| // 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 driver |
| |
| import ( |
| "context" |
| "github.com/mongodb/mongo-go-driver/bson/bsoncodec" |
| "github.com/mongodb/mongo-go-driver/x/bsonx" |
| |
| "github.com/mongodb/mongo-go-driver/mongo/options" |
| "github.com/mongodb/mongo-go-driver/x/mongo/driver/session" |
| "github.com/mongodb/mongo-go-driver/x/mongo/driver/topology" |
| "github.com/mongodb/mongo-go-driver/x/mongo/driver/uuid" |
| "github.com/mongodb/mongo-go-driver/x/network/command" |
| "github.com/mongodb/mongo-go-driver/x/network/description" |
| "time" |
| ) |
| |
| // CountDocuments handles the full cycle dispatch and execution of a countDocuments command against the provided |
| // topology. |
| func CountDocuments( |
| ctx context.Context, |
| cmd command.CountDocuments, |
| topo *topology.Topology, |
| selector description.ServerSelector, |
| clientID uuid.UUID, |
| pool *session.Pool, |
| registry *bsoncodec.Registry, |
| opts ...*options.CountOptions, |
| ) (int64, error) { |
| |
| ss, err := topo.SelectServer(ctx, selector) |
| if err != nil { |
| return 0, err |
| } |
| |
| desc := ss.Description() |
| conn, err := ss.Connection(ctx) |
| if err != nil { |
| return 0, err |
| } |
| defer conn.Close() |
| |
| rp, err := getReadPrefBasedOnTransaction(cmd.ReadPref, cmd.Session) |
| if err != nil { |
| return 0, err |
| } |
| cmd.ReadPref = rp |
| |
| // If no explicit session and deployment supports sessions, start implicit session. |
| if cmd.Session == nil && topo.SupportsSessions() { |
| cmd.Session, err = session.NewClientSession(pool, clientID, session.Implicit) |
| if err != nil { |
| return 0, err |
| } |
| defer cmd.Session.EndSession() |
| } |
| |
| countOpts := options.MergeCountOptions(opts...) |
| |
| // ignore Skip and Limit because we already have these options in the pipeline |
| if countOpts.MaxTime != nil { |
| cmd.Opts = append(cmd.Opts, bsonx.Elem{ |
| "maxTimeMS", bsonx.Int64(int64(*countOpts.MaxTime / time.Millisecond)), |
| }) |
| } |
| if countOpts.Collation != nil { |
| if desc.WireVersion.Max < 5 { |
| return 0, ErrCollation |
| } |
| cmd.Opts = append(cmd.Opts, bsonx.Elem{"collation", bsonx.Document(countOpts.Collation.ToDocument())}) |
| } |
| if countOpts.Hint != nil { |
| hintElem, err := interfaceToElement("hint", countOpts.Hint, registry) |
| if err != nil { |
| return 0, err |
| } |
| |
| cmd.Opts = append(cmd.Opts, hintElem) |
| } |
| |
| return cmd.RoundTrip(ctx, desc, conn) |
| } |