javascript / expert
Snippet
Atomic Array Buffer Mutations for Zero-Copy Svelte Reactive Arrays
Standard JavaScript array mutations in high-frequency Svelte reactive bindings cause excessive object allocation and garbage collection. By utilizing SharedArrayBuffer with Int32Array typed views and Atomics operations, binary arrays can be modified in-place with thread-safe atomic guarantees.
snippet.js
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export function createBinaryArrayView(bufferLength) {const sharedBuffer = new SharedArrayBuffer(bufferLength * Int32Array.BYTES_PER_ELEMENT);const typedView = new Int32Array(sharedBuffer);return {mutateIndex(index, value) {Atomics.store(typedView, index, value);return typedView;},readIndex(index) {return Atomics.load(typedView, index);}};}
svelte
Breakdown
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const sharedBuffer = new SharedArrayBuffer(bufferLength * Int32Array.BYTES_PER_ELEMENT);
Allocates a raw binary memory buffer suitable for shared concurrent array data access.
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const typedView = new Int32Array(sharedBuffer);
Wraps the raw buffer with a typed integer array view for element-level indexed operations.
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Atomics.store(typedView, index, value);
Performs a thread-safe atomic write to the typed array at the specified memory index.
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return Atomics.load(typedView, index);
Reads the 32-bit integer value atomically, avoiding partial reads during memory access.