dongpa5277
2015-10-11 18:18 阅读 98
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gocb:批量获取操作示例

The recently released gocb lib (the official golang client for couchbase) offers API for performing bulk operations (Get, Delete, etc). I would love to see a complete example of such an operation, alas - my go skills are lacking and there's nothing online.

I'd like to see a snippet that (1) compiles and (2) performs multi-get and finally (3) manages to access the values returned from couchbase.

here's what little documentation exists online: http://developer.couchbase.com/documentation/server/4.0/sdks/go-beta/bulk-operations.html

the following code (which performs insert) is not enough: I want Get (and specifically - how one would review the contents of the get-operation results).

myBucket, _ := myCluster.OpenBucket("default", "")

var items []gocb.BulkOp
items = append(items, &gocb.InsertOp{Key: "document_name_1", Value: "Hello World 1"})
items = append(items, &gocb.InsertOp{Key: "document_name_2", Value: "Hello World 2"})

err := bucket.Do(items)
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2条回答 默认 最新

  • 已采纳
    doumen5895 doumen5895 2015-10-12 15:39

    Just replace the *InsertOp values with *GetOp values, then read their Value field:

    package main
    
    import "fmt"
    import "gopkg.in/couchbaselabs/gocb.v1"
    
    func main() {
            getKeys()
    }
    
    func getKeys() {
            myCluster, err := gocb.Connect("couchbase://<couchbase-address>")
            if err != nil {
                    fmt.Println("cluster error:", err)
            }
            myBucket, err := myCluster.OpenBucket("Test", "") //case sensitive!
            if err != nil {
                    fmt.Println("bucket error:", err)
            }
    
            var items []gocb.BulkOp
            items = append(items, &gocb.GetOp{Key: "document_name_1"})
            items = append(items, &gocb.GetOp{Key: "document_name_2"})
    
            err = myBucket.Do(items)
    
            if err != nil {
                    fmt.Println("Do error:", err)
                    panic(err)
            }
    
            for _, g := range items {
                    //"downcast" the instance back to its concrete type - GetOp
                    t := g.(*gocb.GetOp)
                    fmt.Println(t)
            }
    }
    
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  • dongsi7067 dongsi7067 2017-02-19 12:06

    This is a working version, but I think it's quite verbose

    package main
    
    import (
        "fmt"
    
        "gopkg.in/couchbase/gocb.v1"
    )
    
    const (
        COUCH_OP_COUNT = 3
    )
    
    // data interchange with Couchbase store
    type StorageUrl struct {
        Url string
    }
    
    func storeThings(b *gocb.Bucket) {
        var ops []gocb.BulkOp
        for i := 0; i < COUCH_OP_COUNT; i++ {
            k := fmt.Sprintf("key_%v", i)
            ops = append(ops, &gocb.UpsertOp{
                Key:   k,
                Value: StorageUrl{Url: fmt.Sprintf("http://www.i-%v.com", i)},
            })
        }
    
        b.Do(ops)
    }
    
    func fetchThings(b *gocb.Bucket) {
        var err error
        var ops []gocb.BulkOp
        var results []interface{}
        for i := 0; i < COUCH_OP_COUNT; i++ {
            k := fmt.Sprintf("key_%v", i)
            results = append(results, &StorageUrl{})
            ops = append(ops, &gocb.GetOp{
                Key:   k,
                Value: results[i],
            })
        }
    
        err = b.Do(ops)
        if err != nil {
            fmt.Println(err)
            return
        }
    
        for _, op := range ops {
            getOp := op.(*gocb.GetOp)
            v := getOp.Value.(*StorageUrl)
            fmt.Println(v)
        }
    }
    
    func main() {
        cluster, err := gocb.Connect("couchbase://127.0.0.1")
        if err != nil {
            fmt.Println(err)
            return
        }
    
        bucket, err := cluster.OpenBucket("test", "")
        if err != nil {
            fmt.Println(err)
            return
        }
    
        storeThings(bucket)
        fetchThings(bucket)
    }
    
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