| // Copyright (C) MongoDB, Inc. 2017-present. |
| // |
| // 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 |
| |
| package command |
| |
| import ( |
| "context" |
| |
| "github.com/mongodb/mongo-go-driver/bson" |
| "github.com/mongodb/mongo-go-driver/x/bsonx" |
| "github.com/mongodb/mongo-go-driver/x/mongo/driver/session" |
| "github.com/mongodb/mongo-go-driver/x/network/description" |
| "github.com/mongodb/mongo-go-driver/x/network/wiremessage" |
| ) |
| |
| // GetMore represents the getMore command. |
| // |
| // The getMore command retrieves additional documents from a cursor. |
| type GetMore struct { |
| ID int64 |
| NS Namespace |
| Opts []bsonx.Elem |
| Clock *session.ClusterClock |
| Session *session.Client |
| |
| result bson.Raw |
| err error |
| } |
| |
| // Encode will encode this command into a wire message for the given server description. |
| func (gm *GetMore) Encode(desc description.SelectedServer) (wiremessage.WireMessage, error) { |
| cmd, err := gm.encode(desc) |
| if err != nil { |
| return nil, err |
| } |
| |
| return cmd.Encode(desc) |
| } |
| |
| func (gm *GetMore) encode(desc description.SelectedServer) (*Read, error) { |
| cmd := bsonx.Doc{ |
| {"getMore", bsonx.Int64(gm.ID)}, |
| {"collection", bsonx.String(gm.NS.Collection)}, |
| } |
| |
| for _, opt := range gm.Opts { |
| switch opt.Key { |
| case "maxAwaitTimeMS": |
| cmd = append(cmd, bsonx.Elem{"maxTimeMs", opt.Value}) |
| default: |
| cmd = append(cmd, opt) |
| } |
| } |
| |
| return &Read{ |
| Clock: gm.Clock, |
| DB: gm.NS.DB, |
| Command: cmd, |
| Session: gm.Session, |
| }, nil |
| } |
| |
| // Decode will decode the wire message using the provided server description. Errors during decoding |
| // are deferred until either the Result or Err methods are called. |
| func (gm *GetMore) Decode(desc description.SelectedServer, wm wiremessage.WireMessage) *GetMore { |
| rdr, err := (&Read{}).Decode(desc, wm).Result() |
| if err != nil { |
| gm.err = err |
| return gm |
| } |
| |
| return gm.decode(desc, rdr) |
| } |
| |
| func (gm *GetMore) decode(desc description.SelectedServer, rdr bson.Raw) *GetMore { |
| gm.result = rdr |
| return gm |
| } |
| |
| // Result returns the result of a decoded wire message and server description. |
| func (gm *GetMore) Result() (bson.Raw, error) { |
| if gm.err != nil { |
| return nil, gm.err |
| } |
| |
| return gm.result, nil |
| } |
| |
| // Err returns the error set on this command. |
| func (gm *GetMore) Err() error { return gm.err } |
| |
| // RoundTrip handles the execution of this command using the provided wiremessage.ReadWriter. |
| func (gm *GetMore) RoundTrip(ctx context.Context, desc description.SelectedServer, rw wiremessage.ReadWriter) (bson.Raw, error) { |
| cmd, err := gm.encode(desc) |
| if err != nil { |
| return nil, err |
| } |
| |
| rdr, err := cmd.RoundTrip(ctx, desc, rw) |
| if err != nil { |
| return nil, err |
| } |
| |
| return gm.decode(desc, rdr).Result() |
| } |