Database fuse

On peut monter la db avec fuse pour stocker les karas de manière centralisée.

• Création de dossiers pour la création de playlists
• Le ln/touch/qqchose peut ajouter des karas à des playlists
• La lecture de fichiers permet de lire des karas (qui sont contenus en tant que blobs dans la db)
• La lecture de dossiers permet de lire le contenue de playlists / de la base

player/src/db/lektor_fuse.c

+#include "sqlite3.h"
+
+
+#define FUSE_USE_VERSION 31
+#define _GNU_SOURCE
+
+
+#include <fuse3/fuse.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <assert.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <strings.h>
+
+
+static volatile const char * database_path = NULL;  /**<< @brief The path to the database. */
+static volatile const char * database = NULL;       /**<< @brief The database that contains all the karas. */
+
+
+static void * lektor_init(struct fuse_conn_info * conn, struct fuse_config * cfg)
+{
+  (void) conn;
+  (void) cfg;
+
+  if (sqlite3_open((const char *) database_path, (sqlite3 **) &database) != 0)
+  { fprintf(stderr, "[LEKTOR_FUSE] error while opening database <%s>\n", database_path); }
+
+  return NULL;
+}
+
+
+static int lektor_getattr(const char * path, struct stat * stbuf, struct fuse_file_info * info)
+{
+  (void) info;
+  int res = -ENOENT;
+  memset(stbuf, 0, sizeof(struct fuse_file_info));
+  size_t length = strlen(path);
+
+  if (length == 1 && strncmp(path, "/", 1) == 0)
+  {
+    stbuf->st_mode = S_IFDIR | 0755;
+    stbuf->st_nlink = 2;
+    return 0;
+  }
+  else if (strncmp(path, "/playlists", 10) == 0)
+  {
+    if (length == 10)
+    {
+      // The directory otself
+      stbuf->st_mode = S_IFDIR | 0777;
+      stbuf->st_nlink = 2;
+      return 0;
+    }
+    else if (strncmp(path + 10, "/README", 7) == 0)
+    {
+      stbuf->st_mode = S_IFREG | 0444;
+      stbuf->st_nlink = 1;
+      return 0;
+    }
+  }
+  else if (strncmp(path, "/authors", 8) == 0)
+  {
+    if (length == 8)
+    {
+      // The directory itself
+      stbuf->st_mode = S_IFDIR | 0755;
+      stbuf->st_nlink = 2;
+      return 0;
+    }
+    else if (strncmp(path + 8, "/README", 7) == 0)
+    {
+      stbuf->st_mode = S_IFREG | 0444;
+      stbuf->st_nlink = 1;
+      return 0;
+    }
+  }
+  else
+  { res = -ENOENT; }
+
+  return res;
+}
+
+
+// static int lektor_mkdir(const char * path, mode_t mode)
+// {
+// }
+//
+//
+// static int lektor_rmdir(const char * path)
+// {
+// }
+
+
+static int lektor_read(const char * path, char * buf, size_t size, off_t offset, struct fuse_file_info * info)
+{
+  (void) info;
+  (void) offset;
+  (void) size;
+  size_t length = strlen(path);
+
+  if (length > strlen("README") && strncmp(path + (length - 6), "README", 6) == 0)
+  {
+    memcpy(buf, "sample readme", strlen("sample readme"));
+    return 0;
+  }
+  else
+  {
+    return -ENOENT;
+  }
+}
+
+
+// static int lektor_open(const char * path, struct fuse_file_info * info)
+// {
+// }
+
+
+static int lektor_readdir(const char * path,
+                          void * buf,
+                          fuse_fill_dir_t filler,
+                          off_t offset,
+                          struct fuse_file_info * fi,
+                          enum fuse_readdir_flags flags)
+{
+  (void) offset;
+  (void) fi;
+  (void) flags;
+  size_t length = strlen(path);
+
+  if (length == 0 || path[0] != '/')
+  { return -ENOENT; }
+
+  filler(buf, ".", NULL, 0, 0);
+  filler(buf, "..", NULL, 0, 0);
+  path++;   // Skip the first '/'
+  length--; // Skip the first '/'
+  struct stat simple_readonly =
+  {
+    .st_mode = S_IFREG | 0444,
+    .st_uid  = 0,
+    .st_gid  = 0,
+  };
+
+  if (length == 0)
+  {
+    /* We are in the root directory */
+    filler(buf, "playlists", NULL, 0, 0);
+    filler(buf, "authors", NULL, 0, 0);
+  }
+  else if (length == 7 && strncmp(path, "authors", 7) == 0)
+  {
+    filler(buf, "README", &simple_readonly, 0, 0);
+  }
+  else if (length == 9 && strncmp(path, "playlists", 9) == 0)
+  {
+    filler(buf, "README", &simple_readonly, 0, 0);
+  }
+  else
+  { return -ENOENT; }
+
+  return 0;
+}
+
+
+static void lektor_deinit(void * ptr)
+{
+  (void) ptr;
+
+  if (database == NULL)
+  { return; }
+
+  sqlite3_close((sqlite3 *) database);
+}
+
+static struct fuse_operations lektor_oper =
+{
+  .init     = lektor_init,
+  .destroy  = lektor_deinit,
+  .getattr  = lektor_getattr,
+  // .open     = lektor_open,
+  .read     = lektor_read,
+  // .mkdir    = lektor_mkdir,
+  // .rmdir    = lektor_rmdir,
+  .readdir  = lektor_readdir,
+};
+
+
+int main(int argc, char * argv[])
+{
+  struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
+  return fuse_main(args.argc, args.argv, &lektor_oper, NULL);
+}