Compressing SimpleLibrary with GZIP

[Aleksey Shipilev]

Hi guys,

I'm keeping an eye on footprint of Jigsaw library. I understand the code
we have not by any means complete, and one should anticipate changes to
binary format
for modules.

However, can we compress it with GZIP at this point? That will require
just a few one-liner changes [1], but the benefit is obvious:

 a. jre-module-image size is down from 161Mb to 158Mb
 b. dummy multi-module projects (which have plenty of metadata) are
consuming 5-6 times less space

-Aleksey.

[1] diff -r 55c21bd558ac
src/share/classes/org/openjdk/jigsaw/SimpleLibrary.java
--- a/src/share/classes/org/openjdk/jigsaw/SimpleLibrary.java	Tue Mar 06
16:33:00 2012 -0800
+++ b/src/share/classes/org/openjdk/jigsaw/SimpleLibrary.java	Tue Mar 13
16:47:34 2012 +0400
@@ -89,8 +89,8 @@

         void store() throws IOException {
             try (OutputStream fos = new FileOutputStream(file);
-                 BufferedOutputStream bos = new BufferedOutputStream(fos);
-                 DataOutputStream out = new DataOutputStream(bos)) {
+                 GZIPOutputStream gos = new GZIPOutputStream(fos, 64*1024);
+                 DataOutputStream out = new DataOutputStream(gos)) {
                 out.writeInt(FileConstants.MAGIC);
                 out.writeShort(type.value());
                 out.writeShort(majorVersion);
@@ -104,8 +104,8 @@

         protected void load() throws IOException {
             try (InputStream fis = new FileInputStream(file);
-                 BufferedInputStream bis = new BufferedInputStream(fis);
-                 DataInputStream in = new DataInputStream(bis)) {
+                 GZIPInputStream gis = new GZIPInputStream(fis, 64*1024);
+                 DataInputStream in = new DataInputStream(gis)) {
                 if (in.readInt() != FileConstants.MAGIC)
                     throw new IOException(file + ": Invalid magic number");
                 if (in.readShort() != type.value())