add script for metadata-calculation

tools/metadata-calculation.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+
+set -o pipefail
+set -e
+
+filename=$1
+
+response=$(cat $filename | stream-commp 2>&1)
+
+# Example response:
+# cat epoch-0-1.car| stream-commp
+
+# CommPCid: baga6ea4seaqlenpkttfecrwa74hkwfp3pnmkaatmiiwpvuclwtxcl4uvkajemea
+# Payload:          1004138576 bytes
+# Unpadded piece:   1065353216 bytes
+# Padded piece:     1073741824 bytes
+
+# CARv1 detected in stream
+
+commp=$(echo $response | grep -o "CommPCid.*" | cut -f 2 -d ":" | xargs)
+paddedSize=$(echo $response | grep -o "Padded piece:.*" | cut -f 2 -d ":" | sed "s/bytes//" |  xargs)
+
+echo $filename, $commp, $paddedSize