Dmitry Ivankov wrote: > How about adding a new bit field "no_delta" instead? Currently the layout of "struct tree_entry_ms" is: uint16_t mode; two bytes unsigned char sha1[20] 20 bytes which adds up to 22 bytes. Here is "struct tree_entry": struct tree_entry *tree; one machine word struct atom_str *name; one machine word struct tree_entry_ms versions[2]; 44 bytes Although it only looks like it adds one byte per tree entry, in practice I suspect your patch adds four. Is that worth it? (The answer might be yes. I'm not sure.) > The patch is > smaller this way. Also could 04000 theoretically be S_IFDIR on some > platform? No, these modes are part of the format of objects as written on disk and over the wire, so when we meet a platform with S_IFDIR != 040000, there will have to be bigger changes (to distinguish between the platform's idea of file status and git's idea of modes). > - switch to a separate no_delta bit in tree_entry If it doesn't cost too much, this is a good idea. > - when setting no_delta = 1 don't check for S_ISDIR(versions[0].mode), > this is a redundant check and logic duplication. Who knows, maybe some > day we'll want to delta a tree against blob. :) Why? When versions[0] is not a tree, the hack is not needed, since versions[0].mode and versions[0].sha1 accurately describe the delta base and are not inconsistent with anything. Thanks, that was helpful. -- 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