| // 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 wiremessage |
| |
| import ( |
| "errors" |
| "fmt" |
| "github.com/mongodb/mongo-go-driver/x/bsonx" |
| "strings" |
| ) |
| |
| // GetMore represents the OP_GET_MORE message of the MongoDB wire protocol. |
| type GetMore struct { |
| MsgHeader Header |
| Zero int32 |
| FullCollectionName string |
| NumberToReturn int32 |
| CursorID int64 |
| } |
| |
| // MarshalWireMessage implements the Marshaler and WireMessage interfaces. |
| func (gm GetMore) MarshalWireMessage() ([]byte, error) { |
| b := make([]byte, 0, gm.Len()) |
| return gm.AppendWireMessage(b) |
| } |
| |
| // ValidateWireMessage implements the Validator and WireMessage interfaces. |
| func (gm GetMore) ValidateWireMessage() error { |
| if int(gm.MsgHeader.MessageLength) != gm.Len() { |
| return errors.New("incorrect header: message length is not correct") |
| } |
| if gm.MsgHeader.OpCode != OpGetMore { |
| return errors.New("incorrect header: op code is not OpGetMore") |
| } |
| if strings.Index(gm.FullCollectionName, ".") == -1 { |
| return errors.New("incorrect header: collection name does not contain a dot") |
| } |
| |
| return nil |
| } |
| |
| // AppendWireMessage implements the Appender and WireMessage interfaces. |
| // |
| // AppendWireMessage will set the MessageLength property of the MsgHeader |
| // if it is zero. It will also set the OpCode to OpGetMore if the OpCode is |
| // zero. If either of these properties are non-zero and not correct, this |
| // method will return both the []byte with the wire message appended to it |
| // and an invalid header error. |
| func (gm GetMore) AppendWireMessage(b []byte) ([]byte, error) { |
| var err error |
| err = gm.MsgHeader.SetDefaults(gm.Len(), OpGetMore) |
| |
| b = gm.MsgHeader.AppendHeader(b) |
| b = appendInt32(b, gm.Zero) |
| b = appendCString(b, gm.FullCollectionName) |
| b = appendInt32(b, gm.NumberToReturn) |
| b = appendInt64(b, gm.CursorID) |
| return b, err |
| } |
| |
| // String implements the fmt.Stringer interface. |
| func (gm GetMore) String() string { |
| return fmt.Sprintf( |
| `OP_GET_MORE{MsgHeader: %s, Zero: %d, FullCollectionName: %s, NumberToReturn: %d, CursorID: %d}`, |
| gm.MsgHeader, gm.Zero, gm.FullCollectionName, gm.NumberToReturn, gm.CursorID, |
| ) |
| } |
| |
| // Len implements the WireMessage interface. |
| func (gm GetMore) Len() int { |
| // Header + Zero + CollectionName + Null Terminator + Return + CursorID |
| return 16 + 4 + len(gm.FullCollectionName) + 1 + 4 + 8 |
| } |
| |
| // UnmarshalWireMessage implements the Unmarshaler interface. |
| func (gm *GetMore) UnmarshalWireMessage([]byte) error { |
| panic("not implemented") |
| } |
| |
| // CommandDocument creates a BSON document representing this command. |
| func (gm GetMore) CommandDocument() bsonx.Doc { |
| parts := strings.Split(gm.FullCollectionName, ".") |
| collName := parts[len(parts)-1] |
| |
| doc := bsonx.Doc{ |
| {"getMore", bsonx.Int64(gm.CursorID)}, |
| {"collection", bsonx.String(collName)}, |
| } |
| if gm.NumberToReturn != 0 { |
| doc = doc.Append("batchSize", bsonx.Int32(gm.NumberToReturn)) |
| } |
| |
| return doc |
| } |
| |
| // DatabaseName returns the name of the database for this command. |
| func (gm GetMore) DatabaseName() string { |
| return strings.Split(gm.FullCollectionName, ".")[0] |
| } |