23 lines
No EOL
815 B
C#
23 lines
No EOL
815 B
C#
using Iceshrimp.Backend.Core.Extensions;
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namespace Iceshrimp.Backend.Core.Helpers;
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public static class IdHelpers
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{
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private const long Time2000 = 946684800000;
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public static string GenerateSnowflakeId(DateTime? createdAt = null)
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{
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if (createdAt is { Kind: not DateTimeKind.Utc })
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createdAt = createdAt.Value.ToUniversalTime();
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createdAt ??= DateTime.UtcNow;
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// We want to use a charset with a power-of-two amount of possible characters for optimal CSPRNG performance.
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var random = CryptographyHelpers.GenerateRandomString(8, CryptographyHelpers.Charset.CrockfordBase32Lower);
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var now = createdAt.Value.Subtract(DateTime.UnixEpoch).GetTotalMilliseconds();
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var time = Math.Max(now - Time2000, 0);
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var timestamp = time.ToBase36().PadLeft(8, '0');
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return timestamp + random;
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}
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} |