source: mainline/uspace/srv/fs/exfat/exfat_directory.c@ 25c60f4

/*
 * Copyright (c) 2011 Oleg Romanenko
 * All rights reserved.
 *
 * 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/** @addtogroup fs
 * @{
 */ 

/**
 * @file        exfat_directory.c
 * @brief       Functions that work with FAT directory.
 */

#include "exfat_directory.h"
#include "exfat_fat.h"
#include <libblock.h>
#include <errno.h>
#include <byteorder.h>
#include <mem.h>
#include <str.h>


void exfat_directory_init(exfat_directory_t *di)
{
        di->b = NULL;
        di->nodep = NULL;
        di->bs = NULL;
        di->blocks = 0;
        di->pos = 0;
        di->bnum = 0;
        di->last = false;
}

int exfat_directory_open(exfat_node_t *nodep, exfat_directory_t *di)
{
        exfat_directory_init(di);
        di->nodep = nodep;      
        if (di->nodep->type != EXFAT_DIRECTORY)
                return EINVAL;

        di->bs = block_bb_get(di->nodep->idx->devmap_handle);
        di->blocks = di->nodep->size / BPS(di->bs);
        return EOK;
}

int exfat_directory_close(exfat_directory_t *di)
{
        int rc=EOK;
        
        if (di->b)
                rc = block_put(di->b);
        
        return rc;
}

static int exfat_directory_block_load(exfat_directory_t *di)
{
        uint32_t i;
        int rc;

        i = (di->pos * sizeof(exfat_dentry_t)) / BPS(di->bs);
        if (i < di->blocks) {
                if (di->b && di->bnum != i) {
                        block_put(di->b);
                        di->b = NULL;
                }
                if (!di->b) {
                        rc = exfat_block_get(&di->b, di->bs, di->nodep, i, BLOCK_FLAGS_NONE);
                        if (rc != EOK) {
                                di->b = NULL;
                                return rc;
                        }
                        di->bnum = i;
                }
                return EOK;
        }
        return ENOENT;
}

int exfat_directory_next(exfat_directory_t *di)
{
        int rc;

        di->pos += 1;
        rc = exfat_directory_block_load(di);
        if (rc!=EOK)
                di->pos -= 1;
        
        return rc;
}

int exfat_directory_prev(exfat_directory_t *di)
{
        int rc=EOK;
        
        if (di->pos > 0) {
                di->pos -= 1;
                rc=exfat_directory_block_load(di);
        }
        else
                return ENOENT;
        
        if (rc!=EOK)
                di->pos += 1;
        
        return rc;
}

int exfat_directory_seek(exfat_directory_t *di, aoff64_t pos)
{
        aoff64_t _pos = di->pos;
        int rc;

        di->pos = pos;
        rc = exfat_directory_block_load(di);
        if (rc!=EOK)
                di->pos = _pos;
        
        return rc;
}

int exfat_directory_get(exfat_directory_t *di, exfat_dentry_t **d)
{
        int rc;
        
        rc = exfat_directory_block_load(di);
        if (rc == EOK) {
                aoff64_t o = di->pos % (BPS(di->bs) / sizeof(exfat_dentry_t));
                *d = ((exfat_dentry_t *)di->b->data) + o;
        }
        
        return rc;
}

int exfat_directory_find(exfat_directory_t *di, exfat_dentry_clsf_t type, exfat_dentry_t **d)
{
        do {
                if (exfat_directory_get(di, d) == EOK) {
                        if (exfat_classify_dentry(*d) == type)
                                return EOK;
                } else
                        return ENOENT;
        } while (exfat_directory_next(di) == EOK);
        
        return ENOENT;
}

int exfat_directory_find_continue(exfat_directory_t *di, exfat_dentry_clsf_t type, exfat_dentry_t **d)
{
        int rc;
        rc = exfat_directory_next(di);
        if (rc != EOK)
                return rc;
        return exfat_directory_find(di, type, d);
}


int exfat_directory_read_file(exfat_directory_t *di, char *name, size_t size, 
    exfat_file_dentry_t *df, exfat_stream_dentry_t *ds)
{
        uint16_t wname[EXFAT_FILENAME_LEN+1];
        exfat_dentry_t *d = NULL;
        int rc, i;
        size_t offset = 0;
        aoff64_t start_pos = 0;
        
        rc = exfat_directory_find(di, EXFAT_DENTRY_FILE, &d);
        if (rc != EOK)
                return rc;
        start_pos = di->pos;
        *df = d->file;

        rc = exfat_directory_next(di);
        if (rc != EOK)
                return rc;
        rc = exfat_directory_get(di, &d); 
        if (rc != EOK)
                return rc;
        if (exfat_classify_dentry(d) != EXFAT_DENTRY_STREAM)
                return ENOENT;
        *ds  = d->stream;
        
        if (ds->name_size > size)
                return EOVERFLOW;

        for (i=0; i<df->count-1; i++) {
                rc = exfat_directory_next(di);
                if (rc != EOK)
                        return rc;
                rc = exfat_directory_get(di, &d); 
                if (rc != EOK)
                        return rc;
                if (exfat_classify_dentry(d) != EXFAT_DENTRY_NAME)
                        return ENOENT;
                exfat_dentry_get_name(&d->name, ds->name_size, wname, &offset);
        }
        rc = utf16_to_str(name, size, wname);
        if (rc != EOK)
                return rc;

        exfat_directory_seek(di, start_pos);
        return EOK;
}

int exfat_directory_write_file(exfat_directory_t *di, const char *name)
{
        /* TODO */
        return EOK;
}

int exfat_directory_erase_file(exfat_directory_t *di, aoff64_t pos)
{
        /* TODO */
        return EOK;
}


/**
 * @}
 */