Tools.h++ Class Reference

Persistence
None
Public Constructor
RWFileManager(const char* filename, const char* mode = 0);
Constructs an RWFileManager for the file with path name filename using mode mode.
The mode is as given by the Standard C library function fopen(). If mode is zero (the
default) then the constructor will attempt to open an existing file with the given filename
for update (mode "rb+"). If this is not possible, then it will attempt to create a new file
with the given filename (mode "wb+"). If the file exists and is not empty, then the
constructor assumes it contains an existing file manager; other contents will cause an
exception of type RWExternalErr to be thrown. If no file exists or if an existing file is
empty, then the constructor will attempt to create the file (if necessary) and initialize it
with a new file manager. The resultant object should be checked for validity using
function isValid(). A possible exception that could occur is RWFileErr.
Public Member Functions
RWoffset
allocate(RWspace s);
Allocates s bytes of storage in the file. Returns the offset to the start of the storage
location. The very first allocation for the file is considered "special" and can be returned
at any later time by the function start(). A possible exception that could occur is
RWFileErr.
void
deallocate(RWoffset t);
Deallocates (frees) the storage space starting at offset t. This space must have been
previously allocated by a call to allocate(). The very first allocation ever made in the file
is considered "special" and cannot be deallocated. A possible exception that could occur
is RWFileErr.
RWoffset
endData();
Returns an offset just past the end of the file.
RWoffset
start();
Returns the offset of the first space ever allocated for data in this file. If no space has ever
been allocated, returns RWNIL. This is typically used to "get started" and find the rest of
the data in the file.