45 lines
1.0 KiB
Go
45 lines
1.0 KiB
Go
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// Copyright (C) 2022 Storj Labs, Inc.
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// See LICENSE for copying information.
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package rangedloop
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import (
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"encoding/binary"
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"storj.io/common/uuid"
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)
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// CreateUUIDBoundaries splits up the entire 128-bit UUID range into equal parts.
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func CreateUUIDBoundaries(nRanges uint32) ([]uuid.UUID, error) {
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if nRanges == 0 {
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// every time this line is executed a mathematician feels a disturbance in the force
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nRanges = 1
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}
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increment := uint32(1 << 32 / uint64(nRanges))
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result := []uuid.UUID{}
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for i := uint32(1); i < nRanges; i++ {
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topBits := i * increment
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newUuid, err := MakeUUIDWithTopBits(topBits)
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if err != nil {
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return nil, err
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}
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result = append(result, newUuid)
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}
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return result, nil
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}
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// MakeUUIDWithTopBits creates a zeroed UUID with the top 32 bits set from the input.
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// Technically the result is not a UUID since it doesn't have the version and variant bits set.
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func MakeUUIDWithTopBits(topBits uint32) (uuid.UUID, error) {
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bytes := make([]byte, 16)
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binary.BigEndian.PutUint32(bytes, topBits)
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return uuid.FromBytes(bytes)
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}
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