src/utils/win/SkIStream.cpp

/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */


#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include <ole2.h>
#include "SkIStream.h"
#include "SkStream.h"

/**
 * SkBaseIStream
 */
SkBaseIStream::SkBaseIStream() : _refcount(1) { }
SkBaseIStream::~SkBaseIStream() { }

HRESULT STDMETHODCALLTYPE SkBaseIStream::QueryInterface(REFIID iid
                                                      , void ** ppvObject)
{
    if (NULL == ppvObject) {
        return E_INVALIDARG;
    }
    if (iid == __uuidof(IUnknown)
        || iid == __uuidof(IStream)
        || iid == __uuidof(ISequentialStream))
    {
        *ppvObject = static_cast<IStream*>(this);
        AddRef();
        return S_OK;
    } else {
        *ppvObject = NULL;
        return E_NOINTERFACE; 
    }
}

ULONG STDMETHODCALLTYPE SkBaseIStream::AddRef(void) {
    return (ULONG)InterlockedIncrement(&_refcount);
}

ULONG STDMETHODCALLTYPE SkBaseIStream::Release(void) {
    ULONG res = (ULONG) InterlockedDecrement(&_refcount);
    if (0 == res) {
        delete this;
    }
    return res;
}

// ISequentialStream Interface
HRESULT STDMETHODCALLTYPE SkBaseIStream::Read(void* pv
                                            , ULONG cb
                                            , ULONG* pcbRead)
{ return E_NOTIMPL; }

HRESULT STDMETHODCALLTYPE SkBaseIStream::Write(void const* pv
                                             , ULONG cb
                                             , ULONG* pcbWritten)
{ return E_NOTIMPL; }

// IStream Interface
HRESULT STDMETHODCALLTYPE SkBaseIStream::SetSize(ULARGE_INTEGER) 
{ return E_NOTIMPL; }

HRESULT STDMETHODCALLTYPE SkBaseIStream::CopyTo(IStream*
                                              , ULARGE_INTEGER
                                              , ULARGE_INTEGER*
                                              , ULARGE_INTEGER*)
{ return E_NOTIMPL; }

HRESULT STDMETHODCALLTYPE SkBaseIStream::Commit(DWORD)
{ return E_NOTIMPL; }

HRESULT STDMETHODCALLTYPE SkBaseIStream::Revert(void)
{ return E_NOTIMPL; }

HRESULT STDMETHODCALLTYPE SkBaseIStream::LockRegion(ULARGE_INTEGER
                                                  , ULARGE_INTEGER
                                                  , DWORD)
{ return E_NOTIMPL; }

HRESULT STDMETHODCALLTYPE SkBaseIStream::UnlockRegion(ULARGE_INTEGER
                                                    , ULARGE_INTEGER
                                                    , DWORD)
{ return E_NOTIMPL; }

HRESULT STDMETHODCALLTYPE SkBaseIStream::Clone(IStream **)
{ return E_NOTIMPL; }

HRESULT STDMETHODCALLTYPE SkBaseIStream::Seek(LARGE_INTEGER liDistanceToMove
                                            , DWORD dwOrigin
                                            , ULARGE_INTEGER* lpNewFilePointer)
{ return E_NOTIMPL; }

HRESULT STDMETHODCALLTYPE SkBaseIStream::Stat(STATSTG* pStatstg
                                            , DWORD grfStatFlag)
{ return E_NOTIMPL; }


/**
 * SkIStream
 */
SkIStream::SkIStream(SkStream* stream, bool unrefOnRelease)
    : SkBaseIStream()
    , fSkStream(stream)
    , fUnrefOnRelease(unrefOnRelease)
    , fLocation()
{
    this->fSkStream->rewind();
}

SkIStream::~SkIStream() {
    if (NULL != this->fSkStream && fUnrefOnRelease) {
        this->fSkStream->unref();
    }
}

HRESULT SkIStream::CreateFromSkStream(SkStream* stream
                                    , bool unrefOnRelease
                                    , IStream ** ppStream)
{
    *ppStream = new SkIStream(stream, unrefOnRelease);
    return S_OK;
}

// ISequentialStream Interface
HRESULT STDMETHODCALLTYPE SkIStream::Read(void* pv, ULONG cb, ULONG* pcbRead) {
    *pcbRead = this->fSkStream->read(pv, cb);
    this->fLocation.QuadPart += *pcbRead;
    return (*pcbRead == cb) ? S_OK : S_FALSE;
}

HRESULT STDMETHODCALLTYPE SkIStream::Write(void const* pv
                                         , ULONG cb
                                         , ULONG* pcbWritten)
{
    return STG_E_CANTSAVE;
}

// IStream Interface
HRESULT STDMETHODCALLTYPE SkIStream::Seek(LARGE_INTEGER liDistanceToMove
                                        , DWORD dwOrigin
                                        , ULARGE_INTEGER* lpNewFilePointer)
{
    HRESULT hr = S_OK;

    switch(dwOrigin) {
    case STREAM_SEEK_SET: {
        if (!this->fSkStream->rewind()) {
            hr = E_FAIL;
        } else {
            size_t skipped = this->fSkStream->skip(
                liDistanceToMove.QuadPart
            );
            this->fLocation.QuadPart = skipped;
            if (skipped != liDistanceToMove.QuadPart) {
                hr = E_FAIL;
            }
        }
        break;
    }
    case STREAM_SEEK_CUR: {
        size_t skipped = this->fSkStream->skip(liDistanceToMove.QuadPart);
        this->fLocation.QuadPart += skipped;
        if (skipped != liDistanceToMove.QuadPart) {
            hr = E_FAIL;
        }
        break;
    }
    case STREAM_SEEK_END: {
        if (!this->fSkStream->rewind()) {
            hr = E_FAIL;
        } else {
            LONGLONG skip = this->fSkStream->getLength()
                          + liDistanceToMove.QuadPart;
            size_t skipped = this->fSkStream->skip(skip);
            this->fLocation.QuadPart = skipped;
            if (skipped != skip) {
                hr = E_FAIL;
            }
        }
        break;
    }
    default:
        hr = STG_E_INVALIDFUNCTION;
        break;
    }
    
    if (NULL != lpNewFilePointer) {
        lpNewFilePointer->QuadPart = this->fLocation.QuadPart;
    }
    return hr;
}

HRESULT STDMETHODCALLTYPE SkIStream::Stat(STATSTG* pStatstg
                                        , DWORD grfStatFlag)
{
    if (0 == grfStatFlag & STATFLAG_NONAME) {
        return STG_E_INVALIDFLAG;
    }
    pStatstg->pwcsName = NULL;
    pStatstg->cbSize.QuadPart = this->fSkStream->getLength();
    pStatstg->clsid = CLSID_NULL;
    pStatstg->type = STGTY_STREAM;
    pStatstg->grfMode = STGM_READ;
    return S_OK;
}


/**
 * SkIWStream
 */
SkWIStream::SkWIStream(SkWStream* stream)
    : SkBaseIStream()
    , fSkWStream(stream)
{ }

SkWIStream::~SkWIStream() {
    if (NULL != this->fSkWStream) {
        this->fSkWStream->flush();
    }
}

HRESULT SkWIStream::CreateFromSkWStream(SkWStream* stream
                                      , IStream ** ppStream)
{
    *ppStream = new SkWIStream(stream);
    return S_OK;
}

// ISequentialStream Interface
HRESULT STDMETHODCALLTYPE SkWIStream::Write(void const* pv
                                          , ULONG cb
                                          , ULONG* pcbWritten)
{
    HRESULT hr = S_OK;
    bool wrote = this->fSkWStream->write(pv, cb);
    if (wrote) {
        *pcbWritten = cb;
    } else {
        *pcbWritten = 0;
        hr = S_FALSE;
    }
    return hr;
}

// IStream Interface
HRESULT STDMETHODCALLTYPE SkWIStream::Commit(DWORD) {
    this->fSkWStream->flush();
    return S_OK;
}

HRESULT STDMETHODCALLTYPE SkWIStream::Stat(STATSTG* pStatstg
                                         , DWORD grfStatFlag)
{
    if (0 == grfStatFlag & STATFLAG_NONAME) {
        return STG_E_INVALIDFLAG;
    }
    pStatstg->pwcsName = NULL;
    pStatstg->cbSize.QuadPart = 0;
    pStatstg->clsid = CLSID_NULL;
    pStatstg->type = STGTY_STREAM;
    pStatstg->grfMode = STGM_WRITE;
    return S_OK;
}