physfs_internal.h
author Ryan C. Gordon <icculus@icculus.org>
Sun, 08 Jul 2001 13:57:28 +0000
changeset 23 bd6ba9c8717c
parent 22 49f6101707b4
child 28 529214f57d1b
permissions -rw-r--r--
Initial debugging: dropped PhysicsFS routines into the Build engine, replacing Ken's groupfile management. Not finished, but lots of initial debugging is complete. More bugs, likely in OUR groupfile code, are waiting to be fixed, but the KenBuild editor runs without crashing (er...but the palette doesn't seem to be loading... :) ) --ryan.

/*
 * Internal function/structure declaration. Do NOT include in your
 *  application.
 *
 * Please see the file LICENSE in the source's root directory.
 *
 *  This file written by Ryan C. Gordon.
 */

#ifndef _INCLUDE_PHYSFS_INTERNAL_H_
#define _INCLUDE_PHYSFS_INTERNAL_H_

#ifndef __PHYSICSFS_INTERNAL__
#error Do not include this header from your applications.
#endif

struct __PHYSFS_DIRHANDLE__;
struct __PHYSFS_FILEFUNCTIONS__;


typedef struct __PHYSFS_LINKEDSTRINGLIST__
{
    char *str;
    struct __PHYSFS_LINKEDSTRINGLIST__ *next;
} LinkedStringList;


typedef struct __PHYSFS_FILEHANDLE__
{
        /*
         * This is reserved for the driver to store information.
         */
    void *opaque;

        /*
         * This should be the DirHandle that created this FileHandle.
         */
    const struct __PHYSFS_DIRHANDLE__ *dirHandle;

        /*
         * Pointer to the file i/o functions for this filehandle.
         */
    const struct __PHYSFS_FILEFUNCTIONS__ *funcs;
} FileHandle;


typedef struct __PHYSFS_FILEFUNCTIONS__
{
        /*
         * Read more from the file.
         * Returns number of objects of (objSize) bytes read from file, -1
         *  if complete failure.
         * On failure, call __PHYSFS_setError().
         */
    int (*read)(FileHandle *handle, void *buffer,
                unsigned int objSize, unsigned int objCount);

        /*
         * Write more to the file. Archives don't have to implement this.
         *  (Set it to NULL if not implemented).
         * Returns number of objects of (objSize) bytes written to file, -1
         *  if complete failure.
         * On failure, call __PHYSFS_setError().
         */
    int (*write)(FileHandle *handle, void *buffer,
                 unsigned int objSize, unsigned int objCount);

        /*
         * Returns non-zero if at end of file.
         */
    int (*eof)(FileHandle *handle);

        /*
         * Returns byte offset from start of file.
         */
    int (*tell)(FileHandle *handle);

        /*
         * Move read/write pointer to byte offset from start of file.
         *  Returns non-zero on success, zero on error.
         * On failure, call __PHYSFS_setError().
         */
    int (*seek)(FileHandle *handle, int offset);

        /*
         * Close the file, and free the FileHandle structure (including "opaque").
         *  returns non-zero on success, zero if can't close file.
         * On failure, call __PHYSFS_setError().
         */
    int (*fileClose)(FileHandle *handle);
} FileFunctions;


typedef struct __PHYSFS_DIRHANDLE__
{
        /*
         * This is reserved for the driver to store information.
         */
    void *opaque;

        /*
         * Pointer to the directory i/o functions for this handle.
         */
    const struct __PHYSFS_DIRFUNCTIONS__ *funcs;
} DirHandle;


/*
 * Symlinks should always be followed; PhysicsFS will use
 *  DirFunctions->isSymLink() and make a judgement on whether to
 *  continue to call other methods based on that.
 */
typedef struct __PHYSFS_DIRFUNCTIONS__
{
        /*
         * Returns non-zero if (filename) is a valid archive that this
         *  driver can handle. This filename is in platform-dependent
         *  notation. forWriting is non-zero if this is to be used for
         *  the write directory, and zero if this is to be used for an
         *  element of the search path.
         */
    int (*isArchive)(const char *filename, int forWriting);

        /*
         * Return a DirHandle for dir/archive (name).
         *  This filename is in platform-dependent notation.
         *  forWriting is non-zero if this is to be used for
         *  the write directory, and zero if this is to be used for an
         *  element of the search path.
         * Returns NULL on failure, and calls __PHYSFS_setError().
         */
    DirHandle *(*openArchive)(const char *name, int forWriting);

        /*
         * Returns a list of all files in dirname. Each element of this list
         *  (and its "str" field) will be deallocated with the system's free()
         *  function by the caller, so be sure to explicitly malloc() each
         *  chunk.
         * If you have a memory failure, return as much as you can.
         *  This dirname is in platform-independent notation.
         */
    LinkedStringList *(*enumerateFiles)(DirHandle *r, const char *dirname);

        /*
         * Returns non-zero if filename can be opened for reading.
         *  This filename is in platform-independent notation.
         */
    int (*exists)(DirHandle *r, const char *name);

        /*
         * Returns non-zero if filename is really a directory.
         *  This filename is in platform-independent notation.
         */
    int (*isDirectory)(DirHandle *r, const char *name);

        /*
         * Returns non-zero if filename is really a symlink.
         *  This filename is in platform-independent notation.
         */
    int (*isSymLink)(DirHandle *r, const char *name);

        /*
         * Open file for reading, and return a FileHandle.
         *  This filename is in platform-independent notation.
         * If you can't handle multiple opens of the same file,
         *  you can opt to fail for the second call.
         * Fail if the file does not exist.
         * Returns NULL on failure, and calls __PHYSFS_setError().
         */
    FileHandle *(*openRead)(DirHandle *r, const char *filename);

        /*
         * Open file for writing, and return a FileHandle.
         * If the file does not exist, it should be created. If it exists,
         *  it should be truncated to zero bytes. The writing
         *  offset should be the start of the file.
         * This filename is in platform-independent notation.
         *  This method may be NULL.
         * If you can't handle multiple opens of the same file,
         *  you can opt to fail for the second call.
         * Returns NULL on failure, and calls __PHYSFS_setError().
         */
    FileHandle *(*openWrite)(DirHandle *r, const char *filename);

        /*
         * Open file for appending, and return a FileHandle.
         * If the file does not exist, it should be created. The writing
         *  offset should be the end of the file.
         * This filename is in platform-independent notation.
         *  This method may be NULL.
         * If you can't handle multiple opens of the same file,
         *  you can opt to fail for the second call.
         * Returns NULL on failure, and calls __PHYSFS_setError().
         */
    FileHandle *(*openAppend)(DirHandle *r, const char *filename);

        /*
         * Delete a file in the archive/directory.
         *  Return non-zero on success, zero on failure.
         *  This filename is in platform-independent notation.
         *  This method may be NULL.
         * On failure, call __PHYSFS_setError().
         */
    int (*remove)(DirHandle *r, const char *filename);

        /*
         * Create a directory in the archive/directory.
         *  If the application is trying to make multiple dirs, PhysicsFS
         *  will split them up into multiple calls before passing them to
         *  your driver.
         *  Return non-zero on success, zero on failure.
         *  This filename is in platform-independent notation.
         *  This method may be NULL.
         * On failure, call __PHYSFS_setError().
         */
    int (*mkdir)(DirHandle *r, const char *filename);

        /*
         * Close directories/archives, and free the handle, including
         *  the "opaque" entry. This should assume that it won't be called if
         *  there are still files open from this DirHandle.
         */
    void (*dirClose)(DirHandle *r);
} DirFunctions;


/* error messages... */
#define ERR_IS_INITIALIZED       "Already initialized"
#define ERR_NOT_INITIALIZED      "Not initialized"
#define ERR_INVALID_ARGUMENT     "Invalid argument"
#define ERR_FILES_STILL_OPEN     "Files still open"
#define ERR_NO_DIR_CREATE        "Failed to create directories"
#define ERR_OUT_OF_MEMORY        "Out of memory"
#define ERR_NOT_IN_SEARCH_PATH   "No such entry in search path"
#define ERR_NOT_SUPPORTED        "Operation not supported"
#define ERR_UNSUPPORTED_ARCHIVE  "Archive type unsupported"
#define ERR_NOT_A_HANDLE         "Not a file handle"
#define ERR_INSECURE_FNAME       "Insecure filename"
#define ERR_SYMLINK_DISALLOWED   "Symbolic links are disabled"
#define ERR_NO_WRITE_DIR         "Write directory is not set"
#define ERR_NO_SUCH_FILE         "No such file"
#define ERR_PAST_EOF             "Past end of file"
#define ERR_ARC_IS_READ_ONLY     "Archive is read-only"

/*
 * Call this to set the message returned by PHYSFS_getLastError().
 *  Please only use the ERR_* constants above, or add new constants to the
 *  above group, but I want these all in one place.
 *
 * Calling this with a NULL argument is a safe no-op.
 */
void __PHYSFS_setError(const char *err);


/*
 * Convert (dirName) to platform-dependent notation, then prepend (prepend)
 *  and append (append) to the converted string.
 *
 *  So, on Win32, calling:
 *     __PHYSFS_convertToDependent("C:\", "my/files", NULL);
 *  ...will return the string "C:\my\files".
 *
 * This is a convenience function; you might want to hack something out that
 *  is less generic (and therefore more efficient).
 *
 * Be sure to free() the return value when done with it.
 */
char *__PHYSFS_convertToDependent(const char *prepend,
                                  const char *dirName,
                                  const char *append);

/*
 * Verify that (fname) (in platform-independent notation), in relation
 *  to (h) is secure. That means that each element of fname is checked
 *  for symlinks (if they aren't permitted). Also, elements such as
 *  ".", "..", or ":" are flagged.
 *
 * Returns non-zero if string is safe, zero if there's a security issue.
 *  PHYSFS_getLastError() will specify what was wrong.
 */
int __PHYSFS_verifySecurity(DirHandle *h, const char *fname);


/* This gets used all over for lessening code clutter. */
#define BAIL_IF_MACRO(c, e, r) if (c) { __PHYSFS_setError(e); return r; }




/*--------------------------------------------------------------------------*/
/*--------------------------------------------------------------------------*/
/*------------                                              ----------------*/
/*------------  You MUST implement the following functions  ----------------*/
/*------------        if porting to a new platform.         ----------------*/
/*------------         (see unix.c for an example)          ----------------*/
/*------------                                              ----------------*/
/*--------------------------------------------------------------------------*/
/*--------------------------------------------------------------------------*/


/*
 * The dir separator; "/" on unix, "\\" on win32, ":" on MacOS, etc...
 *  Obviously, this isn't a function, but it IS a null-terminated string.
 */
extern const char *__PHYSFS_platformDirSeparator;

/*
 * Platform implementation of PHYSFS_getCdRomDirs()...
 *  See physfs.h. The retval should be freeable via PHYSFS_freeList().
 */
char **__PHYSFS_platformDetectAvailableCDs(void);

/*
 * Calculate the base dir, if your platform needs special consideration.
 *  Just return NULL if the standard routines will suffice. (see
 *  calculateBaseDir() in physfs.c ...)
 *  Caller will free() the retval if it's not NULL.
 */
char *__PHYSFS_platformCalcBaseDir(const char *argv0);

/*
 * Get the platform-specific user name.
 *  Caller will free() the retval if it's not NULL. If it's NULL, the username
 *  will default to "default".
 */
char *__PHYSFS_platformGetUserName(void);

/*
 * Get the platform-specific user dir.
 *  Caller will free() the retval if it's not NULL. If it's NULL, the userdir
 *  will default to basedir/username.
 */
char *__PHYSFS_platformGetUserDir(void);

/*
 * Return a number that uniquely identifies the current thread.
 *  On a platform without threading, (1) will suffice. These numbers are
 *  arbitrary; the only requirement is that no two threads have the same
 *  number.
 */
int __PHYSFS_platformGetThreadID(void);

/*
 * This is a pass-through to whatever stricmp() is called on your platform.
 */
int __PHYSFS_platformStricmp(const char *str1, const char *str2);

/*
 * Return non-zero if filename (in platform-dependent notation) exists.
 *  Symlinks should be followed; if what the symlink points to is missing,
 *  then the retval is false.
 */
int __PHYSFS_platformExists(const char *fname);

/*
 * Return non-zero if filename (in platform-dependent notation) is a symlink.
 */
int __PHYSFS_platformIsSymLink(const char *fname);

/*
 * Return non-zero if filename (in platform-dependent notation) is a symlink.
 *  Symlinks should be followed; if what the symlink points to is missing,
 *  or isn't a directory, then the retval is false.
 */
int __PHYSFS_platformIsDirectory(const char *fname);

/*
 * Convert (dirName) to platform-dependent notation, then prepend (prepend)
 *  and append (append) to the converted string.
 *
 *  So, on Win32, calling:
 *     __PHYSFS_platformCvtToDependent("C:\", "my/files", NULL);
 *  ...will return the string "C:\my\files".
 *
 * This can be implemented in a platform-specific manner, so you can get
 *  get a speed boost that the default implementation can't, since
 *  you can make assumptions about the size of strings, etc..
 *
 * Platforms that choose not to implement this may just call
 *  __PHYSFS_convertToDependent() as a passthrough.
 *
 * Be sure to free() the return value when done with it.
 */
char *__PHYSFS_platformCvtToDependent(const char *prepend,
                                      const char *dirName,
                                      const char *append);

/*
 * Make the current thread give up a timeslice. This is called in a loop
 *  while waiting for various external forces to get back to us.
 */
void __PHYSFS_platformTimeslice(void);


/*
 * Enumerate a directory of files. This follows the rules for the
 *  DirFunctions->enumerateFiles() method (see above), except that the
 *  (dirName) that is passed to this function is converted to
 *  platform-DEPENDENT notation by the caller. The DirFunctions version
 *  uses platform-independent notation.
 */
LinkedStringList *__PHYSFS_platformEnumerateFiles(const char *dirname);


#ifdef __cplusplus
extern "C" {
#endif

#endif

/* end of physfs_internal.h ... */