, available, low-memory threshold and flag), the Java heap (Runtime) and the native heap (Debug.getNativeHeapAllocatedSize), polled every 2 s. purgeCaches() requests a GC and re-reads; it does not pretend to free system RAM. It reads on mount and every 2,000 ms thereafter.

Signature

function useMemory(): {
 totalRAMMB: number;
 freeRAMMB: number;
 usedRAMMB: number;
 isLowMemory: boolean;
 lowMemoryThresholdMB: number;
 appJavaHeapMB: number;
 appJavaHeapMaxMB: number;
 appNativeHeapMB: number;
 purgeCaches: () => void;
 source: TelemetrySource;
};

Outputs

Field	Type	Description
totalRAMMB	number	Total physical RAM in MB from ActivityManager.MemoryInfo.totalMem. 0 before the first read; 11,647 MB on this device.
freeRAMMB	number	Available RAM in MB (availMem): what the kernel says it can hand out now.
usedRAMMB	number	totalRAMMB − freeRAMMB. Includes reclaimable page cache, so it reads higher than “app memory”.
isLowMemory	boolean	Kernel low-memory flag: available RAM is below the threshold and the system is killing processes.
lowMemoryThresholdMB	number	The threshold in MB at which that flag flips.
appJavaHeapMB	number	This process’s Java heap in use, to one decimal.
appJavaHeapMaxMB	number	Ceiling for that heap; exceeding it is an OutOfMemoryError.
appNativeHeapMB	number	This process’s native heap (Hermes, decoded images, JSI buffers), to one decimal.
source	TelemetrySource	'hardware' with the native module present, 'unavailable' otherwise.

Functions

Function	Inputs	Returns	Description
purgeCaches()	none	void — the refreshed reading lands in the returned fields	Requests a garbage collection and re-reads memory immediately. It frees this app’s garbage only; it cannot free system RAM. The amount reclaimed is logged as freedMB.