80 lines
2.3 KiB
Go
80 lines
2.3 KiB
Go
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// Copyright 2016 Google Inc. All rights reserved.
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// Use of this source code is governed by the Apache 2.0
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// license that can be found in the LICENSE file.
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package datastore
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import "golang.org/x/net/context"
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// Datastore kinds for the metadata entities.
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const (
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namespaceKind = "__namespace__"
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kindKind = "__kind__"
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propertyKind = "__property__"
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entityGroupKind = "__entitygroup__"
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)
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// Namespaces returns all the datastore namespaces.
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func Namespaces(ctx context.Context) ([]string, error) {
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// TODO(djd): Support range queries.
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q := NewQuery(namespaceKind).KeysOnly()
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keys, err := q.GetAll(ctx, nil)
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if err != nil {
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return nil, err
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}
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// The empty namespace key uses a numeric ID (==1), but luckily
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// the string ID defaults to "" for numeric IDs anyway.
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return keyNames(keys), nil
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}
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// Kinds returns the names of all the kinds in the current namespace.
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func Kinds(ctx context.Context) ([]string, error) {
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// TODO(djd): Support range queries.
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q := NewQuery(kindKind).KeysOnly()
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keys, err := q.GetAll(ctx, nil)
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if err != nil {
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return nil, err
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}
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return keyNames(keys), nil
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}
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// keyNames returns a slice of the provided keys' names (string IDs).
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func keyNames(keys []*Key) []string {
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n := make([]string, 0, len(keys))
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for _, k := range keys {
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n = append(n, k.StringID())
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}
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return n
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}
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// KindProperties returns all the indexed properties for the given kind.
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// The properties are returned as a map of property names to a slice of the
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// representation types. The representation types for the supported Go property
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// types are:
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// "INT64": signed integers and time.Time
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// "DOUBLE": float32 and float64
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// "BOOLEAN": bool
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// "STRING": string, []byte and ByteString
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// "POINT": appengine.GeoPoint
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// "REFERENCE": *Key
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// "USER": (not used in the Go runtime)
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func KindProperties(ctx context.Context, kind string) (map[string][]string, error) {
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// TODO(djd): Support range queries.
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kindKey := NewKey(ctx, kindKind, kind, 0, nil)
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q := NewQuery(propertyKind).Ancestor(kindKey)
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propMap := map[string][]string{}
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props := []struct {
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Repr []string `datastore:property_representation`
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}{}
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keys, err := q.GetAll(ctx, &props)
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if err != nil {
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return nil, err
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}
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for i, p := range props {
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propMap[keys[i].StringID()] = p.Repr
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}
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return propMap, nil
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}
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