Initial commit of a libnetfs-based tarfs including a gzip/bzip2 store.

1 files changed, 123 insertions, 0 deletions

diff --git a/backend.h b/backend.h
new file mode 100644
index 000000000..ab8f92f9c
--- /dev/null
+++ b/backend.h
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+/* tarfs - A GNU tar filesystem for the Hurd.
+   Copyright (C) 2002, Ludovic Courtès <ludo@type-z.org>
+ 
+   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; either version 2 of the
+   License, or * (at your option) any later version.
+ 
+   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 */
+
+/*
+ * A general filesystem backend.
+ */
+
+#ifndef __FS_BACKEND__
+#define __FS_BACKEND__
+
+#include <hurd/netfs.h>
+#include <dirent.h>
+#include <argp.h>
+#include <assert.h>
+
+
+/* Generic (fs independent) netnode structure.  */
+struct netnode
+{
+  char *name;		/* node name */
+  char *symlink;	/* link's target path (in the case of a symlink) */
+  struct node *hardlink;/* hard link's target or zero */
+  struct node *entries;	/* directory entries (when applies) */
+  struct node *dir;	/* parent directory */
+
+  void *info;		/* fs defined data (node related info) */
+};
+
+/* Substitute for '/' and chars lower than 32 in node names.
+   If SUBST_LOWER isn't defined, then lower chars won't be filtered. */
+#define SUBST_SLASH '|'
+//#define SUBST_LOWER '.'
+
+
+/* Each filesystem backend should define a struct fs_backend variable with
+   the appropriate functions.  */
+struct fs_backend
+{
+  /* Initialize filesystem (create root node *N, etc.) */
+  error_t (* init)(struct node **n, struct iouser *user);
+
+  /* Get filesystem's struct argp. */
+  void (* get_argp)(struct argp *s);
+
+  /* Get arguments (see netfs_append_args()). */
+  error_t (*get_args)(char **argz, unsigned *argz_len);
+
+  /* Set options (see netfs_set_options()). */
+  error_t (*set_options)(char *argz, size_t argz_len);
+
+
+  /* 
+   * Directory scan functions (used in netfs_get_dirents ()).
+   */
+
+  /* Set current directory. */
+  int (* set_curr_dir)(struct node *dir);
+
+  /* Skip N entries in current directory, returns non-zero if
+     no more entries are available.  */
+  int (* skip_entries)(int n);
+  
+  /* Returns a newly-allocated entry in ENTRY. Returns non-zero when
+     no more entries are available.  */
+  int (* get_next_entry)(struct dirent **entry);
+
+  /* Reading a node */
+  error_t (* lookup_node)(struct node **np, struct node* dir, const char* name);
+  error_t (* read_node)  (struct node *np, off_t offset,
+			  size_t *len, void* data);
+
+
+  /* Changing a node */
+  error_t (* write_node) (struct node *np, off_t offset,
+  			  size_t *len, void* data);
+
+  /* Change NP's stats.  */
+  error_t (* change_stat)(struct node *np, const io_statbuf_t *new_stat);
+
+  /* Creates a node named NAME in DIR which is locked.  */
+  error_t (* create_node) (struct node **new, struct node *dir,
+  			   char *name, mode_t m);
+
+  /* Unlinks NODE.  NODE can be a directory in which case it is empty.  */
+  error_t (* unlink_node) (struct node *node);
+
+  /* Tries to create a hard link named NAME in DIR to file NODE.  */
+  error_t (* link_node) (struct node *dir, struct node *target,
+  			 char *name, int excl); /* Same as netfs semantics */
+
+  /* Makes NODE a symlink to TARGET.  */
+  error_t (* symlink_node) (struct node *node, const char *target);
+
+  /* Tries to turn NODE into a device of type TYPE (either S_IFBLK
+     or S_IFCHR).  */
+  error_t (* mkdev_node)   (struct node *node, mode_t type, dev_t indexes);
+
+  /* Free all resources associated to NODE.  */
+  void (* free_node) (struct node *node);
+
+  /* Synchronize filesystem.  */
+  error_t (* sync_fs) (int wait);
+
+  /* Filesystem destructor */
+  error_t (* go_away) ();
+};
+
+#endif