Artifact [9af404eba1]

Artifact 9af404eba1cd668bffdf95a28660b785353605412900359c615864c2bd5a2127:

• File simio/rand.go — part of check-in [f5744359d3] at 2026-04-19 16:30:54 on branch trunk — Initial open source release

  libfossil is a pure-Go implementation of the Fossil SCM, reading and writing the same .fossil SQLite repository format as upstream Fossil.

  This is the first public release of code that previously lived in a private repository. The module path is github.com/danmestas/libfossil and the binary is named libfossil to avoid $PATH collisions with upstream fossil.

  Included: - Repo lifecycle (create, clone), checkout/checkin, timeline, merge, diff, annotate, shun, tag, branch, bisect, stash, undo/redo - Sync-over-HTTP protocol (client and handler) - Two SQLite drivers: modernc (pure Go, default) and ncruces (wasm-capable) - Observer interfaces (SyncObserver, CheckoutObserver) with an optional OpenTelemetry implementation in observer/otel (separate submodule) - Deterministic simulation testing harness with BUGGIFY fault injection - Kong-based embeddable CLI under cli/ and a standalone binary under cmd/libfossil/ (user: [email protected], size: 648) [annotate] [blame] [check-ins using]

package simio

import (
	"crypto/rand"
	"io"
	mrand "math/rand"
)

// Rand abstracts random byte generation for deterministic simulation.
type Rand interface {
	Read(p []byte) (n int, err error)
}

// CryptoRand delegates to crypto/rand (production use).
type CryptoRand struct{}

func (CryptoRand) Read(p []byte) (int, error) { return rand.Read(p) }

// SeededRand uses a seeded math/rand source for deterministic output.
type SeededRand struct {
	src io.Reader
}

func NewSeededRand(seed int64) *SeededRand {
	return &SeededRand{src: mrand.New(mrand.NewSource(seed))}
}

func (r *SeededRand) Read(p []byte) (int, error) {
	return r.src.Read(p)
}