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 wiremessage |
| 8 | |
| 9 | import ( |
| 10 | "errors" |
| 11 | "fmt" |
| 12 | "github.com/mongodb/mongo-go-driver/x/bsonx" |
| 13 | "strings" |
| 14 | ) |
| 15 | |
| 16 | // GetMore represents the OP_GET_MORE message of the MongoDB wire protocol. |
| 17 | type GetMore struct { |
| 18 | MsgHeader Header |
| 19 | Zero int32 |
| 20 | FullCollectionName string |
| 21 | NumberToReturn int32 |
| 22 | CursorID int64 |
| 23 | } |
| 24 | |
| 25 | // MarshalWireMessage implements the Marshaler and WireMessage interfaces. |
| 26 | func (gm GetMore) MarshalWireMessage() ([]byte, error) { |
| 27 | b := make([]byte, 0, gm.Len()) |
| 28 | return gm.AppendWireMessage(b) |
| 29 | } |
| 30 | |
| 31 | // ValidateWireMessage implements the Validator and WireMessage interfaces. |
| 32 | func (gm GetMore) ValidateWireMessage() error { |
| 33 | if int(gm.MsgHeader.MessageLength) != gm.Len() { |
| 34 | return errors.New("incorrect header: message length is not correct") |
| 35 | } |
| 36 | if gm.MsgHeader.OpCode != OpGetMore { |
| 37 | return errors.New("incorrect header: op code is not OpGetMore") |
| 38 | } |
| 39 | if strings.Index(gm.FullCollectionName, ".") == -1 { |
| 40 | return errors.New("incorrect header: collection name does not contain a dot") |
| 41 | } |
| 42 | |
| 43 | return nil |
| 44 | } |
| 45 | |
| 46 | // AppendWireMessage implements the Appender and WireMessage interfaces. |
| 47 | // |
| 48 | // AppendWireMessage will set the MessageLength property of the MsgHeader |
| 49 | // if it is zero. It will also set the OpCode to OpGetMore if the OpCode is |
| 50 | // zero. If either of these properties are non-zero and not correct, this |
| 51 | // method will return both the []byte with the wire message appended to it |
| 52 | // and an invalid header error. |
| 53 | func (gm GetMore) AppendWireMessage(b []byte) ([]byte, error) { |
| 54 | var err error |
| 55 | err = gm.MsgHeader.SetDefaults(gm.Len(), OpGetMore) |
| 56 | |
| 57 | b = gm.MsgHeader.AppendHeader(b) |
| 58 | b = appendInt32(b, gm.Zero) |
| 59 | b = appendCString(b, gm.FullCollectionName) |
| 60 | b = appendInt32(b, gm.NumberToReturn) |
| 61 | b = appendInt64(b, gm.CursorID) |
| 62 | return b, err |
| 63 | } |
| 64 | |
| 65 | // String implements the fmt.Stringer interface. |
| 66 | func (gm GetMore) String() string { |
| 67 | return fmt.Sprintf( |
| 68 | `OP_GET_MORE{MsgHeader: %s, Zero: %d, FullCollectionName: %s, NumberToReturn: %d, CursorID: %d}`, |
| 69 | gm.MsgHeader, gm.Zero, gm.FullCollectionName, gm.NumberToReturn, gm.CursorID, |
| 70 | ) |
| 71 | } |
| 72 | |
| 73 | // Len implements the WireMessage interface. |
| 74 | func (gm GetMore) Len() int { |
| 75 | // Header + Zero + CollectionName + Null Terminator + Return + CursorID |
| 76 | return 16 + 4 + len(gm.FullCollectionName) + 1 + 4 + 8 |
| 77 | } |
| 78 | |
| 79 | // UnmarshalWireMessage implements the Unmarshaler interface. |
| 80 | func (gm *GetMore) UnmarshalWireMessage([]byte) error { |
| 81 | panic("not implemented") |
| 82 | } |
| 83 | |
| 84 | // CommandDocument creates a BSON document representing this command. |
| 85 | func (gm GetMore) CommandDocument() bsonx.Doc { |
| 86 | parts := strings.Split(gm.FullCollectionName, ".") |
| 87 | collName := parts[len(parts)-1] |
| 88 | |
| 89 | doc := bsonx.Doc{ |
| 90 | {"getMore", bsonx.Int64(gm.CursorID)}, |
| 91 | {"collection", bsonx.String(collName)}, |
| 92 | } |
| 93 | if gm.NumberToReturn != 0 { |
| 94 | doc = doc.Append("batchSize", bsonx.Int32(gm.NumberToReturn)) |
| 95 | } |
| 96 | |
| 97 | return doc |
| 98 | } |
| 99 | |
| 100 | // DatabaseName returns the name of the database for this command. |
| 101 | func (gm GetMore) DatabaseName() string { |
| 102 | return strings.Split(gm.FullCollectionName, ".")[0] |
| 103 | } |