/* $Id$
 * reactos Cache Manager (Cc*) pin Bcb handling of libcaptive
 * Copyright (C) 2003 Jan Kratochvil <project-captive@jankratochvil.net>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; exactly version 2 of June 1991 is required
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "config.h"

#include "privatebcbpin.h"
#include "reactos/ddk/ccfuncs.h"
#include "privatebcb.h"
#include "captive/macros.h"


/**
 * CcPinMappedData:
 * @FileObject: Initialized open #FileObject to map.
 * %NULL value is forbidden.
 * @MappedFileOffset: The @FileObject file offset from where to map the region from.
 * Negative value is forbidden.
 * @MappedLength: Requested length of the region to map from @FileObject.
 * FIXME: Value %0 is currently forbidden by libcaptive; it should be allowed.
 * @Wait: Whether disk waiting is permitted for this function.
 * Value currently ignored by libcaptive as the data must have been mapped by CcMapData() already anyway.
 * @Flags: %PIN_WAIT means whether disk waiting is permitted for this function.
 * Value without %PIN_WAIT is currently permtted by libcaptive as the data must have been mapped by CcMapData() already anyway.
 * %PIN_NO_READ is the same as %MAP_NO_READ - see CcMapData().
 * FIXME: %PIN_EXCLUSIVE for exclusive @Bcb access is now ignored by libcaptive.
 * %PIN_IF_BCB if @Bcb should never be created; function is successful only if @Bcb already exists.
 * @Bcb: Returns initialized #PUBLIC_BCB to refer to the mapped region.
 * The memory region can be larger than requested as it is %PAGE_SIZE aligned.
 * %NULL pointer is forbidden.
 * @Buffer: Returns the mapped memory region start address.
 * This address may not be %PAGE_SIZE aligned.
 * %NULL pointer is forbidden.
 *
 * This function will allow you to modify the data mapped by CcMapData().
 * libcaptive does not differentiate this function with CcMapData().
 *
 * This call does not set the buffer as dirty - such buffer will not be flushed automatically.
 *
 * NEVER re-read any memory from FileObject here!
 * at least fastfat.sys directory create relies on the fact of CcPinRead()
 * with already modified buffers to be left intact.
 *
 * This call will proceed as CcPinRead() if such #Bcb does not yet exist.
 * This is IMO just a bug workaround for a peruse by fastfat.sys FatLocateVolumeLabel().
 *
 * Every call to this function must be matched by a one corresponding CcUnpinData() call.
 *
 * Returns: %TRUE if the region was successfuly mapped.
 * @Bcb with the initialized new memory region.
 * @Buffer with the address of the exact byte specified by @FileOffset.
 */
BOOLEAN CcPinMappedData
		(IN PFILE_OBJECT FileObject,IN PLARGE_INTEGER FileOffset,IN ULONG Length,IN ULONG Flags,OUT PVOID *Bcb)
{
CaptiveSharedCacheMapObject *SharedCacheMap;
CaptivePrivateBcbPinObject *captive_private_bcb_pin_object;
BOOLEAN r;

	g_log(G_LOG_DOMAIN,G_LOG_LEVEL_DEBUG,"enter: CcPinMappedData: FileObject=0x%lX,FileOffset=0x%lX,Length=0x%lX,Flags=0x%lX",
			(long)FileObject,(!FileOffset ? -1 : (long)FileOffset->QuadPart),Length,Flags);

	g_return_val_if_fail(FileObject!=NULL,FALSE);
	g_return_val_if_fail(FileOffset!=NULL,FALSE);
	g_return_val_if_fail(FileOffset->QuadPart>=0,FALSE);
	g_return_val_if_fail(Length>0,FALSE);	/* FIXME: not handled below; 0 should be allowed */
	g_return_val_if_fail(Flags==PIN_WAIT,FALSE);	/* FIXME */
	g_return_val_if_fail(Bcb!=NULL,FALSE);

	g_assert(Length<=PAGE_SIZE);
	/* Check PAGE_SIZE crossing */
	g_assert((FileOffset->QuadPart&~(PAGE_SIZE-1))==((FileOffset->QuadPart+Length-1)&~(PAGE_SIZE-1)));

	SharedCacheMap=captive_FileObject_to_SharedCacheMap(FileObject);
	/* Do not invalide 'map'ped data otherwise ntfs.sys of NT-5.1sp1 mount crashes.
	 */
	captive_private_bcb_pin_object=captive_private_bcb_pin_object_get_ref(SharedCacheMap,
			CAPTIVE_ROUND_DOWN64(FileOffset->QuadPart,PAGE_SIZE),
			FALSE);	/* invalidate_new */

	captive_shared_cache_map_data_validate_noread(SharedCacheMap,FileOffset->QuadPart,FileOffset->QuadPart+Length);

	*Bcb=captive_private_bcb_object_get_PublicBcb(CAPTIVE_PRIVATE_BCB_OBJECT(captive_private_bcb_pin_object));
	r=TRUE;

	g_log(G_LOG_DOMAIN,G_LOG_LEVEL_DEBUG,"leave: CcPinMappedData: r=%d,Bcb=0x%lX",
			r,(!Bcb ? -1 : (long)*Bcb));

	return r;
}


/**
 * CcPinRead:
 * @FileObject: Initialized open #FileObject to map.
 * %NULL value is forbidden.
 * @FileOffset: The @FileObject file offset from where to map the region from.
 * Negative value is forbidden.
 * @Length: Requested length of the region to map from @FileObject.
 * FIXME: Value %0 is currently forbidden by libcaptive; it should be allowed.
 * @Flags: %PIN_WAIT means whether disk waiting is permitted for this function.
 * Value without %PIN_WAIT is currently permtted by libcaptive as the data must have been mapped by CcMapData() already anyway.
 * %PIN_NO_READ is the same as %MAP_NO_READ - see CcMapData().
 * FIXME: %PIN_EXCLUSIVE for exclusive @Bcb access is now ignored by libcaptive.
 * %PIN_IF_BCB if @Bcb should never be created; function is successful only if @Bcb already exists.
 * @Bcb: Returns initialized #PUBLIC_BCB to refer to the mapped region.
 * The memory region can be larger than requested as it is %PAGE_SIZE aligned.
 * %NULL pointer is forbidden.
 * @Buffer: Returns the mapped memory region start address.
 * This address may not be %PAGE_SIZE aligned.
 * %NULL pointer is forbidden.
 *
 * Merely a shortcut call for CcMapData() and CcPinMappedData() afterwards.
 * See these two functions for the details. It has a difference to subsequent
 * calling of CcMapData() and CcPinMappedData() instead as this call counts
 * only as one function for a corresponding CcUnpinData() call.
 *
 * This call does not set the buffer as dirty - such buffer will not be flushed automatically.
 *
 * Every call to this function must be matched by a one corresponding CcUnpinData() call.
 *
 * Returns: %TRUE if the region was successfuly mapped.
 * @Bcb with the initialized new memory region.
 * @Buffer with the address of the exact byte specified by @FileOffset.
 */
BOOLEAN CcPinRead(IN PFILE_OBJECT FileObject,
		IN PLARGE_INTEGER FileOffset,IN ULONG Length,IN ULONG Flags,OUT PVOID *Bcb,OUT PVOID *Buffer)
{
CaptiveSharedCacheMapObject *SharedCacheMap;
CaptivePrivateBcbPinObject *captive_private_bcb_pin_object;
BOOLEAN r;

	g_log(G_LOG_DOMAIN,G_LOG_LEVEL_DEBUG,"enter: CcPinRead: FileObject=0x%lX,FileOffset=0x%lX,Length=0x%lX,Flags=0x%lX",
			(long)FileObject,(!FileOffset ? -1 : (long)FileOffset->QuadPart),Length,Flags);

	g_return_val_if_fail(FileObject!=NULL,FALSE);
	g_return_val_if_fail(FileOffset!=NULL,FALSE);
	g_return_val_if_fail(FileOffset->QuadPart>=0,FALSE);
	g_return_val_if_fail(Length>0,FALSE);	/* FIXME: not handled below; 0 should be allowed */
	g_return_val_if_fail((Flags&~PIN_IF_BCB)==PIN_WAIT,FALSE);	/* FIXME */
	g_return_val_if_fail(Bcb!=NULL,FALSE);
	g_return_val_if_fail(Buffer!=NULL,FALSE);

	g_assert(Length<=PAGE_SIZE);
	/* Check PAGE_SIZE crossing */
	g_assert((FileOffset->QuadPart&~(PAGE_SIZE-1))==((FileOffset->QuadPart+Length-1)&~(PAGE_SIZE-1)));

	SharedCacheMap=captive_FileObject_to_SharedCacheMap(FileObject);

	if (Flags&PIN_IF_BCB) {
		if ((captive_private_bcb_pin_object=captive_private_bcb_pin_object_get(SharedCacheMap,
				CAPTIVE_ROUND_DOWN64(FileOffset->QuadPart,PAGE_SIZE))))
			g_object_ref(captive_private_bcb_pin_object);
		}
	else {
		/* Invalide possibly only 'map'ped data as we need to re-read them on CcPinRead().
		 * Otherwise any file written by fastfat.sys of NT-5.1sp1 will corrupt
		 * the code+55AA of DOS boot sector (disk offset 0x0).
		 */
		captive_private_bcb_pin_object=captive_private_bcb_pin_object_get_ref(SharedCacheMap,
				CAPTIVE_ROUND_DOWN64(FileOffset->QuadPart,PAGE_SIZE),
				TRUE);	/* invalidate_new */
		}

	if (captive_private_bcb_pin_object) {
		captive_shared_cache_map_data_validate_read(SharedCacheMap,FileObject,FileOffset->QuadPart,FileOffset->QuadPart+Length);

		*Bcb=captive_private_bcb_object_get_PublicBcb(CAPTIVE_PRIVATE_BCB_OBJECT(captive_private_bcb_pin_object));
		}
	*Buffer=captive_shared_cache_map_get_buffer(SharedCacheMap)+FileOffset->QuadPart;
	r=!!captive_private_bcb_pin_object;

	g_log(G_LOG_DOMAIN,G_LOG_LEVEL_DEBUG,"leave: CcPinRead: r=%d,Bcb=0x%lX,Buffer=0x%lX",
			r,(!Bcb ? -1 : (long)*Bcb),(!Buffer ? -1 : (long)*Buffer));

	return r;
}


/**
 * CcSetDirtyPinnedData:
 * @Bcb: #PUBLIB_BCB to be unpinned from CcRepinBcb().
 * %NULL value is forbidden.
 * @Lsn: Optional LSN (Linear Sequence Number) to assign to @Bcb.
 * %NULL pointer is permitted.
 *
 * This call will set the buffer as dirty - such buffer will be flushed automatically.
 *
 * You should call it only on CcPin*() buffers - not just CcMapData() buffers
 * although libcaptive does not differentiate it.
 */
VOID CcSetDirtyPinnedData(IN PVOID Bcb,IN PLARGE_INTEGER Lsn OPTIONAL)
{
CaptivePrivateBcbPinObject *captive_private_bcb_pin_object;

	g_log(G_LOG_DOMAIN,G_LOG_LEVEL_DEBUG,"enter: CcSetDirtyPinnedData: BcbVoid=0x%lX,Lsn=0x%lX",
			(long)Bcb,(!Lsn ? -1 : (long)Lsn->QuadPart));

	g_return_if_fail(Bcb!=NULL);

	captive_private_bcb_pin_object=CAPTIVE_PRIVATE_BCB_PIN_OBJECT(captive_PublicBcb_to_PrivateBcbObject(Bcb));

	captive_private_bcb_pin_object_set_dirty(captive_private_bcb_pin_object);
	if (Lsn)
		captive_private_bcb_pin_object_set_lsn(captive_private_bcb_pin_object,Lsn->QuadPart);

	g_log(G_LOG_DOMAIN,G_LOG_LEVEL_DEBUG,"leave: CcSetDirtyPinnedData");
}


/**
 * CcPreparePinWrite:
 * @FileObject: Initialized open #FileObject to map.
 * %NULL value is forbidden.
 * @FileOffset: The @FileObject file offset from where to map the region from.
 * Negative value is forbidden.
 * @Length: Requested length of the region to map from @FileObject.
 * FIXME: Value %0 is currently forbidden by libcaptive; it should be allowed.
 * @Zero: %TRUE if the area of @FileOffset...@FileOffset+@Length should be cleared.
 * @Flags: %PIN_WAIT means whether disk waiting is permitted for this function.
 * Value without %PIN_WAIT is currently permtted by libcaptive as the data must have been mapped by CcMapData() already anyway.
 * %PIN_NO_READ is the same as %MAP_NO_READ - see CcMapData().
 * FIXME: %PIN_EXCLUSIVE for exclusive @Bcb access is now ignored by libcaptive.
 * %PIN_IF_BCB if @Bcb should never be created; function is successful only if @Bcb already exists.
 * @Bcb: Returns initialized #PUBLIC_BCB to refer to the mapped region.
 * The memory region can be larger than requested as it is %PAGE_SIZE aligned.
 * %NULL pointer is forbidden.
 * @Buffer: Returns the mapped memory region start address.
 * This address may not be %PAGE_SIZE aligned.
 * %NULL pointer is forbidden.
 *
 * Wrapper for a pair of CcPinRead() and CcSetDirtyPinnedData().
 * The mapped range can be also optionally cleared if @Zero is specified.
 * See CcPinRead() for a more detailed documentation.
 *
 * This call will set the buffer as dirty - such buffer will be flushed automatically.
 *
 * Returns: %TRUE if the mapping was successful.
 */
BOOLEAN CcPreparePinWrite(IN PFILE_OBJECT FileObject,
		IN PLARGE_INTEGER FileOffset,IN ULONG Length,IN BOOLEAN Zero,IN ULONG Flags,OUT PVOID *Bcb,OUT PVOID *Buffer)
{
CaptiveSharedCacheMapObject *SharedCacheMap;
CaptivePrivateBcbPinObject *captive_private_bcb_pin_object;
BOOLEAN r;

	g_log(G_LOG_DOMAIN,G_LOG_LEVEL_DEBUG,"enter: CcPreparePinWrite: FileObject=0x%lX,FileOffset=0x%lX,Length=0x%lX,Zero=%d,Flags=0x%lX",
			(long)FileObject,(!FileOffset ? -1 : (long)FileOffset->QuadPart),Length,Zero,Flags);

	g_return_val_if_fail(FileObject!=NULL,FALSE);
	g_return_val_if_fail(FileOffset!=NULL,FALSE);
	g_return_val_if_fail(FileOffset->QuadPart>=0,FALSE);
	g_return_val_if_fail(Length>0,FALSE);	/* FIXME: not handled below; 0 should be allowed */
	g_return_val_if_fail(Flags==PIN_WAIT,FALSE);	/* FIXME */
	g_return_val_if_fail(Bcb!=NULL,FALSE);
	g_return_val_if_fail(Buffer!=NULL,FALSE);

	g_assert(0==CAPTIVE_ROUND_DOWN_EXCEEDING64(FileOffset->QuadPart,PAGE_SIZE));	/* NOT YET IMPLEMENTED */
	g_assert(Length==PAGE_SIZE);	/* NOT YET IMPLEMENTED */

	SharedCacheMap=captive_FileObject_to_SharedCacheMap(FileObject);
	captive_private_bcb_pin_object=captive_private_bcb_pin_object_get_ref(SharedCacheMap,
			CAPTIVE_ROUND_DOWN64(FileOffset->QuadPart,PAGE_SIZE),
			FALSE);	/* invalidate_new: FIXME: Is it compatible? */

	captive_shared_cache_map_set_data_valid(SharedCacheMap,FileOffset->QuadPart,FileOffset->QuadPart+Length);
	if (Zero)
		memset(captive_shared_cache_map_get_buffer(SharedCacheMap)+FileOffset->QuadPart,0,Length);
	captive_shared_cache_map_set_dirty(SharedCacheMap,FileOffset->QuadPart,FileOffset->QuadPart+Length);

	*Bcb=captive_private_bcb_object_get_PublicBcb(CAPTIVE_PRIVATE_BCB_OBJECT(captive_private_bcb_pin_object));
	*Buffer=captive_shared_cache_map_get_buffer(SharedCacheMap)+FileOffset->QuadPart;
	r=TRUE;

	g_log(G_LOG_DOMAIN,G_LOG_LEVEL_DEBUG,"leave: CcPreparePinWrite: r=%d,Bcb=0x%lX,Buffer=0x%lX",
			r,(!Bcb ? -1 : (long)*Bcb),(!Buffer ? -1 : (long)*Buffer));

	return r;
}