Initial checkin of gRPC to third_party/

third_party/grpc/tools/http2_interop/settings.go

+package http2interop
+
+import (
+        "encoding/binary"
+        "fmt"
+        "io"
+)
+
+const (
+        SETTINGS_ACK = 1
+)
+
+type SettingsFrame struct {
+        Header FrameHeader
+        Params []SettingsParameter
+}
+
+type SettingsIdentifier uint16
+
+const (
+        SettingsHeaderTableSize      SettingsIdentifier = 1
+        SettingsEnablePush           SettingsIdentifier = 2
+        SettingsMaxConcurrentStreams SettingsIdentifier = 3
+        SettingsInitialWindowSize    SettingsIdentifier = 4
+        SettingsMaxFrameSize         SettingsIdentifier = 5
+        SettingsMaxHeaderListSize    SettingsIdentifier = 6
+)
+
+const (
+        SETTINGS_FLAG_ACK byte = 0x01
+)
+
+func (si SettingsIdentifier) String() string {
+        switch si {
+        case SettingsHeaderTableSize:
+                return "SETTINGS_HEADER_TABLE_SIZE"
+        case SettingsEnablePush:
+                return "SETTINGS_ENABLE_PUSH"
+        case SettingsMaxConcurrentStreams:
+                return "SETTINGS_MAX_CONCURRENT_STREAMS"
+        case SettingsInitialWindowSize:
+                return "SETTINGS_INITIAL_WINDOW_SIZE"
+        case SettingsMaxFrameSize:
+                return "SETTINGS_MAX_FRAME_SIZE"
+        case SettingsMaxHeaderListSize:
+                return "SETTINGS_MAX_HEADER_LIST_SIZE"
+        default:
+                return fmt.Sprintf("SETTINGS_UNKNOWN(%d)", uint16(si))
+        }
+}
+
+type SettingsParameter struct {
+        Identifier SettingsIdentifier
+        Value      uint32
+}
+
+func (f *SettingsFrame) GetHeader() *FrameHeader {
+        return &f.Header
+}
+
+func (f *SettingsFrame) ParsePayload(r io.Reader) error {
+        raw := make([]byte, f.Header.Length)
+        if _, err := io.ReadFull(r, raw); err != nil {
+                return err
+        }
+        return f.UnmarshalPayload(raw)
+}
+
+func (f *SettingsFrame) UnmarshalPayload(raw []byte) error {
+        if f.Header.Length != len(raw) {
+                return fmt.Errorf("Invalid Payload length %d != %d", f.Header.Length, len(raw))
+        }
+
+        if f.Header.Length%6 != 0 {
+                return fmt.Errorf("Invalid Payload length %d", f.Header.Length)
+        }
+
+        f.Params = make([]SettingsParameter, 0, f.Header.Length/6)
+        for i := 0; i < len(raw); i += 6 {
+                f.Params = append(f.Params, SettingsParameter{
+                        Identifier: SettingsIdentifier(binary.BigEndian.Uint16(raw[i : i+2])),
+                        Value:      binary.BigEndian.Uint32(raw[i+2 : i+6]),
+                })
+        }
+        return nil
+}
+
+func (f *SettingsFrame) MarshalPayload() ([]byte, error) {
+        raw := make([]byte, len(f.Params)*6)
+        for i, p := range f.Params {
+                binary.BigEndian.PutUint16(raw[i*6:i*6+2], uint16(p.Identifier))
+                binary.BigEndian.PutUint32(raw[i*6+2:i*6+6], p.Value)
+        }
+        return raw, nil
+}
+
+func (f *SettingsFrame) MarshalBinary() ([]byte, error) {
+        payload, err := f.MarshalPayload()
+        if err != nil {
+                return nil, err
+        }
+
+        f.Header.Length = len(payload)
+        f.Header.Type = SettingsFrameType
+        header, err := f.Header.MarshalBinary()
+        if err != nil {
+                return nil, err
+        }
+        header = append(header, payload...)
+
+        return header, nil
+}