| 44 | | = Compression of input files = |
| 45 | | |
| 46 | | Starting with version 5.4, the BOINC client is able to handle HTTP Content-Encoding types 'deflate' (zlib algorithm) and 'gzip' (gzip algorithm). The client decompresses these files 'on the fly' and stores them on disk in uncompressed form. |
| 47 | | |
| 48 | | You can use this in two ways: |
| 49 | | |
| 50 | | * Use the Apache 2.0 mod_deflate module to automatically compress files on the fly. This method will work with all BOINC clients, but it will do compression only for 5.4+ clients. Here is a [http://boinc.berkeley.edu/apache_deflate.txt cookbook] on how to configure this. |
| 51 | | * Compress files and give them a filename suffix such as '.gz'. The name used in your <file_info> elements, however, is the original filename without '.gz'. |
| 52 | | |
| 53 | | Include the following line in httpd.conf: |
| 54 | | |
| 55 | | |
| 56 | | {{{ |
| 57 | | AddEncoding x-gzip .gz |
| 58 | | }}} |
| 59 | | |
| 60 | | |
| 61 | | This will add the content encoding to the header so that the client will decompress the file automatically. This method has the advantage of reducing server disk usage and server CPU load, but it will only work with 5.4+ clients. Use the 'min_core_version' field of the app_version table to enforce this. You can use this in conjunction because the mod_deflate module allows you to exempt certain filetypes from on-the-fly compression. |
| 62 | | |
| 63 | | Both methods store files uncompressed on the client. If you need compression on the client, you must do it at the application level. The BOINC source distribution includes [http://boinc.berkeley.edu/boinc_zip.txt a version of the zip library] designed for use by BOINC applications on any platform. |
| 64 | | |
| 65 | | = Compression of output files = |
| 66 | | |
| 67 | | If you include the <gzip_when_done> tag in an [http://boinc.berkeley.edu/xml.php#file output file description], the file will be gzip-compressed after it has been generated. |
