Hardware Reference
In-Depth Information
FIGURE 20.1: An architecture for ecient stochastic simulation data man-
agement using HDF5.
and implement any kind of behavior before and after the actual calls to original
the HDF5 functions. This way, the behavior of an existing VFL driver could
be modified without actually modifying the code of the HDF5 library, thus
minimizing the need to patch the library every time a new version is made
available. One advantage of this approach is detouring the functions that
open and close files. This function can then be replaced with a function that
locks the file handle right after it has been acquired and unlocks it directly
before closing it. The process synchronization module provides appropriate
file locking mechanisms that enforce synchronization between processes on
different operating systems. Other potential uses of this technique include
\xing" bugs of the library without actually touching it. For example this
way it is possible to rectify HDF5 shortcomings that render a file unreadable
when a disk is full.
Proprietary VFL drivers are required to implement data manipulation at
higher or terminal level, for example, a driver for writing to the RAM instead
of the disk. These drivers are used by the HDF5 library alongside the filters
module, in order to implement encryption, compression, and lossy or lossless
data type{aware transformations.
