From ad6956af739853d8d63023549e64bd378f18cd2d Mon Sep 17 00:00:00 2001
From: "Kyle J. McKay" <mackyle@gmail.com>
Date: Tue, 9 Jun 2020 19:50:11 -0700
Subject: [PATCH] gc-git-svn: arrange for `git-svn fetch` to run gc-git-svn.sh

When `git svn fetch` runs `git gc --auto`, arrange for it to
end up running the `jobd/gc-git-svn.sh` script.

This will allow Girocco to perform any needed loose object
packing during a long `git-svn fetch` operation.

Up until now, all garbage collection has been entirely
suppressed during `git-svn fetch` operations potentially
resulting in an excessively large number of loose objects
being created before they were ultimately packed up.

The `gc-git-svn.sh` script currently does nothing but will
be filled in by a future commit.

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
---
 hooks/pre-auto-gc  |  6 ++++++
 jobd/gc-git-svn.sh | 26 ++++++++++++++++++++++++++
 jobd/update.sh     | 13 +++++++++++++
 shlib.sh           |  1 +
 taskd/clone.sh     | 13 +++++++++++++
 5 files changed, 59 insertions(+)
 create mode 100755 jobd/gc-git-svn.sh

diff --git a/hooks/pre-auto-gc b/hooks/pre-auto-gc
index e224a6f..98769bf 100755
--- a/hooks/pre-auto-gc
+++ b/hooks/pre-auto-gc
@@ -8,6 +8,12 @@
 # If GIROCCO_SUPPRESS_AUTO_GC_UPDATE immediately exit suppressing auto gc
 [ "${GIROCCO_SUPPRESS_AUTO_GC_UPDATE:-0}" = "0" ] || exit 1
 
+# If GIROCCO_DIVERT_GIT_SVN_AUTO_GC divert to $basedir/jobd/gc-git-svn.sh
+[ "${GIROCCO_DIVERT_GIT_SVN_AUTO_GC:-0}" = "0" ] || {
+	@basedir@/jobd/gc-git-svn.sh
+	exit 1
+}
+
 # If we're in the chroot immediately exit suppressing auto gc
 [ -x @perlbin@ ] || exit 1
 
diff --git a/jobd/gc-git-svn.sh b/jobd/gc-git-svn.sh
new file mode 100755
index 0000000..80c5e0d
--- /dev/null
+++ b/jobd/gc-git-svn.sh
@@ -0,0 +1,26 @@
+#!/bin/sh
+
+# Girocco installs a pre-auto-gc hook.
+# When $GIROCCO_DIVERT_GIT_SVN_AUTO_GC is set to 1
+# that hook, when executed, runs this script and
+# no matter what exit code this script uses, the
+# pre-auto-gc hook always exits with a code of 1
+# immediately after this script finishes thereby
+# aborting any Git-directed gc.
+
+# The `git-svn fetch` operation periodically runs
+# `git gc --auto` which ultimately causes this
+# script to run provided the correct conditions
+# are met and $GIROCCO_DIVERT_GIT_SVN_AUTO_GC is
+# set to 1 in the environment.
+
+# Both the jobd/update.sh and taskd/clone.sh scripts
+# set and export GIROCCO_DIVERT_GIT_SVN_AUTO_GC=1
+# and force `gc.auto=1` as well whenever they process
+# a `git-svn` mirror.
+
+. @basedir@/shlib.sh
+
+set -e
+
+exit 0
diff --git a/jobd/update.sh b/jobd/update.sh
index f6c86a5..794da5c 100755
--- a/jobd/update.sh
+++ b/jobd/update.sh
@@ -313,7 +313,20 @@ case "$url" in
 		# remove any stale *.lock files greater than 1 hour old in case
 		# git-svn was killed on the last update because it took too long
 		find -L svn -type f -name '*.lock' -mmin +60 -exec rm -f '{}' + 2>/dev/null || :
+		GIROCCO_DIVERT_GIT_SVN_AUTO_GC=1
+		export GIROCCO_DIVERT_GIT_SVN_AUTO_GC
+		unset GIROCCO_SUPPRESS_AUTO_GC_UPDATE
+		saveconfig="$GIT_CONFIG_PARAMETERS"
+		git_add_config 'gc.auto=1'
 		GIT_DIR=. bang git svn fetch --log-window-size=$var_log_window_size --username="$svnuser" --quiet <"$mtlinesfile"
+		GIROCCO_SUPPRESS_AUTO_GC_UPDATE=1
+		export GIROCCO_SUPPRESS_AUTO_GC_UPDATE
+		unset GIROCCO_DIVERT_GIT_SVN_AUTO_GC
+		unset GIT_CONFIG_PARAMETERS
+		[ -z "$saveconfig" ] || {
+			GIT_CONFIG_PARAMETERS="$saveconfig"
+			export GIT_CONFIG_PARAMETERS
+		}
 		# git svn does not preserve group permissions in the svn subdirectory
 		chmod -R ug+rw,o+r svn
 		# git svn also leaves behind ref turds that end with @nnn
diff --git a/shlib.sh b/shlib.sh
index b65bb1e..6dcd432 100644
--- a/shlib.sh
+++ b/shlib.sh
@@ -240,6 +240,7 @@ if [ -n "$defined_cfg_git_client_ua" ]; then
 	export GIT_USER_AGENT
 fi
 unset GIT_CONFIG_PARAMETERS
+unset GIROCCO_DIVERT_GIT_SVN_AUTO_GC
 
 #
 ## IMPORTANT!
diff --git a/taskd/clone.sh b/taskd/clone.sh
index c3d10aa..c7db20b 100755
--- a/taskd/clone.sh
+++ b/taskd/clone.sh
@@ -369,8 +369,21 @@ case "$url" in
 		while [ "$svn_retries" -gt 0 ]; do
 			svn_retries="$(( $svn_retries - 1 ))"
 			svn_err=0
+			GIROCCO_DIVERT_GIT_SVN_AUTO_GC=1
+			export GIROCCO_DIVERT_GIT_SVN_AUTO_GC
+			unset GIROCCO_SUPPRESS_AUTO_GC_UPDATE
+			saveconfig="$GIT_CONFIG_PARAMETERS"
+			git_add_config 'gc.auto=1'
 			# Again, be careful to use GIT_DIR=. here or else new .git subdirectory!
 			GIT_DIR=. git svn fetch --log-window-size=$var_log_window_size --username="$svnuser" --quiet <"$mtlinesfile" || svn_err="$?"
+			GIROCCO_SUPPRESS_AUTO_GC_UPDATE=1
+			export GIROCCO_SUPPRESS_AUTO_GC_UPDATE
+			unset GIROCCO_DIVERT_GIT_SVN_AUTO_GC
+			unset GIT_CONFIG_PARAMETERS
+			[ -z "$saveconfig" ] || {
+				GIT_CONFIG_PARAMETERS="$saveconfig"
+				export GIT_CONFIG_PARAMETERS
+			}
 			[ "${svn_err:-1}" -ne 0 ] || break # success!
 			# Check to see if we made any progress
 			v_get_svn_progress_fingerprint svn_progress_now
-- 
2.11.4.GIT