Usage Examples

This guide demonstrates how to use GoBatch through practical examples. The complete example code can be found in the gobatch-example/basic directory.

Prerequisites

Before getting started, please ensure all dependency requirements are met, especially the MySQL database configuration.

Writing Steps

Simple Step Example

A simple step executes business logic in a single thread:

// Define a simple task function
func mytask() {
    fmt.Println("mytask executed")
}

// Build the step
step1 := gobatch.NewStep("mytask").Handler(mytask).Build()

Chunk Step Example

A chunk step processes data in chunks using the read-process-write pattern.

1. Create Reader

type myReader struct {}

func (r *myReader) Read(chunkCtx *gobatch.ChunkContext) (interface{}, gobatch.BatchError) {
    curr, _ := chunkCtx.StepExecution.StepContext.GetInt("read.num", 0)
    if curr < 100 {
        chunkCtx.StepExecution.StepContext.Put("read.num", curr+1)
        return fmt.Sprintf("value-%v", curr), nil
    }
    return nil, nil
}

1. Create Processor

type myProcessor struct {}

func (r *myProcessor) Process(item interface{}, chunkCtx *gobatch.ChunkContext) (interface{}, gobatch.BatchError) {
    return fmt.Sprintf("processed-%v", item), nil
}

1. Create Writer

type myWriter struct {}

func (r *myWriter) Write(items []interface{}, chunkCtx *gobatch.ChunkContext) gobatch.BatchError {
    fmt.Printf("write: %v\n", items)
    return nil
}

1. Build Chunk Step

step2 := gobatch.NewStep("my_step").
    Reader(&myReader{}).
    Processor(&myProcessor{}).
    Writer(&myWriter{}).
    ChunkSize(10).
    Build()

Building and Running a Job

1. Configure Database Connection

db, err := sql.Open("mysql", "user:password@tcp(127.0.0.1:3306)/gobatch?charset=utf8&parseTime=true")
if err != nil {
    panic(err)
}
gobatch.SetDB(db)

Note: Please replace user, password, 127.0.0.1:3306, and gobatch with your actual database username, password, host:port, and database name.

2. Build and Register Job

// Build job with steps
job := gobatch.NewJob("my_job").Step(step1, step2).Build()

// Register job
gobatch.Register(job)

3. Run Job

// Run synchronously with parameters
params, _ := util.JsonString(map[string]interface{}{
    "rand": time.Now().Nanosecond(),
})
gobatch.Start(context.Background(), job.Name(), params)

// Or run asynchronously
// gobatch.StartAsync(context.Background(), job.Name(), "")

Complete Example

The complete example code can be found in gobatch-example/basic/main.go.