VirtualFileSystem

class VirtualFileSystem

A hierarchy of directories and files that appears to be one continuous file system, even though the files may originate from several different sources that may not be related to the actual OS’s file system.

For instance, a VirtualFileSystem can transparently mount one or more Multifiles as their own subdirectory hierarchies.

Inheritance diagram

Inheritance diagram of VirtualFileSystem

enum MountFlags
enumerator MF_read_only = 2
VirtualFileSystem(void)
bool chdir(Filename const &new_directory)

Changes the current directory. This is used to resolve relative pathnames in get_file() and/or find_file(). Returns true if successful, false otherwise.

static void close_read_file(std::istream *stream)

Closes a file opened by a previous call to open_read_file(). This really just deletes the istream pointer, but it is recommended to use this interface instead of deleting it explicitly, to help work around compiler issues.

static void close_read_write_file(std::iostream *stream)

Closes a file opened by a previous call to open_read_write_file(). This really just deletes the iostream pointer, but it is recommended to use this interface instead of deleting it explicitly, to help work around compiler issues.

static void close_write_file(std::ostream *stream)

Closes a file opened by a previous call to open_write_file(). This really just deletes the ostream pointer, but it is recommended to use this interface instead of deleting it explicitly, to help work around compiler issues.

bool copy_file(Filename const &orig_filename, Filename const &new_filename)

Attempts to copy the contents of the indicated file to the indicated file. Returns true on success, false on failure.

PointerTo<VirtualFile> create_file(Filename const &filename)

Attempts to create a file by the indicated name in the filesystem, if possible, and returns it. If a file by this name already exists, returns the same thing as get_file(). If the filename is located within a read- only directory, or the directory doesn’t exist, returns NULL.

bool delete_file(Filename const &filename)

Attempts to delete the indicated file or directory. This can remove a single file or an empty directory. It will not remove a nonempty directory. Returns true on success, false on failure.

bool exists(Filename const &filename) const

Convenience function; returns true if the named file exists.

int find_all_files(Filename const &filename, DSearchPath const &searchpath, DSearchPath::Results &results) const

Searches all the directories in the search list for the indicated file, in order. Fills up the results list with all of the matching filenames found, if any. Returns the number of matches found.

It is the responsibility of the the caller to clear the results list first; otherwise, the newly-found files will be appended to the list.

PointerTo<VirtualFile> find_file(Filename const &filename, DSearchPath const &searchpath, bool status_only = false) const

Uses the indicated search path to find the file within the file system. Returns the first occurrence of the file found, or NULL if the file cannot be found.

Filename get_cwd(void) const

Returns the current directory name. See chdir().

PointerTo<VirtualFile> get_file(Filename const &filename, bool status_only = false) const

Looks up the file by the indicated name in the file system. Returns a VirtualFile pointer representing the file if it is found, or NULL if it is not.

If status_only is true, the file will be checked for existence and length and so on, but the returned file’s contents cannot be read. This is an optimization which is especially important for certain mount types, for instance HTTP, for which opening a file to determine its status is substantially less expensive than opening it to read its contents.

static VirtualFileSystem *get_global_ptr(void)

Returns the default global VirtualFileSystem. You may create your own personal VirtualFileSystem objects and use them for whatever you like, but Panda will attempt to load models and stuff from this default object.

Initially, the global VirtualFileSystem is set up to mount the OS filesystem to root; i.e. it is equivalent to the OS filesystem. This may be subsequently adjusted by the user.

PointerTo<VirtualFileMount> get_mount(int n) const

Returns the nth mount in the system.

int get_num_mounts(void) const

Returns the number of individual mounts in the system.

bool is_directory(Filename const &filename) const

Convenience function; returns true if the named file exists and is a directory.

bool is_regular_file(Filename const &filename) const

Convenience function; returns true if the named file exists and is a regular file.

void ls(Filename const &filename) const

Convenience function; lists the files within the indicated directory.

void ls_all(Filename const &filename) const

Convenience function; lists the files within the indicated directory, and all files below, recursively.

bool make_directory(Filename const &filename)

Attempts to create a directory within the file system. Returns true on success, false on failure (for instance, because the parent directory does not exist, or is read-only). If the directory already existed prior to this call, returns true.

bool make_directory_full(Filename const &filename)

Attempts to create a directory within the file system. Will also create any intervening directories needed. Returns true on success, false on failure.

bool mount(Multifile *multifile, Filename const &mount_point, int flags)
bool mount(Filename const &physical_filename, Filename const &mount_point, int flags, std::string const &password = "")
bool mount(VirtualFileMount *mount, Filename const &mount_point, int flags)

Mounts the indicated Multifile at the given mount point.

Mounts the indicated system file or directory at the given mount point. If the named file is a directory, mounts the directory. If the named file is a Multifile, mounts it as a Multifile. Returns true on success, false on failure.

A given system directory may be mounted to multiple different mount point, and the same mount point may share multiple system directories. In the case of ambiguities (that is, two different files with exactly the same full pathname), the most-recently mounted system wins.

The filename specified as the first parameter must refer to a real, physical filename on disk; it cannot be a virtual file already appearing within the vfs filespace. However, it is possible to mount such a file; see mount_loop() for this.

Note that a mounted VirtualFileSystem directory is fully case-sensitive, unlike the native Windows file system, so you must refer to files within the virtual file system with exactly the right case.

Adds the given VirtualFileMount object to the mount list. This is a lower- level function than the other flavors of mount(); it requires you to create a VirtualFileMount object specifically.

bool mount_loop(Filename const &virtual_filename, Filename const &mount_point, int flags, std::string const &password = "")

This is similar to mount(), but it receives the name of a Multifile that already appears within the virtual file system. It can be used to mount a Multifile that is itself hosted within a virtually-mounted Multifile.

This interface can also be used to mount physical files (that appear within the virtual filespace), but it cannot be used to mount directories. Use mount() if you need to mount a directory.

Note that there is additional overhead, in the form of additional buffer copies of the data, for recursively mounting a multifile like this.

std::ostream *open_append_file(Filename const &filename)

Works like open_write_file(), but the file is opened in append mode. Like open_write_file(), the returned pointer should eventually be passed to close_write_file().

std::iostream *open_read_append_file(Filename const &filename)

Works like open_read_write_file(), but the file is opened in append mode. Like open_read_write_file(), the returned pointer should eventually be passed to close_read_write_file().

std::istream *open_read_file(Filename const &filename, bool auto_unwrap) const

Convenience function; returns a newly allocated istream if the file exists and can be read, or NULL otherwise. Does not return an invalid istream.

If auto_unwrap is true, an explicitly-named .pz file is automatically decompressed and the decompressed contents are returned. This is different than vfs-implicit-pz, which will automatically decompress a file if the extension .pz is not given.

std::iostream *open_read_write_file(Filename const &filename, bool truncate)

Convenience function; returns a newly allocated iostream if the file exists and can be written, or NULL otherwise. Does not return an invalid iostream.

std::ostream *open_write_file(Filename const &filename, bool auto_wrap, bool truncate)

Convenience function; returns a newly allocated ostream if the file exists and can be written, or NULL otherwise. Does not return an invalid ostream.

If auto_wrap is true, an explicitly-named .pz file is automatically compressed while writing. If truncate is true, the file is truncated to zero length before writing.

PyObject *read_file(Filename const &filename, bool auto_unwrap) const

Convenience function; returns the entire contents of the indicated file as a string.

If auto_unwrap is true, an explicitly-named .pz/.gz file is automatically decompressed and the decompressed contents are returned. This is different than vfs-implicit-pz, which will automatically decompress a file if the extension .pz is not given.

Convenience function; fills the string up with the data from the indicated file, if it exists and can be read. Returns true on success, false otherwise.

If auto_unwrap is true, an explicitly-named .pz/.gz file is automatically decompressed and the decompressed contents are returned. This is different than vfs-implicit-pz, which will automatically decompress a file if the extension .pz is not given.

Convenience function; fills the pvector up with the data from the indicated file, if it exists and can be read. Returns true on success, false otherwise.

If auto_unwrap is true, an explicitly-named .pz/.gz file is automatically decompressed and the decompressed contents are returned. This is different than vfs-implicit-pz, which will automatically decompress a file if the extension .pz is not given.

bool rename_file(Filename const &orig_filename, Filename const &new_filename)

Attempts to move or rename the indicated file or directory. If the original file is an ordinary file, it will quietly replace any already- existing file in the new filename (but not a directory). If the original file is a directory, the new filename must not already exist.

If the file is a directory, the new filename must be within the same mount point. If the file is an ordinary file, the new filename may be anywhere; but if it is not within the same mount point then the rename operation is automatically performed as a two-step copy-and-delete operation.

bool resolve_filename(Filename &filename, DSearchPath const &searchpath, std::string const &default_extension = string()) const

Searches the given search path for the filename. If it is found, updates the filename to the full pathname found and returns true; otherwise, returns false.

PointerTo<VirtualFileList> scan_directory(Filename const &filename) const

If the file represents a directory (that is, is_directory() returns true), this returns the list of files within the directory at the current time. Returns NULL if the file is not a directory or if the directory cannot be read.

int unmount(Multifile *multifile)
int unmount(Filename const &physical_filename)
int unmount(VirtualFileMount *mount)

Unmounts all appearances of the indicated Multifile from the file system. Returns the number of appearances unmounted.

Unmounts all appearances of the indicated directory name or multifile name from the file system. Returns the number of appearances unmounted.

Unmounts the indicated VirtualFileMount object from the file system. Returns the number of appearances unmounted.

int unmount_all(void)

Unmounts all files from the file system. Returns the number of systems unmounted.

int unmount_point(Filename const &mount_point)

Unmounts all systems attached to the given mount point from the file system. Returns the number of appearances unmounted.

void write(std::ostream &out) const

Print debugging information. (e.g. from Python or gdb prompt).

PyObject *write_file(Filename const &filename, PyObject *data, bool auto_wrap)

Convenience function; writes the entire contents of the indicated file as a string.

If auto_wrap is true, an explicitly-named .pz file is automatically compressed while writing.

Convenience function; writes the entire contents of the indicated file as a block of data.

If auto_wrap is true, an explicitly-named .pz file is automatically compressed while writing.