Script for timing large snapshot

Not sure if we wanna merge this, but I'll push a draft PR to share
my hacky script.

Somewhat on-topic for...

Ref: https://issues.redhat.com/browse/EC-976

hack/large-snapshot-times.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SNAPSHOT=./large.yaml
+PUBLIC_KEY=./key-rhel-osci.pub
+POLICY_CONFIGURATION=github.com/enterprise-contract/config//redhat
+
+#VERSIONS_TO_TEST=(
+#  v0.6.94
+#  v0.6.129
+#  v0.6.138
+#  v0.6.142
+#)
+
+#VERSIONS_TO_TEST=(v0.6.94)
+VERSIONS_TO_TEST=(main)
+
+#WORKERS=5
+WORKERS=20
+
+GOOS=$(go env GOOS)
+GOARCH=$(go env GOARCH)
+EC=./dist/ec_${GOOS}_${GOARCH}
+
+TIME=/usr/bin/time
+TIME_FORMAT='User CPU time: %U\nSystem CPU time: %S\nElapsed time: %e\nPeak memory usage: %M kb'
+
+for ref in ${VERSIONS_TO_TEST[@]}; do
+  EC_REF=${EC}_${ref}
+
+  if [[ ! -x "$EC_REF" ]]; then
+    git reset --hard "${ref}"
+    make ${EC}
+    cp ${EC} ${EC_REF}
+    cp ${EC}.sha256 ${EC_REF}.sha256
+  fi
+
+  title="Ref ${ref}"
+  echo "$title"
+  echo "$title" | tr '[:print:]' '='
+
+  git log --format="Commit: %h %s%nDate: %cd" -n 1 ${ref}
+  echo "Started: $(date)"
+
+  ${TIME} --format "${TIME_FORMAT}" \
+    ${EC_REF} validate image \
+      --images large.yaml \
+      --public-key key-rhel-osci.pub \
+      --policy ${POLICY_CONFIGURATION} \
+      --ignore-rekor \
+      --output json=/dev/null \
+      --output yaml=/dev/null \
+      --show-successes \
+      --timeout 60m \
+      --workers ${WORKERS} \
+      --info \
+      2>&1 | tee "out-$ref.log"
+
+  echo ""
+
+done