Update threads to use model/store (#97)

2026-01-11 19:04:35 +00:00 · 2021-05-11 12:41:53 +01:00
parent f74cfdf674
commit 7e13403d9b
31 changed files with 1309 additions and 1143 deletions
--- a/pkg/model/model.go
+++ b/pkg/model/model.go
@@ -0,0 +1,175 @@
+// package model helps with data modelling on top of the store
+package model
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+
+	"github.com/micro/micro/v3/service/store"
+)
+
+var (
+	ErrNotFound      = errors.New("not found")
+	ErrAlreadyExists = errors.New("already exists")
+)
+
+type Entity interface {
+	// The primary key
+	Key(ctx context.Context) string
+	// The index for the entity
+	Index(ctx context.Context) string
+	// The raw value of the entity
+	Value() interface{}
+}
+
+type Query struct {
+	Limit  uint
+	Offset uint
+	Order  string
+}
+
+func Create(ctx context.Context, e Entity) error {
+	key := e.Key(ctx)
+	val := e.Value()
+	idx := e.Index(ctx)
+
+	// read the existing record
+	recs, err := store.Read(key, store.ReadLimit(1))
+	if err != nil && err != store.ErrNotFound {
+		return err
+	}
+
+	if len(recs) > 0 {
+		return ErrAlreadyExists
+	}
+
+	// write the record
+	if err := store.Write(store.NewRecord(key, val)); err != nil {
+		return err
+	}
+
+	// only write the index if it exists
+	if len(idx) == 0 {
+		return nil
+	}
+
+	// write the index
+	return store.Write(store.NewRecord(idx, val))
+}
+
+func ReadIndex(ctx context.Context, e Entity) error {
+	recs, err := store.Read(e.Index(ctx), store.ReadLimit(1))
+	if err == store.ErrNotFound {
+		return ErrNotFound
+	} else if err != nil {
+		return err
+	}
+	if len(recs) == 0 {
+		return ErrNotFound
+	}
+	return recs[0].Decode(e)
+}
+
+func Read(ctx context.Context, e Entity) error {
+	recs, err := store.Read(e.Key(ctx), store.ReadLimit(1))
+	if err == store.ErrNotFound {
+		return ErrNotFound
+	} else if err != nil {
+		return err
+	}
+	if len(recs) == 0 {
+		return ErrNotFound
+	}
+	return recs[0].Decode(e)
+}
+
+func Update(ctx context.Context, e Entity) error {
+	key := e.Key(ctx)
+	val := e.Value()
+	idx := e.Index(ctx)
+
+	// write the record
+	if err := store.Write(store.NewRecord(key, val)); err != nil {
+		return err
+	}
+
+	// only write the index if it exists
+	if len(idx) == 0 {
+		return nil
+	}
+
+	// write the index
+	return store.Write(store.NewRecord(idx, val))
+}
+
+func List(ctx context.Context, e Entity, rsp interface{}, q Query) error {
+	opts := []store.ReadOption{
+		store.ReadPrefix(),
+	}
+
+	if q.Limit > 0 {
+		opts = append(opts, store.ReadLimit(q.Limit))
+	}
+	if q.Offset > 0 {
+		opts = append(opts, store.ReadOffset(q.Offset))
+	}
+	if len(q.Order) > 0 {
+		if q.Order == "desc" {
+			opts = append(opts, store.ReadOrder(store.OrderDesc))
+		} else {
+			opts = append(opts, store.ReadOrder(store.OrderAsc))
+		}
+	}
+
+	recs, err := store.Read(e.Index(ctx), opts...)
+	if err != nil {
+		return err
+	}
+
+	jsBuffer := []byte("[")
+
+	for i, rec := range recs {
+		jsBuffer = append(jsBuffer, rec.Value...)
+		if i < len(recs)-1 {
+			jsBuffer = append(jsBuffer, []byte(",")...)
+		}
+	}
+
+	jsBuffer = append(jsBuffer, []byte("]")...)
+	return json.Unmarshal(jsBuffer, rsp)
+}
+
+func Delete(ctx context.Context, e Entity) error {
+	key := e.Key(ctx)
+	idx := e.Index(ctx)
+
+	if len(key) > 0 {
+		if err := store.Delete(key); err != nil && err != store.ErrNotFound {
+			return err
+		}
+	}
+
+	recs, err := store.Read(idx, store.ReadPrefix())
+	if err != nil && err != store.ErrNotFound {
+		return err
+	}
+
+	// delete every record by index
+	for _, rec := range recs {
+		var val interface{}
+		if err := rec.Decode(val); err != nil || val == nil {
+			continue
+		}
+		// convert to an entity
+		e, ok := val.(Entity)
+		if !ok {
+			continue
+		}
+		if err := store.Delete(e.Key(ctx)); err != store.ErrNotFound {
+			return err
+		}
+	}
+
+	return nil
+}