Using patch files for storing the npm registry

compress.sh

#!/bin/bash

# Remove anything that may have been left over by a previous run
rm -rf patch orig new
mkdir patch

for TARBALL in `ls - | node semver-sort.js`
do
        tar -xzf "./-/${TARBALL}"

        # If this is the first tarball we are looking at, we have
        # nothing to diff against
        if [ ! -e orig ]
        then
                cp -r package "patch/${TARBALL%.tgz}"
                mv package orig
                continue
        fi

        # Generate a diff
        mv package new
        diff -ruN orig new > "patch/${TARBALL}.patch"
        rm -rf orig
        mv new orig

	grep -irE '^Binary files .* differ$' "patch/${TARBALL}.patch" > /dev/null

	if [ "$?" -eq "0" ]
	then
		echo "patch/${TARBALL}.patch contains binary files, not able to compress!"
		cp -r orig "patch/${TARBALL%.tgz}"
		rm "patch/${TARBALL}.patch"
		continue
	fi	

        # If the patch file is larger than the uncompressed package, just
        # use the package!
        TSIZE=`du -s ./orig | cut -f 1`
        PSIZE=`du -s ./patch/${TARBALL}.patch | cut -f 1`
        if [ "${PSIZE}" -ge "${TSIZE}" ]
        then
		cp -r orig "patch/${TARBALL%.tgz}"
		echo `du -hs ./patch/${TARBALL%.tgz}`
		rm "patch/${TARBALL}.patch"
        else
		echo `du -hs ./patch/${TARBALL}.patch`
        fi
done

echo "Generating final patch tarball"
# Compress the entire patch directory as one big file
tar -c ./patch | gzip > patch.tar.gz

# Remove all state
rm -rf orig patch package

# Print out the space savings
du -hs '-' 'patch.tar.gz'