-
Notifications
You must be signed in to change notification settings - Fork 7
/
data_loader_generator.go
250 lines (199 loc) · 5.99 KB
/
data_loader_generator.go
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
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
package dataloader
import (
"bytes"
"fmt"
"io"
"os"
"text/template"
"time"
"github.com/EGT-Ukraine/dataloaden/pkg/generator"
"github.com/pkg/errors"
"golang.org/x/tools/imports"
"github.com/EGT-Ukraine/go2gql/generator/plugins/graphql"
"github.com/EGT-Ukraine/go2gql/generator/plugins/graphql/lib/importer"
)
const DefaultWaitDuration = 10 * time.Millisecond
type LoadersHeadContext struct {
Imports []importer.Import
}
type LoadersBodyContext struct {
Loaders []Loader
Services []Service
}
type Loader struct {
LoaderTypeName string
Service Service
FetchCode string
RequestGoType graphql.GoType
ResponseGoType graphql.GoType
OutputGraphqlType graphql.TypeResolver
Name string
WaitDuration time.Duration
}
type LoaderGenerator struct {
dataLoader *DataLoader
importer *importer.Importer
}
func NewLoaderGenerator(dataLoader *DataLoader) *LoaderGenerator {
return &LoaderGenerator{dataLoader: dataLoader, importer: &importer.Importer{}}
}
func (p *LoaderGenerator) GenerateDataLoaders() error {
if err := os.MkdirAll(p.dataLoader.OutputPath, os.ModePerm); err != nil {
return errors.Wrap(err, "failed to create output path dir "+p.dataLoader.OutputPath)
}
if err := p.generateSchemaLoaders(); err != nil {
return err
}
for _, dataLoader := range p.dataLoader.Loaders {
if err := p.generateLoaders(dataLoader.OutputGraphqlTypeName, dataLoader.InputGoType, dataLoader.OutputGoType, dataLoader.Slice); err != nil {
return errors.Wrapf(err, "failed to generate %s data loader", dataLoader.Name)
}
}
return nil
}
func (p *LoaderGenerator) generateLoaders(outputGraphqlTypeName string, requestGoType graphql.GoType, responseGoType graphql.GoType, slice bool) (rerr error) {
keyType := requestGoType.ElemType.Kind.String()
var typeName string
if slice {
typeName = responseGoType.ElemType.ElemType.Pkg + "." + responseGoType.ElemType.ElemType.Name
} else {
typeName = responseGoType.ElemType.Pkg + "." + responseGoType.ElemType.Name
}
defer func() {
if v := recover(); v != nil {
rerr = fmt.Errorf("failed to generate dataloader: %v", v)
}
}()
if err := generator.Generate(outputGraphqlTypeName, typeName, keyType, slice, true, p.dataLoader.OutputPath); err != nil {
return errors.Wrapf(err, "Failed to generate loader for '%s'", typeName)
}
return nil
}
func (p *LoaderGenerator) generateSchemaLoaders() error {
path := p.dataLoader.OutputPath + "/loaders.go"
file, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0666)
if err != nil {
return errors.Wrapf(err, "failed to open loaders %s output file for write", path)
}
err = p.renderLoaders(file)
if err != nil {
if cerr := file.Close(); cerr != nil {
err = errors.Wrap(err, cerr.Error())
}
return errors.Wrapf(err, "failed to generate loaders file %s", path)
}
if file.Close(); err != nil {
return errors.Wrapf(err, "failed to close generated loaders %s file", path)
}
return nil
}
func (p *LoaderGenerator) generateBody() ([]byte, error) {
buf := new(bytes.Buffer)
tmpl, err := templatesLoaders_bodyGohtmlBytes()
if err != nil {
return nil, errors.Wrap(err, "failed to get loaders template")
}
importFunc := func(importPath string) func() string {
return func() string {
return p.importer.New(importPath)
}
}
templateFuncs := map[string]interface{}{
"timePkg": importFunc("time"),
"goType": func(typ graphql.GoType) string {
return typ.String(p.importer)
},
"duration": func(duration time.Duration) int64 {
if duration == 0 {
return int64(DefaultWaitDuration)
}
return int64(duration)
},
}
servicesTpl, err := template.New("loaders_body").Funcs(templateFuncs).Parse(string(tmpl))
if err != nil {
return nil, errors.Wrap(err, "failed to parse template")
}
var loaders []Loader
for _, dataLoaderModel := range p.dataLoader.Loaders {
service := dataLoaderModel.Service
requestGoType := dataLoaderModel.InputGoType
responseGoType := dataLoaderModel.OutputGoType
loaderTypeName := dataLoaderModel.OutputGraphqlTypeName
if dataLoaderModel.Slice {
loaderTypeName += "Slice"
}
loaders = append(loaders, Loader{
LoaderTypeName: loaderTypeName + "Loader",
Service: *service,
FetchCode: dataLoaderModel.FetchCode(p.importer),
RequestGoType: requestGoType,
ResponseGoType: responseGoType,
Name: dataLoaderModel.Name,
WaitDuration: dataLoaderModel.WaitDuration,
})
}
servicesSet := map[Service]struct{}{}
for _, loader := range loaders {
servicesSet[loader.Service] = struct{}{}
}
var services []Service
for service := range servicesSet {
services = append(services, service)
}
context := LoadersBodyContext{
Loaders: loaders,
Services: services,
}
err = servicesTpl.Execute(buf, context)
if err != nil {
return nil, errors.Wrap(err, "failed to execute template")
}
return buf.Bytes(), nil
}
func (p *LoaderGenerator) generateHead() ([]byte, error) {
buf := new(bytes.Buffer)
tmpl, err := templatesLoaders_headGohtmlBytes()
if err != nil {
return nil, errors.Wrap(err, "failed to get head template")
}
bodyTpl, err := template.New("loaders_head").Parse(string(tmpl))
if err != nil {
return nil, errors.Wrap(err, "failed to parse template")
}
context := LoadersHeadContext{
Imports: p.importer.Imports(),
}
err = bodyTpl.Execute(buf, context)
if err != nil {
return nil, errors.Wrap(err, "failed to execute template")
}
return buf.Bytes(), nil
}
func (p *LoaderGenerator) renderLoaders(out io.Writer) error {
body, err := p.generateBody()
if err != nil {
return errors.Wrap(err, "failed to generate body")
}
head, err := p.generateHead()
if err != nil {
return errors.Wrap(err, "failed to generate head")
}
r := bytes.Join([][]byte{
head,
body,
}, nil)
res, err := imports.Process("file", r, &imports.Options{
Comments: true,
})
if err != nil {
fmt.Fprintln(os.Stderr, err.Error())
} else {
r = res
}
_, err = out.Write(r)
if err != nil {
return errors.Wrap(err, "failed to write output")
}
return nil
}