32 lines
689 B
Go
32 lines
689 B
Go
package rand
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import (
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"crypto/rand"
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"fmt"
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"io"
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"math/big"
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)
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func init() {
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Reader = rand.Reader
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}
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// Reader provides a random reader that can reset during testing.
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var Reader io.Reader
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// Int63n returns a int64 between zero and value of max, read from an io.Reader source.
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func Int63n(reader io.Reader, max int64) (int64, error) {
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bi, err := rand.Int(reader, big.NewInt(max))
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if err != nil {
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return 0, fmt.Errorf("failed to read random value, %w", err)
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}
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return bi.Int64(), nil
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}
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// CryptoRandInt63n returns a random int64 between zero and value of max
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//obtained from the crypto rand source.
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func CryptoRandInt63n(max int64) (int64, error) {
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return Int63n(Reader, max)
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}
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