From e4f6809bbc51ceac3eea354a3f264b3cf0c483d3 Mon Sep 17 00:00:00 2001
From: cjwatson <cjwatson@localhost>
Date: Mon, 26 Oct 2009 16:28:04 +0000
Subject: [PATCH] 2009-10-26  Colin Watson  <cjwatson@ubuntu.com>

	Improve grub-mkconfig performance when there are several menu
	entries on a single filesystem.

	* util/grub.d/10_linux.in (linux_entry): Cache the output of
	prepare_grub_to_access_device.
	* util/grub.d/10_kfreebsd.in (kfreebsd_entry): Likewise.
	* util/grub.d/30_os-prober.in: Likewise.
---
 ChangeLog                   | 10 ++++++++++
 util/grub.d/10_kfreebsd.in  |  6 +++++-
 util/grub.d/10_linux.in     |  6 +++++-
 util/grub.d/30_os-prober.in |  6 +++++-
 4 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6ca49a0e2..e7e01fa37 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2009-10-26  Colin Watson  <cjwatson@ubuntu.com>
+
+	Improve grub-mkconfig performance when there are several menu
+	entries on a single filesystem.
+
+	* util/grub.d/10_linux.in (linux_entry): Cache the output of
+	prepare_grub_to_access_device.
+	* util/grub.d/10_kfreebsd.in (kfreebsd_entry): Likewise.
+	* util/grub.d/30_os-prober.in: Likewise.
+
 2009-10-26  Robert Millan  <rmh.grub@aybabtu.com>
 
 	* util/grub.d/10_freebsd.in: Remove.
diff --git a/util/grub.d/10_kfreebsd.in b/util/grub.d/10_kfreebsd.in
index 4fb704c49..cd8c186be 100644
--- a/util/grub.d/10_kfreebsd.in
+++ b/util/grub.d/10_kfreebsd.in
@@ -31,7 +31,10 @@ kfreebsd_entry ()
   cat << EOF
 menuentry "$1" {
 EOF
-  prepare_grub_to_access_device ${GRUB_DEVICE_BOOT} | sed -e "s/^/\t/"
+  if [ -z "${prepare_boot_cache}" ]; then
+    prepare_boot_cache="$(prepare_grub_to_access_device ${GRUB_DEVICE_BOOT} | sed -e "s/^/\t/")"
+  fi
+  printf '%s\n' "${prepare_boot_cache}"
   cat << EOF
 	kfreebsd			${rel_dirname}/${basename}
 EOF
@@ -58,6 +61,7 @@ EOF
 list=`for i in /boot/kfreebsd-* /boot/kernel/kernel ; do
         if grub_file_is_not_garbage "$i" ; then echo -n "$i " ; fi
       done`
+prepare_boot_cache=
 
 while [ "x$list" != "x" ] ; do
   kfreebsd=`version_find_latest $list`
diff --git a/util/grub.d/10_linux.in b/util/grub.d/10_linux.in
index 1473a42a2..f17955846 100644
--- a/util/grub.d/10_linux.in
+++ b/util/grub.d/10_linux.in
@@ -47,7 +47,10 @@ linux_entry ()
   cat << EOF
 menuentry "$1" {
 EOF
-  prepare_grub_to_access_device ${GRUB_DEVICE_BOOT} | sed -e "s/^/\t/"
+  if [ -z "${prepare_boot_cache}" ]; then
+    prepare_boot_cache="$(prepare_grub_to_access_device ${GRUB_DEVICE_BOOT} | sed -e "s/^/\t/")"
+  fi
+  printf '%s\n' "${prepare_boot_cache}"
   cat << EOF
 	linux	${rel_dirname}/${basename} root=${linux_root_device_thisversion} ro $2
 EOF
@@ -64,6 +67,7 @@ EOF
 list=`for i in /boot/vmlinu[xz]-* /vmlinu[xz]-* ; do
         if grub_file_is_not_garbage "$i" ; then echo -n "$i " ; fi
       done`
+prepare_boot_cache=
 
 while [ "x$list" != "x" ] ; do
   linux=`version_find_latest $list`
diff --git a/util/grub.d/30_os-prober.in b/util/grub.d/30_os-prober.in
index 84e227ee7..6fd97fc4e 100644
--- a/util/grub.d/30_os-prober.in
+++ b/util/grub.d/30_os-prober.in
@@ -74,6 +74,7 @@ EOF
     ;;
     linux)
       LINUXPROBED="`linux-boot-prober ${DEVICE} 2> /dev/null | tr ' ' '^' | paste -s -d ' '`"
+      prepare_boot_cache=
 
       for LINUX in ${LINUXPROBED} ; do
         LROOT="`echo ${LINUX} | cut -d ':' -f 1`"
@@ -90,7 +91,10 @@ EOF
         cat << EOF
 menuentry "${LLABEL} (on ${DEVICE})" {
 EOF
-	prepare_grub_to_access_device ${DEVICE} | sed -e "s/^/\t/"
+	if [ -z "${prepare_boot_cache}" ]; then
+	  prepare_boot_cache="$(prepare_grub_to_access_device ${DEVICE} | sed -e "s/^/\t/")"
+	fi
+	printf '%s\n' "${prepare_boot_cache}"
 	cat <<  EOF
 	linux ${LKERNEL} ${LPARAMS}
 EOF