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documentation! w00t

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This was SVN commit r385.
This commit is contained in:
janwas 2004-06-03 13:57:00 +00:00
parent d9b1daf2e4
commit cb75497412
2 changed files with 249 additions and 87 deletions
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185
source/lib/res/vfs.cpp
View File

@ -688,6 +688,12 @@ void vfs_shutdown(void)
}
// mount either a single archive or a directory into the VFS at
// <vfs_mount_point>, which is created if it does not yet exist.
// new files override the previous VFS contents if pri(ority) is higher.
// if <name> is a directory, all archives in that directory (but not
// its subdirs - see add_dirent_cb) are also mounted in alphabetical order.
// name = "." or "./" isn't allowed - see implementation for rationale.
int vfs_mount(const char* const vfs_mount_point, const char* const name, const uint pri)
{
ONCE(atexit2(vfs_shutdown));
@ -700,6 +706,10 @@ int vfs_mount(const char* const vfs_mount_point, const char* const name, const u
return -1;
}
CHECK_PATH(name);
// TODO: disallow mounting parent directory of a previous mounting
// disallow . because "./" isn't supported on Windows.
// the more important reason is that mount points must not overlap
// (i.e. mount $install/data and then $install/data/mods/official -
@ -718,6 +728,12 @@ int vfs_mount(const char* const vfs_mount_point, const char* const name, const u
}
// rebuild the VFS, i.e. re-mount everything. open files are not affected.
// necessary after loose files or directories change, so that the VFS
// "notices" the changes and updates file locations. res calls this after
// FAM reports changes; can also be called from the console after a
// rebuild command. there is no provision for updating single VFS dirs -
// it's not worth the trouble.
int vfs_rebuild()
{
tree_clear();
@ -728,6 +744,7 @@ int vfs_rebuild()
}
// unmount a previously mounted item, and rebuild the VFS afterwards.
int vfs_unmount(const char* name)
{
for(MountIt it = mounts.begin(); it != mounts.end(); ++it)
@ -752,46 +769,13 @@ int vfs_unmount(const char* name)
///////////////////////////////////////////////////////////////////////////////
int vfs_realpath(const char* fn, char* full_path)
{
const FileLoc* loc;
CHECK_ERR(tree_lookup(fn, &loc));
if(loc->archive > 0)
{
const char* archive_fn = h_filename(loc->archive);
if(!archive_fn)
return -1;
strncpy(full_path, archive_fn, PATH_MAX);
}
else
{
strncpy(full_path, loc->dir.c_str(), PATH_MAX);
}
return 0;
}
int vfs_stat(const char* fn, struct stat* s)
{
const FileLoc* loc;
CHECK_ERR(tree_lookup(fn, &loc));
if(loc->archive > 0)
return zip_stat(loc->archive, fn, s);
else
{
const char* dir = loc->dir.c_str();
return file_stat(dir, s);
}
}
struct VDir
{
// we need to cache the complete contents of the directory:
//
// if we reference the real directory and it changes,
// the c_str pointers may become invalid, and some files
// may be returned out of order / not at all.
// we copy the directory's subdirectory and file containers.
SubDirs* subdirs;
SubDirIt subdir_it;
Files* files;
@ -817,6 +801,7 @@ static int VDir_reload(VDir* vd, const char* path)
Dir* dir;
CHECK_ERR(tree_lookup(path, 0, &dir));
// rationale for copy: see VDir definition
vd->subdirs = new SubDirs(dir->subdirs);
vd->subdir_it = vd->subdirs->begin();
vd->files = new Files(dir->files);
@ -825,28 +810,34 @@ static int VDir_reload(VDir* vd, const char* path)
}
Handle vfs_open_dir(const char* const path)
// open a directory for reading its entries via vfs_next_dirent.
// directory contents are cached here; subsequent changes to the dir
// are not returned by this handle. rationale: see VDir definition.
Handle vfs_open_dir(const char* const dir)
{
return h_alloc(H_VDir, path, 0);
return h_alloc(H_VDir, dir, 0);
}
// close the handle to a directory.
// all vfsDirEnt.name strings are now invalid.
int vfs_close_dir(Handle& hd)
{
return h_free(hd, H_VDir);
}
// filter:
// 0: any file
// ".": file without extension (filename doesn't contain '.')
// ".ext": file with extension <ext> (which must not contain '.')
// "/": subdirectory
// get the next directory entry (in alphabetical order) that matches filter.
// return 0 on success. filter values:
// - 0: any file;
// - ".": any file without extension (filename doesn't contain '.');
// - ".ext": any file with extension ".ext" (which must not contain '.');
// - "/": any subdirectory
int vfs_next_dirent(const Handle hd, vfsDirEnt* ent, const char* const filter)
{
H_DEREF(hd, VDir, vd);
// interpret filter
// interpret filter (paranoid)
bool filter_dir = false;
bool filter_no_ext = false;
if(filter)
@ -871,6 +862,13 @@ int vfs_next_dirent(const Handle hd, vfsDirEnt* ent, const char* const filter)
}
}
// rationale: the filename is currently stored internally as
// std::string (=> less manual memory allocation). we don't want to
// return a reference, because that would break C compatibility.
// we're trying to avoid fixed-size buffers, so that is out as well.
// finally, allocating a copy is not so good because it has to be
// freed by the user (won't happen). returning a volatile pointer
// to the string itself via c_str is the only remaining option.
const char* fn;
// caller wants a subdirectory; return the next one.
@ -914,6 +912,50 @@ have_match:
}
// return actual path to the specified file:
// "<real_directory>/fn" or "<archive_name>/fn".
int vfs_realpath(const char* fn, char* full_path)
{
const FileLoc* loc;
CHECK_ERR(tree_lookup(fn, &loc));
const char* dir;
// file is in normal directory
if(loc->archive <= 0)
dir = loc->dir.c_str();
// file is in archive
{
// "dir" is the archive filename
dir = h_filename(loc->archive);
if(!dir)
return -1;
}
CHECK_ERR(path_append(full_path, dir, fn));
return 0;
}
// return information about the specified file as in stat(2),
// most notably size. stat buffer is undefined on error.
int vfs_stat(const char* fn, struct stat* s)
{
const FileLoc* loc;
CHECK_ERR(tree_lookup(fn, &loc));
if(loc->archive > 0)
return zip_stat(loc->archive, fn, s);
else
{
// similar to realpath, but don't bother splitting it out.
char path[VFS_MAX_PATH];
path_append(path, loc->dir.c_str(), fn);
return file_stat(path, s);
}
}
///////////////////////////////////////////////////////////////////////////////
//
// file
@ -1038,6 +1080,8 @@ static int VFile_reload(VFile* vf, const char* path)
}
// open the file for synchronous or asynchronous IO. write access is
// requested via VFS_WRITE flag, and is not possible for files in archives.
Handle vfs_open(const char* fn, uint flags /* = 0 */)
{
Handle h = h_alloc(H_VFile, fn, 0, flags);
@ -1051,6 +1095,7 @@ debug_out("vfs_open fn=%s %I64x\n", fn, h);
}
// close the handle to a file.
inline int vfs_close(Handle& h)
{
#ifdef PARANOIA
@ -1061,7 +1106,11 @@ debug_out("vfs_close %I64x\n", h);
}
ssize_t vfs_io(Handle hf, off_t ofs, size_t size, void*& p)
// try to transfer <size> bytes, starting at <ofs>, to/from the given file.
// (read or write access was chosen at file-open time).
// return bytes of actual data transferred, or a negative error code.
// TODO: buffer types
ssize_t vfs_io(const Handle hf, const off_t ofs, const size_t size, void*& p)
{
#ifdef PARANOIA
debug_out("vfs_io ofs=%d size=%d\n", ofs, size);
@ -1080,7 +1129,9 @@ debug_out("vfs_io ofs=%d size=%d\n", ofs, size);
}
Handle vfs_load(const char* fn, void*& p, size_t& size)
// load the entire file <fn> into memory; return a handle to the memory
// and the buffer address/size. output parameters are zeroed on failure.
Handle vfs_load(const char* const fn, void*& p, size_t& size)
{
#ifdef PARANOIA
debug_out("vfs_load fn=%s\n", fn);
@ -1144,9 +1195,12 @@ int vfs_store(const char* const fn, void* p, const size_t size)
}
///////////////////////////////////////////////////////////////////////////////
//
// memory mapping
//
///////////////////////////////////////////////////////////////////////////////
// map the entire file <hf> into memory. if already currently mapped,
// return the previous mapping (reference-counted).
@ -1185,3 +1239,40 @@ int vfs_unmap(const Handle hf)
else
return file_unmap(&vf->f);
}
///////////////////////////////////////////////////////////////////////////////
//
// asynchronous I/O
//
///////////////////////////////////////////////////////////////////////////////
// begin transferring <size> bytes, starting at <ofs>. get result
// with vfs_wait_read; when no longer needed, free via vfs_discard_io.
Handle vfs_start_io(Handle hf, off_t ofs, size_t size, void* buf)
{
H_DEREF(hf, VFile, vf);
if(vf_flags(vf) & VF_ZIP)
;
return 0;
}
// wait until the transfer <hio> completes, and return its buffer.
// output parameters are zeroed on error.
int vfs_wait_io(Handle hio, void*& p, size_t& size)
{
p = 0;
size = 0;
return 0;
}
// finished with transfer <hio> - free its buffer (returned by vfs_wait_read)
int vfs_discard_io(Handle& hio)
{
return 0;
}

151
source/lib/res/vfs.h
View File

@ -20,25 +20,109 @@
#ifndef __VFS_H__
#define __VFS_H__
#include "h_mgr.h"
#include "h_mgr.h" // Handle
#include "posix.h" // struct stat
// the VFS doesn't require this length restriction - VFS internal storage
// is not fixed-length. the purpose here is to allow fixed-sized path buffers
// allocated on the stack.
//
// length includes trailing '\0'.
// VFS tree
//
// the VFS doesn't require this length restriction - VFS internal storage
// is not fixed-length. the purpose here is to give an indication of how
// large fixed-size user buffers should be. length includes trailing '\0'.
#define VFS_MAX_PATH 256
extern int vfs_mount(const char* vfs_mount_point, const char* name, uint pri);
extern int vfs_umount(const char* name);
// VFS paths are of the form:
// "[dir/{subdir/}]file" or "[dir/{subdir/}]dir[/]".
// in English: '/' as path separator; trailing '/' allowed for dir names;
// no leading '/', since "" is the root dir.
extern int vfs_stat(const char* fn, struct stat*);
// mount either a single archive or a directory into the VFS at
// <vfs_mount_point>, which is created if it does not yet exist.
// new files override the previous VFS contents if pri(ority) is higher.
// if <name> is a directory, all archives in that directory (but not
// its subdirs - see add_dirent_cb) are also mounted in alphabetical order.
// name = "." or "./" isn't allowed - see implementation for rationale.
extern int vfs_mount(const char* vfs_mount_point, const char* name, uint pri);
// rebuild the VFS, i.e. re-mount everything. open files are not affected.
// necessary after loose files or directories change, so that the VFS
// "notices" the changes and updates file locations. res calls this after
// FAM reports changes; can also be called from the console after a
// rebuild command. there is no provision for updating single VFS dirs -
// it's not worth the trouble.
extern int vfs_rebuild();
// unmount a previously mounted item, and rebuild the VFS afterwards.
extern int vfs_unmount(const char* name);
//
// directory entry
//
// information about a directory entry, returned by vfs_next_dirent.
struct vfsDirEnt
{
// name of directory entry - does not include path.
// valid until the directory handle is closed. must not be modified!
// rationale for pointer and invalidation: see vfs_next_dirent.
const char* name;
};
// open the directory for reading its entries via vfs_next_dirent.
// directory contents are cached here; subsequent changes to the dir
// are not returned by this handle. rationale: see VDir definition.
extern Handle vfs_open_dir(const char* dir);
// close the handle to a directory.
// all vfsDirEnt.name strings are now invalid.
extern int vfs_close_dir(Handle& hd);
// get the next directory entry (in alphabetical order) that matches filter.
// return 0 on success. filter values:
// - 0: any file;
// - ".": any file without extension (filename doesn't contain '.');
// - ".ext": any file with extension ".ext" (which must not contain '.');
// - "/": any subdirectory
extern int vfs_next_dirent(Handle hd, vfsDirEnt* ent, const char* filter);
//
// file
//
// return actual path to the specified file:
// "<real_directory>/fn" or "<archive_name>/fn".
extern int vfs_realpath(const char* fn, char* realpath);
extern Handle vfs_load(const char* fn, void*& p, size_t& size);
// return information about the specified file as in stat(2),
// most notably size. stat buffer is undefined on error.
extern int vfs_stat(const char* fn, struct stat*);
// vfs_open flags - keep in sync with file.cpp flag definitions!
enum vfsOpenFlags
{
// write-only access; otherwise, read only
VFS_WRITE = 0x01,
// buffers returned may be read-only (allows some caching optimizations)
VFS_MEM_READONLY = 0x02,
// don't cache the whole file, e.g. if kept in memory elsewhere anyway.
VFS_NOCACHE = 0x04,
// random access hint
VFS_RANDOM = 0x08
};
// open the file for synchronous or asynchronous IO. write access is
// requested via VFS_WRITE flag, and is not possible for files in archives.
extern Handle vfs_open(const char* fn, uint flags = 0);
// close the handle to a file.
extern int vfs_close(Handle& h);
@ -65,47 +149,34 @@ extern int vfs_unmap(Handle hf);
//
// directory entry enumeration
// asynchronous I/O
//
struct vfsDirEnt
{
// the filename is currently stored internally as std::string. returning as char* for C compat
// stored internally as std::string. returning as char* for C compat
// would mean we have to return a copy. we try to avoid fixed-size
// buffers, so that leaves a reference.
const char* name;
};
// begin transferring <size> bytes, starting at <ofs>. get result
// with vfs_wait_read; when no longer needed, free via vfs_discard_io.
extern Handle vfs_start_io(Handle hf, off_t ofs, size_t size, void* buf);
extern Handle vfs_open_dir(const char* path);
extern int vfs_close_dir(Handle& hd);
extern int vfs_next_dirent(Handle hd, vfsDirEnt* ent, const char* filter);
// wait until the transfer <hio> completes, and return its buffer.
// output parameters are zeroed on error.
extern int vfs_wait_io(Handle hio, void*& p, size_t& size);
// finished with transfer <hio> - free its buffer (returned by vfs_wait_read).
extern int vfs_discard_io(Handle& hio);
//
// async read interface
// synchronous I/O
//
extern Handle vfs_start_read(const Handle hf, off_t ofs, size_t& advance, void* buf);
extern int vfs_wait_read(Handle hr, void*& p, size_t& size);
extern int vfs_discard_read(Handle& hr);
// try to transfer <size> bytes, starting at <ofs>.
// (read or write access was chosen at file-open time).
// return bytes of actual data transferred, or a negative error code.
// TODO: buffer types
extern ssize_t vfs_io(Handle hf, off_t ofs, size_t size, void*& p);
// keep in sync with File flags!
enum
{
VFS_WRITE = 1, // write-only access; otherwise, read only
VFS_MEM_READONLY = 2, // !want to be able to change in memory data
VFS_NOCACHE = 4, // don't cache whole file, e.g. if cached on a higher level
VFS_RANDOM = 8 // random access hint, allow offset
};
extern int vfs_rebuild();
// load the entire file <fn> into memory; return a memory handle to the
// buffer and its address/size. output parameters are zeroed on failure.
extern Handle vfs_load(const char* fn, void*& p, size_t& size);
#endif // #ifndef __VFS_H__