/*             ----> DO NOT REMOVE THE FOLLOWING NOTICE <----
 *
 *                 Copyright (c) 2014-2015 Datalight, Inc.
 *                     All Rights Reserved Worldwide.
 *
 *  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; use version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but "AS-IS," 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.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

/*  Businesses and individuals that for commercial or other reasons cannot
 *  comply with the terms of the GPLv2 license may obtain a commercial license
 *  before incorporating Reliance Edge into proprietary software for
 *  distribution in any form.  Visit http://www.datalight.com/reliance-edge for
 *  more information.
 */

/** @file
 *  @brief Implements routines for the inline imap.
 *
 *  The inline imap is used on volumes that are small enough for the imap bitmap
 *  to be entirely contained within the metaroot.
 */
#include <redfs.h>

#if REDCONF_IMAP_INLINE == 1

    #include <redcore.h>


/** @brief Get the allocation bit of a block from either metaroot.
 *
 *  @param bMR          The metaroot index: either 0 or 1.
 *  @param ulBlock      The block number to query.
 *  @param pfAllocated  On successful return, populated with the allocation bit
 *                      of the block.
 *
 *  @return A negated ::REDSTATUS code indicating the operation result.
 *
 *  @retval 0           Operation was successful.
 *  @retval -RED_EINVAL @p bMR is out of range; or @p ulBlock is out of range;
 *                      @p pfAllocated is `NULL`; or the current volume does not
 *                      use the inline imap.
 */
    REDSTATUS RedImapIBlockGet( uint8_t bMR,
                                uint32_t ulBlock,
                                bool * pfAllocated )
    {
        REDSTATUS ret;

        if( ( !gpRedCoreVol->fImapInline ) ||
            ( bMR > 1U ) ||
            ( ulBlock < gpRedCoreVol->ulInodeTableStartBN ) ||
            ( ulBlock >= gpRedVolume->ulBlockCount ) ||
            ( pfAllocated == NULL ) )
        {
            REDERROR();
            ret = -RED_EINVAL;
        }
        else
        {
            *pfAllocated = RedBitGet( gpRedCoreVol->aMR[ bMR ].abEntries, ulBlock - gpRedCoreVol->ulInodeTableStartBN );
            ret = 0;
        }

        return ret;
    }


    #if REDCONF_READ_ONLY == 0

/** @brief Set the allocation bit of a block in the working metaroot.
 *
 *  @param ulBlock      The block number to allocate or free.
 *  @param fAllocated   Whether to allocate the block (true) or free it (false).
 *
 *  @return A negated ::REDSTATUS code indicating the operation result.
 *
 *  @retval 0           Operation was successful.
 *  @retval -RED_EINVAL @p ulBlock is out of range; or the current volume does
 *                      not use the inline imap.
 */
        REDSTATUS RedImapIBlockSet( uint32_t ulBlock,
                                    bool fAllocated )
        {
            REDSTATUS ret;

            if( ( !gpRedCoreVol->fImapInline ) ||
                ( ulBlock < gpRedCoreVol->ulInodeTableStartBN ) ||
                ( ulBlock >= gpRedVolume->ulBlockCount ) )
            {
                REDERROR();
                ret = -RED_EINVAL;
            }
            else
            {
                uint32_t ulOffset = ulBlock - gpRedCoreVol->ulInodeTableStartBN;

                if( RedBitGet( gpRedMR->abEntries, ulOffset ) == fAllocated )
                {
                    /*  The driver shouldn't ever set a bit in the imap to its current
                     *  value.  This is more of a problem with the external imap, but it
                     *  is checked here for consistency.
                     */
                    CRITICAL_ERROR();
                    ret = -RED_EFUBAR;
                }
                else if( fAllocated )
                {
                    RedBitSet( gpRedMR->abEntries, ulOffset );
                    ret = 0;
                }
                else
                {
                    RedBitClear( gpRedMR->abEntries, ulOffset );
                    ret = 0;
                }
            }

            return ret;
        }
    #endif /* if REDCONF_READ_ONLY == 0 */

#endif /* REDCONF_IMAP_INLINE == 1 */