/*

* Copyright (c) 2003-2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

* Name        : Udvm.h

* Part of     : SigComp / UDVM

* Interface   : 

* UDVM core

* Version     : 1.0

*

*/

/**

 @internalComponent

*/

#ifndef UDVM_H

#define UDVM_H

//  INCLUDES

#include <e32base.h>

#include <hash.h>

class CUdvmMemory;

class CMessageReader;

//consts

static const TUint KMaxUdvmMemorySize = 65536;

static const TUint KMaxUdvmMemoryMask = 0xffff;

static const TUint KSigCompHeaderMask = 0xF8;

static const TInt KSigCompHeaderTBit = 2;

static const TInt KSigCompHeaderTMask = (1 << KSigCompHeaderTBit);

static const TInt KSigCompHeaderLenMask = 0x03;

static const TInt KReturnedFeedbackFieldBit = 7;

static const TInt KReturnedFeedbackFieldMask =

                                             (1 << KReturnedFeedbackFieldBit);

static const TInt KReturnedFeedbackLengthMask = 0x7f;

static const TUint KMax8BitValueMask = 0xff;

static const TUint KMax16BitValueMask = 0xffff;

static const TUint KMaxStateOperations = 4;

static const TInt KMaxOutputSize = 65536;

// CLASS DECLARATION

/* UDVM memory and registers map

    0             7 8            15

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |       UDVM_memory_size        |  0 - 1

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |        cycles_per_bit         |  2 - 3

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |        SigComp_version        |  4 - 5

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |    partial_state_ID_length    |  6 - 7

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |         state_length          |  8 - 9

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |                               |

   :           reserved            :  10 - 31

   |                               |

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |                               |

   :   zeroed scratch-pad memory   :  32 - 63

   |                               |

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

              registers

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |        byte_copy_left         |  64 - 65

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |        byte_copy_right        |  66 - 67

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |        input_bit_order        |  68 - 69

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   |        stack_location         |  70 - 71

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

*/

/**

*  Class for holding state create/free operation requestes

*  

*

*  @lib sigcomp

*/

class TStateOperationRequest

    {

    public:

        TUint iOperation;

        /** state create parameters */

        TUint16 iStateLength;

        TUint16 iStateAddress;

        TUint16 iStateInstruction;

        TUint16 iMinimumAccessLength;

        TUint16 iStateRetentionPriority;

        CArrayFixFlat<TUint8>* iStateValue;

        /** state free parameters */

        TUint16 iPartialIdentifierStart;

        TUint16 iPartialIdentifierLength;

    };

/**

*  Universal decompression virtual machine core class.

*  

*

*  @lib sigcomp

*/

class CSigCompCompartment;

class CStateMgr;

class TStateItem;

class CUdvm : public CBase

    {

    public:  // enumerators

        /** memory and registers map

        *   as defined in RFC3220 chapter 7.2.

        **/

        enum TMemMap

            {

            EMem_UDVM_memory_size = 0,

            EMem_cycles_per_bit = 2,

            EMem_SigComp_version = 4,

            EMem_partial_state_ID_length = 6,

            EMem_state_length = 8,

            EMem_reserved = 10,

            EMem_scratch_pad = 32,

            EMem_registers = 64,

            //register block definition starts here

            EReg_byte_copy_left = 64,

            EReg_byte_copy_right = 66,

            EReg_input_bit_order = 68,

            EReg_stack_location = 70,

            EMem_user_area = 72

            };

        /** input_bit_order flags */

        enum TIBOFlags

            {

            EIBOFlag_P = 1,

            EIBOFlag_H = 2,

            EIBOFlag_F = 4

            };

        /** requested feedback flags */

        enum TRFFlags

            {

            ERFFlag_I = 1,

            ERFFlag_S = 2,

            ERFFlag_Q = 4

            };

        /** UDVM bytecodes */

        enum TOpcode

            {

            EOpcode_DECOMPRESSION_FAILURE = 0,

            EOpcode_AND = 1,

            EOpcode_OR = 2,

            EOpcode_NOT = 3,

            EOpcode_LSHIFT = 4,

            EOpcode_RSHIFT = 5,

            EOpcode_ADD = 6,

            EOpcode_SUBTRACT = 7,

            EOpcode_MULTIPLY = 8,

            EOpcode_DIVIDE = 9,

            EOpcode_REMAINDER = 10,

            EOpcode_SORT_ASCENDING = 11,

            EOpcode_SORT_DESCENDING = 12,

            EOpcode_SHA_1 = 13,

            EOpcode_LOAD = 14,

            EOpcode_MULTILOAD = 15,

            EOpcode_PUSH = 16,

            EOpcode_POP = 17,

            EOpcode_COPY = 18,

            EOpcode_COPY_LITERAL = 19,

            EOpcode_COPY_OFFSET = 20,

            EOpcode_MEMSET = 21,

            EOpcode_JUMP = 22,

            EOpcode_COMPARE = 23,

            EOpcode_CALL = 24,

            EOpcode_RETURN = 25,

            EOpcode_SWITCH = 26,

            EOpcode_CRC = 27,

            EOpcode_INPUT_BYTES = 28,

            EOpcode_INPUT_BITS = 29,

            EOpcode_INPUT_HUFFMAN = 30,

            EOpcode_STATE_ACCESS = 31,

            EOpcode_STATE_CREATE = 32,

            EOpcode_STATE_FREE = 33,

            EOpcode_OUTPUT = 34,

            EOpcode_END_MESSAGE = 35,

            EOpcodesNumber = 36

            };

    public:  // Constructors and destructor

        /**

         * @param aStateMgr state manager

         * @param aMemSize UDVM memory size in bytes

         * @param aCyclesPerBit the amount of "UDVM cycles" available

         *                      to decompress each bit in SigComp message

         */

        static CUdvm* NewL(CStateMgr* aStateMgr,

                           TUint aMemSize,

                           TUint aCyclesPerBit);

        static CUdvm* NewLC(CStateMgr* aStateMgr,

                            TUint aMemSize,

                            TUint aCyclesPerBit);

        /**

         * Destructor.

         */

        virtual ~CUdvm();

    public: // New functions

        /**

         * Decompress message.

         *

         * @param aMessage message to decompression

         * @param aBytesConsumed on return will contain the number of bytes

         *                       consumed by the decompression from the

         *                       original message 

         *

         * @returns decompressed message, the ownership is transferred

         */

        CBufBase* DecompressL(const TDesC8& aMessage, TUint& aBytesConsumed,

                              TBool aStreamBasedProtocol);

        /**

         * Execute UDVM code.

         *

         * @param aMsgReader message reader.

         *

         */

        void ExecuteCodeL(CMessageReader* aMsgReader);

        /**

         * Allow for state operations.

         *

         * @param aCompartment compartment

         *

         * @returns number of completed state operations

         */

        TInt AllowStateOperationsL(CSigCompCompartment* aCompartment);

        /**

         * Deny state operations.

         *

         */

        void DenyStateOperations();

        /**

         * Resolve "byte copying". Find continuous block in bcl/bcr range from

         * given address. Leave if out of memory bounds.

         *

         * @param aAddress address of area

         * @param aLength length of area

         * @param aBcl UDVM bcl register value

         * @param aBcr UDVM bcr register value

         *

         * @returns number of bytes to copy continuous block

         *

         * @post aAddress and aLength is updated to next block address and

         *       length

         */

        TUint ByteCopyingFragmentL(TUint& aAddress,

                                   TUint& aLength, 

                                   TUint aBcl, TUint aBcr) const;

        /**

         * Compare MinmumStateAccessLength with AccessLength

         * Leave if AccessLength too small.

         *

         * @param aStateItem state item

         * @param aAccessLen candidate access length

         *

         */

        void TestStateAccessLenL(const TStateItem* aStateItem,

                                 TUint aAccessLen) const;

        /**

         * Get a portion of bits from input stream.

         *

         * @param aSize number of bits to get

         * @param aP P flag of input_bit_order UDVM register 

         * @param aF F flag of input_bit_order UDVM register

         *

         * @returns value

         */

        TUint InputMessageBitsL(TUint aSize, TUint aP, TUint aF);

        /**

         * Decode literal bytecode operand.

         *

         * @param aAddress address in UDVM memory

         *

         * @returns value

         *

         * @post aAddress is updated

         */

        TUint DecodeLiteralOperandL(TUint& aAddress) const;

        /**

         * Decode reference bytecode operand.

         *

         * @param aAddress address in UDVM memory

         *

         * @returns address of value in UDVM memory

         *

         * @post aAddress is updated

         */

        TUint DecodeReferenceOperandL(TUint& aAddress) const;

        /**

         * Decode multitype bytecode operand.

         *

         * @param aAddress address in UDVM memory

         *

         * @returns operand value

         *

         * @post aAddress is updated

         */

        TUint DecodeMultitypeOperandL(TUint& aAddress) const;

        /**

         * Decode address bytecode operand.

         *

         * @param aPc current value of UDVM PC "register"

         * @param aAddress address in UDVM memory

         *

         * @returns operand value

         *

         * @post aAddress is updated

         */

        TUint DecodeAddressOperandL(TUint aPC, TUint& aAddress) const;

        /**

         * Upload bytecode, initialize UDVM memory and registers.

         *

         * @param aDest destination address in UDVM memory

         * @param aLen code length

         * @param aMsgReader message reader.

         *

         */

        void UploadCodeL(TUint aDest, TUint aLen, CMessageReader* aMsgReader);

        /**

         * Upload state, initialize UDVM memory and registers.

         *

         * @param aStateLen partial state identifier length

         * @param aState partial state identifier

         *

         */

        void UploadStateL(TUint aStateLen, const TUint8* aState);

        /**

         * Set returned feedback

         *

         * @param aT T flag.

         * @param aMsgReader message reader.

         *

         */

        void SetReturnedFeedbackL(TBool aT, CMessageReader* aMsgReader);

        /**

         * Upload state in message

         *

         * @param aLen length

         * @param aMsgReader message reader.

         *

         */

        void UploadStateInMessageL(TUint aLen, CMessageReader* aMsgReader);

        /**

         * Upload bytecode in message

         *

         * @param aMsgReader message reader.

         *

         */

        void UploadBytecodeInMessageL(CMessageReader* aMsgReader);

#if defined(SIGCOMP_DEBUG)

        /**

         * Get consumed cycles number

         *

         * @returns consumed cycles number.

         *

         */

        TUint CyclesConsumed() const;

#endif

    private:

        CUdvm();

        /**

         * execute opcode "Decompression failure".

         *

         * @param aPc2 program counter

         *

         * @returns ETrue if opcode causes termination of UDVM program

         *

         */

        TBool ExecuteOpcodeDecompressionFailureL(TUint& aPc2);

        /**

         * execute opcode "AND

         *

         * @param aPc2 program counter

         *

         * @returns ETrue if opcode causes termination of UDVM program

         *

         */

        TBool ExecuteOpcodeAndL(TUint& aPc2);

        /**

         * execute opcode "OR

         *

         * @param aPc2 program counter

         *

         * @returns ETrue if opcode causes termination of UDVM program

         *

         */

        TBool ExecuteOpcodeOrL(TUint& aPc2);

        /**

         * execute opcode "NOT

         *

         * @param aPc2 program counter

         *

         * @returns ETrue if opcode causes termination of UDVM program

         *

         */

        TBool ExecuteOpcodeNotL(TUint& aPc2);

        /**

         * execute opcode "LSHIFT

         *

         * @param aPc2 program counter

         *

         * @returns ETrue if opcode causes termination of UDVM program

         *

         */

        TBool ExecuteOpcodeLShiftL(TUint& aPc2);

        /**

         * execute opcode "RSHIFT

         *

         * @param aPc2 program counter

         *

         * @returns ETrue if opcode causes termination of UDVM program

         *

         */

        TBool ExecuteOpcodeRShiftL(TUint& aPc2);

        /**

         * execute opcode "ADD

         *

         * @param aPc2 program counter

         *

         * @returns ETrue if opcode causes termination of UDVM program

         *

         */

        TBool ExecuteOpcodeAddL(TUint& aPc2);

        /**

         * execute opcode "SUBTRACT"

         *

         * @param aPc2 program counter

         *

         * @returns ETrue if opcode causes termination of UDVM program

         *

         */