BadgerKV

BadgerKV is a Go library that provides a standardized key-value store interface built on top of BadgerDB. It implements the github.com/bborbe/kv interface, offering a clean and consistent API for database operations including transactions, buckets, and key-value operations.

Features

• Standardized Interface: Implements the github.com/bborbe/kv interface for consistent database operations
• Transaction Support: Full ACID transaction support with automatic rollback on errors
• Bucket-based Organization: Organize data into logical buckets within transactions
• Memory & Disk Storage: Support for both file-based and in-memory databases
• Iterator Support: Forward and reverse iteration over bucket contents
• Context-aware: Full context support for cancellation and deadlines
• Thread-safe: Safe for concurrent use across multiple goroutines

Installation

go get github.com/bborbe/badgerkv

Quick Start

Basic Usage

package main

import (
    "context"
    "log"
    
    "github.com/bborbe/badgerkv"
)

func main() {
    ctx := context.Background()
    
    // Open a file-based database
    db, err := badgerkv.OpenPath(ctx, "/tmp/mydb")
    if err != nil {
        log.Fatal(err)
    }
    defer db.Close()
    
    // Start a transaction
    err = db.Update(ctx, func(ctx context.Context, tx badgerkv.Tx) error {
        // Get or create a bucket
        bucket, err := tx.CreateBucketIfNotExists([]byte("users"))
        if err != nil {
            return err
        }
        
        // Store a key-value pair
        return bucket.Put([]byte("user:1"), []byte(`{"name": "John", "age": 30}`))
    })
    if err != nil {
        log.Fatal(err)
    }
    
    // Read data
    err = db.View(ctx, func(ctx context.Context, tx badgerkv.Tx) error {
        bucket := tx.Bucket([]byte("users"))
        if bucket == nil {
            return nil // bucket doesn't exist
        }
        
        value, err := bucket.Get([]byte("user:1"))
        if err != nil {
            return err
        }
        
        log.Printf("User data: %s", value)
        return nil
    })
    if err != nil {
        log.Fatal(err)
    }
}

In-Memory Database

// Create an in-memory database (useful for testing)
db, err := badgerkv.OpenMemory(ctx)
if err != nil {
    log.Fatal(err)
}
defer db.Close()

Memory Optimization

// Use minimal memory settings for resource-constrained environments
db, err := badgerkv.OpenPath(ctx, "/tmp/mydb", badgerkv.MinMemoryUsageOptions)
if err != nil {
    log.Fatal(err)
}
defer db.Close()

Iteration

err = db.View(ctx, func(ctx context.Context, tx badgerkv.Tx) error {
    bucket := tx.Bucket([]byte("users"))
    if bucket == nil {
        return nil
    }
    
    // Forward iteration
    iter := bucket.Iterator()
    defer iter.Close()
    
    for iter.First(); iter.Valid(); iter.Next() {
        key := iter.Key().Data()
        value := iter.Item().Value()
        log.Printf("Key: %s, Value: %s", key, value)
    }
    
    return nil
})

Custom BadgerDB Options

import "github.com/dgraph-io/badger/v4"

// Define custom options
customOptions := func(opts *badger.Options) {
    opts.Logger = nil // Disable logging
    opts.SyncWrites = true // Force sync on writes
}

db, err := badgerkv.OpenPath(ctx, "/tmp/mydb", customOptions)

API Overview

Database Operations

• OpenPath(ctx, path, ...options) - Open file-based database
• OpenMemory(ctx, ...options) - Open in-memory database
• DB.View(ctx, fn) - Read-only transaction
• DB.Update(ctx, fn) - Read-write transaction
• DB.Close() - Close database

Transaction Operations

• Tx.Bucket(name) - Get existing bucket
• Tx.CreateBucket(name) - Create new bucket (fails if exists)
• Tx.CreateBucketIfNotExists(name) - Get or create bucket
• Tx.DeleteBucket(name) - Delete bucket and all contents

Bucket Operations

• Bucket.Get(key) - Retrieve value by key
• Bucket.Put(key, value) - Store key-value pair
• Bucket.Delete(key) - Delete key
• Bucket.Iterator() - Create iterator for bucket contents

Iterator Operations

• Iterator.First() - Move to first item
• Iterator.Last() - Move to last item
• Iterator.Next() - Move to next item
• Iterator.Prev() - Move to previous item
• Iterator.Valid() - Check if iterator position is valid
• Iterator.Key() - Get current key
• Iterator.Item() - Get current item

Transaction Context

BadgerKV prevents nested transactions by tracking transaction state in the context. Use IsTransactionOpen(ctx) to check if a transaction is already active.

if badgerkv.IsTransactionOpen(ctx) {
    // Already in a transaction, cannot start nested transaction
    return errors.New("nested transactions not supported")
}

Error Handling

BadgerKV uses the github.com/bborbe/errors package for enhanced error handling with context preservation:

err = db.Update(ctx, func(ctx context.Context, tx badgerkv.Tx) error {
    bucket, err := tx.CreateBucket([]byte("test"))
    if err != nil {
        return errors.Wrapf(ctx, err, "create bucket failed")
    }
    
    return bucket.Put([]byte("key"), []byte("value"))
})

if err != nil {
    log.Printf("Transaction failed: %v", err)
}

Testing

BadgerKV is thoroughly tested using Ginkgo v2 and Gomega:

# Run all tests
go test ./...

# Run tests with coverage
go test -cover ./...

# Run specific test
go test -run TestSpecificFunction ./...

Dependencies

• BadgerDB v4: High-performance key-value database
• github.com/bborbe/kv: Common key-value interface
• github.com/bborbe/errors: Enhanced error handling
• github.com/bborbe/collection: Utility functions

Contributing

1. Fork the repository
2. Create a feature branch
3. Add tests for new functionality
4. Run make precommit to ensure code quality
5. Submit a pull request

License

This project is licensed under the BSD-style license. See the LICENSE file for details.