/**
* This method is called when we receive a WPD_COMMAND_OBJECT_RESOURCES_READ
* command.
*
* The parameters sent to us are:
* - WPD_PROPERTY_OBJECT_RESOURCES_CONTEXT: the context the driver returned to
* the client in OnOpenResource.
* - WPD_PROPERTY_OBJECT_RESOURCES_NUM_BYTES_TO_READ: the number of bytes to
* read from the resource.
*
* The driver should:
* - Read data associated with the resource and return it back to the caller in
* WPD_PROPERTY_OBJECT_RESOURCES_DATA.
* - Report the number of bytes actually read from the resource in
* WPD_PROPERTY_OBJECT_RESOURCES_NUM_BYTES_READ. This number may be smaller
* than WPD_PROPERTY_OBJECT_RESOURCES_NUM_BYTES_TO_READ when reading the last
* chunk of data from the resource.
*/
HRESULT WpdObjectResources::OnReadResource(
_In_ IPortableDeviceValues* pParams,
_In_ IPortableDeviceValues* pResults)
{
HRESULT hr = S_OK;
LPWSTR wszResourceContext = NULL;
DWORD dwNumBytesToRead = 0;
DWORD dwNumBytesRead = 0;
BYTE* pBuffer = NULL;
DWORD cbBuffer = 0;
WpdObjectResourceContext* pResourceContext = NULL;
ContextMap* pContextMap = NULL;
// Get the enumeration context identifier for this enumeration operation. We will
// need this to lookup the specific enumeration context in the client context map.
hr = pParams->GetStringValue(WPD_PROPERTY_OBJECT_RESOURCES_CONTEXT, &wszResourceContext);
if (hr != S_OK)
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing value for WPD_PROPERTY_OBJECT_RESOURCES_CONTEXT");
}
// Get the number of bytes to read
if (hr == S_OK)
{
hr = pParams->GetUnsignedIntegerValue(WPD_PROPERTY_OBJECT_RESOURCES_NUM_BYTES_TO_READ, &dwNumBytesToRead);
CHECK_HR(hr, "Missing value for WPD_PROPERTY_OBJECT_RESOURCES_NUM_BYTES_TO_READ");
}
// Get the destination buffer
if (hr == S_OK)
{
hr = pParams->GetBufferValue(WPD_PROPERTY_OBJECT_RESOURCES_DATA, &pBuffer, &cbBuffer);
CHECK_HR(hr, "Missing value for WPD_PROPERTY_OBJECT_RESOURCES_DATA");
}
// Get the client context map so we can retrieve the resource context for this resource
// operation using the WPD_PROPERTY_OBJECT_RESOURCES_CONTEXT property value obtained above.
if (hr == S_OK)
{
hr = pParams->GetIUnknownValue(PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP, (IUnknown**)&pContextMap);
CHECK_HR(hr, "Failed to get PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP");
}
if (hr == S_OK)
{
pResourceContext = (WpdObjectResourceContext*)pContextMap->GetContext(wszResourceContext);
if (pResourceContext == NULL)
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing resource context");
}
}
// Read the next chunk of data for this request
if (hr == S_OK && pBuffer != NULL)
{
hr = ReadDataFromResource(pResourceContext, pBuffer, dwNumBytesToRead, &dwNumBytesRead);
CHECK_HR(hr, "Failed to read %d bytes from resource", dwNumBytesToRead);
}
if (hr == S_OK && pBuffer != NULL)
{
hr = pResults->SetBufferValue(WPD_PROPERTY_OBJECT_RESOURCES_DATA, pBuffer, dwNumBytesRead);
CHECK_HR(hr, "Failed to set WPD_PROPERTY_OBJECT_RESOURCES_DATA");
}
if (hr == S_OK)
{
hr = pResults->SetUnsignedIntegerValue(WPD_PROPERTY_OBJECT_RESOURCES_NUM_BYTES_READ, dwNumBytesRead);
CHECK_HR(hr, "Failed to set WPD_PROPERTY_OBJECT_RESOURCES_NUM_BYTES_READ");
}
// Free the memory. CoTaskMemFree ignores NULLs so no need to check.
CoTaskMemFree(wszResourceContext);
// Free the memory. CoTaskMemFree ignores NULLs so no need to check.
CoTaskMemFree(pBuffer);
SAFE_RELEASE(pContextMap);
return hr;
}
HRESULT WpdObjectEnumerator::OnFindNext(IPortableDeviceValues* pParams,
IPortableDeviceValues* pResults)
{
HRESULT hr = S_OK;
LPWSTR wszEnumContext = NULL;
DWORD dwNumObjectsRequested = 0;
ContextMap* pContextMap = NULL;
WpdObjectEnumeratorContext* pEnumeratorContext = NULL;
DWORD NumObjectsEnumerated = 0;
CComPtr<IPortableDevicePropVariantCollection> pObjectIDCollection;
// First get ALL parameters for this command. If we cannot get ALL parameters
// then E_INVALIDARG should be returned and no further processing should occur.
// Get the enumeration context identifier for this enumeration operation.
// The enumeration context identifier is needed to lookup the specific
// enumeration context in the client context map for this enumeration operation.
// NOTE that more than one enumeration may be in progress.
hr = pParams->GetStringValue(WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT, &wszEnumContext);
if (hr != S_OK)
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing value for WPD_PROPERTY_OBJECT_ENUMERATION_CONTEXT");
}
// Get the number of objects requested for this enumeration call.
// The driver should always attempt to meet this requested value.
// If there are fewer children than requested, the driver should return the remaining
// children and a return code of S_FALSE.
hr = pParams->GetUnsignedIntegerValue(WPD_PROPERTY_OBJECT_ENUMERATION_NUM_OBJECTS_REQUESTED, &dwNumObjectsRequested);
if (hr != S_OK)
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing value for WPD_PROPERTY_OBJECT_ENUMERATION_NUM_OBJECTS_REQUESTED");
}
// Get the client context map so we can retrieve the enumeration context for this enumeration
// operation.
if (hr == S_OK)
{
hr = pParams->GetIUnknownValue(PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP, (IUnknown**)&pContextMap);
CHECK_HR(hr, "Failed to get PRIVATE_SAMPLE_DRIVER_CLIENT_CONTEXT_MAP");
}
if (hr == S_OK)
{
pEnumeratorContext = (WpdObjectEnumeratorContext*)pContextMap->GetContext(wszEnumContext);
if (pEnumeratorContext == NULL)
{
hr = E_INVALIDARG;
CHECK_HR(hr, "Missing enumeration context");
}
}
// CoCreate a collection to store the object identifiers being returned for this enumeration call.
if (hr == S_OK)
{
hr = CoCreateInstance(CLSID_PortableDevicePropVariantCollection,
NULL,
CLSCTX_INPROC_SERVER,
IID_IPortableDevicePropVariantCollection,
(VOID**) &pObjectIDCollection);
CHECK_HR(hr, "Failed to CoCreate CLSID_PortableDevicePropVariantCollection");
}
// If the enumeration context reports that their are more objects to return, then continue, if not,
// return an empty results set.
if ((hr == S_OK) && (pEnumeratorContext != NULL) && (pEnumeratorContext->HasMoreChildrenToEnumerate() == TRUE))
{
if (pEnumeratorContext->m_strParentObjectID.CompareNoCase(L"") == 0)
{
// We are being asked for the WPD_DEVICE_OBJECT_ID
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, WPD_DEVICE_OBJECT_ID);
CHECK_HR(hr, "Failed to add 'DEVICE' object ID to enumeration collection");
// Update the the number of children we are returning for this enumeration call
NumObjectsEnumerated++;
}
else if (pEnumeratorContext->m_strParentObjectID.CompareNoCase(WPD_DEVICE_OBJECT_ID) == 0)
{
// We are being asked for direct children of the WPD_DEVICE_OBJECT_ID
switch (m_pBaseDriver->m_SensorType)
{
case WpdBaseDriver::UNKNOWN:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::COMPASS:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, COMPASS_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::SENSIRON:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, TEMP_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::FLEX:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, FLEX_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::PING:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, PING_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::PIR:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, PIR_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::MEMSIC:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, MEMSIC_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::QTI:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, QTI_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::PIEZO:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, PIEZO_SENSOR_OBJECT_ID);
break;
case WpdBaseDriver::HITACHI:
hr = AddStringValueToPropVariantCollection(pObjectIDCollection, HITACHI_SENSOR_OBJECT_ID);
break;
default:
break;
}
CHECK_HR(hr, "Failed to add storage object ID to enumeration collection");
// Update the the number of children we are returning for this enumeration call
NumObjectsEnumerated++;
}
}
// Set the collection of object identifiers enumerated in the results
if (hr == S_OK)
{
hr = pResults->SetIPortableDevicePropVariantCollectionValue(WPD_PROPERTY_OBJECT_ENUMERATION_OBJECT_IDS, pObjectIDCollection);
CHECK_HR(hr, "Failed to set WPD_PROPERTY_OBJECT_ENUMERATION_OBJECT_IDS");
}
// If the enumeration context reports that their are no more objects to return then return S_FALSE indicating to the
// caller that we are finished.
if (hr == S_OK)
{
if (pEnumeratorContext != NULL)
{
// Update the number of children we have enumerated and returned to the caller
pEnumeratorContext->m_ChildrenEnumerated += NumObjectsEnumerated;
// Check the number requested against the number enumerated and set the HRESULT
// accordingly.
if (NumObjectsEnumerated < dwNumObjectsRequested)
{
// We returned less than the number of objects requested to the caller
hr = S_FALSE;
}
else
{
// We returned exactly the number of objects requested to the caller
hr = S_OK;
}
}
}
// Free the memory.
CoTaskMemFree(wszEnumContext);
wszEnumContext = NULL;
SAFE_RELEASE(pContextMap);
return hr;
}