implement disk_io metric on osx

metrics/disk_io.sh

@@ -1,31 +1,41 @@
-# #!/bin/sh
+#!/bin/sh
 
-# if [ -z $DISK_IO_MOUNTPOINT ]; then
-#   if is_osx; then
-#     DISK_IO_MOUNTPOINT="disk0"
-#   else
-#     DISK_IO_MOUNTPOINT="/dev/vda"
-#   fi
-# fi
+if [ -z $DISK_IO_MOUNTPOINT ]; then
+  if is_osx; then
+    DISK_IO_MOUNTPOINT="disk0"
+  else
+    DISK_IO_MOUNTPOINT="/dev/vda"
+  fi
+fi
 
-# if is_osx; then
-#   __disk_io_bgproc () {
-#     iostat -K -d -c 99999 -w $INTERVAL $DISK_IO_MOUNTPOINT | while read line; do
-#       echo $line | awk '{print $3}' > ./foobar
-#     done
-#   }
-# else
-#   __disk_io_bgproc () {
-#     echo $(iostat -y -d 1 $DISK_IO_MOUNTPOINT)
-#   }
-# fi
+if is_osx; then
+  __disk_io_bgproc () {
+    iostat -K -d -w $INTERVAL $DISK_IO_MOUNTPOINT | while read line; do
+      echo $line | awk '{print $3}' > $__disk_io_fifo
+    done
+  }
+else
+  __disk_io_bgproc () {
+    echo $(iostat -y -d 1 $DISK_IO_MOUNTPOINT)
+  }
+fi
 
-# init () {
-#   mkfifo ./foobar
-#   #exec 3<> ./foobar
-#   __disk_io_bgproc > ./foobar &
-# }
+__disk_io_fifo=$__TEMP_DIR/disk_io
 
-# collect () {
-#   cat ./foobar
-# }
+init () {
+  __disk_io_bgproc &
+  mkfifo $__disk_io_fifo
+}
+
+collect () {
+  report $(cat $__disk_io_fifo)
+}
+
+terminate () {
+  rm $__disk_io_fifo
+}
+
+docs () {
+  echo "Disk I/O in MB/s."
+  echo "\$DISK_IO_MOUNTPOINT=$DISK_IO_MOUNTPOINT"
+}