feature: limit the number of commits to be validated

Signed-off-by: Phil Davis <phil@jankaritech.com>

hooks/validate.sh

@@ -42,6 +42,7 @@ if [[ ! -d "$DIR" ]]; then DIR="$PWD"; fi
 . "$DIR/timestamping"
 
 declare -i MINVERSION=$TIMESTAMPING_VERSION
+declare -i MAX_COMMITS_TO_CHECK=20
 declare -A PROCESSED_COMMIT
 
 while [[ $# -gt 0 ]]; do
@@ -62,6 +63,16 @@ while [[ $# -gt 0 ]]; do
       shift # past argument
       shift # past value
       ;;
+    -max|--maxcommits)
+      INTEGER_REGEX='^[0-9]+$'
+      if ! [[ "$2" =~ $INTEGER_REGEX ]]; then
+        echo_error "$KEY: expected positive integer"
+        exit 1
+      fi
+      MAX_COMMITS_TO_CHECK="$2"
+      shift # past argument
+      shift # past value
+      ;;
     -v|--verbose)
       OUT_STREAM=/dev/stdout
       shift # past argument
@@ -307,6 +318,8 @@ validate_commit_and_parents() {
   if ! validate_commit "$COMMIT_HASH"; then
     ALL_PASSED=false
   fi
+  NUM_COMMITS_CHECKED=${#PROCESSED_COMMIT[@]}
+  if [[ ${NUM_COMMITS_CHECKED} -lt ${MAX_COMMITS_TO_CHECK} ]] ; then
     local PARENTS=$(git cat-file -p "$COMMIT_HASH" | awk '/^$/{exit} /parent/ {print}' | sed 's/parent //')
     #iterate over all parents of commit
     if [ ! -z "$PARENTS" ]; then
@@ -316,6 +329,7 @@ validate_commit_and_parents() {
         fi
       done <<< $(printf "%s" "$PARENTS")
     fi
+  fi
   if [ "$ALL_PASSED" = true ]; then
     return 0
   fi