Matt, On 25/02/16 12:20, Matthew Fernandez wrote:
I think the salient points at this stage are the following: 1. Poly/ML performs seeks on the save path to rewind the FD and update metadata including byte offsets of other sections in the file. Here I'm referring to SaveRequest::Perform.
This is not a problem because segments can be compressed separately. Seeks are only performed to metadata sections and segment starts, as far as I can tell. The vast majority of the data, within the segments, can be compressed without issues as they are not fseek targets. I had experimented with segment compression earlier, but ran into mysterious segfaults and gave up.
2. LZO is GPL v2, while Poly/ML is LGPL v2.1. Thanks David and Rob for correcting me; I had misread the licence.
There are many alternatives to LZO, such as LZ4 (https://github.com/Cyan4973/lz4, BSD).
3. LZO streams do not appear to be seekable. Gzip streams seem seekable only for reading, and this is acknowledged to be slow.
As for (1). -- Japheth ________________________________ The information in this e-mail may be confidential and subject to legal professional privilege and/or copyright. National ICT Australia Limited accepts no liability for any damage caused by this email or its attachments. _______________________________________________ polyml mailing list [email protected] http://lists.inf.ed.ac.uk/mailman/listinfo/polyml
