Make output concise by default.

tools/resources/optimize-png-files.sh

Index: tools/resources/optimize-png-files.sh
diff --git a/tools/resources/optimize-png-files.sh b/tools/resources/optimize-png-files.sh
index 351e04545e1735aaec7a50b2331db9aa231885f2..6f17c7c52a214287541cd71c8f58ca0d5e028a92 100755
--- a/tools/resources/optimize-png-files.sh
+++ b/tools/resources/optimize-png-files.sh
@@ -49,9 +49,18 @@ PROCESSED_FILE=0
 declare -a THROBBER_STR=('-' '\\' '|' '/')
 THROBBER_COUNT=0
 
+SUBPROCESS=0
+
+# NoOp in subprocess, echo otherwise.
+function info {
+  if [ $SUBPROCESS -eq 0 ]; then
+    echo $@
+  fi
+}
+
 # Show throbber character at current cursor position.
 function throbber {
-  echo -ne "${THROBBER_STR[$THROBBER_COUNT]}\b"
+  info -ne "${THROBBER_STR[$THROBBER_COUNT]}\b"
   let THROBBER_COUNT=($THROBBER_COUNT+1)%4
 }
 
@@ -92,7 +101,7 @@ function get_color_depth_list {
 #
 # TODO(oshima): Experiment with -d0 w/o -c0.
 function process_grayscale {
-  echo -n "|gray"
+  info -n "|gray"
   for opt in $(get_color_depth_list); do
     pngout_loop $file -c0 $opt
   done
@@ -101,7 +110,7 @@ function process_grayscale {
 # Usage: process_grayscale_alpha <file>
 # Optimize grayscale images with alpha for all color bit depths.
 function process_grayscale_alpha {
-  echo -n "|gray-a"
+  info -n "|gray-a"
   pngout_loop $file -c4
   for opt in $(get_color_depth_list); do
     pngout_loop $file -c3 $opt
@@ -111,7 +120,7 @@ function process_grayscale_alpha {
 # Usage: process_rgb <file>
 # Optimize rgb images with or without alpha for all color bit depths.
 function process_rgb {
-  echo -n "|rgb"
+  info -n "|rgb"
   for opt in $(get_color_depth_list); do
     pngout_loop $file -c3 $opt
   done
@@ -123,7 +132,7 @@ function process_rgb {
 # Optimize the huffman blocks.
 function huffman_blocks {
   local file=$1
-  echo -n "|huffman"
+  info -n "|huffman"
   local size=$(stat -c%s $file)
   local min_block_size=$DEFAULT_MIN_BLOCK_SIZE
   local limit_blocks=$DEFAULT_LIMIT_BLOCKS
@@ -149,7 +158,7 @@ function huffman_blocks {
 # TODO(oshima): Try adjusting different parameters for large files to
 # reduce runtime.
 function random_huffman_table_trial {
-  echo -n "|random"
+  info -n "|random"
   local file=$1
   local old_size=$(stat -c%s $file)
   local trials_count=$DEFAULT_RANDOM_TRIALS
@@ -171,7 +180,7 @@ function random_huffman_table_trial {
 # Further compress using optipng and advdef.
 # TODO(oshima): Experiment with 256.
 function final_compression {
-  echo -n "|final"
+  info -n "|final"
   local file=$1
   if [ $OPTIMIZE_LEVEL == 2 ]; then
     for i in 32k 16k 8k 4k 2k 1k 512; do
@@ -183,7 +192,7 @@ function final_compression {
     throbber
     advdef -q -z -$i $file
   done
-  echo -ne "\r"
+  info -ne "\r"
 }
 
 # Usage: get_color_type <file>
@@ -206,7 +215,7 @@ function get_color_type {
 function optimize_size {
   tput el
   local file=$1
-  echo -n "$file "
+  info -n "$file "
 
   advdef -q -z -4 $file
 
@@ -225,7 +234,7 @@ function optimize_size {
     fi
   fi
 
-  echo -n "|filter"
+  info -n "|filter"
   local old_color_type=$(get_color_type $file)
   optipng -q -zc9 -zm8 -zs0-3 -f0-5 $file -out $file.tmp.png
   local new_color_type=$(get_color_type $file.tmp.png)
@@ -236,7 +245,7 @@ function optimize_size {
   # https://sourceforge.net/tracker/?func=detail&aid=3603630&group_id=151404&atid=780913
   if [[ $old_color_type == "RGBA" && $new_color_type =~ gray.* ]] ; then
     rm $file.tmp.png
-    echo -n "[skip opting]"
+    info -n "[skip opting]"
   else
     mv $file.tmp.png $file
   fi
@@ -245,7 +254,7 @@ function optimize_size {
   huffman_blocks $file
 
   # TODO(oshima): Experiment with strategy 1.
-  echo -n "|strategy"
+  info -n "|strategy"
   if [ $OPTIMIZE_LEVEL == 2 ]; then
     for i in 3 2 0; do
       pngout -q -k1 -ks -s$i $file
@@ -300,7 +309,7 @@ function optimize_file {
     let PROCESSED_FILE+=1
   else
     if [ $OPTIMIZE_LEVEL == 0 ]; then
-      echo -ne "$file : skipped\r"
+      info -ne "$file : skipped\r"
     fi
     rm $tmp_file
   fi
@@ -347,7 +356,7 @@ function fail_if_not_installed {
 function show_help {
   local program=$(basename $0)
   echo \
-"Usage: $program [options] dir ...
+"Usage: $program [options] <dir> ...
 
 $program is a utility to reduce the size of png files by removing
 unnecessary chunks and compressing the image.
@@ -364,6 +373,8 @@ Options:
   -r<revision> If this is specified, the script processes only png files
                changed since this revision. The <dir> options will be used
                to narrow down the files under specific directories.
+  -s  Run as subprocess. This may be used to parallelize execution.
+      Usage: find <dir> -name \"*.png\" | xargs -n1 -P16 $program -s -o2
   -h  Print this help text."
   exit 1
 }
@@ -381,7 +392,7 @@ fi
 
 OPTIMIZE_LEVEL=1
 # Parse options
-while getopts o:r:h opts
+while getopts o:r:h:s opts
 do
   case $opts in
     r)
@@ -397,6 +408,9 @@ do
       fi
       OPTIMIZE_LEVEL=$OPTARG
       ;;
+    s)
+      let SUBPROCESS=1
+      ;;
     [h?])
       show_help;;
   esac
@@ -437,7 +451,8 @@ trap "rm -rf $TMP_DIR" EXIT
 DIRS=$@
 set ${DIRS:=$ALL_DIRS}
 
-echo "Optimize level=$OPTIMIZE_LEVEL"
+info "Optimize level=$OPTIMIZE_LEVEL"
+
 if [ -n "$COMMIT" ] ; then
  ALL_FILES=$(git diff --name-only $COMMIT HEAD $DIRS | grep "png$")
  ALL_FILES_LIST=( $ALL_FILES )
@@ -449,6 +464,10 @@ if [ -n "$COMMIT" ] ; then
      echo "Skipping deleted file: $f";
    fi
  done
+elif [ $SUBPROCESS -eq 1 ]; then
+  for f in $DIRS; do
+    optimize_file $f
+  done
 else
   for d in $DIRS; do
     echo "Optimizing png files in $d"
@@ -458,6 +477,10 @@ else
 fi
 
 # Print the results.
+if [ $SUBPROCESS -eq 1 ]; then
+  exit 0
+fi
+
 if [ $PROCESSED_FILE == 0 ]; then
   echo "Did not find any files (out of $TOTAL_FILE files)" \
        "that could be optimized" \