javascript / expert
Snippet
Fine-Grained Authorization with Bitwise Operators
Bitwise operators allow for extremely memory-efficient storage and fast checking of multiple boolean flags (permissions) within a single integer. This is an expert pattern for high-performance authorization systems.
snippet.js
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const Permissions = {READ: 1 << 0, // 0001WRITE: 1 << 1, // 0010DELETE: 1 << 2, // 0100ADMIN: 1 << 3 // 1000};const userPerms = Permissions.READ | Permissions.WRITE;const canWrite = (userPerms & Permissions.WRITE) !== 0;const canDelete = (userPerms & Permissions.DELETE) !== 0;// Next.js Metadata / Access Checkif (!(userPerms & Permissions.ADMIN)) {// Restricted access}
nextjs
Breakdown
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1 << 0, 1 << 1...
Uses the left-shift operator to create unique power-of-two values for each permission flag.
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userPerms = Permissions.READ | Permissions.WRITE;
Combines multiple permissions into a single bitmask using the bitwise OR operator.
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(userPerms & Permissions.WRITE) !== 0
Checks for a specific permission using the bitwise AND operator to isolate the relevant bit.