Hi, On Mon, 14 Aug 2006, Jon Smirl wrote: > Does a zlib dictionary just changes the probabilities in the histogram > or does it turn the dictionary into a pre-loaded encoding tree? I have to admit that I do not know zlib well enough to tell off the top of my head, but I guess it would make more sense to have it as a preloaded encoding tree. > The other compression schemes I looked at let you load in a > precomputed huffman/arithmetic encoding tree. By preloading an > encoding tree you avoid storing the encoding of "void => 010101' in > every item. Removing 1M encoding maps and using one common one should > be a win. Items not in the map would still be stored using internal > additions to the map. > > Changing the probabilities probably won't help much, but there may be > good gains from partially eliminating 1M encoding maps. I _think_ that it would not matter much. The deltas have a more important impact. > > Further, if the pack-file becomes corrupt, you usually still have the > > pack index, or the start of the pack-file, and can reconstruct most of > > the objects. If you use a dictionary, and just one bit flips in it, > > you're screwed. I still think that this is important to think through: Is it worth a couple of kilobytes (I doubt that it would be as much as 1MB in _total_), and be on the unsafe side? Ciao, Dscho - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html