38 lines
1.5 KiB
C#
38 lines
1.5 KiB
C#
using System;
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namespace SharpChat {
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public class RateLimiter {
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private readonly int Size;
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private readonly int MinimumDelay;
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private readonly int RiskyOffset;
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private readonly long[] TimePoints;
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public RateLimiter(int size, int minDelay, int riskyOffset = 0) {
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if(size < 2)
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throw new ArgumentException("Size is too small.", nameof(size));
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if(minDelay < 1000)
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throw new ArgumentException("Minimum delay is inhuman.", nameof(minDelay));
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if(riskyOffset != 0) {
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if(riskyOffset >= size)
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throw new ArgumentException("Risky offset may not be greater or equal to the size.", nameof(riskyOffset));
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else if(riskyOffset < 0)
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throw new ArgumentException("Risky offset may not be negative.", nameof(riskyOffset));
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}
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Size = size;
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MinimumDelay = minDelay;
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RiskyOffset = riskyOffset;
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TimePoints = new long[Size];
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}
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public bool IsRisky => TimePoints[RiskyOffset] != 0 && TimePoints[RiskyOffset + 1] != 0 && TimePoints[RiskyOffset] + MinimumDelay >= TimePoints[Size - 1];
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public bool IsExceeded => TimePoints[0] != 0 && TimePoints[1] != 0 && TimePoints[0] + MinimumDelay >= TimePoints[Size - 1];
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public void Update() {
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for(int i = 1; i < Size; ++i)
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TimePoints[i - 1] = TimePoints[i];
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TimePoints[Size - 1] = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
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}
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}
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}
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