mirror of https://github.com/go-gitea/gitea
Git with a cup of tea, painless self-hosted git service
Mirror for internal git.with.parts use
https://git.with.parts
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
482 lines
14 KiB
482 lines
14 KiB
package gomemcached
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"fmt"
|
|
"io"
|
|
)
|
|
|
|
// The maximum reasonable body length to expect.
|
|
// Anything larger than this will result in an error.
|
|
// The current limit, 20MB, is the size limit supported by ep-engine.
|
|
var MaxBodyLen = int(20 * 1024 * 1024)
|
|
|
|
// MCRequest is memcached Request
|
|
type MCRequest struct {
|
|
// The command being issued
|
|
Opcode CommandCode
|
|
// The CAS (if applicable, or 0)
|
|
Cas uint64
|
|
// An opaque value to be returned with this request
|
|
Opaque uint32
|
|
// The vbucket to which this command belongs
|
|
VBucket uint16
|
|
// Command extras, key, and body
|
|
Extras, Key, Body, ExtMeta []byte
|
|
// Datatype identifier
|
|
DataType uint8
|
|
// len() calls are expensive - cache this in case for collection
|
|
Keylen int
|
|
// Flexible Framing Extras
|
|
FramingExtras []FrameInfo
|
|
// Stored length of incoming framing extras
|
|
FramingElen int
|
|
}
|
|
|
|
// Size gives the number of bytes this request requires.
|
|
func (req *MCRequest) Size() int {
|
|
return HDR_LEN + len(req.Extras) + len(req.Key) + len(req.Body) + len(req.ExtMeta) + req.FramingElen
|
|
}
|
|
|
|
// A debugging string representation of this request
|
|
func (req MCRequest) String() string {
|
|
return fmt.Sprintf("{MCRequest opcode=%s, bodylen=%d, key='%s'}",
|
|
req.Opcode, len(req.Body), req.Key)
|
|
}
|
|
|
|
func (req *MCRequest) fillRegularHeaderBytes(data []byte) int {
|
|
// Byte/ 0 | 1 | 2 | 3 |
|
|
// / | | | |
|
|
// |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
|
|
// +---------------+---------------+---------------+---------------+
|
|
// 0| Magic | Opcode | Key length |
|
|
// +---------------+---------------+---------------+---------------+
|
|
// 4| Extras length | Data type | vbucket id |
|
|
// +---------------+---------------+---------------+---------------+
|
|
// 8| Total body length |
|
|
// +---------------+---------------+---------------+---------------+
|
|
// 12| Opaque |
|
|
// +---------------+---------------+---------------+---------------+
|
|
// 16| CAS |
|
|
// | |
|
|
// +---------------+---------------+---------------+---------------+
|
|
// Total 24 bytes
|
|
|
|
pos := 0
|
|
data[pos] = REQ_MAGIC
|
|
pos++
|
|
data[pos] = byte(req.Opcode)
|
|
pos++
|
|
binary.BigEndian.PutUint16(data[pos:pos+2],
|
|
uint16(len(req.Key)))
|
|
pos += 2
|
|
|
|
// 4
|
|
data[pos] = byte(len(req.Extras))
|
|
pos++
|
|
// Data type
|
|
if req.DataType != 0 {
|
|
data[pos] = byte(req.DataType)
|
|
}
|
|
pos++
|
|
binary.BigEndian.PutUint16(data[pos:pos+2], req.VBucket)
|
|
pos += 2
|
|
|
|
// 8
|
|
binary.BigEndian.PutUint32(data[pos:pos+4],
|
|
uint32(len(req.Body)+len(req.Key)+len(req.Extras)+len(req.ExtMeta)))
|
|
pos += 4
|
|
|
|
// 12
|
|
binary.BigEndian.PutUint32(data[pos:pos+4], req.Opaque)
|
|
pos += 4
|
|
|
|
// 16
|
|
if req.Cas != 0 {
|
|
binary.BigEndian.PutUint64(data[pos:pos+8], req.Cas)
|
|
}
|
|
pos += 8
|
|
|
|
if len(req.Extras) > 0 {
|
|
copy(data[pos:pos+len(req.Extras)], req.Extras)
|
|
pos += len(req.Extras)
|
|
}
|
|
|
|
if len(req.Key) > 0 {
|
|
copy(data[pos:pos+len(req.Key)], req.Key)
|
|
pos += len(req.Key)
|
|
}
|
|
return pos
|
|
}
|
|
|
|
// Returns pos and if trailing by half byte
|
|
func (req *MCRequest) fillFlexHeaderBytes(data []byte) (int, bool) {
|
|
|
|
// Byte/ 0 | 1 | 2 | 3 |
|
|
// / | | | |
|
|
// |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
|
|
// +---------------+---------------+---------------+---------------+
|
|
// 0| Magic (0x08) | Opcode | Framing extras| Key Length |
|
|
// +---------------+---------------+---------------+---------------+
|
|
// 4| Extras length | Data type | vbucket id |
|
|
// +---------------+---------------+---------------+---------------+
|
|
// 8| Total body length |
|
|
// +---------------+---------------+---------------+---------------+
|
|
// 12| Opaque |
|
|
// +---------------+---------------+---------------+---------------+
|
|
// 16| CAS |
|
|
// | |
|
|
// +---------------+---------------+---------------+---------------+
|
|
// Total 24 bytes
|
|
|
|
data[0] = FLEX_MAGIC
|
|
data[1] = byte(req.Opcode)
|
|
data[2] = byte(req.FramingElen)
|
|
data[3] = byte(req.Keylen)
|
|
elen := len(req.Extras)
|
|
data[4] = byte(elen)
|
|
if req.DataType != 0 {
|
|
data[5] = byte(req.DataType)
|
|
}
|
|
binary.BigEndian.PutUint16(data[6:8], req.VBucket)
|
|
binary.BigEndian.PutUint32(data[8:12],
|
|
uint32(len(req.Body)+req.Keylen+elen+len(req.ExtMeta)+req.FramingElen))
|
|
binary.BigEndian.PutUint32(data[12:16], req.Opaque)
|
|
if req.Cas != 0 {
|
|
binary.BigEndian.PutUint64(data[16:24], req.Cas)
|
|
}
|
|
pos := HDR_LEN
|
|
|
|
// Add framing infos
|
|
var framingExtras []byte
|
|
var outputBytes []byte
|
|
var mergeModeSrc []byte
|
|
var frameBytes int
|
|
var halfByteMode bool
|
|
var mergeMode bool
|
|
for _, frameInfo := range req.FramingExtras {
|
|
if !mergeMode {
|
|
outputBytes, halfByteMode = frameInfo.Bytes()
|
|
if !halfByteMode {
|
|
framingExtras = append(framingExtras, outputBytes...)
|
|
frameBytes += len(outputBytes)
|
|
} else {
|
|
mergeMode = true
|
|
mergeModeSrc = outputBytes
|
|
}
|
|
} else {
|
|
outputBytes, halfByteMode = frameInfo.Bytes()
|
|
outputBytes := ShiftByteSliceRight4Bits(outputBytes)
|
|
if halfByteMode {
|
|
// Previous halfbyte merge with this halfbyte will result in a complete byte
|
|
mergeMode = false
|
|
outputBytes = Merge2HalfByteSlices(mergeModeSrc, outputBytes)
|
|
framingExtras = append(framingExtras, outputBytes...)
|
|
frameBytes += len(outputBytes)
|
|
} else {
|
|
// Merge half byte with a non-half byte will result in a combined half-byte that will
|
|
// become the source for the next iteration
|
|
mergeModeSrc = Merge2HalfByteSlices(mergeModeSrc, outputBytes)
|
|
}
|
|
}
|
|
}
|
|
|
|
if mergeMode {
|
|
// Commit the temporary merge area into framingExtras
|
|
framingExtras = append(framingExtras, mergeModeSrc...)
|
|
frameBytes += len(mergeModeSrc)
|
|
}
|
|
|
|
copy(data[pos:pos+frameBytes], framingExtras)
|
|
|
|
pos += frameBytes
|
|
|
|
// Add Extras
|
|
if len(req.Extras) > 0 {
|
|
if mergeMode {
|
|
outputBytes = ShiftByteSliceRight4Bits(req.Extras)
|
|
data = Merge2HalfByteSlices(data, outputBytes)
|
|
} else {
|
|
copy(data[pos:pos+elen], req.Extras)
|
|
}
|
|
pos += elen
|
|
}
|
|
|
|
// Add keys
|
|
if req.Keylen > 0 {
|
|
if mergeMode {
|
|
outputBytes = ShiftByteSliceRight4Bits(req.Key)
|
|
data = Merge2HalfByteSlices(data, outputBytes)
|
|
} else {
|
|
copy(data[pos:pos+req.Keylen], req.Key)
|
|
}
|
|
pos += req.Keylen
|
|
}
|
|
|
|
return pos, mergeMode
|
|
}
|
|
|
|
func (req *MCRequest) FillHeaderBytes(data []byte) (int, bool) {
|
|
if req.FramingElen == 0 {
|
|
return req.fillRegularHeaderBytes(data), false
|
|
} else {
|
|
return req.fillFlexHeaderBytes(data)
|
|
}
|
|
}
|
|
|
|
// HeaderBytes will return the wire representation of the request header
|
|
// (with the extras and key).
|
|
func (req *MCRequest) HeaderBytes() []byte {
|
|
data := make([]byte, HDR_LEN+len(req.Extras)+len(req.Key)+req.FramingElen)
|
|
|
|
req.FillHeaderBytes(data)
|
|
|
|
return data
|
|
}
|
|
|
|
// Bytes will return the wire representation of this request.
|
|
func (req *MCRequest) Bytes() []byte {
|
|
data := make([]byte, req.Size())
|
|
|
|
pos, halfByteMode := req.FillHeaderBytes(data)
|
|
// TODO - the halfByteMode should be revisited for a more efficient
|
|
// way of doing things
|
|
|
|
if len(req.Body) > 0 {
|
|
if halfByteMode {
|
|
shifted := ShiftByteSliceRight4Bits(req.Body)
|
|
data = Merge2HalfByteSlices(data, shifted)
|
|
} else {
|
|
copy(data[pos:pos+len(req.Body)], req.Body)
|
|
}
|
|
}
|
|
|
|
if len(req.ExtMeta) > 0 {
|
|
if halfByteMode {
|
|
shifted := ShiftByteSliceRight4Bits(req.ExtMeta)
|
|
data = Merge2HalfByteSlices(data, shifted)
|
|
} else {
|
|
copy(data[pos+len(req.Body):pos+len(req.Body)+len(req.ExtMeta)], req.ExtMeta)
|
|
}
|
|
}
|
|
return data
|
|
}
|
|
|
|
// Transmit will send this request message across a writer.
|
|
func (req *MCRequest) Transmit(w io.Writer) (n int, err error) {
|
|
if len(req.Body) < 128 {
|
|
n, err = w.Write(req.Bytes())
|
|
} else {
|
|
n, err = w.Write(req.HeaderBytes())
|
|
if err == nil {
|
|
m := 0
|
|
m, err = w.Write(req.Body)
|
|
n += m
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
func (req *MCRequest) receiveHeaderCommon(hdrBytes []byte) (elen, totalBodyLen int) {
|
|
elen = int(hdrBytes[4])
|
|
// Data type at 5
|
|
req.DataType = uint8(hdrBytes[5])
|
|
|
|
req.Opcode = CommandCode(hdrBytes[1])
|
|
// Vbucket at 6:7
|
|
req.VBucket = binary.BigEndian.Uint16(hdrBytes[6:])
|
|
totalBodyLen = int(binary.BigEndian.Uint32(hdrBytes[8:]))
|
|
|
|
req.Opaque = binary.BigEndian.Uint32(hdrBytes[12:])
|
|
req.Cas = binary.BigEndian.Uint64(hdrBytes[16:])
|
|
return
|
|
}
|
|
|
|
func (req *MCRequest) receiveRegHeader(hdrBytes []byte) (elen, totalBodyLen int) {
|
|
elen, totalBodyLen = req.receiveHeaderCommon(hdrBytes)
|
|
req.Keylen = int(binary.BigEndian.Uint16(hdrBytes[2:]))
|
|
return
|
|
}
|
|
|
|
func (req *MCRequest) receiveFlexibleFramingHeader(hdrBytes []byte) (elen, totalBodyLen, framingElen int) {
|
|
elen, totalBodyLen = req.receiveHeaderCommon(hdrBytes)
|
|
|
|
// For flexible framing header, key length is a single byte at byte index 3
|
|
req.Keylen = int(binary.BigEndian.Uint16(hdrBytes[2:]) & 0x0ff)
|
|
// Flexible framing lengh is a single byte at index 2
|
|
framingElen = int(binary.BigEndian.Uint16(hdrBytes[2:]) >> 8)
|
|
req.FramingElen = framingElen
|
|
return
|
|
}
|
|
|
|
func (req *MCRequest) populateRegularBody(r io.Reader, totalBodyLen, elen int) (int, error) {
|
|
var m int
|
|
var err error
|
|
if totalBodyLen > 0 {
|
|
buf := make([]byte, totalBodyLen)
|
|
m, err = io.ReadFull(r, buf)
|
|
if err == nil {
|
|
if req.Opcode >= TAP_MUTATION &&
|
|
req.Opcode <= TAP_CHECKPOINT_END &&
|
|
len(buf) > 1 {
|
|
// In these commands there is "engine private"
|
|
// data at the end of the extras. The first 2
|
|
// bytes of extra data give its length.
|
|
elen += int(binary.BigEndian.Uint16(buf))
|
|
}
|
|
|
|
req.Extras = buf[0:elen]
|
|
req.Key = buf[elen : req.Keylen+elen]
|
|
|
|
// get the length of extended metadata
|
|
extMetaLen := 0
|
|
if elen > 29 {
|
|
extMetaLen = int(binary.BigEndian.Uint16(req.Extras[28:30]))
|
|
}
|
|
|
|
bodyLen := totalBodyLen - req.Keylen - elen - extMetaLen
|
|
if bodyLen > MaxBodyLen {
|
|
return m, fmt.Errorf("%d is too big (max %d)",
|
|
bodyLen, MaxBodyLen)
|
|
}
|
|
|
|
req.Body = buf[req.Keylen+elen : req.Keylen+elen+bodyLen]
|
|
req.ExtMeta = buf[req.Keylen+elen+bodyLen:]
|
|
}
|
|
}
|
|
return m, err
|
|
}
|
|
|
|
func (req *MCRequest) populateFlexBody(r io.Reader, totalBodyLen, elen, framingElen int) (int, error) {
|
|
var m int
|
|
var err error
|
|
if totalBodyLen > 0 {
|
|
buf := make([]byte, totalBodyLen)
|
|
m, err = io.ReadFull(r, buf)
|
|
if err != nil {
|
|
return m, err
|
|
}
|
|
err = req.populateFlexBodyInternal(buf, totalBodyLen, elen, framingElen)
|
|
}
|
|
return m, err
|
|
}
|
|
|
|
func (req *MCRequest) populateFlexBodyInternal(buf []byte, totalBodyLen, elen, framingElen int) error {
|
|
var halfByteOffset bool
|
|
var err error
|
|
if framingElen > 0 {
|
|
var objs []FrameInfo
|
|
objs, err, halfByteOffset = parseFrameInfoObjects(buf, framingElen)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
req.FramingExtras = objs
|
|
}
|
|
|
|
err = req.populateFlexBodyAfterFrames(buf, totalBodyLen, elen, framingElen, halfByteOffset)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func (req *MCRequest) populateFlexBodyAfterFrames(buf []byte, totalBodyLen, elen, framingElen int, halfByteOffset bool) error {
|
|
var idxCursor int = framingElen
|
|
if req.Opcode >= TAP_MUTATION && req.Opcode <= TAP_CHECKPOINT_END && len(buf[idxCursor:]) > 1 {
|
|
// In these commands there is "engine private"
|
|
// data at the end of the extras. The first 2
|
|
// bytes of extra data give its length.
|
|
if !halfByteOffset {
|
|
elen += int(binary.BigEndian.Uint16(buf[idxCursor:]))
|
|
} else {
|
|
// 0 1 2 3 4 .... 19 20 21 22 ... 32
|
|
// ^-----^ ^-------^ ^------------^
|
|
// offset data do not care
|
|
var buffer uint32 = binary.BigEndian.Uint32(buf[idxCursor:])
|
|
buffer &= 0xffff000
|
|
elen += int(buffer >> 12)
|
|
}
|
|
}
|
|
|
|
// Get the extras
|
|
if !halfByteOffset {
|
|
req.Extras = buf[idxCursor : idxCursor+elen]
|
|
} else {
|
|
preShift := buf[idxCursor : idxCursor+elen+1]
|
|
req.Extras = ShiftByteSliceLeft4Bits(preShift)
|
|
}
|
|
idxCursor += elen
|
|
|
|
// Get the Key
|
|
if !halfByteOffset {
|
|
req.Key = buf[idxCursor : idxCursor+req.Keylen]
|
|
} else {
|
|
preShift := buf[idxCursor : idxCursor+req.Keylen+1]
|
|
req.Key = ShiftByteSliceLeft4Bits(preShift)
|
|
}
|
|
idxCursor += req.Keylen
|
|
|
|
// get the length of extended metadata
|
|
extMetaLen := 0
|
|
if elen > 29 {
|
|
extMetaLen = int(binary.BigEndian.Uint16(req.Extras[28:30]))
|
|
}
|
|
idxCursor += extMetaLen
|
|
|
|
bodyLen := totalBodyLen - req.Keylen - elen - extMetaLen - framingElen
|
|
if bodyLen > MaxBodyLen {
|
|
return fmt.Errorf("%d is too big (max %d)",
|
|
bodyLen, MaxBodyLen)
|
|
}
|
|
|
|
if !halfByteOffset {
|
|
req.Body = buf[idxCursor : idxCursor+bodyLen]
|
|
idxCursor += bodyLen
|
|
} else {
|
|
preShift := buf[idxCursor : idxCursor+bodyLen+1]
|
|
req.Body = ShiftByteSliceLeft4Bits(preShift)
|
|
idxCursor += bodyLen
|
|
}
|
|
|
|
if extMetaLen > 0 {
|
|
if !halfByteOffset {
|
|
req.ExtMeta = buf[idxCursor:]
|
|
} else {
|
|
preShift := buf[idxCursor:]
|
|
req.ExtMeta = ShiftByteSliceLeft4Bits(preShift)
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// Receive will fill this MCRequest with the data from a reader.
|
|
func (req *MCRequest) Receive(r io.Reader, hdrBytes []byte) (int, error) {
|
|
if len(hdrBytes) < HDR_LEN {
|
|
hdrBytes = []byte{
|
|
0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0,
|
|
0, 0, 0, 0, 0, 0, 0, 0}
|
|
}
|
|
n, err := io.ReadFull(r, hdrBytes)
|
|
if err != nil {
|
|
fmt.Printf("Err %v\n", err)
|
|
return n, err
|
|
}
|
|
|
|
switch hdrBytes[0] {
|
|
case RES_MAGIC:
|
|
fallthrough
|
|
case REQ_MAGIC:
|
|
elen, totalBodyLen := req.receiveRegHeader(hdrBytes)
|
|
bodyRead, err := req.populateRegularBody(r, totalBodyLen, elen)
|
|
return n + bodyRead, err
|
|
case FLEX_MAGIC:
|
|
elen, totalBodyLen, framingElen := req.receiveFlexibleFramingHeader(hdrBytes)
|
|
bodyRead, err := req.populateFlexBody(r, totalBodyLen, elen, framingElen)
|
|
return n + bodyRead, err
|
|
default:
|
|
return n, fmt.Errorf("bad magic: 0x%02x", hdrBytes[0])
|
|
}
|
|
}
|
|
|