max=5000

reference=$NIX_STORE_DIR/abcdef
touch $reference
(echo $reference && echo && echo 0) | $TOP/src/nix-store/nix-store --register-validity 

echo "registering..."
time for ((n = 0; n < $max; n ++)); do
    storePath=$NIX_STORE_DIR/$n
    touch $storePath
    (echo $storePath && echo && echo 1 && echo $reference)
done | $TOP/src/nix-store/nix-store --register-validity 

echo "collecting garbage..."
time $TOP/src/nix-store/nix-store --gc 2> /dev/null