- Avoid large temporary files from hexdump output and avoid

diff(1) runing OOM by using a fifo (issue#24)

OBS-URL: https://build.opensuse.org/package/show/openSUSE:Tools/build-compare?expand=0&rev=248

build-compare.changes

@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Mon May 28 13:26:44 UTC 2018 - olaf@aepfle.de
+
+- Avoid large temporary files from hexdump output and avoid
+  diff(1) runing OOM by using a fifo (issue#24)
+
 -------------------------------------------------------------------
 Fri Apr 13 07:10:30 UTC 2018 - olaf@aepfle.de
 

build-compare.spec

@@ -21,7 +21,7 @@ Summary:        Build Result Compare Script
 License:        GPL-2.0+
 Group:          Development/Tools/Building
 Url:            https://github.com/openSUSE/build-compare
-Version:        20180413T091103.4639e30
+Version:        20180528T152809.3cec12e
 Release:        0
 Source1:        COPYING
 Source2:        same-build-result.sh

pkg-diff.sh

@@ -280,6 +280,9 @@ dfile=`mktemp`
 
 diff_two_files()
 {
+  local offset length
+  local po pn
+
   if test ! -e old/$file; then
     echo "Missing in old package: $file"
     return 1
@@ -289,15 +292,25 @@ diff_two_files()
     return 1
   fi
 
-  if cmp -s old/$file new/$file; then
+  if cmp -b old/$file new/$file > $dfile ; then
     return 0
   fi
+  if ! test -s $dfile ; then
+    return 1
+  fi
 
-  echo "$file differs ($ftype)"
-  hexdump -C old/$file > $file1 &
-  hexdump -C new/$file > $file2 &
-  wait
-  diff -u $file1 $file2 | $buildcompare_head
+  offset=`sed 's@^.*differ: byte @@;s@,.*@@' < $dfile`
+  echo "$file differs at offset '$offset' ($ftype)"
+  po=`mktemp --dry-run $TMPDIR/old.XXX`
+  pn=`mktemp --dry-run $TMPDIR/new.XXX`
+  mkfifo -m 0600 $po
+  mkfifo -m 0600 $pn
+  offset=$(( ($offset >> 6) << 6 ))
+  length=512
+  hexdump -C -s $offset -l $length old/$file > $po &
+  hexdump -C -s $offset -l $length new/$file > $pn &
+  diff -u $po $pn | $buildcompare_head
+  rm -f $po $pn
   return 1
 }