physdrivefolder.cpp

7z一个高压缩比的压缩程序源代码,重要的是里面的算法值得学习

// PhysDriveFolder.cpp

#include "StdAfx.h"

extern "C"
{
  #include "../../../../C/Alloc.h"
}

#include "PhysDriveFolder.h"
#include "Windows/PropVariant.h"
#include "Windows/FileDevice.h"
#include "Windows/FileSystem.h"

#include "../../PropID.h"

using namespace NWindows;

static const UInt32 kBufferSize = (4 << 20);

static STATPROPSTG kProperties[] =
{
  { NULL, kpidName, VT_BSTR},
  { NULL, kpidSize, VT_UI8}
};

HRESULT CPhysDriveFolder::Init(const UString &path)
{
  _prefix = L"\\\\.\\";
  _path = path;
  NFile::NDevice::CInFile inFile;
  if (!inFile.Open(GetFullPath()))
    return GetLastError();
  return S_OK;
}

STDMETHODIMP CPhysDriveFolder::LoadItems()
{
  _driveType = NFile::NSystem::MyGetDriveType(_path + L"\\");
  _name = _path.Left(1);
  _name += L'.';
  if (_driveType == DRIVE_CDROM)
    _name += L"iso";
  else
    _name += L"img";
  Int32 dummy;
  WasChanged(&dummy);
  return GetLength(_length);
}

STDMETHODIMP CPhysDriveFolder::GetNumberOfItems(UInt32 *numItems)
{
  *numItems = 1;
  return S_OK;
}

STDMETHODIMP CPhysDriveFolder::GetProperty(UInt32 itemIndex, PROPID propID, PROPVARIANT *value)
{
  NCOM::CPropVariant prop;
  if (itemIndex >= 1)
    return E_INVALIDARG;
  switch(propID)
  {
    case kpidIsDir:  prop = false; break;
    case kpidName:  prop = _name; break;
    case kpidSize:  prop = _length; break;
  }
  prop.Detach(value);
  return S_OK;
}

STDMETHODIMP CPhysDriveFolder::BindToFolder(UInt32 /* index */, IFolderFolder ** /* resultFolder */)
  { return E_NOTIMPL; }

STDMETHODIMP CPhysDriveFolder::BindToFolder(const wchar_t * /* name */, IFolderFolder ** /* resultFolder */)
  { return E_NOTIMPL; }

STDMETHODIMP CPhysDriveFolder::BindToParentFolder(IFolderFolder **resultFolder)
{
  *resultFolder = 0;
  return S_OK;
}

STDMETHODIMP CPhysDriveFolder::GetNumberOfProperties(UInt32 *numProperties)
{
  *numProperties = sizeof(kProperties) / sizeof(kProperties[0]);
  return S_OK;
}

STDMETHODIMP CPhysDriveFolder::GetPropertyInfo(UInt32 index,
    BSTR *name, PROPID *propID, VARTYPE *varType)
{
  if (index >= sizeof(kProperties) / sizeof(kProperties[0]))
    return E_INVALIDARG;
  const STATPROPSTG &prop = kProperties[index];
  *propID = prop.propid;
  *varType = prop.vt;
  *name = 0;
  return S_OK;
}


STDMETHODIMP CPhysDriveFolder::GetFolderProperty(PROPID propID, PROPVARIANT *value)
{
  NWindows::NCOM::CPropVariant prop;
  switch(propID)
  {
    case kpidType: prop = L"PhysDrive"; break;
    case kpidPath: prop = (GetFullPath() + L"\\"); break;
  }
  prop.Detach(value);
  return S_OK;
}

STDMETHODIMP CPhysDriveFolder::WasChanged(Int32 *wasChanged)
{
  bool wasChangedMain = false;
  *wasChanged = BoolToInt(wasChangedMain);
  return S_OK;
}
 
STDMETHODIMP CPhysDriveFolder::Clone(IFolderFolder **resultFolder)
{
  CPhysDriveFolder *folderSpec = new CPhysDriveFolder;
  CMyComPtr<IFolderFolder> folderNew = folderSpec;
  folderSpec->Init(_path);
  *resultFolder = folderNew.Detach();
  return S_OK;
}

STDMETHODIMP CPhysDriveFolder::GetItemFullSize(UInt32 index, PROPVARIANT *value, IProgress * /* progress */)
{
  NCOM::CPropVariant prop;
  if (index >= 1)
    return E_INVALIDARG;
  UInt64 size = 0;
  HRESULT result = GetLength(size);
  prop = size;
  prop.Detach(value);
  return result;
}

STDMETHODIMP CPhysDriveFolder::CreateFolder(const wchar_t * /* name */, IProgress * /* progress */)
  { return E_NOTIMPL; }

STDMETHODIMP CPhysDriveFolder::CreateFile(const wchar_t * /* name */, IProgress * /* progress */)
  { return E_NOTIMPL; }

STDMETHODIMP CPhysDriveFolder::Rename(UInt32 /* index */, const wchar_t * /* newName */, IProgress * /* progress */)
  { return E_NOTIMPL; }

STDMETHODIMP CPhysDriveFolder::Delete(const UInt32 * /* indices */, UInt32  /* numItems */, IProgress * /* progress */)
  { return E_NOTIMPL; }

STDMETHODIMP CPhysDriveFolder::SetProperty(UInt32 index, PROPID /* propID */,
    const PROPVARIANT * /* value */, IProgress * /* progress */)
{
  if (index >= 1)
    return E_INVALIDARG;
  return E_NOTIMPL;
}

HRESULT CPhysDriveFolder::GetLength(UInt64 &length) const
{
  NFile::NDevice::CInFile inFile;
  if (!inFile.Open(GetFullPath()))
    return GetLastError();
  if (!inFile.GetLengthSmart(length))
    return GetLastError();
  return S_OK;
}

struct CPhysTempBuffer
{
  void *buffer;
  CPhysTempBuffer(): buffer(0) {}
  ~CPhysTempBuffer() { MyFree(buffer); }
};

HRESULT CopyFileSpec(LPCWSTR fromPath, LPCWSTR toPath, bool writeToDisk, UInt64 fileSize, UInt32 bufferSize, IProgress *progress)
{
  NFile::NIO::CInFile inFile;
  if (!inFile.Open(fromPath))
    return GetLastError();
  if (fileSize == (UInt64)(Int64)-1)
  {
    if (!inFile.GetLength(fileSize))
      ::GetLastError();
  }
  NFile::NIO::COutFile outFile;
  if (writeToDisk)
  {
    if (!outFile.Open(toPath, FILE_SHARE_WRITE, OPEN_EXISTING, 0))
      return GetLastError();
  }
  else
    if (!outFile.Create(toPath, true))
      return GetLastError();
  CPhysTempBuffer tempBuffer;
  tempBuffer.buffer = MyAlloc(bufferSize);
  if (tempBuffer.buffer == 0)
    return E_OUTOFMEMORY;
 
  for (UInt64 pos = 0; pos < fileSize;)
  {
    RINOK(progress->SetCompleted(&pos));
    UInt64 rem = fileSize - pos;
    UInt32 curSize = (UInt32)MyMin(rem, (UInt64)bufferSize);
    UInt32 processedSize;
    if (!inFile.Read(tempBuffer.buffer, curSize, processedSize))
      return GetLastError();
    if (processedSize == 0)
      break;
    curSize = processedSize;
    if (writeToDisk)
    {
      const UInt32 kMask = 0x1FF;
      curSize = (curSize + kMask) & ~kMask;
      if (curSize > bufferSize)
        return E_FAIL;
    }

    if (!outFile.Write(tempBuffer.buffer, curSize, processedSize))
      return GetLastError();
    if (curSize != processedSize)
      return E_FAIL;
    pos += curSize;
  }
  return S_OK;
}

STDMETHODIMP CPhysDriveFolder::CopyTo(const UInt32 * /* indices */, UInt32 numItems,
    const wchar_t *path, IFolderOperationsExtractCallback *callback)
{
  if (numItems == 0)
    return S_OK;
  UString destPath = path;
  if (destPath.IsEmpty())
    return E_INVALIDARG;
  bool directName = (destPath[destPath.Length() - 1] != WCHAR_PATH_SEPARATOR);
  if (directName)
  {
    if (numItems > 1)
      return E_INVALIDARG;
  }
  else
    destPath += _name;

  UInt64 fileSize;
  if (GetLength(fileSize) == S_OK)
  {
    RINOK(callback->SetTotal(fileSize));
  }

  Int32 writeAskResult;
  CMyComBSTR destPathResult;
  RINOK(callback->AskWrite(GetFullPath(), BoolToInt(false), NULL, &fileSize,
      destPath, &destPathResult, &writeAskResult));
  if (!IntToBool(writeAskResult))
    return S_OK;

  RINOK(callback->SetCurrentFilePath(GetFullPathWithName()));

  UInt32 bufferSize = (_driveType == DRIVE_REMOVABLE) ? (18 << 10) * 4 : kBufferSize;
  return CopyFileSpec(GetFullPath(), destPathResult, false, fileSize, bufferSize, callback);
}

/////////////////////////////////////////////////
// Move Operations

STDMETHODIMP CPhysDriveFolder::MoveTo(
    const UInt32 * /* indices */,
    UInt32 /* numItems */,
    const wchar_t * /* path */,
    IFolderOperationsExtractCallback * /* callback */)
{
  return E_NOTIMPL;
}

STDMETHODIMP CPhysDriveFolder::CopyFrom(
    const wchar_t * fromFolderPath,
    const wchar_t ** itemsPaths, UInt32 numItems, IProgress *callback)
{
  if (numItems == 0)
    return S_OK;
  if (numItems != 1)
    return E_INVALIDARG;
  if (_driveType != DRIVE_REMOVABLE /* && _driveType != DRIVE_CDROM */)
    return E_NOTIMPL;
  UInt32 bufferSize = (_driveType == DRIVE_REMOVABLE) ? (18 << 10) * 4 : kBufferSize;
  // MessageBoxW(0, fromFolderPath, itemsPaths[0], 0);
  return CopyFileSpec((UString)fromFolderPath + itemsPaths[0], GetFullPath(), true, (UInt64)(Int64)-1, bufferSize, callback);
}