You should be able to do that pretty easily with HDF5. If you are absolutely certain your datasets will never, ever change in size, you could create an 'empty' database by going through and creating N datasets (H5Dcreate) of desired size (H5Screate_simple) but not actually writing anything to any of the datasets.
Then, as time evolves, you pick a particular dataset to open (H5Dopen), write to (writing afresh if the dataset has yet to be written to or overwriting whats already there if it has already been written to -- makes no difference to the application. It just calls H5Dwrite) and H5Dclose. If you think you might want to be able to vary dataset size over time, use 'chunked' datasets (H5Pset_chunk) instead of the default (contiguous). If you need to maintain other tidbits of information about the datasets such as time of acquisition, sensor # (whatever), and that data is 'small' (<16kb), attach attributes (H5Acreate) to your datasets and overwrite those attributes as you would datasets (H5Aopen, H5Awrite, H5Aclose). Mark On Thu, 2010-03-25 at 13:11, [email protected] wrote: > I am interested in using HDF5 to manage sensor data within a continuous > Circular Database/File. I wish to define a database of a fixed size to > manage a finite amount of historical data. When the database file is full > (i.e. reach the defined capacity) I would like to begin overwriting the > oldest data within the file.) This is for an application for a system > where I only care about the most recent data over a specific duration with > obvious constraints on the amount of storage available. > > Does HDF5 have such capability or is there a recommended > approach/suggestions anyone has? > > Best Regards, > Kirk Harrison > > > > _______________________________________________ > Hdf-forum is for HDF software users discussion. > [email protected] > http://*mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org -- Mark C. Miller, Lawrence Livermore National Laboratory ================!!LLNL BUSINESS ONLY!!================ [email protected] urgent: [email protected] T:8-6 (925)-423-5901 M/W/Th:7-12,2-7 (530)-753-851 _______________________________________________ Hdf-forum is for HDF software users discussion. [email protected] http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
