engine/engine/common/fs.h

#include "hash.h"

/*
Threading:
When the main thread will harm the filesystem tree/hash, it will first lock fs_thread_mutex (FIXME: make a proper rwlock).
Worker threads must thus lock that mutex for any opens (to avoid it changing underneath it), but can unlock it as soon as the open call returns.
Files may be shared between threads, but not simultaneously.
The filesystem driver is responsible for closing the pak/pk3 once all files are closed, and must ensure that opens+reads+closes as well as archive closure are thread safe.
*/

#define FSVER 2


#define FF_NOTFOUND		(0u)	//file wasn't found
#define FF_FOUND		(1u<<0u)	//file was found
#define FF_SYMLINK		(1u<<1u)	//file contents are the name of a different file (symlink). do a recursive lookup on the name
#define FF_DIRECTORY	(1u<<2u)

typedef struct
{
	bucket_t buck;
	int depth;	/*shallower files will remove deeper files*/
} fsbucket_t;
extern hashtable_t filesystemhash;	//this table is the one to build your hash references into
extern int fs_hash_dups;	//for tracking efficiency. no functional use.
extern int fs_hash_files;	//for tracking efficiency. no functional use.
extern qboolean fs_readonly;	//if true, fopen(, "w") should always fail.
extern void *fs_thread_mutex;

struct searchpath_s;
struct searchpathfuncs_s
{
	int				fsver;
	void			(QDECL *ClosePath)(searchpathfuncs_t *handle);

	void			(QDECL *GetPathDetails)(searchpathfuncs_t *handle, char *outdetails, size_t sizeofdetails);
	void			(QDECL *BuildHash)(searchpathfuncs_t *handle, int depth, void (QDECL *FS_AddFileHash)(int depth, const char *fname, fsbucket_t *filehandle, void *pathhandle));
	unsigned int	(QDECL *FindFile)(searchpathfuncs_t *handle, flocation_t *loc, const char *name, void *hashedresult);	//true if found (hashedresult can be NULL)
		//note that if rawfile and offset are set, many Com_FileOpens will read the raw file
		//otherwise ReadFile will be called instead.
	void			(QDECL *ReadFile)(searchpathfuncs_t *handle, flocation_t *loc, char *buffer);	//reads the entire file in one go (size comes from loc, so make sure the loc is valid, this is for performance with compressed archives)
	int				(QDECL *EnumerateFiles)(searchpathfuncs_t *handle, const char *match, int (QDECL *func)(const char *fname, qofs_t fsize, time_t mtime, void *parm, searchpathfuncs_t *spath), void *parm);

	int				(QDECL *GeneratePureCRC) (searchpathfuncs_t *handle, int seed, int usepure);

	vfsfile_t *		(QDECL *OpenVFS)(searchpathfuncs_t *handle, flocation_t *loc, const char *mode);

	qboolean		(QDECL *PollChanges)(searchpathfuncs_t *handle);	//returns true if there were changes

	qboolean		(QDECL *RenameFile)(searchpathfuncs_t *handle, const char *oldname, const char *newname);	//returns true on success, false if source doesn't exist, or if dest does.
	qboolean		(QDECL *RemoveFile)(searchpathfuncs_t *handle, const char *filename);	//returns true on success, false if it wasn't found or is readonly.
	qboolean		(QDECL *MkDir)(searchpathfuncs_t *handle, const char *filename);	//is this really needed?
};
//searchpathfuncs_t *(QDECL *OpenNew)(vfsfile_t *file, const char *desc);	//returns a handle to a new pak/path

//the stdio filesystem is special as that's the starting point of the entire filesystem
//warning: the handle is known to be a string pointer to the dir name
extern searchpathfuncs_t *(QDECL VFSOS_OpenPath) (vfsfile_t *file, const char *desc);
extern searchpathfuncs_t *(QDECL FSZIP_LoadArchive) (vfsfile_t *packhandle, const char *desc);
extern searchpathfuncs_t *(QDECL FSPAK_LoadArchive) (vfsfile_t *packhandle, const char *desc);
extern searchpathfuncs_t *(QDECL FSDWD_LoadArchive) (vfsfile_t *packhandle, const char *desc);
vfsfile_t *QDECL VFSOS_Open(const char *osname, const char *mode);
vfsfile_t *FS_DecompressGZip(vfsfile_t *infile, vfsfile_t *outfile);

int FS_RegisterFileSystemType(void *module, const char *extension, searchpathfuncs_t *(QDECL *OpenNew)(vfsfile_t *file, const char *desc), qboolean loadscan);
void FS_UnRegisterFileSystemType(int idx);
void FS_UnRegisterFileSystemModule(void *module);

void FS_EnumerateKnownGames(qboolean (*callback)(void *usr, ftemanifest_t *man), void *usr);

#define SPF_REFERENCED		1	//something has been loaded from this path. should filter out client references...
#define SPF_COPYPROTECTED	2	//downloads are not allowed fom here.
#define SPF_TEMPORARY		4	//a map-specific path, purged at map change.
#define SPF_EXPLICIT		8	//a root gamedir (bumps depth on gamedir depth checks). 
#define SPF_UNTRUSTED		16	//has been downloaded from somewhere. configs inside it should never be execed with local access rights.
#define SPF_PRIVATE			32	//private to the client. ie: the fte dir.
#define SPF_WRITABLE		64	//safe to write here. lots of weird rules etc.
qboolean FS_LoadPackageFromFile(vfsfile_t *vfs, char *pname, char *localname, int *crc, unsigned int flags);