open-consul/vendor/github.com/SAP/go-hdb/internal/protocol/part.go

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2018-06-21 14:49:35 +00:00
/*
Copyright 2014 SAP SE
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
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package protocol
import (
"fmt"
"github.com/SAP/go-hdb/internal/bufio"
)
const (
partHeaderSize = 16
)
type requestPart interface {
kind() partKind
size() (int, error)
numArg() int
write(*bufio.Writer) error
}
type replyPart interface {
//kind() partKind
setNumArg(int)
read(*bufio.Reader) error
}
// PartAttributes is an interface defining methods for reading query resultset parts.
type PartAttributes interface {
ResultsetClosed() bool
LastPacket() bool
NoRows() bool
}
type partAttributes int8
const (
paLastPacket partAttributes = 0x01
paNextPacket partAttributes = 0x02
paFirstPacket partAttributes = 0x04
paRowNotFound partAttributes = 0x08
paResultsetClosed partAttributes = 0x10
)
var partAttributesText = map[partAttributes]string{
paLastPacket: "lastPacket",
paNextPacket: "nextPacket",
paFirstPacket: "firstPacket",
paRowNotFound: "rowNotFound",
paResultsetClosed: "resultsetClosed",
}
func (k partAttributes) String() string {
t := make([]string, 0, len(partAttributesText))
for attr, text := range partAttributesText {
if (k & attr) != 0 {
t = append(t, text)
}
}
return fmt.Sprintf("%v", t)
}
func (k partAttributes) ResultsetClosed() bool {
return (k & paResultsetClosed) == paResultsetClosed
}
func (k partAttributes) LastPacket() bool {
return (k & paLastPacket) == paLastPacket
}
func (k partAttributes) NoRows() bool {
attrs := paLastPacket | paRowNotFound
return (k & attrs) == attrs
}
// part header
type partHeader struct {
partKind partKind
partAttributes partAttributes
argumentCount int16
bigArgumentCount int32
bufferLength int32
bufferSize int32
}
func (h *partHeader) String() string {
return fmt.Sprintf("part kind %s partAttributes %s argumentCount %d bigArgumentCount %d bufferLength %d bufferSize %d",
h.partKind,
h.partAttributes,
h.argumentCount,
h.bigArgumentCount,
h.bufferLength,
h.bufferSize,
)
}
func (h *partHeader) write(wr *bufio.Writer) error {
wr.WriteInt8(int8(h.partKind))
wr.WriteInt8(int8(h.partAttributes))
wr.WriteInt16(h.argumentCount)
wr.WriteInt32(h.bigArgumentCount)
wr.WriteInt32(h.bufferLength)
wr.WriteInt32(h.bufferSize)
//no filler
if trace {
outLogger.Printf("write part header: %s", h)
}
return nil
}
func (h *partHeader) read(rd *bufio.Reader) error {
h.partKind = partKind(rd.ReadInt8())
h.partAttributes = partAttributes(rd.ReadInt8())
h.argumentCount = rd.ReadInt16()
h.bigArgumentCount = rd.ReadInt32()
h.bufferLength = rd.ReadInt32()
h.bufferSize = rd.ReadInt32()
// no filler
if trace {
outLogger.Printf("read part header: %s", h)
}
return rd.GetError()
}