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8cd0c63595
Add test suite covering thread-safe random number generator with tests for: - Constructor with various seed values (positive, zero, negative) - Deterministic behavior verification with same seeds - Permutation generation and validation - Concurrent access safety with multiple goroutines - Mixed operations under concurrent load Also clarify package documentation to explicitly state this is for load balancing and server selection, not cryptographic use. The math/rand usage is intentional for performance in non-security contexts like upstream server selection and DNS record shuffling. Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>
39 lines
962 B
Go
39 lines
962 B
Go
// Package rand is used for concurrency safe random number generator.
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// This package provides a thread-safe wrapper around math/rand for use in
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// load balancing and server selection. It is NOT suitable for cryptographic
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// purposes and should not be used for security-sensitive operations.
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package rand
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import (
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"math/rand"
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"sync"
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)
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// Rand is used for concurrency safe random number generator.
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type Rand struct {
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m sync.Mutex
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r *rand.Rand
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}
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// New returns a new Rand from seed.
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func New(seed int64) *Rand {
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return &Rand{r: rand.New(rand.NewSource(seed))}
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}
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// Int returns a non-negative pseudo-random int from the Source in Rand.r.
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func (r *Rand) Int() int {
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r.m.Lock()
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v := r.r.Int()
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r.m.Unlock()
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return v
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}
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// Perm returns, as a slice of n ints, a pseudo-random permutation of the
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// integers in the half-open interval [0,n) from the Source in Rand.r.
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func (r *Rand) Perm(n int) []int {
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r.m.Lock()
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v := r.r.Perm(n)
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r.m.Unlock()
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return v
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}
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