refuse/id3fs/id3fs.c

/*
 * Copyright � 2007 Alistair Crooks.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. 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.
 */
#include <sys/types.h>

#include <db.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <fuse.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "virtdir.h"
#include "defs.h"

static char                   *prefix; /* where the music is */
static int                     verbose; /* how chatty are we? */

static BTREEINFO     bt;

static virtdir_t     id3;


/* perform the stat operation */
/* if this is the root, then just synthesise the data */
/* otherwise, retrieve the data, and be sure to fill in the size */
static int
id3fs_getattr(const char *path, struct stat *st)
{
          virt_dirent_t       *ep;

          if (strcmp(path, "/") == 0) {
                    (void) memset(st, 0x0, sizeof(*st));
                    st->st_mode = S_IFDIR | 0755;
                    st->st_nlink = 2;
                    return 0;
          }
          if ((ep = virtdir_find(&id3, path, strlen(path))) == NULL) {
                    return -ENOENT;
          }
          switch(ep->type) {
          case 'f':
                    (void) memcpy(st, &id3.file, sizeof(*st));
                    break;
          case 'd':
                    (void) memcpy(st, &id3.dir, sizeof(*st));
                    break;
          case 'l':
                    (void) memcpy(st, &id3.lnk, sizeof(*st));
                    st->st_size = ep->tgtlen;
                    break;
          }
          return 0;
}

/* readdir operation */
static int
id3fs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
                off_t offset, struct fuse_file_info * fi)
{
          virt_dirent_t       *dp;
          VIRTDIR             *dirp;

          if ((dirp = openvirtdir(&id3, path)) == NULL) {
                    return 0;
          }
          filler(buf, ".", NULL, 0);
          filler(buf, "..", NULL, 0);
          while ((dp = readvirtdir(dirp)) != NULL) {
                    filler(buf, dp->d_name, NULL, 0);
          }
          closevirtdir(dirp);
          return 0;
}

/* open the file in the file system */
static int
id3fs_open(const char *path, struct fuse_file_info * fi)
{
          return 0;
}

/* read the file's contents in the file system */
static int
id3fs_read(const char *path, char *buf, size_t size, off_t offset,
             struct fuse_file_info * fi)
{
          return 0;
}

/* fill in the statvfs struct */
static int
id3fs_statfs(const char *path, struct statvfs *st)
{
          (void) memset(st, 0x0, sizeof(*st));
          return 0;
}

/* read the symbolic link */
static int
id3fs_readlink(const char *path, char *buf, size_t size)
{
          virt_dirent_t       *ep;

          if ((ep = virtdir_find(&id3, path, strlen(path))) == NULL) {
                    return -ENOENT;
          }
          if (ep->tgt == NULL) {
                    return -ENOENT;
          }
          (void) strlcpy(buf, ep->tgt, size);
          return 0;
}

/* operations struct */
static struct fuse_operations id3fs_oper = {
          .getattr = id3fs_getattr,
          .readlink = id3fs_readlink,
          .readdir = id3fs_readdir,
          .open = id3fs_open,
          .read = id3fs_read,
          .statfs = id3fs_statfs
};

/* build up a fuse_tree from the information in the database */
static void
build_id3_tree(DB *db, virtdir_t *tp)
{
          struct stat          dir;
          struct stat          f;
          const char          *d;
          char                 name[MAXPATHLEN];
          char                *slash;
          char                *key;
          char                *val;
          int                  flag;
          DBT                  k;
          DBT                  v;

          (void) stat(".", &dir);
          (void) memcpy(&f, &dir, sizeof(f));
          f.st_mode = S_IFREG | 0644;
          (void) memset(&k, 0x0, sizeof(k));
          (void) memset(&v, 0x0, sizeof(v));
          for (flag = R_FIRST ; (*db->seq)(db, &k, &v, flag) == 0 ; flag = R_NEXT) {
                    key = (char *) k.data;
                    switch (*key) {
                    case 'a':
                              d = "/artists";
                              break;
                    case 'g':
                              d = "/genre";
                              break;
                    case 'y':
                              d = "/year";
                              break;
                    default:
                              continue;
                    }
                    val = (char *) v.data;
                    if ((slash = strrchr(key, '/')) == NULL) {
                              slash = key;
                    }
                    slash += 1;
                    /* add the symbolic link in that directory */
                    (void) snprintf(name, sizeof(name), "%s/%s/%s", d, val, slash);
                    if (!virtdir_find(tp, name, strlen(name))) {
                              virtdir_add(tp, name, strlen(name), 'l', key + 1,
                                        strlen(key + 1));
                    }
          }
}

int
main(int argc, char **argv)
{
          char       name[MAXPATHLEN];
          int        i;
          DB        *db;

          while ((i = getopt(argc, argv, "p:v")) != -1) {
                    switch(i) {
                    case 'p':
                              prefix = optarg;
                              break;
                    case 'v':
                              verbose = 1;
                              break;
                    }
          }
          bt.lorder = 4321;
          (void) snprintf(name, sizeof(name), "%s/%s", (prefix) ? prefix : "/usr/music", ".id3.db");
          if ((db = dbopen(name, O_RDONLY, 0666, DB_BTREE, &bt)) == NULL) {
                    warn("null id3 database");
          }
          build_id3_tree(db, &id3);
          return fuse_main(argc, argv, &id3fs_oper, NULL);
}