| // 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" |
| |
| "errors" |
| |
| "github.com/mongodb/mongo-go-driver/mongo/options" |
| "github.com/mongodb/mongo-go-driver/x/bsonx" |
| "github.com/mongodb/mongo-go-driver/x/bsonx/bsoncore" |
| "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/connection" |
| "github.com/mongodb/mongo-go-driver/x/network/description" |
| ) |
| |
| // ErrFilterType is thrown when a non-string filter is specified. |
| var ErrFilterType = errors.New("filter must be a string") |
| |
| // ListCollections handles the full cycle dispatch and execution of a listCollections command against the provided |
| // topology. |
| func ListCollections( |
| ctx context.Context, |
| cmd command.ListCollections, |
| topo *topology.Topology, |
| selector description.ServerSelector, |
| clientID uuid.UUID, |
| pool *session.Pool, |
| opts ...*options.ListCollectionsOptions, |
| ) (*ListCollectionsBatchCursor, error) { |
| |
| ss, err := topo.SelectServer(ctx, selector) |
| if err != nil { |
| return nil, err |
| } |
| |
| conn, err := ss.Connection(ctx) |
| if err != nil { |
| return nil, err |
| } |
| defer conn.Close() |
| |
| if ss.Description().WireVersion.Max < 3 { |
| return legacyListCollections(ctx, cmd, ss, conn) |
| } |
| |
| rp, err := getReadPrefBasedOnTransaction(cmd.ReadPref, cmd.Session) |
| if err != nil { |
| return nil, 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 nil, err |
| } |
| } |
| |
| lc := options.MergeListCollectionsOptions(opts...) |
| if lc.NameOnly != nil { |
| cmd.Opts = append(cmd.Opts, bsonx.Elem{"nameOnly", bsonx.Boolean(*lc.NameOnly)}) |
| } |
| |
| res, err := cmd.RoundTrip(ctx, ss.Description(), conn) |
| if err != nil { |
| closeImplicitSession(cmd.Session) |
| return nil, err |
| } |
| |
| batchCursor, err := NewBatchCursor(bsoncore.Document(res), cmd.Session, cmd.Clock, ss.Server, cmd.CursorOpts...) |
| if err != nil { |
| closeImplicitSession(cmd.Session) |
| return nil, err |
| } |
| |
| return NewListCollectionsBatchCursor(batchCursor) |
| } |
| |
| func legacyListCollections( |
| ctx context.Context, |
| cmd command.ListCollections, |
| ss *topology.SelectedServer, |
| conn connection.Connection, |
| ) (*ListCollectionsBatchCursor, error) { |
| filter, err := transformFilter(cmd.Filter, cmd.DB) |
| if err != nil { |
| return nil, err |
| } |
| |
| findCmd := command.Find{ |
| NS: command.NewNamespace(cmd.DB, "system.namespaces"), |
| ReadPref: cmd.ReadPref, |
| Filter: filter, |
| } |
| |
| // don't need registry because it's used to create BSON docs for find options that don't exist in this case |
| batchCursor, err := legacyFind(ctx, findCmd, nil, ss, conn) |
| if err != nil { |
| return nil, err |
| } |
| |
| return NewLegacyListCollectionsBatchCursor(batchCursor) |
| } |
| |
| // modify the user-supplied filter to prefix the "name" field with the database name. |
| // returns the original filter if the name field is not present or a copy with the modified name field if it is |
| func transformFilter(filter bsonx.Doc, dbName string) (bsonx.Doc, error) { |
| if filter == nil { |
| return filter, nil |
| } |
| |
| if nameVal, err := filter.LookupErr("name"); err == nil { |
| name, ok := nameVal.StringValueOK() |
| if !ok { |
| return nil, ErrFilterType |
| } |
| |
| filterCopy := filter.Copy() |
| filterCopy.Set("name", bsonx.String(dbName+"."+name)) |
| return filterCopy, nil |
| } |
| return filter, nil |
| } |