From: pg@sweng.stortek.com
Message-id: <199912220157.SAA24108@sanitas>
Subject: [PATCH] mkshadow.sh accelerator
To: new-httpd@apache.org (Apache Developers List)
Date: Tue, 21 Dec 1999 18:57:22 -0700 (MST)
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Sender: new-httpd-owner@apache.org
Precedence: bulk
Reply-To: new-httpd@apache.org
Status: O

On OS/390 the overhead for fork and exec is extremely high.
this make "configure" painfully slow.  Most of the time is
consumed by "mkshadow.sh", which executes 2 or 3 "sed"s and
an "ln -s" for each symbolic link created.  This patch replaces
mkshadow.sh (except for a few comments).  Much of the filtering
by "sed" is replaced by predicates in the "find".  An "awk"
script then batches the commands so a single "ln -s" is issued
for each directory.  This roughly halves the time taken by
"configure" on OS/390, and slightly improves performance on
Solaris.

Furthermore, this fixes a bug that was manifest when the
path to the shadow directory contains a rootward segment ("/../").
Directory levels were counted incorrectly, causing creation
of invalid symbolic links.

Tested in builds on OS/390 and Solaris, and unit tested (no build)
on MkLinux.

-- gil
-- 
StorageTek
INFORMATION made POWERFUL
========================================================================
diff -bru orig/apache-1.3/configure apache-1.3/configure
--- orig/apache-1.3/configure	Wed Dec  8 15:04:15 1999
+++ apache-1.3/configure	Wed Dec  8 13:10:54 1999
@@ -534,7 +534,8 @@
                         echo " + creating external package shadow tree ($shadow)"
                     fi
                     rm -rf $shadow 2>/dev/null
-                    $aux/mkshadow.sh . $shadow
+                    ( export SHELL AWK
+                      $aux/mkshadow.sh . $shadow )
                     for file in $mkf $sedsubst $addconf $tplconf $pldconf $configstatus; do
                         rm -f $shadow/$file 2>/dev/null
                     done
@@ -580,7 +581,8 @@
                 echo " + creating internal platform shadow tree ($shadowsrc)"
             fi
             rm -rf $shadowsrc
-            $aux/mkshadow.sh $src $shadowsrc
+            ( export SHELL AWK
+              $aux/mkshadow.sh $src $shadowsrc )
             #   delegate us to the shadow paths
             mkf=$shadowmkf
             src=$shadowsrc
diff -bru orig/apache-1.3/src/helpers/mkshadow.sh apache-1.3/src/helpers/mkshadow.sh
--- orig/apache-1.3/src/helpers/mkshadow.sh	Tue Jun 29 13:12:58 1999
+++ apache-1.3/src/helpers/mkshadow.sh	Wed Dec  8 15:02:14 1999
@@ -6,24 +6,27 @@
 ##  for the shadow tree generation option (--shadow) of 
 ##  Apache's Autoconf-style Interface (APACI) 
 ##
+#   Heavily modified by Paul Gilmartin <pg@sweng.stortek.com>
+#   for OS/390 performance and for correct operation when
+#   $src or $dst contains "/../" or involve symbolic links.
 #
 # This script falls under the Apache License.
 # See http://www.apache.org/docs/LICENSE
 
 
-#   default IFS
-DIFS=' 	
-'
-
 #   source and destination directory
-src=`echo $1 | sed -e 's:/$::'`
-dst=`echo $2 | sed -e 's:/$::'`
+src="$1"
+dst="$2"
+: ${SHELL=/bin/sh}
 
 #   check whether source exists
-if [ ! -d $src ]; then
+SOURCE=`cd $src && unset PWD && $SHELL -c pwd` || {
     echo "mkshadow.sh:Error: source directory not found" 1>&2
     exit 1
-fi
+    }
+
+SHADOW=`mkdir -p $dst && cd $dst &&
+    unset PWD && $SHELL -c pwd` || exit $?
 
 #   determine if one of the paths is an absolute path,
 #   because then we have to use an absolute symlink
@@ -35,76 +38,61 @@
     /* ) oneisabs=1 ;;
 esac
 
-#   determine reverse directory for destination directory
-dstrevdir=''
-if [ "x$oneisabs" = "x0" ]; then
-    #   (inlined fp2rp)
-    OIFS2="$IFS"; IFS='/'
-    for pe in $dst; do
-        dstrevdir="../$dstrevdir"
-    done
-    IFS="$OIFS2"
-else
-    src="`cd $src; pwd`";
-fi
-
-#   create directory tree at destination
-if [ ! -d $dst ]; then
-    mkdir $dst
-fi
-DIRS="`cd $src; \
-       find . -type d -print |\
-       sed -e '/\/CVS/d' \
-           -e '/^\.$/d' \
-           -e 's:^\./::'`"
-OIFS="$IFS" IFS="$DIFS"
-for dir in $DIRS; do
-    mkdir $dst/$dir
-done
-IFS="$OIFS"
-
-#   fill directory tree with symlinks to files
-FILES="`cd $src; \
-        find . -depth -print |\
-        sed -e '/\.o$/d' \
-            -e '/\.a$/d' \
-            -e '/\.so$/d' \
-            -e '/\.so-o$/d' \
-            -e '/\.cvsignore$/d' \
-            -e '/\/CVS/d' \
-            -e '/\.indent\.pro$/d' \
-            -e '/\.apaci.*/d' \
-            -e '/Makefile$/d' \
-            -e '/\/\.#/d' \
-            -e '/\.orig$/d' \
-            -e 's/^\.\///'`"
-OIFS="$IFS" IFS="$DIFS"
-for file in $FILES; do
-     #  don't use `-type f' above for find because of symlinks
-     if [ -d "$src/$file" ]; then
-         continue
-     fi
-     basename=`echo $file | sed -e 's:^.*/::'`
-     dir=`echo $file | sed -e 's:[^/]*$::' -e 's:/$::' -e 's:$:/:' -e 's:^/$::'`
-     from="$src/$file"
-     to="$dst/$dir$basename"
-     if [ "x$oneisabs" = "x0" ]; then
-         if [ "x$dir" != "x" ]; then
-             subdir=`echo $dir | sed -e 's:/$::'`
-             #   (inlined fp2rp)
-             revdir=''
-             OIFS2="$IFS"; IFS='/'
-             for pe in $subdir; do
-                 revdir="../$revdir"
-             done
-             IFS="$OIFS2"
-             #   finalize from
-             from="$revdir$from"
-         fi
-         from="$dstrevdir$from"
-     fi
-     echo "    $to"
-     ln -s $from $to
-done
-IFS="$OIFS"
-
+( cd $src && find . -name CVS -prune   \
+                 -o ! -name '*.o'          \
+                    ! -name '*.so'         \
+                    ! -name '*.so-o'       \
+                    ! -name '*.cvsignore'  \
+                    ! -name '*.indent.pro' \
+                    ! -name '*.apaci*'     \
+                    ! -name '*Makefile'    \
+                    ! -name '.#*'          \
+                    ! -name '*.orig'       \
+                    ! -name '*.rej'        \
+                    ! -name '*~'           \
+                    ! -type d              \
+                    -print ) |
+    "${AWK-awk}" \
+      ' BEGIN{ }
+	{ if ( ! Back ) {
+	    Relative = ( ! oneisabs )
+		nSrc = split( SOURCE, Src, "/" )
+		nShd = split( SHADOW, Shd, "/" )
+		nSame = 0;
+		if ( Relative ) for ( I = 1; I <= nSrc; I++ ) {
+		    if ( Src[ I ] != Shd [ I ] ) break
+		    nSame =  I }
+
+		Back = ""
+		if ( Relative )
+		    for ( I = nSame + 1; I<=nShd; I++ ) Back = "../"Back
+		else Back = ""
+	        for ( I = nSame + 1; I<=nSrc; I++ ) Back = Back Src[ I ]"/"
+		print( "# Back: " Back "\n" ) }
+
+	  match( $0, "[^/]*$" )
+	  Base = substr( $0, RSTART )
+	  Dir  = substr( $0, 1, RSTART-2 )"/"
+	  sub( "^\\.//*", "", Dir )
+	  Levels = split( Dir, Junk, "/" )
+
+	  Dots = Back
+	  if ( Relative )
+		for ( I = 1; I < Levels; I++ ) Dots = "../"Dots
+	  XDir = SHADOW"//"Dir
+	  ln[ XDir ] = ln[ XDir ] "    "Dots""Dir""Base" \\\n"
+	  rm[ XDir ] = rm[ XDir ] "    "Base" \\\n"
+	  ## lv[ XDir ] = " Levels: " Levels " Dots: " Dots " Dir: " Dir
+	}
+	END{
+	    for ( Dir in ln ) {
+		print( "echo \"\n: ========= Creating links in:\n: "Dir"\"" )
+		printf( "mkdir -p %s//. || exit $?\n", Dir )
+		printf( "( cd "Dir" && rm -f \\\n%s%s", rm[ Dir ], ")\n" )
+		print( "set -v" )
+		printf( "ln -s \\\n%s%s", ln[ Dir ], "  "Dir"//.\n" )
+		print( "set +v\n" )
+		}
+	   }' "SOURCE=$SOURCE" "SHADOW=$SHADOW" "oneisabs=$oneisabs" |
+## cat; exit $?
+"$SHELL"