{"thread":{"id":"30336","subject":"how to analyze binary delta compression","startedAt":"2012-04-25T21:15:32Z","lastAt":"2012-04-25T21:21:25Z","messageCount":2,"participants":["Neal Kreitzinger","Junio C Hamano"],"isPatch":false,"patchVersion":null,"patchTotal":null},"messages":[{"id":"190081","messageId":"jn9phl$t7s$1@dough.gmane.org","threadId":"30336","inReplyTo":null,"subject":"how to analyze binary delta compression","fromName":"Neal Kreitzinger","fromEmail":"nkreitzinger@gmail.com","sentAt":"2012-04-25T21:15:32Z","receivedAt":"2012-04-25T21:15:32Z","isPatch":false,"sender":{"key":"nkreitzinger@gmail.com","avatar":null},"body":"I need to assess the delta compression efficiency of various types of \nbinaries.  Can I do it this way:\n\n(1) Run git diff between two versions of a binary and pipe the result to \na file.  (Sample different types of binaries and changes.)\n(2) Assess the output by size or format or content to determine how well \nit delta differenced?  How would I determine this?  What are good \nabsolute delta sizes?  What are good delta size ratios compared to total \nfile size?  Is the number of hunks in the delta important?\n(3) Compress the delta file with gzip (or something) and then assess the \ncompression ratio?  What is a good compression ratio?  What are good \ndelta compressed absolute sizes?  What are good delta compressed \nrelative sizes to total file size?\n\nI'm sure I may be missing some things here.  I'm new to assessing delta \ncompression efficiency of binaries in general, and specifically for git. \n  Please advise.\n\nv/r,\nneal\n"},{"id":"190082","messageId":"xmqqsjfrbj8q.fsf@junio.mtv.corp.google.com","threadId":"30336","inReplyTo":"jn9phl$t7s$1@dough.gmane.org","subject":"Re: how to analyze binary delta compression","fromName":"Junio C Hamano","fromEmail":"gitster@pobox.com","sentAt":"2012-04-25T21:21:25Z","receivedAt":"2012-04-25T21:21:25Z","isPatch":false,"sender":{"key":"gitster@pobox.com","avatar":"https://avatars.githubusercontent.com/u/54884?v=4"},"body":"Neal Kreitzinger <nkreitzinger@gmail.com> writes:\n\n> I need to assess the delta compression efficiency of various types of\n> binaries.  Can I do it this way:\n\nUse test-delta to see how large the output is, perhaps?\n"}]}