Don Newton | 379ae25 | 2019-04-01 12:17:06 -0400 | [diff] [blame^] | 1 | // Copyright (C) MongoDB, Inc. 2017-present. |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 4 | // not use this file except in compliance with the License. You may obtain |
| 5 | // a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 |
| 6 | |
| 7 | package driver |
| 8 | |
| 9 | import ( |
| 10 | "context" |
| 11 | "fmt" |
| 12 | |
| 13 | "github.com/mongodb/mongo-go-driver/bson" |
| 14 | "github.com/mongodb/mongo-go-driver/bson/bsoncodec" |
| 15 | "github.com/mongodb/mongo-go-driver/bson/bsontype" |
| 16 | "github.com/mongodb/mongo-go-driver/mongo/options" |
| 17 | "github.com/mongodb/mongo-go-driver/x/bsonx" |
| 18 | "github.com/mongodb/mongo-go-driver/x/bsonx/bsoncore" |
| 19 | |
| 20 | "time" |
| 21 | |
| 22 | "github.com/mongodb/mongo-go-driver/x/mongo/driver/session" |
| 23 | "github.com/mongodb/mongo-go-driver/x/mongo/driver/topology" |
| 24 | "github.com/mongodb/mongo-go-driver/x/mongo/driver/uuid" |
| 25 | "github.com/mongodb/mongo-go-driver/x/network/command" |
| 26 | "github.com/mongodb/mongo-go-driver/x/network/description" |
| 27 | ) |
| 28 | |
| 29 | // Aggregate handles the full cycle dispatch and execution of an aggregate command against the provided |
| 30 | // topology. |
| 31 | func Aggregate( |
| 32 | ctx context.Context, |
| 33 | cmd command.Aggregate, |
| 34 | topo *topology.Topology, |
| 35 | readSelector, writeSelector description.ServerSelector, |
| 36 | clientID uuid.UUID, |
| 37 | pool *session.Pool, |
| 38 | registry *bsoncodec.Registry, |
| 39 | opts ...*options.AggregateOptions, |
| 40 | ) (*BatchCursor, error) { |
| 41 | |
| 42 | dollarOut := cmd.HasDollarOut() |
| 43 | |
| 44 | var ss *topology.SelectedServer |
| 45 | var err error |
| 46 | switch dollarOut { |
| 47 | case true: |
| 48 | ss, err = topo.SelectServer(ctx, writeSelector) |
| 49 | if err != nil { |
| 50 | return nil, err |
| 51 | } |
| 52 | case false: |
| 53 | ss, err = topo.SelectServer(ctx, readSelector) |
| 54 | if err != nil { |
| 55 | return nil, err |
| 56 | } |
| 57 | } |
| 58 | |
| 59 | desc := ss.Description() |
| 60 | conn, err := ss.Connection(ctx) |
| 61 | if err != nil { |
| 62 | return nil, err |
| 63 | } |
| 64 | |
| 65 | defer conn.Close() |
| 66 | |
| 67 | rp, err := getReadPrefBasedOnTransaction(cmd.ReadPref, cmd.Session) |
| 68 | if err != nil { |
| 69 | return nil, err |
| 70 | } |
| 71 | cmd.ReadPref = rp |
| 72 | |
| 73 | // If no explicit session and deployment supports sessions, start implicit session. |
| 74 | if cmd.Session == nil && topo.SupportsSessions() { |
| 75 | cmd.Session, err = session.NewClientSession(pool, clientID, session.Implicit) |
| 76 | if err != nil { |
| 77 | return nil, err |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | aggOpts := options.MergeAggregateOptions(opts...) |
| 82 | |
| 83 | if aggOpts.AllowDiskUse != nil { |
| 84 | cmd.Opts = append(cmd.Opts, bsonx.Elem{"allowDiskUse", bsonx.Boolean(*aggOpts.AllowDiskUse)}) |
| 85 | } |
| 86 | var batchSize int32 |
| 87 | if aggOpts.BatchSize != nil { |
| 88 | elem := bsonx.Elem{"batchSize", bsonx.Int32(*aggOpts.BatchSize)} |
| 89 | cmd.Opts = append(cmd.Opts, elem) |
| 90 | cmd.CursorOpts = append(cmd.CursorOpts, elem) |
| 91 | batchSize = *aggOpts.BatchSize |
| 92 | } |
| 93 | if aggOpts.BypassDocumentValidation != nil && desc.WireVersion.Includes(4) { |
| 94 | cmd.Opts = append(cmd.Opts, bsonx.Elem{"bypassDocumentValidation", bsonx.Boolean(*aggOpts.BypassDocumentValidation)}) |
| 95 | } |
| 96 | if aggOpts.Collation != nil { |
| 97 | if desc.WireVersion.Max < 5 { |
| 98 | return nil, ErrCollation |
| 99 | } |
| 100 | cmd.Opts = append(cmd.Opts, bsonx.Elem{"collation", bsonx.Document(aggOpts.Collation.ToDocument())}) |
| 101 | } |
| 102 | if aggOpts.MaxTime != nil { |
| 103 | cmd.Opts = append(cmd.Opts, bsonx.Elem{"maxTimeMS", bsonx.Int64(int64(*aggOpts.MaxTime / time.Millisecond))}) |
| 104 | } |
| 105 | if aggOpts.MaxAwaitTime != nil { |
| 106 | // specified as maxTimeMS on getMore commands |
| 107 | cmd.CursorOpts = append(cmd.CursorOpts, bsonx.Elem{ |
| 108 | "maxTimeMS", bsonx.Int64(int64(*aggOpts.MaxAwaitTime / time.Millisecond)), |
| 109 | }) |
| 110 | } |
| 111 | if aggOpts.Comment != nil { |
| 112 | cmd.Opts = append(cmd.Opts, bsonx.Elem{"comment", bsonx.String(*aggOpts.Comment)}) |
| 113 | } |
| 114 | if aggOpts.Hint != nil { |
| 115 | hintElem, err := interfaceToElement("hint", aggOpts.Hint, registry) |
| 116 | if err != nil { |
| 117 | return nil, err |
| 118 | } |
| 119 | |
| 120 | cmd.Opts = append(cmd.Opts, hintElem) |
| 121 | } |
| 122 | |
| 123 | res, err := cmd.RoundTrip(ctx, desc, conn) |
| 124 | if err != nil { |
| 125 | closeImplicitSession(cmd.Session) |
| 126 | return nil, err |
| 127 | } |
| 128 | |
| 129 | if desc.WireVersion.Max < 4 { |
| 130 | return buildLegacyCommandBatchCursor(res, batchSize, ss.Server) |
| 131 | } |
| 132 | |
| 133 | return NewBatchCursor(bsoncore.Document(res), cmd.Session, cmd.Clock, ss.Server, cmd.CursorOpts...) |
| 134 | } |
| 135 | |
| 136 | func buildLegacyCommandBatchCursor(rdr bson.Raw, batchSize int32, server *topology.Server) (*BatchCursor, error) { |
| 137 | firstBatchDocs, ns, cursorID, err := getCursorValues(rdr) |
| 138 | if err != nil { |
| 139 | return nil, err |
| 140 | } |
| 141 | |
| 142 | return NewLegacyBatchCursor(ns, cursorID, firstBatchDocs, 0, batchSize, server) |
| 143 | } |
| 144 | |
| 145 | // get the firstBatch, cursor ID, and namespace from a bson.Raw |
| 146 | // |
| 147 | // TODO(GODRIVER-617): Change the documents return value into []bsoncore.Document. |
| 148 | func getCursorValues(result bson.Raw) ([]bson.Raw, command.Namespace, int64, error) { |
| 149 | cur, err := result.LookupErr("cursor") |
| 150 | if err != nil { |
| 151 | return nil, command.Namespace{}, 0, err |
| 152 | } |
| 153 | if cur.Type != bson.TypeEmbeddedDocument { |
| 154 | return nil, command.Namespace{}, 0, fmt.Errorf("cursor should be an embedded document but it is a BSON %s", cur.Type) |
| 155 | } |
| 156 | |
| 157 | elems, err := cur.Document().Elements() |
| 158 | if err != nil { |
| 159 | return nil, command.Namespace{}, 0, err |
| 160 | } |
| 161 | |
| 162 | var ok bool |
| 163 | var batch []bson.Raw |
| 164 | var namespace command.Namespace |
| 165 | var cursorID int64 |
| 166 | |
| 167 | for _, elem := range elems { |
| 168 | switch elem.Key() { |
| 169 | case "firstBatch": |
| 170 | arr, ok := elem.Value().ArrayOK() |
| 171 | if !ok { |
| 172 | return nil, command.Namespace{}, 0, fmt.Errorf("firstBatch should be an array but it is a BSON %s", elem.Value().Type) |
| 173 | } |
| 174 | if err != nil { |
| 175 | return nil, command.Namespace{}, 0, err |
| 176 | } |
| 177 | |
| 178 | vals, err := arr.Values() |
| 179 | if err != nil { |
| 180 | return nil, command.Namespace{}, 0, err |
| 181 | } |
| 182 | |
| 183 | for _, val := range vals { |
| 184 | if val.Type != bsontype.EmbeddedDocument { |
| 185 | return nil, command.Namespace{}, 0, fmt.Errorf("element of cursor batch is not a document, but at %s", val.Type) |
| 186 | } |
| 187 | batch = append(batch, val.Value) |
| 188 | } |
| 189 | case "ns": |
| 190 | if elem.Value().Type != bson.TypeString { |
| 191 | return nil, command.Namespace{}, 0, fmt.Errorf("namespace should be a string but it is a BSON %s", elem.Value().Type) |
| 192 | } |
| 193 | namespace = command.ParseNamespace(elem.Value().StringValue()) |
| 194 | err = namespace.Validate() |
| 195 | if err != nil { |
| 196 | return nil, command.Namespace{}, 0, err |
| 197 | } |
| 198 | case "id": |
| 199 | cursorID, ok = elem.Value().Int64OK() |
| 200 | if !ok { |
| 201 | return nil, command.Namespace{}, 0, fmt.Errorf("id should be an int64 but it is a BSON %s", elem.Value().Type) |
| 202 | } |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | return batch, namespace, cursorID, nil |
| 207 | } |