| // 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[:]) |
| } |