prometheus/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/fieldmask.go

71 lines
1.9 KiB
Go

package runtime
import (
"encoding/json"
"io"
"strings"
"github.com/golang/protobuf/protoc-gen-go/generator"
"google.golang.org/genproto/protobuf/field_mask"
)
// FieldMaskFromRequestBody creates a FieldMask printing all complete paths from the JSON body.
func FieldMaskFromRequestBody(r io.Reader) (*field_mask.FieldMask, error) {
fm := &field_mask.FieldMask{}
var root interface{}
if err := json.NewDecoder(r).Decode(&root); err != nil {
if err == io.EOF {
return fm, nil
}
return nil, err
}
queue := []fieldMaskPathItem{{node: root}}
for len(queue) > 0 {
// dequeue an item
item := queue[0]
queue = queue[1:]
if m, ok := item.node.(map[string]interface{}); ok {
// if the item is an object, then enqueue all of its children
for k, v := range m {
queue = append(queue, fieldMaskPathItem{path: append(item.path, generator.CamelCase(k)), node: v})
}
} else if len(item.path) > 0 {
// otherwise, it's a leaf node so print its path
fm.Paths = append(fm.Paths, strings.Join(item.path, "."))
}
}
return fm, nil
}
// fieldMaskPathItem stores a in-progress deconstruction of a path for a fieldmask
type fieldMaskPathItem struct {
// the list of prior fields leading up to node
path []string
// a generic decoded json object the current item to inspect for further path extraction
node interface{}
}
// CamelCaseFieldMask updates the given FieldMask by converting all of its paths to CamelCase, using the same heuristic
// that's used for naming protobuf fields in Go.
func CamelCaseFieldMask(mask *field_mask.FieldMask) {
if mask == nil || mask.Paths == nil {
return
}
var newPaths []string
for _, path := range mask.Paths {
lowerCasedParts := strings.Split(path, ".")
var camelCasedParts []string
for _, part := range lowerCasedParts {
camelCasedParts = append(camelCasedParts, generator.CamelCase(part))
}
newPaths = append(newPaths, strings.Join(camelCasedParts, "."))
}
mask.Paths = newPaths
}