980 lines
30 KiB
C++
Executable File
980 lines
30 KiB
C++
Executable File
//
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// STORAGE.CPP
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//
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// Source file for ArchiveLib 1.0
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//
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// Copyright (c) Greenleaf Software, Inc. 1994
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// All Rights Reserved
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//
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// CONTENTS
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//
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// ALStorage::operator new()
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// ALStorage::ALStorage()
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// ALStorage::~ALStorage()
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// ALStorage::UpdateCrc()
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// ALStorage::Open()
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// ALStorage::Create()
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// ALStorage::Close()
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// ALStorage::GetCrc32()
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// ALStorage::InitCrc32()
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// ALStorage::ReadBuffer()
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// ALStorage::WriteBuffer()
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// ALStorage::WritePortableShort()
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// ALStorage::WritePortableLong()
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// ALStorage::ReadPortableShort()
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// ALStorage::ReadPortableLong()
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// ALStorage::WriteString()
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// ALStorage::ReadString()
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// ALStorage::Tell()
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// ALStorage::YieldTime()
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// ALStorage::WriteStorageObjectData()
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// ALStorage::ReadStorageObjectData()
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//
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// DESCRIPTION
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//
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// This file contains all of the source code for the member functions
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// of ALStorage. AlStorage has pure virtual functions, so you can't
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// ever instantiate one of these guys.
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//
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// REVISION HISTORY
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//
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// May 26, 1994 1.0A : First release
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//
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//
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#include "arclib.h"
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#pragma hdrstop
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#include <string.h>
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//
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// void * ALStorage::operator new( size_t size )
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//
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// ARGUMENTS:
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//
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// size : The number of bytes needed to create a new ALStorage object.
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//
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// RETURNS
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//
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// A pointer to the newly allocated storage area, or 0 if no storage
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// was available.
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//
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// DESCRIPTION
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//
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// When using a DLL, it is easy to get into a dangerous situation when
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// creating objects whose ctor and dtor are both in the DLL. The problem
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// arises because when you create an object using new, the memory for
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// the object will be allocated from the EXE. However, when you destroy
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// the object using delete, the memory is freed inside the DLL. Since
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// the DLL doesn't really own that memory, bad things can happen.
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//
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// But, you say, won't the space just go back to the Windows heap regardless
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// of who tries to free it? Maybe, but maybe not. If the DLL is using
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// a subsegment allocation scheme, it might do some sort of local free
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// before returning the space to the windows heap. That is the point where
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// you could conceivably cook your heap.
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//
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// By providing our own version of operator new inside this class, we
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// ensure that all memory allocation for the class will be done from
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// inside the DLL, not the EXE calling the DLL.
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//
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// REVISION HISTORY
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//
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// May 26, 1994 1.0A : First release
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//
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#if defined( AL_BUILDING_DLL )
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void AL_DLL_FAR * AL_PROTO ALStorage::operator new( size_t size )
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{
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return ::new char[ size ];
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}
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#endif
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//
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// ALStorage::ALStorage( const char *file_name,
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// size_t size,
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// const enum ALStorageType object_type,
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// ALCase name_case )
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//
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// ARGUMENTS:
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//
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// file_name : The name to assign to the mName data member of the
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// newly created storage object.
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//
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// size : The size of the I/O buffer that is going to be used
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// for the storage object. ALFile uses 4096 as a default.
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//
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// object_type : The type of object, as defined in ALDEFS.H. Good
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// values include AL_FILE_OBJECT and AL_MEMORY_OBJECT.
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//
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// name_case : The case sensitivity of the object name. For objects
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// such as ALFile, AL_MIXED is a no-no. Those objects
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// need to be forced to convert names to all upper
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// or all lower, because the operating system considers
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// file names to be case insensitive.
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//
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// RETURNS
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//
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// Nothing, it is a constructor.
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//
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// DESCRIPTION
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//
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// The constructor for ALStorage gets called from the constructor of
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// derived classes. It has to initialize all sorts of data members.
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// First, in the initializer list, it sets up the mName data member,
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// as well as muBufferSize and miStorageObjectType. The latter two
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// data members are set to be const so I can make them public, which
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// means we have to initialize them in the initializer list.
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//
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// In the body of the constructor, we initialize a bunch of data members,
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// none of which mean anything at this point.
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//
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// REVISION HISTORY
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//
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// May 26, 1994 1.0A : First release
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//
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AL_PROTO ALStorage::ALStorage( const char AL_DLL_FAR *file_name,
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size_t size,
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const enum ALStorageType object_type,
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ALCase name_case )
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: mName( file_name, name_case ),
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miStorageObjectType( object_type ),
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muBufferSize( size )
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{
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mpcBuffer = 0;
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muBufferValidData = 0;
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muWriteIndex = 0;
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muReadIndex = 0;
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mlFilePointer = 0;
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miUpdateCrcFlag = 0;
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mlCrc32 = 0xffffffffL;
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mlSize = -1L;
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mpMonitor = 0;
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miCreated = 0;
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if ( mName.GetName() == 0 )
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mStatus.SetError( AL_CANT_OPEN_BUFFER,
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"Allocation of buffer failed in "
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"ALStorage constructor" );
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}
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//
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// ALStorage::~ALStorage()
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//
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// ARGUMENTS:
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//
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// No arguments for destructors.
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//
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// RETURNS
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//
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// No returns from destructors.
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//
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// DESCRIPTION
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//
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// In debug mode, we first check to make sure we are destroying the
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// right type of object.
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//
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// The only thing left to do is free up the I/O buffer if it is still
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// allocated. This piece of work probably isn't necessary. Since this
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// is a virtual destructor, we will be called after the destructors
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// for the derived class. Any derived class that is doing its job
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// will make sure that it calls Close() before destroying itself. If
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// it doesn't, it will probably be leaving unfinished business behind
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// that we aren't going to be able to deal with here. Even so, we will
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// be diligent in our attention to detail.
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//
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// REVISION HISTORY
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//
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// May 26, 1994 1.0A : First release
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//
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AL_PROTO ALStorage::~ALStorage()
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{
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AL_ASSERT( GoodTag(), "~ALStorage: attempting to delete invalid object" );
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if ( mpcBuffer )
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Close();
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}
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//
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// This giant table is used by the CRC routines. These are the coefficients
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// for calculating the CCITT 32 bit CRC. I typed these in from memory, so
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// I hope they are correct.
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//
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static unsigned long ccitt_32[ 256 ] =
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{
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0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL, 0xe963a535L, 0x9e6495a3L,
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0x0edb8832L, 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 0x90bf1d91L,
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0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L,
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0x136c9856L, 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, 0xfa0f3d63L, 0x8d080df5L,
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0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
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0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L,
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0x26d930acL, 0x51de003aL, 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, 0xb8bda50fL,
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0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL,
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0x76dc4190L, 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 0x9fbfe4a5L, 0xe8b8d433L,
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0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
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0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L,
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0x65b0d9c6L, 0x12b7e950L, 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 0xfbd44c65L,
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0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL,
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0x4369e96aL, 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, 0xaa0a4c5fL, 0xdd0d7cc9L,
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0x5005713cL, 0x270241aaL, 0xbe0b1010L, 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
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0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL,
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0xedb88320L, 0x9abfb3b6L, 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, 0x73dc1683L,
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0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L,
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0xf00f9344L, 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, 0x196c3671L, 0x6e6b06e7L,
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0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
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0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL,
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0xd80d2bdaL, 0xaf0a1b4cL, 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, 0x4669be79L,
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0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL,
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0xc5ba3bbeL, 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 0x2cd99e8bL, 0x5bdeae1dL,
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0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
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0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L,
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0x86d3d2d4L, 0xf1d4e242L, 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 0x18b74777L,
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0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L,
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0xa00ae278L, 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, 0x4969474dL, 0x3e6e77dbL,
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0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
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0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 0xcdd70693L, 0x54de5729L, 0x23d967bfL,
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0xb3667a2eL, 0xc4614ab8L, 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 0x2d02ef8dL
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};
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//
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// void ALStorage::UpdateCrc( size_t count )
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//
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// ARGUMENTS:
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//
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// count : The number of characters to process in the I/O buffer.
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//
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// RETURNS
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//
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// Nothing.
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//
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// DESCRIPTION
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//
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// If CRC checking has been turned on for the storage object, this
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// routine will be called every time LoadBuffer() or FlushBuffer()
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// are called. It does CRC checking on a buffer full of data at
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// a time. Hopefully this means the compiler can optimize the
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// heck out of this code.
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//
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// REVISION HISTORY
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//
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// May 26, 1994 1.0A : First release
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//
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void AL_PROTO ALStorage::UpdateCrc( size_t count )
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{
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unsigned char *p = (unsigned char *) mpcBuffer;
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while ( count-- != 0 )
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mlCrc32 = ( ( mlCrc32 >> 8 ) & 0x00FFFFFFL ) ^
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( ccitt_32[ ( (int) mlCrc32 ^ *p++ ) & 0xff ] );
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}
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//
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// int ALStorage::Open()
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//
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// ARGUMENTS:
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//
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// None.
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//
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// RETURNS
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//
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// AL_SUCCESS, or AL_CANT_OPEN_BUFFER on memory allocation failure.
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// If the object was already in an error state, it is very possible to
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// get some other error code < 0.
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//
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// DESCRIPTION
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//
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// Any derived class needs to have its own Open() function. However,
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// the derived class can also call this Open() function in the base
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// class to do some odds and ends for it. The most important thing it
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// does is allocate the I/O buffer, which is what makes ALStorage a
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// relatively fast way to read and write data. Although the buffer
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// is in place, there is no data in it, so this guy also sets up the
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// indices and pointers to reflect that.
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//
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// Upon exit, all you need to to is start reading or writing, and the
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// whole thing should be ready to go.
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//
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// REVISION HISTORY
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//
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// May 26, 1994 1.0A : First release
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//
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int AL_PROTO ALStorage::Open()
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{
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if ( mStatus < AL_SUCCESS )
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return mStatus;
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if ( muBufferSize != 0 )
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mpcBuffer = new unsigned char[ muBufferSize ];
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muBufferValidData = 0;
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muWriteIndex = 0;
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muReadIndex = 0;
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mlFilePointer = 0;
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miUpdateCrcFlag = 0;
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mlCrc32 = 0xffffffffL;
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if ( mpcBuffer == 0 )
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return mStatus.SetError( AL_CANT_OPEN_BUFFER,
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"Allocation of buffer failed in Open()" );
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return AL_SUCCESS;
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}
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//
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// int ALStorage::Create()
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//
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// ARGUMENTS:
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//
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// None.
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//
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// RETURNS
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//
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// AL_SUCCESS, or AL_CANT_OPEN_BUFFER on memory allocation failure.
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// If the object was already in an error state, it is very possible to
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// get some other error code < 0.
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//
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// DESCRIPTION
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//
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// This function is nearly identical to ALStorage::Open().
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//
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// Any derived class needs to have its own Create() function. However,
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// the derived class can also call this Create() function in the base
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// class to do some odds and ends for it. The most important thing it
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// does is allocate the I/O buffer, which is what makes ALStorage a
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// relatively fast way to read and write data. Although the buffer
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// is in place, there is no data in it, so this guy also sets up the
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// indices and pointers to reflect that.
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//
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// Upon exit, all you need to to is start writing, and the
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// whole thing should be ready to go.
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//
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// REVISION HISTORY
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//
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// May 26, 1994 1.0A : First release
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//
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int AL_PROTO ALStorage::Create()
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{
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if ( mStatus < AL_SUCCESS )
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return mStatus;
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mpcBuffer = new unsigned char[ muBufferSize ];
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muBufferValidData = 0;
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muWriteIndex = 0;
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muReadIndex = 0;
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mlFilePointer = 0;
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miUpdateCrcFlag = 0;
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mlCrc32 = 0xffffffffL;
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miCreated = 1;
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if ( mpcBuffer == 0 )
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return mStatus.SetError( AL_CANT_OPEN_BUFFER,
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"Allocation of buffer failed in Open()" );
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return AL_SUCCESS;
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}
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//
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// int ALStorage::Close()
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//
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// ARGUMENTS:
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//
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// None.
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//
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// RETURNS
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//
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// The current integer status of the object. Hopefully this will be
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// AL_SUCCESS, but it could well be a value < AL_SUCCESS.
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//
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// DESCRIPTION
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//
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// Just like with Open(), must derived classes will have their own
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// versions of Close(). They can call this version to delete the I/O
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// buffer if they feel like it is too hard to do themselves.
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//
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// REVISION HISTORY
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//
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// May 26, 1994 1.0A : First release
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//
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int AL_PROTO ALStorage::Close()
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{
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if ( mpcBuffer ) {
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delete[] mpcBuffer;
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mpcBuffer = 0;
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}
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return mStatus;
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}
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//
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// long ALStorage::GetCrc32()
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//
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// ARGUMENTS:
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//
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// None.
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//
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// RETURNS
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//
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// The current value of the CRC-32.
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//
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// DESCRIPTION
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//
|
|
// This function is used to get the CRC-32 of a storage object. But it
|
|
// does a little bit more than just give you the CRC. First, it makes
|
|
// sure the buffers have been flushed, so that the CRC is accurate. If
|
|
// we didn't do this we might try to get the CRC on an incompletely
|
|
// written file.
|
|
//
|
|
// Once we get the CRC,the miUpdateCrcFlag is set to 0, which means
|
|
// that from here on out the value will not be updated. So retrieving
|
|
// the CRC means you are no longer interested in further calculation.
|
|
// It also means you can trust the value you just read, because it
|
|
// will never be modified again.
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
long AL_PROTO ALStorage::GetCrc32()
|
|
{
|
|
if ( IsOpen() && miUpdateCrcFlag )
|
|
FlushBuffer();
|
|
miUpdateCrcFlag = 0;
|
|
return mlCrc32;
|
|
}
|
|
|
|
//
|
|
// void ALStorage::InitCrc32( unsigned long seed = 0xffffffffL )
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// seed : The long value to start the CRC off at. There is probably
|
|
// no reason to change this from the default value, although
|
|
// I won't be surprised if someone comes up with one.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// Nothing.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// Calling this function kicks off the CRC calculation for a given
|
|
// storage object should be done immediately after the object is
|
|
// opened. Once the miUpdateCrcFlag is set, the CRC will be updated
|
|
// every time a LoadBuffer() or FlushBuffer() is called.
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
void AL_PROTO ALStorage::InitCrc32( unsigned long seed /* = 0xffffffffL */ )
|
|
{
|
|
miUpdateCrcFlag = 1;
|
|
mlCrc32 = seed;
|
|
}
|
|
|
|
|
|
//
|
|
// size_t ALStorage::ReadBuffer( unsigned char *buf, size_t length )
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// buf : The buffer that is going to receive input characters.
|
|
//
|
|
// length : The number of bytes you want to read.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// The number of bytes read in, always. If this function generates an
|
|
// error, it will be found in the mStatus member.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// We could write a simple version of this function by just calling
|
|
// ReadChar() over and over, but it would be nice to do things
|
|
// a little more efficiently. Since we have this nice big buffer
|
|
// full of data ready to read, it makes sense to copy big chunks of
|
|
// it in one fell swoop. That is what this guy does. It sits in a loop
|
|
// doing a memcpy() followed by LoadBuffer() until all of the data
|
|
// that has been asked for got moved. As data is read in, we have to
|
|
// update the data member muReadIndex. Other data members will get
|
|
// updated by LoadBuffer().
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
size_t AL_PROTO ALStorage::ReadBuffer( unsigned char *buf,
|
|
size_t length )
|
|
{
|
|
size_t bytes_left_to_read = length;
|
|
size_t buffer_bytes_available;
|
|
|
|
while ( bytes_left_to_read ) {
|
|
buffer_bytes_available = muBufferValidData - muReadIndex;
|
|
if ( buffer_bytes_available == 0 ) {
|
|
if ( LoadBuffer( mlFilePointer ) < 0 )
|
|
return length - bytes_left_to_read;
|
|
buffer_bytes_available = muBufferValidData;
|
|
}
|
|
if ( bytes_left_to_read <= buffer_bytes_available ) {
|
|
memcpy( buf, mpcBuffer + muReadIndex, bytes_left_to_read );
|
|
muReadIndex += bytes_left_to_read;
|
|
return length;
|
|
} else {
|
|
memcpy( buf, mpcBuffer + muReadIndex, buffer_bytes_available );
|
|
buf += buffer_bytes_available;
|
|
bytes_left_to_read -= buffer_bytes_available;
|
|
muReadIndex += buffer_bytes_available;
|
|
if ( LoadBuffer( mlFilePointer ) < 0 )
|
|
return length - bytes_left_to_read;
|
|
}
|
|
}
|
|
return length;
|
|
}
|
|
|
|
//
|
|
// size_t ALStorage::WriteBuffer( const unsigned char *buf,
|
|
// size_t length )
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// buf : The buffer that is contains the output data.
|
|
//
|
|
// length : The number of bytes you want to write.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// The number of bytes written, always. If this function generates an
|
|
// error, it will be found in the mStatus member.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// We could write a simple version of this function by just calling
|
|
// WriteChar() over and over, but it would be nice to do things
|
|
// a little more efficiently. Since we have this nice big buffer
|
|
// just waiting for data, it makes sense to copy big chunks to
|
|
// it in one fell swoop. That is what this guy does. It sits in a loop
|
|
// doing a memcpy() followed by FlushBuffer() until all of the data
|
|
// that was ready to go has been sent. As data is written, we have to
|
|
// update the data member muWriteIndex. Other data members will get
|
|
// updated by FlushBuffer().
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
size_t AL_PROTO ALStorage::WriteBuffer( const unsigned char *buf,
|
|
size_t length )
|
|
{
|
|
size_t buffer_bytes_free;
|
|
size_t write_bytes_left = length;
|
|
|
|
if ( mStatus < 0 )
|
|
return 0;
|
|
while ( write_bytes_left > 0 ) {
|
|
buffer_bytes_free = muBufferSize - muWriteIndex;
|
|
if ( buffer_bytes_free == 0 ) {
|
|
if ( FlushBuffer() < 0 )
|
|
return length - write_bytes_left;
|
|
buffer_bytes_free = muBufferSize;
|
|
}
|
|
if ( write_bytes_left <= buffer_bytes_free ) {
|
|
memcpy( mpcBuffer + muWriteIndex, buf, write_bytes_left );
|
|
muWriteIndex += write_bytes_left;
|
|
return length;
|
|
} else {
|
|
memcpy( mpcBuffer + muWriteIndex, buf, buffer_bytes_free );
|
|
muWriteIndex += buffer_bytes_free;
|
|
buf += buffer_bytes_free;
|
|
write_bytes_left -= buffer_bytes_free;
|
|
if ( FlushBuffer() < 0 )
|
|
return length - write_bytes_left;
|
|
}
|
|
}
|
|
return length;
|
|
}
|
|
|
|
//
|
|
// int ALStorage::WritePortableShort( short int short_data )
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// short_data : A 16 bit int that is going to be written out in
|
|
// little endian format.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// AL_SUCCESS if all goes well. Otherwise, some error code < AL_STATUS.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// In order to make sure our archives can be read and written on all sorts
|
|
// of systems, we have a few functions that are used to write numerical
|
|
// data in a portable fashion. This function writes short integers in
|
|
// little endian format (which is not native Intel format). The complementary
|
|
// function, ReadPortableShort(), reads short integers back using the
|
|
// same format.
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
int AL_PROTO ALStorage::WritePortableShort( short int short_data )
|
|
{
|
|
WriteChar( short_data >> 8 );
|
|
WriteChar( short_data );
|
|
return mStatus;
|
|
}
|
|
|
|
//
|
|
// int ALStorage::WritePortableLong( long int long_data )
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// long_data : A 32 bit long int that is going to be written out in
|
|
// little endian format.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// AL_SUCCESS if all goes well. Otherwise, some error code < AL_STATUS.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// In order to make sure our archives can be read and written on all sorts
|
|
// of systems, we have a few functions that are used to write numerical
|
|
// data in a portable fashion. This function writes long integers in
|
|
// little endian format (which is not native Intel format). The
|
|
// complementary function, ReadPortableLong(), reads long integers back
|
|
// using the same format.
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
int AL_PROTO ALStorage::WritePortableLong( long long_data )
|
|
{
|
|
WriteChar( (int) ( long_data >> 24 ) );
|
|
WriteChar( (int) ( long_data >> 16 ) );
|
|
WriteChar( (int) ( long_data >> 8 ) );
|
|
WriteChar( (int) long_data );
|
|
return mStatus;
|
|
}
|
|
|
|
//
|
|
// int ALStorage::ReadPortableShort( short int &short_data )
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// short_data : A reference to a 16 bit integer that is going to
|
|
// have data read in from this storage object.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// AL_SUCCESS if all goes well. Otherwise, some error code < AL_STATUS.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// In order to make sure our archives can be read and written on all sorts
|
|
// of systems, we have a few functions that are used to read numerical
|
|
// data in a portable fashion. This function reads short integers in
|
|
// little endian format (which is not native Intel format). The
|
|
// complementary function, WritePortableShort(), writes short integers out
|
|
// using the same format.
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
int AL_PROTO ALStorage::ReadPortableShort( short int & short_data )
|
|
{
|
|
short_data = (short int) ( ReadChar() << 8 );
|
|
short_data |= (short int) ReadChar();
|
|
return mStatus;
|
|
}
|
|
|
|
//
|
|
// int ALStorage::ReadPortableLong( long int &short_data )
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// long_data : A reference to a 32 bit integer that is going to
|
|
// have data read in from this storage object.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// AL_SUCCESS if all goes well. Otherwise, some error code < AL_STATUS.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// In order to make sure our archives can be read and written on all sorts
|
|
// of systems, we have a few functions that are used to read numerical
|
|
// data in a portable fashion. This function reads long integers in
|
|
// little endian format (which is not native Intel format). The
|
|
// complementary function, WritePortableLong(), writes long integers out
|
|
// using the same format.
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
int AL_PROTO ALStorage::ReadPortableLong( long & long_data )
|
|
{
|
|
long_data = (long) ReadChar() << 24;
|
|
long_data |= (long) ReadChar() << 16;
|
|
long_data |= (long) ReadChar() << 8;
|
|
long_data |= ReadChar();
|
|
return mStatus;
|
|
}
|
|
|
|
//
|
|
// int ALStorage::WriteString( const char *string_data )
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// string_data : A string to be written out in our portable format.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// AL_SUCCESS if things work, or an error code < AL_SUCCESS if an error
|
|
// occurs writing the data out.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// We write random length data to archive directories using this special
|
|
// format, which is a 16 bit int describing the length of the data,
|
|
// followed by the data itself. All of the storage objects and compression
|
|
// engines write their own private data out using this format. This
|
|
// means that even if another class doesn't understand the content of data
|
|
// stored in this format, at least it knows how to read it in so as to
|
|
// move past it.
|
|
//
|
|
// This function won't write just any random data, it is specifically
|
|
// oriented towards C strings. This means it is mostly used to write
|
|
// file names and comments. Their are a few places where classes
|
|
// write private data that isn't kept in C strings, they just manually
|
|
// write the length with WritePortableShort(), followed by the data.
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
int AL_PROTO ALStorage::WriteString( const char *string_data )
|
|
{
|
|
short unsigned int len;
|
|
if ( string_data != 0 )
|
|
len = (short unsigned int) strlen( string_data );
|
|
else
|
|
len = 0;
|
|
WritePortableShort( len );
|
|
if ( len )
|
|
WriteBuffer( (unsigned char *) string_data, len );
|
|
return mStatus;
|
|
}
|
|
|
|
// PROTECTED MEMBER FUNCTION
|
|
//
|
|
// char * ALStorage::ReadString()
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// None.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// A pointer to a string. This string has been allocated by the library,
|
|
// which can cause a problem if you are using a DLL. If an EXE tried
|
|
// to free a string pointer allocated by the DLL, havoc would result.
|
|
// Because of this hassle, this is a protected function.
|
|
//
|
|
// The solution to this is to write a new version of this that returns
|
|
// an ALName object. I thought of that, but too late.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// This function is used internally by ArchiveLib. It is used to read
|
|
// random length blocks of data out of archives (or other storage objects).
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
char AL_DLL_FAR * AL_PROTO ALStorage::ReadString()
|
|
{
|
|
short int len;
|
|
|
|
if ( ReadPortableShort( len ) < 0 )
|
|
return 0;
|
|
char *new_string = new char[ len + 1 ];
|
|
if ( new_string ) {
|
|
ReadBuffer( (unsigned char *) new_string, len );
|
|
new_string[ len ] = '\0';
|
|
return new_string;
|
|
} else {
|
|
mStatus.SetError( AL_CANT_ALLOCATE_MEMORY,
|
|
"Error allocating buffer space in call "
|
|
"to ReadString() for object %s",
|
|
mName.GetSafeName() );
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
//
|
|
// long ALStorage::Tell()
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// None.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// A long integer indicating the current position of the read/write
|
|
// pointer for the file.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// Because we are using buffered I/O here, figuring out the current
|
|
// position of the read write pointer is just a tiny bit more complicated
|
|
// than just checking a pointer. We have to find the physical location of
|
|
// the file pointer, then add in any offset created by the presence of
|
|
// data in the I/O buffer.
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
long AL_PROTO ALStorage::Tell()
|
|
{
|
|
if ( muWriteIndex )
|
|
return mlFilePointer + muWriteIndex;
|
|
else
|
|
return mlFilePointer - muBufferValidData + muReadIndex;
|
|
|
|
}
|
|
|
|
//
|
|
// void ALStorage::YieldTime()
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// None.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// Nothing.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// This function has two important things to do. It gets called
|
|
// at a few different points in the process of reading or writing data
|
|
// from storage objects. During normal reading and writing, it
|
|
// will get called every time the buffer is loaded or flushed.
|
|
//
|
|
// If we are in Windows mode, we execute a PeekMessage() loop. This
|
|
// makes sure that we aren't hogging the CPU. By doing it this way,
|
|
// the programmer can be ensure that he/she is being a good citizen
|
|
// without any significant effort.
|
|
//
|
|
// The second important function is that of calling the monitor function.
|
|
// The user interface elements need to be updated regularly, and this
|
|
// is done via this call.
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
void AL_PROTO ALStorage::YieldTime()
|
|
{
|
|
if ( mpMonitor )
|
|
mpMonitor->Progress( Tell(), *this );
|
|
/*
|
|
* For right now I am going to put the PeekMessage loop in the load
|
|
* buffer routine by default. Most Windows applications are going
|
|
* to want to use this, right?
|
|
*/
|
|
#if defined( AL_WINDOWS_GUI )
|
|
MSG msg;
|
|
|
|
while ( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) ) {
|
|
TranslateMessage( &msg );
|
|
DispatchMessage(&msg);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
//
|
|
// int ALStorage::WriteStorageObjectData( ALStorage * archive )
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// archive : A pointer to the storage object where we are going to
|
|
// write the private data.
|
|
//
|
|
// RETURNS
|
|
//
|
|
// AL_SUCCESS if things went okay, otherwise an error code < AL_SUCCESS.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// All storage objects have the ability to create a private data block
|
|
// that will be stored along with the directory when creating an archive.
|
|
// None of the classes predefined in ArchiveLib use this data block, which
|
|
// means they use this function instead of providing their own virtual
|
|
// substitute. This function writes a private data block of exactly 0
|
|
// bytes in length. Our internal storage format means that a block
|
|
// of 0 bytes length takes 2 bytes to store.
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
int AL_PROTO ALStorage::WriteStorageObjectData( ALStorage * archive )
|
|
{
|
|
return archive->WritePortableShort( 0 );
|
|
}
|
|
|
|
//
|
|
// int ALStorage::ReadStorageObjectData( ALStorage * archive )
|
|
//
|
|
// ARGUMENTS:
|
|
//
|
|
// archive : A pointer to the storage object where we are going to
|
|
// read in the private data..
|
|
//
|
|
// RETURNS
|
|
//
|
|
// AL_SUCCESS if things went okay, otherwise an error code < AL_SUCCESS.
|
|
//
|
|
// DESCRIPTION
|
|
//
|
|
// All storage objects have the ability to create a private data block
|
|
// that will be stored along with the directory when creating an archive.
|
|
// None of the classes predefined in ArchiveLib use this data block, which
|
|
// means they use this function instead of providing their own virtual
|
|
// substitute. This function reads a private data block of exactly 0
|
|
// bytes in length. Our internal storage format means that a block
|
|
// of 0 bytes length takes 2 bytes to store.
|
|
//
|
|
// In debug mode, we get really bent out of shape if this data block
|
|
// doesn't look exactly like we expect it to.
|
|
//
|
|
// REVISION HISTORY
|
|
//
|
|
// May 26, 1994 1.0A : First release
|
|
//
|
|
|
|
int AL_PROTO ALStorage::ReadStorageObjectData( ALStorage * archive )
|
|
{
|
|
short int temp;
|
|
int status = archive->ReadPortableShort( temp );
|
|
AL_ASSERT( temp == 0, "ReadStorageObjectData: stored data is not null" );
|
|
return status;
|
|
}
|