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calibre-web/cps/static/js/archive/rarvm.js

858 lines
24 KiB
JavaScript

/**
* rarvm.js
*
* Licensed under the MIT License
*
* Copyright(c) 2017 Google Inc.
*/
/**
* CRC Implementation.
*/
var CRCTab = new Array(256).fill(0);
function InitCRC() {
for (var i = 0; i < 256; ++i) {
var c = i;
for (var j = 0; j < 8; ++j) {
// Read http://stackoverflow.com/questions/6798111/bitwise-operations-on-32-bit-unsigned-ints
// for the bitwise operator issue (JS interprets operands as 32-bit signed
// integers and we need to deal with unsigned ones here).
c = ((c & 1) ? ((c >>> 1) ^ 0xEDB88320) : (c >>> 1)) >>> 0;
}
CRCTab[i] = c;
}
}
/**
* @param {number} startCRC
* @param {Uint8Array} arr
* @return {number}
*/
function CRC(startCRC, arr) {
if (CRCTab[1] == 0) {
InitCRC();
}
/*
#if defined(LITTLE_ENDIAN) && defined(PRESENT_INT32) && defined(ALLOW_NOT_ALIGNED_INT)
while (Size>0 && ((long)Data & 7))
{
StartCRC=CRCTab[(byte)(StartCRC^Data[0])]^(StartCRC>>8);
Size--;
Data++;
}
while (Size>=8)
{
StartCRC^=*(uint32 *)Data;
StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
StartCRC^=*(uint32 *)(Data+4);
StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
StartCRC=CRCTab[(byte)StartCRC]^(StartCRC>>8);
Data+=8;
Size-=8;
}
#endif
*/
for (var i = 0; i < arr.length; ++i) {
var byte = ((startCRC ^ arr[i]) >>> 0) & 0xff;
startCRC = (CRCTab[byte] ^ (startCRC >>> 8)) >>> 0;
}
return startCRC;
}
// ============================================================================================== //
/**
* RarVM Implementation.
*/
var VM_MEMSIZE = 0x40000;
var VM_MEMMASK = (VM_MEMSIZE - 1);
var VM_GLOBALMEMADDR = 0x3C000;
var VM_GLOBALMEMSIZE = 0x2000;
var VM_FIXEDGLOBALSIZE = 64;
var MAXWINSIZE = 0x400000;
var MAXWINMASK = (MAXWINSIZE - 1);
/**
*/
var VM_Commands = {
VM_MOV: 0,
VM_CMP: 1,
VM_ADD: 2,
VM_SUB: 3,
VM_JZ: 4,
VM_JNZ: 5,
VM_INC: 6,
VM_DEC: 7,
VM_JMP: 8,
VM_XOR: 9,
VM_AND: 10,
VM_OR: 11,
VM_TEST: 12,
VM_JS: 13,
VM_JNS: 14,
VM_JB: 15,
VM_JBE: 16,
VM_JA: 17,
VM_JAE: 18,
VM_PUSH: 19,
VM_POP: 20,
VM_CALL: 21,
VM_RET: 22,
VM_NOT: 23,
VM_SHL: 24,
VM_SHR: 25,
VM_SAR: 26,
VM_NEG: 27,
VM_PUSHA: 28,
VM_POPA: 29,
VM_PUSHF: 30,
VM_POPF: 31,
VM_MOVZX: 32,
VM_MOVSX: 33,
VM_XCHG: 34,
VM_MUL: 35,
VM_DIV: 36,
VM_ADC: 37,
VM_SBB: 38,
VM_PRINT: 39,
/*
#ifdef VM_OPTIMIZE
VM_MOVB, VM_MOVD, VM_CMPB, VM_CMPD,
VM_ADDB, VM_ADDD, VM_SUBB, VM_SUBD, VM_INCB, VM_INCD, VM_DECB, VM_DECD,
VM_NEGB, VM_NEGD,
#endif
*/
// TODO: This enum value would be much larger if VM_OPTIMIZE.
VM_STANDARD: 40,
};
/**
*/
var VM_StandardFilters = {
VMSF_NONE: 0,
VMSF_E8: 1,
VMSF_E8E9: 2,
VMSF_ITANIUM: 3,
VMSF_RGB: 4,
VMSF_AUDIO: 5,
VMSF_DELTA: 6,
VMSF_UPCASE: 7,
};
/**
*/
var VM_Flags = {
VM_FC: 1,
VM_FZ: 2,
VM_FS: 0x80000000,
};
/**
*/
var VM_OpType = {
VM_OPREG: 0,
VM_OPINT: 1,
VM_OPREGMEM: 2,
VM_OPNONE: 3,
};
/**
* Finds the key that maps to a given value in an object. This function is useful in debugging
* variables that use the above enums.
* @param {Object} obj
* @param {number} val
* @return {string} The key/enum value as a string.
*/
function findKeyForValue(obj, val) {
for (var key in obj) {
if (obj[key] === val) {
return key;
}
}
return null;
}
function getDebugString(obj, val) {
var s = 'Unknown.';
if (obj === VM_Commands) {
s = 'VM_Commands.';
} else if (obj === VM_StandardFilters) {
s = 'VM_StandardFilters.';
} else if (obj === VM_Flags) {
s = 'VM_OpType.';
} else if (obj === VM_OpType) {
s = 'VM_OpType.';
}
return s + findKeyForValue(obj, val);
}
/**
* @struct
* @constructor
*/
var VM_PreparedOperand = function() {
/** @type {VM_OpType} */
this.Type;
/** @type {number} */
this.Data = 0;
/** @type {number} */
this.Base = 0;
// TODO: In C++ this is a uint*
/** @type {Array<number>} */
this.Addr = null;
};
/** @return {string} */
VM_PreparedOperand.prototype.toString = function() {
if (this.Type === null) {
return 'Error: Type was null in VM_PreparedOperand';
}
return '{ ' +
'Type: ' + getDebugString(VM_OpType, this.Type) +
', Data: ' + this.Data +
', Base: ' + this.Base +
' }';
};
/**
* @struct
* @constructor
*/
var VM_PreparedCommand = function() {
/** @type {VM_Commands} */
this.OpCode;
/** @type {boolean} */
this.ByteMode = false;
/** @type {VM_PreparedOperand} */
this.Op1 = new VM_PreparedOperand();
/** @type {VM_PreparedOperand} */
this.Op2 = new VM_PreparedOperand();
};
/** @return {string} */
VM_PreparedCommand.prototype.toString = function(indent) {
if (this.OpCode === null) {
return 'Error: OpCode was null in VM_PreparedCommand';
}
indent = indent || '';
return indent + '{\n' +
indent + ' OpCode: ' + getDebugString(VM_Commands, this.OpCode) + ',\n' +
indent + ' ByteMode: ' + this.ByteMode + ',\n' +
indent + ' Op1: ' + this.Op1.toString() + ',\n' +
indent + ' Op2: ' + this.Op2.toString() + ',\n' +
indent + '}';
};
/**
* @struct
* @constructor
*/
var VM_PreparedProgram = function() {
/** @type {Array<VM_PreparedCommand>} */
this.Cmd = [];
/** @type {Array<VM_PreparedCommand>} */
this.AltCmd = null;
/** @type {Uint8Array} */
this.GlobalData = new Uint8Array();
/** @type {Uint8Array} */
this.StaticData = new Uint8Array(); // static data contained in DB operators
/** @type {Uint32Array} */
this.InitR = new Uint32Array(7);
/**
* A pointer to bytes that have been filtered by a program.
* @type {Uint8Array}
*/
this.FilteredData = null;
};
/** @return {string} */
VM_PreparedProgram.prototype.toString = function() {
var s = '{\n Cmd: [\n';
for (var i = 0; i < this.Cmd.length; ++i) {
s += this.Cmd[i].toString(' ') + ',\n';
}
s += '],\n';
// TODO: Dump GlobalData, StaticData, InitR?
s += ' }\n';
return s;
};
/**
* @struct
* @constructor
*/
var UnpackFilter = function() {
/** @type {number} */
this.BlockStart = 0;
/** @type {number} */
this.BlockLength = 0;
/** @type {number} */
this.ExecCount = 0;
/** @type {boolean} */
this.NextWindow = false;
// position of parent filter in Filters array used as prototype for filter
// in PrgStack array. Not defined for filters in Filters array.
/** @type {number} */
this.ParentFilter = null;
/** @type {VM_PreparedProgram} */
this.Prg = new VM_PreparedProgram();
};
var VMCF_OP0 = 0;
var VMCF_OP1 = 1;
var VMCF_OP2 = 2;
var VMCF_OPMASK = 3;
var VMCF_BYTEMODE = 4;
var VMCF_JUMP = 8;
var VMCF_PROC = 16;
var VMCF_USEFLAGS = 32;
var VMCF_CHFLAGS = 64;
var VM_CmdFlags = [
/* VM_MOV */
VMCF_OP2 | VMCF_BYTEMODE,
/* VM_CMP */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_ADD */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_SUB */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_JZ */
VMCF_OP1 | VMCF_JUMP | VMCF_USEFLAGS,
/* VM_JNZ */
VMCF_OP1 | VMCF_JUMP | VMCF_USEFLAGS,
/* VM_INC */
VMCF_OP1 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_DEC */
VMCF_OP1 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_JMP */
VMCF_OP1 | VMCF_JUMP,
/* VM_XOR */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_AND */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_OR */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_TEST */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_JS */
VMCF_OP1 | VMCF_JUMP | VMCF_USEFLAGS,
/* VM_JNS */
VMCF_OP1 | VMCF_JUMP | VMCF_USEFLAGS,
/* VM_JB */
VMCF_OP1 | VMCF_JUMP | VMCF_USEFLAGS,
/* VM_JBE */
VMCF_OP1 | VMCF_JUMP | VMCF_USEFLAGS,
/* VM_JA */
VMCF_OP1 | VMCF_JUMP | VMCF_USEFLAGS,
/* VM_JAE */
VMCF_OP1 | VMCF_JUMP | VMCF_USEFLAGS,
/* VM_PUSH */
VMCF_OP1,
/* VM_POP */
VMCF_OP1,
/* VM_CALL */
VMCF_OP1 | VMCF_PROC,
/* VM_RET */
VMCF_OP0 | VMCF_PROC,
/* VM_NOT */
VMCF_OP1 | VMCF_BYTEMODE,
/* VM_SHL */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_SHR */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_SAR */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_NEG */
VMCF_OP1 | VMCF_BYTEMODE | VMCF_CHFLAGS,
/* VM_PUSHA */
VMCF_OP0,
/* VM_POPA */
VMCF_OP0,
/* VM_PUSHF */
VMCF_OP0 | VMCF_USEFLAGS,
/* VM_POPF */
VMCF_OP0 | VMCF_CHFLAGS,
/* VM_MOVZX */
VMCF_OP2,
/* VM_MOVSX */
VMCF_OP2,
/* VM_XCHG */
VMCF_OP2 | VMCF_BYTEMODE,
/* VM_MUL */
VMCF_OP2 | VMCF_BYTEMODE,
/* VM_DIV */
VMCF_OP2 | VMCF_BYTEMODE,
/* VM_ADC */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_USEFLAGS | VMCF_CHFLAGS,
/* VM_SBB */
VMCF_OP2 | VMCF_BYTEMODE | VMCF_USEFLAGS | VMCF_CHFLAGS,
/* VM_PRINT */
VMCF_OP0,
];
/**
* @param {number} length
* @param {number} crc
* @param {VM_StandardFilters} type
* @struct
* @constructor
*/
var StandardFilterSignature = function(length, crc, type) {
/** @type {number} */
this.Length = length;
/** @type {number} */
this.CRC = crc;
/** @type {VM_StandardFilters} */
this.Type = type;
};
/**
* @type {Array<StandardFilterSignature>}
*/
var StdList = [
new StandardFilterSignature(53, 0xad576887, VM_StandardFilters.VMSF_E8),
new StandardFilterSignature(57, 0x3cd7e57e, VM_StandardFilters.VMSF_E8E9),
new StandardFilterSignature(120, 0x3769893f, VM_StandardFilters.VMSF_ITANIUM),
new StandardFilterSignature(29, 0x0e06077d, VM_StandardFilters.VMSF_DELTA),
new StandardFilterSignature(149, 0x1c2c5dc8, VM_StandardFilters.VMSF_RGB),
new StandardFilterSignature(216, 0xbc85e701, VM_StandardFilters.VMSF_AUDIO),
new StandardFilterSignature(40, 0x46b9c560, VM_StandardFilters.VMSF_UPCASE),
];
/**
* @constructor
*/
var RarVM = function() {
/** @private {Uint8Array} */
this.mem_ = null;
/** @private {Uint32Array<number>} */
this.R_ = new Uint32Array(8);
/** @private {number} */
this.flags_ = 0;
};
/**
* Initializes the memory of the VM.
*/
RarVM.prototype.init = function() {
if (!this.mem_) {
this.mem_ = new Uint8Array(VM_MEMSIZE);
}
};
/**
* @param {Uint8Array} code
* @return {VM_StandardFilters}
*/
RarVM.prototype.isStandardFilter = function(code) {
var codeCRC = (CRC(0xffffffff, code, code.length) ^ 0xffffffff) >>> 0;
for (var i = 0; i < StdList.length; ++i) {
if (StdList[i].CRC == codeCRC && StdList[i].Length == code.length)
return StdList[i].Type;
}
return VM_StandardFilters.VMSF_NONE;
};
/**
* @param {VM_PreparedOperand} op
* @param {boolean} byteMode
* @param {bitjs.io.BitStream} bstream A rtl bit stream.
*/
RarVM.prototype.decodeArg = function(op, byteMode, bstream) {
var data = bstream.peekBits(16);
if (data & 0x8000) {
op.Type = VM_OpType.VM_OPREG; // Operand is register (R[0]..R[7])
bstream.readBits(1); // 1 flag bit and...
op.Data = bstream.readBits(3); // ... 3 register number bits
op.Addr = [this.R_[op.Data]] // TODO &R[Op.Data] // Register address
} else {
if ((data & 0xc000) == 0) {
op.Type = VM_OpType.VM_OPINT; // Operand is integer
bstream.readBits(2); // 2 flag bits
if (byteMode) {
op.Data = bstream.readBits(8); // Byte integer.
} else {
op.Data = RarVM.readData(bstream); // 32 bit integer.
}
} else {
// Operand is data addressed by register data, base address or both.
op.Type = VM_OpType.VM_OPREGMEM;
if ((data & 0x2000) == 0) {
bstream.readBits(3); // 3 flag bits
// Base address is zero, just use the address from register.
op.Data = bstream.readBits(3); // (Data>>10)&7
op.Addr = [this.R_[op.Data]]; // TODO &R[op.Data]
op.Base = 0;
} else {
bstream.readBits(4); // 4 flag bits
if ((data & 0x1000) == 0) {
// Use both register and base address.
op.Data = bstream.readBits(3);
op.Addr = [this.R_[op.Data]]; // TODO &R[op.Data]
} else {
// Use base address only. Access memory by fixed address.
op.Data = 0;
}
op.Base = RarVM.readData(bstream); // Read base address.
}
}
}
};
/**
* @param {VM_PreparedProgram} prg
*/
RarVM.prototype.execute = function(prg) {
this.R_.set(prg.InitR);
var globalSize = Math.min(prg.GlobalData.length, VM_GLOBALMEMSIZE);
if (globalSize) {
this.mem_.set(prg.GlobalData.subarray(0, globalSize), VM_GLOBALMEMADDR);
}
var staticSize = Math.min(prg.StaticData.length, VM_GLOBALMEMSIZE - globalSize);
if (staticSize) {
this.mem_.set(prg.StaticData.subarray(0, staticSize), VM_GLOBALMEMADDR + globalSize);
}
this.R_[7] = VM_MEMSIZE;
this.flags_ = 0;
var preparedCodes = prg.AltCmd ? prg.AltCmd : prg.Cmd;
if (prg.Cmd.length > 0 && !this.executeCode(preparedCodes)) {
// Invalid VM program. Let's replace it with 'return' command.
preparedCode.OpCode = VM_Commands.VM_RET;
}
var dataView = new DataView(this.mem_.buffer, VM_GLOBALMEMADDR);
var newBlockPos = dataView.getUint32(0x20, true /* little endian */ ) & VM_MEMMASK;
var newBlockSize = dataView.getUint32(0x1c, true /* little endian */ ) & VM_MEMMASK;
if (newBlockPos + newBlockSize >= VM_MEMSIZE) {
newBlockPos = newBlockSize = 0;
}
prg.FilteredData = this.mem_.subarray(newBlockPos, newBlockPos + newBlockSize);
prg.GlobalData = new Uint8Array(0);
var dataSize = Math.min(dataView.getUint32(0x30),
(VM_GLOBALMEMSIZE - VM_FIXEDGLOBALSIZE));
if (dataSize != 0) {
var len = dataSize + VM_FIXEDGLOBALSIZE;
prg.GlobalData = new Uint8Array(len);
prg.GlobalData.set(mem.subarray(VM_GLOBALMEMADDR, VM_GLOBALMEMADDR + len));
}
};
/**
* @param {Array<VM_PreparedCommand>} preparedCodes
* @return {boolean}
*/
RarVM.prototype.executeCode = function(preparedCodes) {
var codeIndex = 0;
var cmd = preparedCodes[codeIndex];
// TODO: Why is this an infinite loop instead of just returning
// when a VM_RET is hit?
while (1) {
switch (cmd.OpCode) {
case VM_Commands.VM_RET:
if (this.R_[7] >= VM_MEMSIZE) {
return true;
}
//SET_IP(GET_VALUE(false,(uint *)&Mem[R[7] & VM_MEMMASK]));
this.R_[7] += 4;
continue;
case VM_Commands.VM_STANDARD:
this.executeStandardFilter(cmd.Op1.Data);
break;
default:
console.error('RarVM OpCode not supported: ' + getDebugString(VM_Commands, cmd.OpCode));
break;
} // switch (cmd.OpCode)
codeIndex++;
cmd = preparedCodes[codeIndex];
}
};
/**
* @param {number} filterType
*/
RarVM.prototype.executeStandardFilter = function(filterType) {
switch (filterType) {
case VM_StandardFilters.VMSF_DELTA:
var dataSize = this.R_[4];
var channels = this.R_[0];
var srcPos = 0;
var border = dataSize * 2;
//SET_VALUE(false,&Mem[VM_GLOBALMEMADDR+0x20],DataSize);
var dataView = new DataView(this.mem_.buffer, VM_GLOBALMEMADDR);
dataView.setUint32(0x20, dataSize, true /* little endian */ );
if (dataSize >= VM_GLOBALMEMADDR / 2) {
break;
}
// Bytes from same channels are grouped to continual data blocks,
// so we need to place them back to their interleaving positions.
for (var curChannel = 0; curChannel < channels; ++curChannel) {
var prevByte = 0;
for (var destPos = dataSize + curChannel; destPos < border; destPos += channels) {
prevByte = (prevByte - this.mem_[srcPos++]) & 0xff;
this.mem_[destPos] = prevByte;
}
}
break;
default:
console.error('RarVM Standard Filter not supported: ' + getDebugString(VM_StandardFilters, filterType));
break;
}
};
/**
* @param {Uint8Array} code
* @param {VM_PreparedProgram} prg
*/
RarVM.prototype.prepare = function(code, prg) {
var codeSize = code.length;
//InitBitInput();
//memcpy(InBuf,Code,Min(CodeSize,BitInput::MAX_SIZE));
var bstream = new bitjs.io.BitStream(code.buffer, true /* rtl */ );
// Calculate the single byte XOR checksum to check validity of VM code.
var xorSum = 0;
for (var i = 1; i < codeSize; ++i) {
xorSum ^= code[i];
}
bstream.readBits(8);
prg.Cmd = []; // TODO: Is this right? I don't see it being done in rarvm.cpp.
// VM code is valid if equal.
if (xorSum == code[0]) {
var filterType = this.isStandardFilter(code);
if (filterType != VM_StandardFilters.VMSF_NONE) {
// VM code is found among standard filters.
var curCmd = new VM_PreparedCommand();
prg.Cmd.push(curCmd);
curCmd.OpCode = VM_Commands.VM_STANDARD;
curCmd.Op1.Data = filterType;
// TODO: Addr=&CurCmd->Op1.Data
curCmd.Op1.Addr = [curCmd.Op1.Data];
curCmd.Op2.Addr = [null]; // &CurCmd->Op2.Data;
curCmd.Op1.Type = VM_OpType.VM_OPNONE;
curCmd.Op2.Type = VM_OpType.VM_OPNONE;
codeSize = 0;
}
var dataFlag = bstream.readBits(1);
// Read static data contained in DB operators. This data cannot be
// changed, it is a part of VM code, not a filter parameter.
if (dataFlag & 0x8000) {
var dataSize = RarVM.readData(bstream) + 1;
// TODO: This accesses the byte pointer of the bstream directly. Is that ok?
for (var i = 0; i < bstream.bytePtr < codeSize && i < dataSize; ++i) {
// Append a byte to the program's static data.
var newStaticData = new Uint8Array(prg.StaticData.length + 1);
newStaticData.set(prg.StaticData);
newStaticData[newStaticData.length - 1] = bstream.readBits(8);
prg.StaticData = newStaticData;
}
}
while (bstream.bytePtr < codeSize) {
var curCmd = new VM_PreparedCommand();
prg.Cmd.push(curCmd); // Prg->Cmd.Add(1)
var flag = bstream.peekBits(1);
if (!flag) { // (Data&0x8000)==0
curCmd.OpCode = bstream.readBits(4);
} else {
curCmd.OpCode = (bstream.readBits(6) - 24);
}
if (VM_CmdFlags[curCmd.OpCode] & VMCF_BYTEMODE) {
curCmd.ByteMode = (bstream.readBits(1) != 0);
} else {
curCmd.ByteMode = 0;
}
curCmd.Op1.Type = VM_OpType.VM_OPNONE;
curCmd.Op2.Type = VM_OpType.VM_OPNONE;
var opNum = (VM_CmdFlags[curCmd.OpCode] & VMCF_OPMASK);
curCmd.Op1.Addr = null;
curCmd.Op2.Addr = null;
if (opNum > 0) {
this.decodeArg(curCmd.Op1, curCmd.ByteMode, bstream); // reading the first operand
if (opNum == 2) {
this.decodeArg(curCmd.Op2, curCmd.ByteMode, bstream); // reading the second operand
} else {
if (curCmd.Op1.Type == VM_OpType.VM_OPINT && (VM_CmdFlags[curCmd.OpCode] & (VMCF_JUMP | VMCF_PROC))) {
// Calculating jump distance.
var distance = curCmd.Op1.Data;
if (distance >= 256) {
distance -= 256;
} else {
if (distance >= 136) {
distance -= 264;
} else {
if (distance >= 16) {
distance -= 8;
} else {
if (distance >= 8) {
distance -= 16;
}
}
}
distance += prg.Cmd.length;
}
curCmd.Op1.Data = distance;
}
}
} // if (OpNum>0)
} // while ((uint)InAddr<CodeSize)
} // if (XorSum==Code[0])
var curCmd = new VM_PreparedCommand();
prg.Cmd.push(curCmd);
curCmd.OpCode = VM_Commands.VM_RET;
// TODO: Addr=&CurCmd->Op1.Data
curCmd.Op1.Addr = [curCmd.Op1.Data];
curCmd.Op2.Addr = [curCmd.Op2.Data];
curCmd.Op1.Type = VM_OpType.VM_OPNONE;
curCmd.Op2.Type = VM_OpType.VM_OPNONE;
// If operand 'Addr' field has not been set by DecodeArg calls above,
// let's set it to point to operand 'Data' field. It is necessary for
// VM_OPINT type operands (usual integers) or maybe if something was
// not set properly for other operands. 'Addr' field is required
// for quicker addressing of operand data.
for (var i = 0; i < prg.Cmd.length; ++i) {
var cmd = prg.Cmd[i];
if (cmd.Op1.Addr == null) {
cmd.Op1.Addr = [cmd.Op1.Data];
}
if (cmd.Op2.Addr == null) {
cmd.Op2.Addr = [cmd.Op2.Data];
}
}
/*
#ifdef VM_OPTIMIZE
if (CodeSize!=0)
Optimize(Prg);
#endif
*/
};
/**
* @param {Uint8Array} arr The byte array to set a value in.
* @param {number} value The unsigned 32-bit value to set.
* @param {number} offset Offset into arr to start setting the value, defaults to 0.
*/
RarVM.prototype.setLowEndianValue = function(arr, value, offset) {
var i = offset || 0;
arr[i] = value & 0xff;
arr[i + 1] = (value >>> 8) & 0xff;
arr[i + 2] = (value >>> 16) & 0xff;
arr[i + 3] = (value >>> 24) & 0xff;
};
/**
* Sets a number of bytes of the VM memory at the given position from a
* source buffer of bytes.
* @param {number} pos The position in the VM memory to start writing to.
* @param {Uint8Array} buffer The source buffer of bytes.
* @param {number} dataSize The number of bytes to set.
*/
RarVM.prototype.setMemory = function(pos, buffer, dataSize) {
if (pos < VM_MEMSIZE) {
var numBytes = Math.min(dataSize, VM_MEMSIZE - pos);
for (var i = 0; i < numBytes; ++i) {
this.mem_[pos + i] = buffer[i];
}
}
};
/**
* Static function that reads in the next set of bits for the VM
* (might return 4, 8, 16 or 32 bits).
* @param {bitjs.io.BitStream} bstream A RTL bit stream.
* @return {number} The value of the bits read.
*/
RarVM.readData = function(bstream) {
// Read in the first 2 bits.
var flags = bstream.readBits(2);
switch (flags) { // Data&0xc000
// Return the next 4 bits.
case 0:
return bstream.readBits(4); // (Data>>10)&0xf
case 1: // 0x4000
// 0x3c00 => 0011 1100 0000 0000
if (bstream.peekBits(4) == 0) { // (Data&0x3c00)==0
// Skip the 4 zero bits.
bstream.readBits(4);
// Read in the next 8 and pad with 1s to 32 bits.
return (0xffffff00 | bstream.readBits(8)) >>> 0; // ((Data>>2)&0xff)
}
// Else, read in the next 8.
return bstream.readBits(8);
// Read in the next 16.
case 2: // 0x8000
var val = bstream.getBits();
bstream.readBits(16);
return val; //bstream.readBits(16);
// case 3
default:
return (bstream.readBits(16) << 16) | bstream.readBits(16);
}
};
// ============================================================================================== //