1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
// Copyright (C) MongoDB, Inc. 2014-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 mongoexport
import (
"bytes"
"fmt"
"github.com/mongodb/mongo-tools/common/bsonutil"
"github.com/mongodb/mongo-tools/common/json"
"gopkg.in/mgo.v2/bson"
"io"
)
// JSONExportOutput is an implementation of ExportOutput that writes documents
// to the output in JSON format.
type JSONExportOutput struct {
// ArrayOutput when set to true indicates that the output should be written
// as a JSON array, where each document is an element in the array.
ArrayOutput bool
// Pretty when set to true indicates that the output will be written in pretty mode.
PrettyOutput bool
Encoder *json.Encoder
Out io.Writer
NumExported int64
}
// NewJSONExportOutput creates a new JSONExportOutput in array mode if specified,
// configured to write data to the given io.Writer.
func NewJSONExportOutput(arrayOutput bool, prettyOutput bool, out io.Writer) *JSONExportOutput {
return &JSONExportOutput{
arrayOutput,
prettyOutput,
json.NewEncoder(out),
out,
0,
}
}
// WriteHeader writes the opening square bracket if in array mode, otherwise it
// behaves as a no-op.
func (jsonExporter *JSONExportOutput) WriteHeader() error {
if jsonExporter.ArrayOutput {
// TODO check # bytes written?
_, err := jsonExporter.Out.Write([]byte{json.ArrayStart})
if err != nil {
return err
}
}
return nil
}
// WriteFooter writes the closing square bracket if in array mode, otherwise it
// behaves as a no-op.
func (jsonExporter *JSONExportOutput) WriteFooter() error {
if jsonExporter.ArrayOutput {
_, err := jsonExporter.Out.Write([]byte{json.ArrayEnd, '\n'})
// TODO check # bytes written?
if err != nil {
return err
}
}
if jsonExporter.PrettyOutput {
jsonExporter.Out.Write([]byte("\n"))
}
return nil
}
// Flush is a no-op for JSON export formats.
func (jsonExporter *JSONExportOutput) Flush() error {
return nil
}
// ExportDocument converts the given document to extended JSON, and writes it
// to the output.
func (jsonExporter *JSONExportOutput) ExportDocument(document bson.D) error {
if jsonExporter.ArrayOutput || jsonExporter.PrettyOutput {
if jsonExporter.NumExported >= 1 {
if jsonExporter.ArrayOutput {
jsonExporter.Out.Write([]byte(","))
}
if jsonExporter.PrettyOutput {
jsonExporter.Out.Write([]byte("\n"))
}
}
extendedDoc, err := bsonutil.ConvertBSONValueToJSON(document)
if err != nil {
return err
}
jsonOut, err := json.Marshal(extendedDoc)
if err != nil {
return fmt.Errorf("error converting BSON to extended JSON: %v", err)
}
if jsonExporter.PrettyOutput {
var jsonFormatted bytes.Buffer
json.Indent(&jsonFormatted, jsonOut, "", "\t")
jsonOut = jsonFormatted.Bytes()
}
jsonExporter.Out.Write(jsonOut)
} else {
extendedDoc, err := bsonutil.ConvertBSONValueToJSON(document)
if err != nil {
return err
}
err = jsonExporter.Encoder.Encode(extendedDoc)
if err != nil {
return err
}
}
jsonExporter.NumExported++
return nil
}
|
