loadcodecs.cpp

一个7ZIP的解压源码。比较详细。里面含有四种语言的实现代码。

// LoadCodecs.cpp

#include "StdAfx.h"

#include "LoadCodecs.h"

#include "../../../Common/MyCom.h"
#ifdef NEW_FOLDER_INTERFACE
#include "../../../Common/StringToInt.h"
#endif
#include "../../../Windows/PropVariant.h"

#include "../../ICoder.h"
#include "../../Common/RegisterArc.h"

#ifdef EXTERNAL_CODECS
#include "../../../Windows/FileFind.h"
#include "../../../Windows/DLL.h"
#ifdef NEW_FOLDER_INTERFACE
#include "../../../Windows/ResourceString.h"
static const UINT kIconTypesResId = 100;
#endif

#ifdef _WIN32
#include "Windows/Registry.h"
#endif

using namespace NWindows;
using namespace NFile;

#ifdef _WIN32
extern HINSTANCE g_hInstance;
#endif

static CSysString GetLibraryFolderPrefix()
{
  #ifdef _WIN32
  TCHAR fullPath[MAX_PATH + 1];
  ::GetModuleFileName(g_hInstance, fullPath, MAX_PATH);
  CSysString path = fullPath;
  int pos = path.ReverseFind(TEXT(CHAR_PATH_SEPARATOR));
  return path.Left(pos + 1);
  #else
  return CSysString(); // FIX IT
  #endif
}

#define kCodecsFolderName TEXT("Codecs")
#define kFormatsFolderName TEXT("Formats")
static TCHAR *kMainDll = TEXT("7z.dll");

#ifdef _WIN32
static LPCTSTR kRegistryPath = TEXT("Software\\7-zip");
static LPCTSTR kProgramPathValue = TEXT("Path");
static bool ReadPathFromRegistry(HKEY baseKey, CSysString &path)
{
  NRegistry::CKey key;
  if(key.Open(baseKey, kRegistryPath, KEY_READ) == ERROR_SUCCESS)
    if (key.QueryValue(kProgramPathValue, path) == ERROR_SUCCESS)
    {
      NName::NormalizeDirPathPrefix(path);
      return true;
    }
  return false;
}

#endif

CSysString GetBaseFolderPrefixFromRegistry()
{
  CSysString moduleFolderPrefix = GetLibraryFolderPrefix();
  NFind::CFileInfo fileInfo;
  if (NFind::FindFile(moduleFolderPrefix + kMainDll, fileInfo))
    if (!fileInfo.IsDirectory())
      return moduleFolderPrefix;
  if (NFind::FindFile(moduleFolderPrefix + kCodecsFolderName, fileInfo))
    if (fileInfo.IsDirectory())
      return moduleFolderPrefix;
  if (NFind::FindFile(moduleFolderPrefix + kFormatsFolderName, fileInfo))
    if (fileInfo.IsDirectory())
      return moduleFolderPrefix;
  #ifdef _WIN32
  CSysString path;
  if (ReadPathFromRegistry(HKEY_CURRENT_USER, path))
    return path;
  if (ReadPathFromRegistry(HKEY_LOCAL_MACHINE, path))
    return path;
  #endif
  return moduleFolderPrefix;
}

typedef UInt32 (WINAPI *GetNumberOfMethodsFunc)(UInt32 *numMethods);
typedef UInt32 (WINAPI *GetNumberOfFormatsFunc)(UInt32 *numFormats);
typedef UInt32 (WINAPI *GetHandlerPropertyFunc)(PROPID propID, PROPVARIANT *value);
typedef UInt32 (WINAPI *GetHandlerPropertyFunc2)(UInt32 index, PROPID propID, PROPVARIANT *value);
typedef UInt32 (WINAPI *CreateObjectFunc)(const GUID *clsID, const GUID *iid, void **outObject);
typedef UInt32 (WINAPI *SetLargePageModeFunc)();


static HRESULT GetCoderClass(GetMethodPropertyFunc getMethodProperty, UInt32 index, 
    PROPID propId, CLSID &clsId, bool &isAssigned)
{
  NWindows::NCOM::CPropVariant prop;
  isAssigned = false;
  RINOK(getMethodProperty(index, propId, &prop));
  if (prop.vt == VT_BSTR)
  {
    isAssigned = true;
    clsId = *(const GUID *)prop.bstrVal;
  }
  else if (prop.vt != VT_EMPTY)
    return E_FAIL;
  return S_OK;
}

HRESULT CCodecs::LoadCodecs()
{
  CCodecLib &lib = Libs.Back();
  lib.GetMethodProperty = (GetMethodPropertyFunc)lib.Lib.GetProcAddress("GetMethodProperty");
  if (lib.GetMethodProperty == NULL)
    return S_OK;

  UInt32 numMethods = 1;
  GetNumberOfMethodsFunc getNumberOfMethodsFunc = (GetNumberOfMethodsFunc)lib.Lib.GetProcAddress("GetNumberOfMethods");
  if (getNumberOfMethodsFunc != NULL)
  {
    RINOK(getNumberOfMethodsFunc(&numMethods));
  }

  for(UInt32 i = 0; i < numMethods; i++)
  {
    CDllCodecInfo info;
    info.LibIndex = Libs.Size() - 1;
    info.CodecIndex = i;

    RINOK(GetCoderClass(lib.GetMethodProperty, i, NMethodPropID::kEncoder, info.Encoder, info.EncoderIsAssigned));
    RINOK(GetCoderClass(lib.GetMethodProperty, i, NMethodPropID::kDecoder, info.Decoder, info.DecoderIsAssigned));

    Codecs.Add(info);
  }
  return S_OK;
}

static HRESULT ReadProp(
    GetHandlerPropertyFunc getProp, 
    GetHandlerPropertyFunc2 getProp2, 
    UInt32 index, PROPID propID, NCOM::CPropVariant &prop)
{
  if (getProp2)
    return getProp2(index, propID, &prop);;
  return getProp(propID, &prop);
}

static HRESULT ReadBoolProp(
    GetHandlerPropertyFunc getProp, 
    GetHandlerPropertyFunc2 getProp2, 
    UInt32 index, PROPID propID, bool &res)
{
  NCOM::CPropVariant prop;
  RINOK(ReadProp(getProp, getProp2, index, propID, prop));
  if (prop.vt == VT_BOOL)
    res = VARIANT_BOOLToBool(prop.boolVal);
  else if (prop.vt != VT_EMPTY)
    return E_FAIL;
  return S_OK;
}

static HRESULT ReadStringProp(
    GetHandlerPropertyFunc getProp, 
    GetHandlerPropertyFunc2 getProp2, 
    UInt32 index, PROPID propID, UString &res)
{
  NCOM::CPropVariant prop;
  RINOK(ReadProp(getProp, getProp2, index, propID, prop));
  if (prop.vt == VT_BSTR)
    res = prop.bstrVal;
  else if (prop.vt != VT_EMPTY)
    return E_FAIL;
  return S_OK;
}

#endif

static const unsigned int kNumArcsMax = 32;
static unsigned int g_NumArcs = 0;
static const CArcInfo *g_Arcs[kNumArcsMax]; 
void RegisterArc(const CArcInfo *arcInfo) 
{ 
  if (g_NumArcs < kNumArcsMax)
    g_Arcs[g_NumArcs++] = arcInfo; 
}

static void SplitString(const UString &srcString, UStringVector &destStrings)
{
  destStrings.Clear();
  UString s;
  int len = srcString.Length();
  if (len == 0)
    return;
  for (int i = 0; i < len; i++)
  {
    wchar_t c = srcString[i];
    if (c == L' ')
    {
      if (!s.IsEmpty())
      {
        destStrings.Add(s);
        s.Empty();
      }
    }
    else
      s += c;
  }
  if (!s.IsEmpty())
    destStrings.Add(s);
}

void CArcInfoEx::AddExts(const wchar_t* ext, const wchar_t* addExt)
{
  UStringVector exts, addExts;
  SplitString(ext, exts);
  if (addExt != 0)
    SplitString(addExt, addExts);
  for (int i = 0; i < exts.Size(); i++)
  {
    CArcExtInfo extInfo;
    extInfo.Ext = exts[i];
    if (i < addExts.Size())
    {
      extInfo.AddExt = addExts[i];
      if (extInfo.AddExt == L"*")
        extInfo.AddExt.Empty();
    }
    Exts.Add(extInfo);
  }
}

#ifdef EXTERNAL_CODECS

HRESULT CCodecs::LoadFormats()
{
  const NDLL::CLibrary &lib = Libs.Back().Lib;
  GetHandlerPropertyFunc getProp = 0;
  GetHandlerPropertyFunc2 getProp2 = (GetHandlerPropertyFunc2)
      lib.GetProcAddress("GetHandlerProperty2");
  if (getProp2 == NULL)
  {
    getProp = (GetHandlerPropertyFunc)
        lib.GetProcAddress("GetHandlerProperty");
    if (getProp == NULL)
      return S_OK;
  }

  UInt32 numFormats = 1;
  GetNumberOfFormatsFunc getNumberOfFormats = (GetNumberOfFormatsFunc)
    lib.GetProcAddress("GetNumberOfFormats");
  if (getNumberOfFormats != NULL)
  {
    RINOK(getNumberOfFormats(&numFormats));
  }
  if (getProp2 == NULL)
    numFormats = 1;

  for(UInt32 i = 0; i < numFormats; i++)
  {
    CArcInfoEx item;
    item.LibIndex = Libs.Size() - 1;
    item.FormatIndex = i;

    RINOK(ReadStringProp(getProp, getProp2, i, NArchive::kName, item.Name));

    NCOM::CPropVariant prop;
    if (ReadProp(getProp, getProp2, i, NArchive::kClassID, prop) != S_OK)
      continue;
    if (prop.vt != VT_BSTR)
      continue;
    item.ClassID = *(const GUID *)prop.bstrVal;
    prop.Clear();

    UString ext, addExt;
    RINOK(ReadStringProp(getProp, getProp2, i, NArchive::kExtension, ext));
    RINOK(ReadStringProp(getProp, getProp2, i, NArchive::kAddExtension, addExt));
    item.AddExts(ext, addExt);

    ReadBoolProp(getProp, getProp2, i, NArchive::kUpdate, item.UpdateEnabled);
    if (item.UpdateEnabled)
      ReadBoolProp(getProp, getProp2, i, NArchive::kKeepName, item.KeepName);
    
    if (ReadProp(getProp, getProp2, i, NArchive::kStartSignature, prop) == S_OK)
      if (prop.vt == VT_BSTR)
      {
        UINT len = ::SysStringByteLen(prop.bstrVal);
        item.StartSignature.SetCapacity(len);
        memmove(item.StartSignature, prop.bstrVal, len);
      }
    Formats.Add(item);
  }
  return S_OK;
}

#ifdef NEW_FOLDER_INTERFACE
void CCodecLib::LoadIcons()
{
  UString iconTypes = MyLoadStringW((HMODULE)Lib, kIconTypesResId);
  UStringVector pairs;
  SplitString(iconTypes, pairs);
  for (int i = 0; i < pairs.Size(); i++)
  {
    const UString &s = pairs[i];
    int pos = s.Find(L':');
    if (pos < 0)
      continue;
    CIconPair iconPair;
    const wchar_t *end;
    UString num = s.Mid(pos + 1);
    iconPair.IconIndex = (UInt32)ConvertStringToUInt64(num, &end);
    if (*end != L'\0')
      continue;
    iconPair.Ext = s.Left(pos);
    IconPairs.Add(iconPair);
  }
}