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- // Copyright 2017 Google LLC
- //
- // Licensed under the Apache License, Version 2.0 (the "License");
- // you may not use this file except in compliance with the License.
- // You may obtain a copy of the License at
- //
- // http://www.apache.org/licenses/LICENSE-2.0
- //
- // Unless required by applicable law or agreed to in writing, software
- // distributed under the License is distributed on an "AS IS" BASIS,
- // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- // See the License for the specific language governing permissions and
- // limitations under the License.
-
- package firestore
-
- import (
- "math/rand"
- "os"
- "sync"
- "time"
-
- "golang.org/x/net/context"
- )
-
- // A CollectionRef is a reference to Firestore collection.
- type CollectionRef struct {
- c *Client
-
- // Typically Parent.Path, or c.path if Parent is nil.
- // May be different if this CollectionRef was created from a stored reference
- // to a different project/DB.
- parentPath string
-
- // Parent is the document of which this collection is a part. It is
- // nil for top-level collections.
- Parent *DocumentRef
-
- // The full resource path of the collection: "projects/P/databases/D/documents..."
- Path string
-
- // ID is the collection identifier.
- ID string
-
- // Use the methods of Query on a CollectionRef to create and run queries.
- Query
- }
-
- func newTopLevelCollRef(c *Client, dbPath, id string) *CollectionRef {
- return &CollectionRef{
- c: c,
- ID: id,
- parentPath: dbPath,
- Path: dbPath + "/documents/" + id,
- Query: Query{c: c, collectionID: id, parentPath: dbPath},
- }
- }
-
- func newCollRefWithParent(c *Client, parent *DocumentRef, id string) *CollectionRef {
- return &CollectionRef{
- c: c,
- Parent: parent,
- ID: id,
- parentPath: parent.Path,
- Path: parent.Path + "/" + id,
- Query: Query{c: c, collectionID: id, parentPath: parent.Path},
- }
- }
-
- // Doc returns a DocumentRef that refers to the document in the collection with the
- // given identifier.
- func (c *CollectionRef) Doc(id string) *DocumentRef {
- if c == nil {
- return nil
- }
- return newDocRef(c, id)
- }
-
- // NewDoc returns a DocumentRef with a uniquely generated ID.
- func (c *CollectionRef) NewDoc() *DocumentRef {
- return c.Doc(uniqueID())
- }
-
- // Add generates a DocumentRef with a unique ID. It then creates the document
- // with the given data, which can be a map[string]interface{}, a struct or a
- // pointer to a struct.
- //
- // Add returns an error in the unlikely event that a document with the same ID
- // already exists.
- func (c *CollectionRef) Add(ctx context.Context, data interface{}) (*DocumentRef, *WriteResult, error) {
- d := c.NewDoc()
- wr, err := d.Create(ctx, data)
- if err != nil {
- return nil, nil, err
- }
- return d, wr, nil
- }
-
- const alphanum = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
-
- var (
- rngMu sync.Mutex
- rng = rand.New(rand.NewSource(time.Now().UnixNano() ^ int64(os.Getpid())))
- )
-
- func uniqueID() string {
- var b [20]byte
- rngMu.Lock()
- for i := 0; i < len(b); i++ {
- b[i] = alphanum[rng.Intn(len(alphanum))]
- }
- rngMu.Unlock()
- return string(b[:])
- }
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