appcds

#!/bin/bash
#
# Create a class cache for zprint-filter to allow sub-second startup.
#
# The zprint-filter reads Clojure(script) code from stdin and writes 
# pretty-printed Clojure(script) code on stdout.
#
# This script takes as input a zprint-filter from:
#   https://github.com/kkinnear/zprint
# and produces a bash shell script which will startup the zprint-filter
# in less than one second. 
#
# To download the zprint-filter uberjar, look at the "Releases" tab
# on the zprint repository, and download the latest one.  
# This script is also available from the same place.
#
# Place the zprint-filter in a directory where you are willing to
# keep it and the class cache.  Once you run this script, you can't
# move the zprint-filter, so find some place you can leave it alone.
#
# Steps:
#
# 1. Put this script and the zprint-filter in the directory where you
#    can leave it alone after you run the script.
#
# 2. Decide what you want to call the shell script (the script-name) which 
#    will run the zprint-filter.  Probably you want the name to be short, 
#    since you might be typing the name to run it from your editor or IDE.
#
# Usage:
#
# ./appcds zprint-filter-i.j.k script-name
#
# To use the script script-name produced by this script:
#
# script-name <yourfile.clj >yourfile.out.clj
#
# But the real point is to be able to pipe Clojure(script) code through
# the filter from your favorite editor or IDE.
#

helptext="Usage: ./appcds zprint-filter output-command-name"

if [[ -z "$1" ]]
	then
	echo "Missing first required argument: zprint-filter-file (e.g. zprint-filter-1.2.2)"
	echo "$helptext"
	exit 1
fi 

if [[ -z "$2" ]]
	then
	echo "Missing second required argument: output command name (e.g. za)"
	echo "$helptext"
	exit 1
fi 

filter="$1"
output_command_name="$2"
current_path=$(pwd)
filter_path="$current_path/$filter"

if [[ ! -e "$filter_path" ]]
	then
	echo "Specified file $filter_path does not exist"
	exit 1
fi

#
# We used to check for the java version, but the simple minded Java
# version check code below fails on some newer versions, and also
# on graalvm, so we don't do it anymore.
#
# java_version=$(java -version 2>&1 | grep "java" | grep -o -E "([0-9]+\.[0-9])+")
# 
# java_update=$(java -version 2>&1 | grep "java" | grep -o -E "(\_[0-9]+)" | grep -o -E "[0-9]+")
# 
# echo "Your Java version is: $java_version"
# echo "Your Java update is: $java_update"
# 
# if [[ $java_version < "1.8" ]]
# then
# 	echo "Java 1.8 update 40 or greater is required"
# 	exit 1
# fi
# 
# if [[ $java_version == "1.8" && $java_update -gt 39 ]]
# 	then
# 	echo "Java 1.8 update 40 or greater detected, proceeding..."
# else 
# 	echo "Java 1.8 update 40 or greater is required"
# 	exit 1
# fi

echo ""

echo "Creating helloworld.clj to prime the cache..."

echo '"Hello World!"' > helloworld.clj


echo "Creating loaded class list..."
java -XX:+UnlockCommercialFeatures -XX:+UseAppCDS -Xshare:off -XX:DumpLoadedClassList=zprint.filter.classlist -cp "$filter_path" zprint.main < helloworld.clj > /dev/null

echo "Creating loaded class cache from list..."
java -XX:+UnlockCommercialFeatures -XX:+UseAppCDS -Xshare:dump -XX:SharedClassListFile=zprint.filter.classlist -XX:SharedArchiveFile="$current_path/zprint.filter.cache" -cp "$filter_path" zprint.main < helloworld.clj 

echo "Creating output command: $output_command_name"
echo "#!/bin/bash" > "$output_command_name"
echo "java -XX:+UnlockCommercialFeatures -XX:+UseAppCDS -Xshare:on -XX:SharedArchiveFile="$current_path/zprint.filter.cache" -cp "$filter_path" zprint.main " '"${1//\\}"' >> "$output_command_name"

chmod +x "$output_command_name"

echo "Cleaning up temporary files..."
rm zprint.filter.classlist

echo "Done"
echo ""
echo "Try it out with: "
echo "./$output_command_name < helloworld.clj"
echo "which should print Hello World!"
echo "Afterwards, you can delete helloworld.clj"
echo ""
echo ""
echo "The files:"
echo "  $current_path/zprint.filter.cache"
echo "  $filter_path"
echo "must remain at their current locations with respect to"
echo "their absolute paths.  You can, however, move $output_command_name"
echo "anywhere you wish, for example to a location on your PATH"