# [PATCH 1/2] pack-objects: document --delta-base-offset option 8 messages from 2006-10-13 to 2006-10-13. Participants: Junio C Hamano, Nicolas Pitre, Jakub Narebski. Thread: https://gitlist.dev/t/5912 ## Junio C Hamano, 2006-10-13 05:35 Subject: [PATCH 1/2] pack-objects: document --delta-base-offset option Message-ID: <11607177011745-git-send-email-junkio@cox.net> URL: https://gitlist.dev/e/11607177011745-git-send-email-junkio%40cox.net ``` Signed-off-by: Junio C Hamano --- Documentation/git-pack-objects.txt | 13 ++++++++++++- builtin-pack-objects.c | 2 +- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/Documentation/git-pack-objects.txt b/Documentation/git-pack-objects.txt index d4661dd..5788709 100644 --- a/Documentation/git-pack-objects.txt +++ b/Documentation/git-pack-objects.txt @@ -9,7 +9,7 @@ git-pack-objects - Create a packed archi SYNOPSIS -------- [verse] -'git-pack-objects' [-q] [--no-reuse-delta] [--non-empty] +'git-pack-objects' [-q] [--no-reuse-delta] [--delta-base-offset] [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] [--revs [--unpacked | --all]*] [--stdout | base-name] < object-list @@ -110,6 +110,17 @@ base-name:: This flag tells the command not to reuse existing deltas but compute them from scratch. +--delta-base-offset:: + A packed archive can express base object of a delta as + either 20-byte object name or as an offset in the + stream, but older version of git does not understand the + latter. By default, git-pack-objects only uses the + former format for better compatibility. This option + allows the command to use the latter format for + compactness. Depending on the average delta chain + length, this option typically shrinks the resulting + packfile by 3-5 per-cent. + Author ------ diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c index ee5f031..41e1e74 100644 --- a/builtin-pack-objects.c +++ b/builtin-pack-objects.c @@ -15,7 +15,7 @@ #include "list-objects.h" #include #include -static const char pack_usage[] = "git-pack-objects [-q] [--no-reuse-delta] [--non-empty] [--local] [--incremental] [--window=N] [--depth=N] [--revs [--unpacked | --all]*] [--stdout | base-name] URL: https://gitlist.dev/e/11607177024171-git-send-email-junkio%40cox.net In-Reply-To: <11607177011745-git-send-email-junkio@cox.net> ``` This new option makes the resulting pack express the delta base with more compact "offset" format. Signed-off-by: Junio C Hamano --- Documentation/git-repack.txt | 8 +++++++- git-repack.sh | 1 + 2 files changed, 8 insertions(+), 1 deletions(-) diff --git a/Documentation/git-repack.txt b/Documentation/git-repack.txt index 49f7e0a..5f5530d 100644 --- a/Documentation/git-repack.txt +++ b/Documentation/git-repack.txt @@ -9,7 +9,7 @@ objects into pack files. SYNOPSIS -------- -'git-repack' [-a] [-d] [-f] [-l] [-n] [-q] [--window=N] [--depth=N] +'git-repack' [-a] [-b] [-d] [-f] [-l] [-n] [-q] [--window=N] [--depth=N] DESCRIPTION ----------- @@ -35,6 +35,12 @@ OPTIONS about people fetching via dumb protocols from it. Use with '-d'. +-b:: + Pass the `--delta-base-offset` to `git pack-objects`; + see gitlink:git-pack-objects[1]. Do not use this option + if you want the repository to be accessible by older + versions of git. + -d:: After packing, if the newly created packs make some existing packs redundant, remove the redundant packs. diff --git a/git-repack.sh b/git-repack.sh index b525fc5..25dae5e 100755 --- a/git-repack.sh +++ b/git-repack.sh @@ -14,6 +14,7 @@ do -n) no_update_info=t ;; -a) all_into_one=t ;; -d) remove_redundant=t ;; + -b) extra="$extra --delta-base-offset" ;; -q) quiet=-q ;; -f) no_reuse_delta=--no-reuse-delta ;; -l) local=--local ;; -- 1.4.3.rc2.g51ca ``` ## Nicolas Pitre, 2006-10-13 13:20 Subject: Re: [PATCH 2/2] git-repack: -b to pass --delta-base-offset Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.64.0610130912500.2435%40xanadu.home In-Reply-To: <11607177024171-git-send-email-junkio@cox.net> ``` On Thu, 12 Oct 2006, Junio C Hamano wrote: > This new option makes the resulting pack express the delta base > with more compact "offset" format. Actually I thought about making it the default whenever git-pack-objects supported it, and use a negative option with git-repack to disable it instead. The fact is that there is little reason for not using delta base offsets in most cases and specifying -b all the time would become more of an annoyance. What do you think? Nicolas ``` ## Jakub Narebski, 2006-10-13 13:51 Subject: Re: [PATCH 2/2] git-repack: -b to pass --delta-base-offset Message-ID: URL: https://gitlist.dev/e/ego5kp%24fm4%241%40sea.gmane.org In-Reply-To: ``` Nicolas Pitre wrote: > On Thu, 12 Oct 2006, Junio C Hamano wrote: > >> This new option makes the resulting pack express the delta base >> with more compact "offset" format. > > Actually I thought about making it the default whenever git-pack-objects > supported it, and use a negative option with git-repack to disable it > instead. > > The fact is that there is little reason for not using delta base offsets > in most cases and specifying -b all the time would become more of an > annoyance. Perhaps we should leave it to configuretion variable, instead? And turn the new format on by default, like core.legacyHeaders -- Jakub Narebski Warsaw, Poland ShadeHawk on #git ``` ## Junio C Hamano, 2006-10-13 21:22 Subject: Re: [PATCH 2/2] git-repack: -b to pass --delta-base-offset Message-ID: <7v64endi6x.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7v64endi6x.fsf%40assigned-by-dhcp.cox.net In-Reply-To: ``` Nicolas Pitre writes: > On Thu, 12 Oct 2006, Junio C Hamano wrote: > >> This new option makes the resulting pack express the delta base >> with more compact "offset" format. > > Actually I thought about making it the default whenever git-pack-objects > supported it, and use a negative option with git-repack to disable it > instead. > > The fact is that there is little reason for not using delta base offsets > in most cases and specifying -b all the time would become more of an > annoyance. > > What do you think? The only time it matters is if the packs in repository being repacked needs to be readable by older git, which I think is only when somebody with older git uses commit walkers to download the pack into a remote repository to use. Using or not using delta-base-offset is tied to each repository, and in a sense that is similar to "repository format version". So how about [core] repackUseDeltaBase = true ``` ## Jakub Narebski, 2006-10-13 21:29 Subject: Re: [PATCH 2/2] git-repack: -b to pass --delta-base-offset Message-ID: URL: https://gitlist.dev/e/egp0fk%2415b%241%40sea.gmane.org In-Reply-To: <7v64endi6x.fsf@assigned-by-dhcp.cox.net> ``` Junio C Hamano wrote: > So how about > >         [core] >                 repackUseDeltaBase = true +1, but I'd rather first it default to false. -- Jakub Narebski Warsaw, Poland ShadeHawk on #git ``` ## Nicolas Pitre, 2006-10-13 21:58 Subject: Re: [PATCH 2/2] git-repack: -b to pass --delta-base-offset Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.64.0610131757050.2435%40xanadu.home In-Reply-To: <7v64endi6x.fsf@assigned-by-dhcp.cox.net> ``` On Fri, 13 Oct 2006, Junio C Hamano wrote: > Nicolas Pitre writes: > > > On Thu, 12 Oct 2006, Junio C Hamano wrote: > > > >> This new option makes the resulting pack express the delta base > >> with more compact "offset" format. > > > > Actually I thought about making it the default whenever git-pack-objects > > supported it, and use a negative option with git-repack to disable it > > instead. > > > > The fact is that there is little reason for not using delta base offsets > > in most cases and specifying -b all the time would become more of an > > annoyance. > > > > What do you think? > > The only time it matters is if the packs in repository being > repacked needs to be readable by older git, which I think is > only when somebody with older git uses commit walkers to > download the pack into a remote repository to use. Using or not > using delta-base-offset is tied to each repository, and in a > sense that is similar to "repository format version". > > So how about > > [core] > repackUseDeltaBase = true I agree, although "repackUseDeltaBase" is a bit vague as both delta types do use a delta base. Nicolas ``` ## Junio C Hamano, 2006-10-13 22:11 Subject: Re: [PATCH 2/2] git-repack: -b to pass --delta-base-offset Message-ID: <7vslhrc1e1.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7vslhrc1e1.fsf%40assigned-by-dhcp.cox.net In-Reply-To: ``` Nicolas Pitre writes: >> So how about >> >> [core] >> repackUseDeltaBase = true > > I agree, although "repackUseDeltaBase" is a bit vague as both delta > types do use a delta base. True; core.repackUseDeltaBaseOffset that is. ```