blob: 89a83b34c06cfa33d402d389261cd5db68c9ae9b [file] [log] [blame]
#include "rar.hpp"
QuickOpen::QuickOpen()
{
Buf=NULL;
Init(NULL,false);
}
QuickOpen::~QuickOpen()
{
Close();
delete[] Buf;
}
void QuickOpen::Init(Archive *Arc,bool WriteMode)
{
if (Arc!=NULL) // Unless called from constructor.
Close();
QuickOpen::Arc=Arc;
QuickOpen::WriteMode=WriteMode;
ListStart=NULL;
ListEnd=NULL;
if (Buf==NULL)
Buf=new byte[MaxBufSize];
CurBufSize=0; // Current size of buffered data in write mode.
Loaded=false;
}
void QuickOpen::Close()
{
QuickOpenItem *Item=ListStart;
while (Item!=NULL)
{
QuickOpenItem *Next=Item->Next;
delete[] Item->Header;
delete Item;
Item=Next;
}
}
void QuickOpen::Load(uint64 BlockPos)
{
if (!Loaded)
{
// If loading for the first time, perform additional intialization.
SeekPos=Arc->Tell();
UnsyncSeekPos=false;
SaveFilePos SavePos(*Arc);
Arc->Seek(BlockPos,SEEK_SET);
// If BlockPos points to original main header, we'll have the infinite
// recursion, because ReadHeader() for main header will attempt to load
// QOpen and call QuickOpen::Load again. If BlockPos points to long chain
// of other main headers, we'll have multiple recursive calls of this
// function wasting resources. So we prohibit QOpen temporarily to
// prevent this. ReadHeader() calls QOpen.Init and sets MainHead Locator
// and QOpenOffset fields, so we cannot use them to prohibit QOpen.
Arc->SetProhibitQOpen(true);
size_t ReadSize=Arc->ReadHeader();
Arc->SetProhibitQOpen(false);
if (ReadSize==0 || Arc->GetHeaderType()!=HEAD_SERVICE ||
!Arc->SubHead.CmpName(SUBHEAD_TYPE_QOPEN))
return;
QOHeaderPos=Arc->CurBlockPos;
RawDataStart=Arc->Tell();
RawDataSize=Arc->SubHead.UnpSize;
Loaded=true; // Set only after all file processing calls like Tell, Seek, ReadHeader.
}
if (Arc->SubHead.Encrypted)
{
RAROptions *Cmd=Arc->GetRAROptions();
#ifndef RAR_NOCRYPT
if (Cmd->Password.IsSet())
Crypt.SetCryptKeys(false,CRYPT_RAR50,&Cmd->Password,Arc->SubHead.Salt,
Arc->SubHead.InitV,Arc->SubHead.Lg2Count,
Arc->SubHead.HashKey,Arc->SubHead.PswCheck);
else
#endif
{
Loaded=false;
return;
}
}
RawDataPos=0;
ReadBufSize=0;
ReadBufPos=0;
LastReadHeader.Reset();
LastReadHeaderPos=0;
ReadBuffer();
}
bool QuickOpen::Read(void *Data,size_t Size,size_t &Result)
{
if (!Loaded)
return false;
// Find next suitable cached block.
while (LastReadHeaderPos+LastReadHeader.Size()<=SeekPos)
if (!ReadNext())
break;
if (!Loaded)
{
// If something wrong happened, let's set the correct file pointer
// and stop further quick open processing.
if (UnsyncSeekPos)
Arc->File::Seek(SeekPos,SEEK_SET);
return false;
}
if (SeekPos>=LastReadHeaderPos && SeekPos+Size<=LastReadHeaderPos+LastReadHeader.Size())
{
memcpy(Data,LastReadHeader+size_t(SeekPos-LastReadHeaderPos),Size);
Result=Size;
SeekPos+=Size;
UnsyncSeekPos=true;
}
else
{
if (UnsyncSeekPos)
{
Arc->File::Seek(SeekPos,SEEK_SET);
UnsyncSeekPos=false;
}
int ReadSize=Arc->File::Read(Data,Size);
if (ReadSize<0)
{
Loaded=false;
return false;
}
Result=ReadSize;
SeekPos+=ReadSize;
}
return true;
}
bool QuickOpen::Seek(int64 Offset,int Method)
{
if (!Loaded)
return false;
// Normally we process an archive sequentially from beginning to end,
// so we read quick open data sequentially. But some operations like
// archive updating involve several passes. So if we detect that file
// pointer is moved back, we reload quick open data from beginning.
if (Method==SEEK_SET && (uint64)Offset<SeekPos && (uint64)Offset<LastReadHeaderPos)
Load(QOHeaderPos);
if (Method==SEEK_SET)
SeekPos=Offset;
if (Method==SEEK_CUR)
SeekPos+=Offset;
UnsyncSeekPos=true;
if (Method==SEEK_END)
{
Arc->File::Seek(Offset,SEEK_END);
SeekPos=Arc->File::Tell();
UnsyncSeekPos=false;
}
return true;
}
bool QuickOpen::Tell(int64 *Pos)
{
if (!Loaded)
return false;
*Pos=SeekPos;
return true;
}
uint QuickOpen::ReadBuffer()
{
SaveFilePos SavePos(*Arc);
Arc->File::Seek(RawDataStart+RawDataPos,SEEK_SET);
size_t SizeToRead=(size_t)Min(RawDataSize-RawDataPos,MaxBufSize-ReadBufSize);
if (Arc->SubHead.Encrypted)
SizeToRead &= ~CRYPT_BLOCK_MASK;
if (SizeToRead==0)
return 0;
int ReadSize=Arc->File::Read(Buf+ReadBufSize,SizeToRead);
if (ReadSize<=0)
return 0;
#ifndef RAR_NOCRYPT
if (Arc->SubHead.Encrypted)
Crypt.DecryptBlock(Buf+ReadBufSize,ReadSize & ~CRYPT_BLOCK_MASK);
#endif
RawDataPos+=ReadSize;
ReadBufSize+=ReadSize;
return ReadSize;
}
// Fill RawRead object from buffer.
bool QuickOpen::ReadRaw(RawRead &Raw)
{
if (MaxBufSize-ReadBufPos<0x100) // We are close to end of buffer.
{
// Ensure that we have enough data to read CRC and header size.
size_t DataLeft=ReadBufSize-ReadBufPos;
memcpy(Buf,Buf+ReadBufPos,DataLeft);
ReadBufPos=0;
ReadBufSize=DataLeft;
ReadBuffer();
}
const size_t FirstReadSize=7;
if (ReadBufPos+FirstReadSize>ReadBufSize)
return false;
Raw.Read(Buf+ReadBufPos,FirstReadSize);
ReadBufPos+=FirstReadSize;
uint SavedCRC=Raw.Get4();
uint SizeBytes=Raw.GetVSize(4);
uint64 BlockSize=Raw.GetV();
int SizeToRead=int(BlockSize);
SizeToRead-=FirstReadSize-SizeBytes-4; // Adjust overread size bytes if any.
if (SizeToRead<0 || SizeBytes==0 || BlockSize==0)
{
Loaded=false; // Invalid data.
return false;
}
// If rest of block data crosses Buf boundary, read it in loop.
while (SizeToRead>0)
{
size_t DataLeft=ReadBufSize-ReadBufPos;
size_t CurSizeToRead=Min(DataLeft,(size_t)SizeToRead);
Raw.Read(Buf+ReadBufPos,CurSizeToRead);
ReadBufPos+=CurSizeToRead;
SizeToRead-=int(CurSizeToRead);
if (SizeToRead>0) // We read the entire buffer and still need more data.
{
ReadBufPos=0;
ReadBufSize=0;
if (ReadBuffer()==0)
return false;
}
}
return SavedCRC==Raw.GetCRC50();
}
// Read next cached header.
bool QuickOpen::ReadNext()
{
RawRead Raw(NULL);
if (!ReadRaw(Raw)) // Read internal quick open header preceding stored block.
return false;
uint Flags=(uint)Raw.GetV();
uint64 Offset=Raw.GetV();
size_t HeaderSize=(size_t)Raw.GetV();
if (HeaderSize>MAX_HEADER_SIZE_RAR5)
return false;
LastReadHeader.Alloc(HeaderSize);
Raw.GetB(&LastReadHeader[0],HeaderSize);
// Calculate the absolute position as offset from quick open service header.
LastReadHeaderPos=QOHeaderPos-Offset;
return true;
}