This block provides the
NDB file system
abstraction layer, and is located in the directory
contains the following files:
AsyncFile.hpp: Defines the
AsyncFile class, which represents an
asynchronous file. All actions are executed concurrently
with the other activities carried out by the process.
Because all actions are performed in a separate thread, the
result of an action is sent back through a memory channel.
For the asyncronous notification of a finished request, each
callincludes a request as a parameter. This class is used
for writing or reading data to and from disk concurrently
with other activities.
AsyncFile.cpp: Defines the actions
possible for an asynchronous file, and implements them.
Filename.hpp: Defines the
Filename class. Takes a 128-bit value (as
a array of four longs) and makes a file name out of it. This
file name encodes information about the file, such as
whether it is a file or a directory, and if the former, the
type of file. Possible types include data file, fragment
log, fragment list, table list, schema log, and system file,
set() methods for the
Basic program for testing reads from and writes to a memory
channel (that is, reading from and writing to a circular
OpenFiles.hpp: Implements an
OpenFiles class, which provides some
convenience methods for determining whether or not a given
file is already open.
VoidFs.cpp: Used for diskless
operation. Generates a “dummy” acknowledgment
to write operations.
CircularIndex class, defined in this
file, serves as the building block for implementing circular
buffers. It increments as a normal index until it reaches
maximum size, then resets to zero.
CircularIndex.cpp: Contains only a
#define, not actually used at this
MemoryChannel.hpp: Defines the
which provide a pointer-based channel for communication
between two threads. It does not copy any data into or out
of the channel, so the item that is put in can not be used
untill the other thread has given it back. There is no
support for detecting the return of an item.
file, not used at this time.
Ndbfs.hpp: Because an
NDB signal request can result in multiple
AsyncFile, one class (defined
in this file) is responsible for keeping track of all
outstanding requests, and when all are finished, reporting
the outcome back to the sending block.
Ndbfs.cpp: Implements initialization
and signal-handling methods for the
Pool.hpp: Creates and manages a pool of
objects for use by
Ndbfs and other
classes in this block.
program, used to test and benchmark functionality of