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go/internal/msgframe.dont/msgframe.go

-// Copyright (C) 2020  Nexedi SA and Contributors.
-//                     Kirill Smelkov <kirr@nexedi.com>
-//
-// This program is free software: you can Use, Study, Modify and Redistribute
-// it under the terms of the GNU General Public License version 3, or (at your
-// option) any later version, as published by the Free Software Foundation.
-//
-// You can also Link and Combine this program with other software covered by
-// the terms of any of the Free Software licenses or any of the Open Source
-// Initiative approved licenses and Convey the resulting work. Corresponding
-// source of such a combination shall include the source code for all other
-// software used.
-//
-// This program is distributed WITHOUT ANY WARRANTY; without even the implied
-// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-//
-// See COPYING file for full licensing terms.
-// See https://www.nexedi.com/licensing for rationale and options.
-
-// XXX -> use msgp.Raw.DecodeMsg
-// +build ignore
-
-
-// Package msgframe helps extract MsgPack frames from stream of bytes.
-//
-// The sole reason this package exists is because unlike ZEO/py NEO/py switched
-// to MsgPack without wrapping payload into frames with size header.
-package msgframe
-
-// Framer helps extract full MsgPack frames from stream of raw bytes.
-type Framer struct {
-	todoObj int // number of pending msgpack objects to complete
-	todoRaw int // number of pending bytes to complete current object
-}
-
-// Feed feeds next data to framer.
-//
-// returns:
-// - n:  how many bytes from chunk was analyzed	// XXX kill?
-// - ok: whether chunk[:n] completes a frame.
-//
-// XXX chunk must be non-empty?
-func (f *Framer) Feed(chunk []byte) (ok bool) {	// XXX +n ?
-	if f.todoRaw > 0 {
-		l := len(chunk)
-		if l > f.todoRaw {
-			l = f.todoRaw
-		}
-		f.todoRaw -= l
-		chunk = chunk[l:]
-
-		if f.todoRaw == 0 && f.todoObj == 0 {
-			return true	// XXX remaining part of chunk?
-		}
-	}
-
-	if len(chunk) == 0 {
-		return false
-	}
-
-	op := chunk[0]
-	f.todoObj--
-	chunk = chunk[1:]
-
-	switch {
-	// positive fixint
-	//          0xxxxxxx	0x00 - 0x7f
-	case op & 0b1_0000000 == 0b0_0000000:
-
-	// fixmap
-	//          1000xxxx	0x80 - 0x8f 2N·objects
-	case op & 0b1111_0000 == 0b1000_0000
-		f.todoObj += 2*(op & 0x0f)
-
-	// fixarray
-	//          1001xxxx	0x90 - 0x9f  N·objects
-	case op & 0b1111_0000 == 0b1001_0000:
-		f.todoObj += op & 0x0f
-
-	// fixstr
-	//          101xxxxx	0xa0 - 0xbf  data
-	case op & 0b111_00000 == 0b101_00000:
-		f.todoRaw += op & 0b000_11111
-
-	// nil		11000000 0xc0
-	case op == 0xc0:
-
-	// (never used) 11000001 0xc1
-
-	// false	11000010 0xc2
-	case op == 0xc2:
-
-	// true		11000011 0xc3
-	case op == 0xc3:
-
-	// bin8		11000100 0xc4  XXXXXXXX  data  
-	case op == 0xc4:
-		l := chunk[1]; chunk = chunk[1:]	// XXX overflow
-		f.todoRaw += l
-
-	// bin16	11000101 0xc5  YYYYYYYY YYYYYYYY   data
-	case op == 0xc5:
-		l := be.Uint16(chunk); chunk = chunk[2:]	// XXX overflow
-		f.todoRaw += l
-
-	// bin32	11000110 0xc6  ZZZZZZZZ ZZZZZZZZ ZZZZZZZZ ZZZZZZZZ  data 
-	case op == 0xc6:
-		l := be.Uint32(chunk); chunk = chunk[4:]	// XXX overflow
-		f.todoRaw += l
-
-	// ext8		11000111 0xc7  XXXXXXXX  type  data
-	case op == 0xc7:
-		l := chunk[0]; chunk = chunk[1+1/*type*/:]	// XXX overflow
-		f.todoRaw += l
-
-	// ext16	11001000 0xc8  YYYYYYYY YYYYYYYY  type  data 
-	case op == 0xc8:
-		l := be.Uint16(chunk); chunk = chunk[2+1/*type*/:]	// XXX overflow
-		f.todoRaw += l
-
-	// ext32	11001001 0xc9  ZZZZZZZZ ZZZZZZZZ ZZZZZZZZ ZZZZZZZZ  type  data
-	case op == 0xc9:
-		l := be.Uint32(chunk); chunk = chunk[4+1/*type*/:]	// XXX overflow
-		f.todoRaw += l
-
-	// float32	11001010 0xca  XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX
-	case op == 0xca:
-		f.todoRaw += 4
-
-	// float64	11001011 0xcb  Y Y Y Y Y Y Y Y
-	case op == 0xcb:
-		f.todoRaw += 8
-
-	case op == 0xcc:  f.todoRaw += 1	// uint8   11001100 0xcc
-	case op == 0xcd:  f.todoRaw += 2	// uint16  11001101 0xcd
-	case op == 0xce:  f.todoRaw += 4	// uint32  11001110 0xce
-	case op == 0xcf:  f.todoRaw += 8	// uint64  11001111 0xcf
-	case op == 0xd0:  f.todoRaw += 1	//  int8   11010000 0xd0
-	case op == 0xd1:  f.todoRaw += 2	//  int16  11010001 0xd1
-	case op == 0xd2:  f.todoRaw += 4	//  int32  11010010 0xd2
-
-
-
-
-
-
-
-
-	}
-}