typescript / expert
Snippet
Zero-Allocation TypedArray View Manipulations via DataView
DataView allows precise binary reading and writing over an existing ArrayBuffer without allocating intermediary JavaScript objects. Controlling byte endianness and offsets directly enables high-performance low-level data structure processing.
snippet.ts
typescript
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function mutateBufferInPlace(buffer: ArrayBuffer, offset: number, value: number): void {const view = new DataView(buffer, offset, 8);const currentHi = view.getUint32(0, true);const currentLo = view.getUint32(4, true);view.setFloat64(0, value, true);}
Breakdown
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function mutateBufferInPlace(buffer: ArrayBuffer, offset: number, value: number): void {
Defines a function operating directly on a raw shared ArrayBuffer memory region.
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const view = new DataView(buffer, offset, 8);
Creates a non-allocating window view over 8 bytes at the specified byte offset.
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const currentHi = view.getUint32(0, true);
Reads 32-bit unsigned integer using little-endian byte ordering.
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view.setFloat64(0, value, true);
Overwrites the 8-byte memory slice directly with a 64-bit floating point value in place.