Serge Bazanski | cc25bdf | 2018-10-25 14:02:58 +0200 | [diff] [blame] | 1 | // Copyright 2015 go-swagger maintainers |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package runtime |
| 16 | |
| 17 | import ( |
| 18 | "bytes" |
| 19 | "encoding" |
| 20 | "errors" |
| 21 | "fmt" |
| 22 | "io" |
| 23 | "reflect" |
| 24 | |
| 25 | "github.com/go-openapi/swag" |
| 26 | ) |
| 27 | |
| 28 | func defaultCloser() error { return nil } |
| 29 | |
| 30 | type byteStreamOpt func(opts *byteStreamOpts) |
| 31 | |
| 32 | // ClosesStream when the bytestream consumer or producer is finished |
| 33 | func ClosesStream(opts *byteStreamOpts) { |
| 34 | opts.Close = true |
| 35 | } |
| 36 | |
| 37 | type byteStreamOpts struct { |
| 38 | Close bool |
| 39 | } |
| 40 | |
| 41 | // ByteStreamConsumer creates a consmer for byte streams, |
| 42 | // takes a Writer/BinaryUnmarshaler interface or binary slice by reference, |
| 43 | // and reads from the provided reader |
| 44 | func ByteStreamConsumer(opts ...byteStreamOpt) Consumer { |
| 45 | var vals byteStreamOpts |
| 46 | for _, opt := range opts { |
| 47 | opt(&vals) |
| 48 | } |
| 49 | |
| 50 | return ConsumerFunc(func(reader io.Reader, data interface{}) error { |
| 51 | if reader == nil { |
| 52 | return errors.New("ByteStreamConsumer requires a reader") // early exit |
| 53 | } |
| 54 | |
| 55 | close := defaultCloser |
| 56 | if vals.Close { |
| 57 | if cl, ok := reader.(io.Closer); ok { |
| 58 | close = cl.Close |
| 59 | } |
| 60 | } |
| 61 | defer close() |
| 62 | |
| 63 | if wrtr, ok := data.(io.Writer); ok { |
| 64 | _, err := io.Copy(wrtr, reader) |
| 65 | return err |
| 66 | } |
| 67 | |
| 68 | buf := new(bytes.Buffer) |
| 69 | _, err := buf.ReadFrom(reader) |
| 70 | if err != nil { |
| 71 | return err |
| 72 | } |
| 73 | b := buf.Bytes() |
| 74 | |
| 75 | if bu, ok := data.(encoding.BinaryUnmarshaler); ok { |
| 76 | return bu.UnmarshalBinary(b) |
| 77 | } |
| 78 | |
| 79 | if t := reflect.TypeOf(data); data != nil && t.Kind() == reflect.Ptr { |
| 80 | v := reflect.Indirect(reflect.ValueOf(data)) |
| 81 | if t = v.Type(); t.Kind() == reflect.Slice && t.Elem().Kind() == reflect.Uint8 { |
| 82 | v.SetBytes(b) |
| 83 | return nil |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | return fmt.Errorf("%v (%T) is not supported by the ByteStreamConsumer, %s", |
| 88 | data, data, "can be resolved by supporting Writer/BinaryUnmarshaler interface") |
| 89 | }) |
| 90 | } |
| 91 | |
| 92 | // ByteStreamProducer creates a producer for byte streams, |
| 93 | // takes a Reader/BinaryMarshaler interface or binary slice, |
| 94 | // and writes to a writer (essentially a pipe) |
| 95 | func ByteStreamProducer(opts ...byteStreamOpt) Producer { |
| 96 | var vals byteStreamOpts |
| 97 | for _, opt := range opts { |
| 98 | opt(&vals) |
| 99 | } |
| 100 | return ProducerFunc(func(writer io.Writer, data interface{}) error { |
| 101 | if writer == nil { |
| 102 | return errors.New("ByteStreamProducer requires a writer") // early exit |
| 103 | } |
| 104 | close := defaultCloser |
| 105 | if vals.Close { |
| 106 | if cl, ok := writer.(io.Closer); ok { |
| 107 | close = cl.Close |
| 108 | } |
| 109 | } |
| 110 | defer close() |
| 111 | |
| 112 | if rdr, ok := data.(io.Reader); ok { |
| 113 | _, err := io.Copy(writer, rdr) |
| 114 | return err |
| 115 | } |
| 116 | |
| 117 | if bm, ok := data.(encoding.BinaryMarshaler); ok { |
| 118 | bytes, err := bm.MarshalBinary() |
| 119 | if err != nil { |
| 120 | return err |
| 121 | } |
| 122 | |
| 123 | _, err = writer.Write(bytes) |
| 124 | return err |
| 125 | } |
| 126 | |
| 127 | if data != nil { |
| 128 | if e, ok := data.(error); ok { |
| 129 | _, err := writer.Write([]byte(e.Error())) |
| 130 | return err |
| 131 | } |
| 132 | |
| 133 | v := reflect.Indirect(reflect.ValueOf(data)) |
| 134 | if t := v.Type(); t.Kind() == reflect.Slice && t.Elem().Kind() == reflect.Uint8 { |
| 135 | _, err := writer.Write(v.Bytes()) |
| 136 | return err |
| 137 | } |
| 138 | if t := v.Type(); t.Kind() == reflect.Struct || t.Kind() == reflect.Slice { |
| 139 | b, err := swag.WriteJSON(data) |
| 140 | if err != nil { |
| 141 | return err |
| 142 | } |
| 143 | _, err = writer.Write(b) |
| 144 | return err |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | return fmt.Errorf("%v (%T) is not supported by the ByteStreamProducer, %s", |
| 149 | data, data, "can be resolved by supporting Reader/BinaryMarshaler interface") |
| 150 | }) |
| 151 | } |