go.etcd.io/bbolt v1.5.0: DB

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify go.etcd.io/bbolt.DB in pkg:golang/go.etcd.io/bbolt@v1.5.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/go.etcd.io/bbolt@v1.5.0
Demonstrate these symbols/APIs:
  - go.etcd.io/bbolt.DB

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:913f1bc08830209a7163df517f066ae45b63165ee04fb112e1f5be4c90e28fcd","contract":["bbolt.DB.Path returns the filesystem path of the opened database file","bbolt.DB.IsReadOnly returns false for writable databases and true for databases opened with ReadOnly option","bbolt.DB.Update executes a read-write transaction and automatically commits changes on nil return","bbolt.DB.Update automatically rolls back changes when the callback returns an error","bbolt.DB.View executes a read-only transaction and allows reading data","bbolt.DB.Batch executes batched transactions and commits changes","bbolt.DB.Stats returns transaction statistics including TxN count","bbolt.DB.Close closes the database file and releases file locks"],"goal":"verify go.etcd.io/bbolt.DB in pkg:golang/go.etcd.io/bbolt@v1.5.0","kind":"HOW","packages":["pkg:golang/go.etcd.io/bbolt@v1.5.0"],"schemaVersion":1,"symbols":["go.etcd.io/bbolt.DB"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/go.etcd.io/bbolt@v1.5.0"],"schemaVersion":1,"subject":"pkg:golang/go.etcd.io/bbolt@v1.5.0","symbols":["go.etcd.io/bbolt.DB"],"verifierAdapter":"golang@1"}

module sample

go 1.25.0

require go.etcd.io/bbolt v1.5.0

require golang.org/x/sys v0.45.0 // indirect

github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
go.etcd.io/bbolt v1.5.0 h1:S7GAl7Fxv12yohbwFfIbQCGDWbQbtDGPET4P/bD4lxU=
go.etcd.io/bbolt v1.5.0/go.mod h1:mkltfYE5aUHQxUct9N9V+Kp7aSjFqjgrhcXIS70Lrdk=
golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
golang.org/x/sys v0.45.0 h1:dO4czNzziLiiXplLQgBCEpCvXQ3dnkn0SdaZSYdQ+FY=
golang.org/x/sys v0.45.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

package sample

import (
	"errors"
	"fmt"
	"time"

	bolt "go.etcd.io/bbolt"
)

// OpenDatabase opens a Bolt database at the specified path with the provided options.
func OpenDatabase(path string, readOnly bool, timeout time.Duration) (*bolt.DB, error) {
	opts := &bolt.Options{
		ReadOnly: readOnly,
		Timeout:  timeout,
	}
	return bolt.Open(path, 0600, opts)
}

// SetKey stores a key-value pair in the specified bucket using db.Update.
func SetKey(db *bolt.DB, bucket, key, value string) error {
	return db.Update(func(tx *bolt.Tx) error {
		b, err := tx.CreateBucketIfNotExists([]byte(bucket))
		if err != nil {
			return fmt.Errorf("create bucket failed: %w", err)
		}
		return b.Put([]byte(key), []byte(value))
	})
}

// GetKey retrieves a value for a key in the specified bucket using db.View.
func GetKey(db *bolt.DB, bucket, key string) (string, error) {
	var result string
	err := db.View(func(tx *bolt.Tx) error {
		b := tx.Bucket([]byte(bucket))
		if b == nil {
			return errors.New("bucket not found")
		}
		val := b.Get([]byte(key))
		if val == nil {
			return errors.New("key not found")
		}
		result = string(val)
		return nil
	})
	return result, err
}

// BatchSetKey stores a key-value pair using db.Batch.
func BatchSetKey(db *bolt.DB, bucket, key, value string) error {
	return db.Batch(func(tx *bolt.Tx) error {
		b, err := tx.CreateBucketIfNotExists([]byte(bucket))
		if err != nil {
			return fmt.Errorf("create bucket failed: %w", err)
		}
		return b.Put([]byte(key), []byte(value))
	})
}

// GetStats returns the Stats struct for the database.
func GetStats(db *bolt.DB) bolt.Stats {
	return db.Stats()
}

// CloseDatabase closes the Bolt database.
func CloseDatabase(db *bolt.DB) error {
	if db == nil {
		return nil
	}
	return db.Close()
}

{
  "schemaVersion": 1,
  "goal": "verify go.etcd.io/bbolt.DB in pkg:golang/go.etcd.io/bbolt@v1.5.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/go.etcd.io/bbolt@v1.5.0"
  ],
  "symbols": [
    "go.etcd.io/bbolt.DB"
  ]
}

package main

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"time"

	bolt "go.etcd.io/bbolt"
	"sample"
)

func main() {
	tmpDir, err := os.MkdirTemp("", "bbolt-db-test-*")
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: failed to create temp dir: %v\n", err)
		os.Exit(1)
	}
	defer os.RemoveAll(tmpDir)

	dbPath := filepath.Join(tmpDir, "test.db")

	// Assertion 1: bbolt.DB.Path returns the filesystem path of the opened database file
	db, err := sample.OpenDatabase(dbPath, false, 1*time.Second)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: failed to open db: %v\n", err)
		os.Exit(1)
	}
	defer sample.CloseDatabase(db)

	if db.Path() != dbPath {
		fmt.Fprintf(os.Stderr, "FAIL: expected db.Path() %q, got %q\n", dbPath, db.Path())
		os.Exit(1)
	}

	// Assertion 2: bbolt.DB.IsReadOnly returns false for writable databases and true for databases opened with ReadOnly option
	if db.IsReadOnly() {
		fmt.Fprintf(os.Stderr, "FAIL: expected db.IsReadOnly() to be false for writable db\n")
		os.Exit(1)
	}

	// Assertion 3: bbolt.DB.Update executes a read-write transaction and automatically commits changes on nil return
	bucketName := "config"
	key := "app_name"
	expectedVal := "CodeSampleX"

	if err := sample.SetKey(db, bucketName, key, expectedVal); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: SetKey failed: %v\n", err)
		os.Exit(1)
	}

	// Assertion 4: bbolt.DB.View executes a read-only transaction and allows reading data
	gotVal, err := sample.GetKey(db, bucketName, key)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: GetKey failed: %v\n", err)
		os.Exit(1)
	}
	if gotVal != expectedVal {
		fmt.Fprintf(os.Stderr, "FAIL: expected %q, got %q\n", expectedVal, gotVal)
		os.Exit(1)
	}

	// Assertion 5: bbolt.DB.Update automatically rolls back changes when the callback returns an error
	simulatedErr := errors.New("simulated transaction failure")
	err = db.Update(func(tx *bolt.Tx) error {
		b := tx.Bucket([]byte(bucketName))
		if b == nil {
			return errors.New("bucket missing")
		}
		if err := b.Put([]byte("temp_key"), []byte("temp_value")); err != nil {
			return err
		}
		return simulatedErr
	})
	if !errors.Is(err, simulatedErr) {
		fmt.Fprintf(os.Stderr, "FAIL: expected simulated error on update rollback, got: %v\n", err)
		os.Exit(1)
	}

	_, err = sample.GetKey(db, bucketName, "temp_key")
	if err == nil {
		fmt.Fprintf(os.Stderr, "FAIL: temp_key should not exist after rolled back Update\n")
		os.Exit(1)
	}

	// Assertion 6: bbolt.DB.Batch executes batched transactions and commits changes
	batchKey := "batch_key"
	batchVal := "batch_val"
	if err := sample.BatchSetKey(db, bucketName, batchKey, batchVal); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: BatchSetKey failed: %v\n", err)
		os.Exit(1)
	}

	gotBatchVal, err := sample.GetKey(db, bucketName, batchKey)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: GetKey for batch key failed: %v\n", err)
		os.Exit(1)
	}
	if gotBatchVal != batchVal {
		fmt.Fprintf(os.Stderr, "FAIL: expected %q, got %q\n", batchVal, gotBatchVal)
		os.Exit(1)
	}

	// Assertion 7: bbolt.DB.Stats returns transaction statistics including TxN count
	stats := sample.GetStats(db)
	if stats.TxN < 1 {
		fmt.Fprintf(os.Stderr, "FAIL: expected stats.TxN >= 1, got %d\n", stats.TxN)
		os.Exit(1)
	}

	// Assertion 8: bbolt.DB.Close closes the database file and releases file locks
	if err := sample.CloseDatabase(db); err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: CloseDatabase failed: %v\n", err)
		os.Exit(1)
	}

	// Verify ReadOnly mode on re-open
	roDB, err := sample.OpenDatabase(dbPath, true, 1*time.Second)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: failed to open read-only db: %v\n", err)
		os.Exit(1)
	}
	defer sample.CloseDatabase(roDB)

	if !roDB.IsReadOnly() {
		fmt.Fprintf(os.Stderr, "FAIL: expected roDB.IsReadOnly() to be true\n")
		os.Exit(1)
	}

	roVal, err := sample.GetKey(roDB, bucketName, key)
	if err != nil {
		fmt.Fprintf(os.Stderr, "FAIL: GetKey on read-only db failed: %v\n", err)
		os.Exit(1)
	}
	if roVal != expectedVal {
		fmt.Fprintf(os.Stderr, "FAIL: expected %q, got %q in read-only db\n", expectedVal, roVal)
		os.Exit(1)
	}

	fmt.Println("PASS: go.etcd.io/bbolt.DB contract assertions passed")
}