comrogue-pi/kernel/lib/objhelp_enumgeneric.c

223 lines
7.1 KiB
C

/*
* This file is part of the COMROGUE Operating System for Raspberry Pi
*
* Copyright (c) 2013, Eric J. Bowersox / Erbosoft Enterprises
* All rights reserved.
*
* This program is free for commercial and non-commercial use as long as the following conditions are
* adhered to.
*
* Copyright in this file remains Eric J. Bowersox and/or Erbosoft, and as such any copyright notices
* in the code are not to be removed.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted
* provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this list of conditions and
* the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and
* the following disclaimer in the documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* "Raspberry Pi" is a trademark of the Raspberry Pi Foundation.
*/
#include <comrogue/types.h>
#include <comrogue/intlib.h>
#include <comrogue/str.h>
#include <comrogue/objectbase.h>
#include <comrogue/allocator.h>
#include <comrogue/objhelp.h>
#include <comrogue/stdobj.h>
#include "enumgeneric.h"
/*---------------------------------------
* IEnumUnknown interface implementation
*---------------------------------------
*/
static HRESULT enumGeneric_QueryInterface(IUnknown *pThis, REFIID riid, PPVOID ppvObject)
{
PENUMGENERIC peg = (PENUMGENERIC)pThis;
if (!ppvObject)
return E_POINTER;
if (IsEqualIID(riid, &IID_IUnknown) || IsEqualIID(riid, peg->riidActual))
{
*ppvObject = pThis;
IUnknown_AddRef((PUNKNOWN)(*ppvObject));
return S_OK;
}
*ppvObject = NULL;
return E_NOINTERFACE;
}
static UINT32 enumGeneric_AddRef(IUnknown *pThis)
{
return ++(((PENUMGENERIC)pThis)->uiRefCount);
}
static UINT32 enumGeneric_Release(IUnknown *pThis)
{
register PENUMGENERIC peg = (PENUMGENERIC)pThis; /* pointer to actual data block */
register UINT32 rc; /* return from this function */
IMalloc *pAllocator; /* temporary for allocator */
PENUMGENERICDATA pegd; /* temporary for underlying objects data block */
rc = --(peg->uiRefCount);
if (rc == 0)
{ /* save off allocator before deallocating */
pAllocator = peg->pAllocator;
IUnknown_AddRef(pAllocator);
/* save off payload too */
pegd = peg->pPayload;
/* erase enumerator */
IUnknown_Release(peg->pAllocator);
IMalloc_Free(pAllocator, peg);
if (--(pegd->uiRefCount) == 0)
{ /* we need to erase the data block too */
_ObjHlpDiscardEnumGenericData(pegd);
IMalloc_Free(pAllocator, pegd);
}
IUnknown_Release(pAllocator); /* release temporary reference we added */
}
return rc;
}
static HRESULT enumGeneric_Next(IEnumUnknown *pThis, UINT32 celt, IUnknown **rgelt, UINT32 *pceltFetched)
{
register PENUMGENERIC peg = (PENUMGENERIC)pThis; /* pointer to data block */
register UINT32 i; /* loop counter */
if (celt == 0)
{ /* nothing to retrieve */
if (pceltFetched)
*pceltFetched = 0;
return S_OK;
}
if (!pceltFetched)
return E_POINTER; /* invalid pointer */
/* get number of items to fetch */
*pceltFetched = intMin(peg->pPayload->nObjects - peg->nCurrent, celt);
for (i = 0; i < *pceltFetched; i++)
{ /* fetch the items */
rgelt[i] = peg->pPayload->rgObjects[i + peg->nCurrent];
IUnknown_AddRef(rgelt[i]);
}
peg->nCurrent += *pceltFetched; /* advance pointer */
return (*pceltFetched == celt) ? S_OK : S_FALSE;
}
static HRESULT enumGeneric_Skip(IEnumUnknown *pThis, UINT32 celt)
{
register PENUMGENERIC peg = (PENUMGENERIC)pThis; /* pointer to data block */
register HRESULT rc = S_OK; /* return from this function */
peg->nCurrent += celt;
if (peg->nCurrent > peg->pPayload->nObjects)
{ /* clamp current pointer and return FALSE */
peg->nCurrent = peg->pPayload->nObjects;
rc = S_FALSE;
}
return rc;
}
static HRESULT enumGeneric_Reset(IEnumUnknown *pThis)
{
((PENUMGENERIC)pThis)->nCurrent = 0;
return S_OK;
}
static HRESULT enumGeneric_Clone(IEnumUnknown *pThis, IEnumUnknown **ppEnum)
{
register PENUMGENERIC peg = (PENUMGENERIC)pThis; /* pointer to data block */
register PENUMGENERIC pegNew; /* pointer to new enumerator */
if (!ppEnum) /* no pointer? */
return E_INVALIDARG;
*ppEnum = NULL;
pegNew = _ObjHlpAllocateEnumGeneric(peg->pAllocator, peg->riidActual, peg->pPayload, peg->nCurrent);
if (!pegNew) /* failed to allocate? */
return E_OUTOFMEMORY;
IUnknown_QueryInterface((IUnknown *)pegNew, peg->riidActual, (PPVOID)ppEnum);
return S_OK;
}
static const SEG_RODATA struct IEnumUnknownVTable vtblEnum =
{
.QueryInterface = enumGeneric_QueryInterface,
.AddRef = enumGeneric_AddRef,
.Release = enumGeneric_Release,
.Next = enumGeneric_Next,
.Skip = enumGeneric_Skip,
.Reset = enumGeneric_Reset,
.Clone = enumGeneric_Clone
};
/*---------------------------------
* IEnum[Generic] helper functions
*---------------------------------
*/
PENUMGENERICDATA _ObjHlpAllocateEnumGenericData(IMalloc *pAllocator, UINT32 nCapacity)
{
register PENUMGENERICDATA rc; /* return from this function */
register SIZE_T cbReturn = sizeof(ENUMGENERICDATA) + (nCapacity * sizeof(PUNKNOWN)); /* bytes to allocate */
rc = (PENUMGENERICDATA)(IMalloc_Alloc(pAllocator, cbReturn));
if (rc != NULL)
{
StrSetMem(rc, 0, cbReturn);
rc->uiRefCount = 0;
rc->nObjects = 0;
}
return rc;
}
void _ObjHlpAddToEnumGenericData(PENUMGENERICDATA pegd, IUnknown *pUnk)
{
pegd->rgObjects[pegd->nObjects] = pUnk;
IUnknown_AddRef(pegd->rgObjects[pegd->nObjects]);
pegd->nObjects++;
}
void _ObjHlpDiscardEnumGenericData(PENUMGENERICDATA pegd)
{
register UINT32 i; /* loop counter */
for (i = 0; i < pegd->nObjects; i++)
IUnknown_Release(pegd->rgObjects[i]);
}
PENUMGENERIC _ObjHlpAllocateEnumGeneric(IMalloc *pAllocator, REFIID riidActual, PENUMGENERICDATA pegd,
UINT32 nCurrent)
{
register PENUMGENERIC rc; /* return from this function */
rc = (PENUMGENERIC)(IMalloc_Alloc(pAllocator, sizeof(ENUMGENERIC)));
if (rc)
{ /* initialize all the fields */
rc->enumUnknown.pVTable = &vtblEnum;
rc->uiRefCount = 0;
rc->riidActual = riidActual;
rc->nCurrent = nCurrent;
rc->pPayload = pegd;
pegd->uiRefCount++;
rc->pAllocator = pAllocator;
IUnknown_AddRef(rc->pAllocator);
}
return rc;
}