8293499: Provide jmod --compress option

src/jdk.jlink/share/classes/jdk/tools/jmod/JmodOutputStream.java

@@ -55,16 +55,17 @@ class JmodOutputStream extends OutputStream implements AutoCloseable {
      * This method creates (or overrides, if exists) the JMOD file,
      * returning the output stream to write to the JMOD file.
      */
-    static JmodOutputStream newOutputStream(Path file, LocalDateTime date) throws IOException {
+    static JmodOutputStream newOutputStream(Path file, LocalDateTime date, int compressLevel) throws IOException {
         OutputStream out = Files.newOutputStream(file);
         BufferedOutputStream bos = new BufferedOutputStream(out);
-        return new JmodOutputStream(bos, date);
+        return new JmodOutputStream(bos, date, compressLevel);
     }
 
     private final ZipOutputStream zos;
     private final LocalDateTime date;
-    private JmodOutputStream(OutputStream out, LocalDateTime date) {
+    private JmodOutputStream(OutputStream out, LocalDateTime date, int compLevel) {
         this.zos = new ZipOutputStream(out);
+        this.zos.setLevel(compLevel);
         this.date = date;
         try {
             JmodFile.writeMagicNumber(out);

src/jdk.jlink/share/classes/jdk/tools/jmod/JmodTask.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -60,6 +60,7 @@
 import java.util.regex.PatternSyntaxException;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
+import java.util.zip.Deflater;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipException;
 import java.util.zip.ZipFile;
@@ -167,6 +168,7 @@ static class Options {
         List<PathMatcher> excludes;
         Path extractDir;
         LocalDateTime date;
+        int compressLevel;
     }
 
     // Valid --date range
@@ -438,7 +440,7 @@ private boolean create() throws IOException {
         Path target = options.jmodFile;
         Path tempTarget = jmodTempFilePath(target);
         try {
-            try (JmodOutputStream jos = JmodOutputStream.newOutputStream(tempTarget, options.date)) {
+            try (JmodOutputStream jos = JmodOutputStream.newOutputStream(tempTarget, options.date, options.compressLevel)) {
                 jmod.write(jos);
             }
             Files.move(tempTarget, target);
@@ -1024,7 +1026,7 @@ private void updateJmodFile(Path target, Path tempTarget,
         {
 
             try (JmodFile jf = new JmodFile(target);
-                 JmodOutputStream jos = JmodOutputStream.newOutputStream(tempTarget, options.date))
+                 JmodOutputStream jos = JmodOutputStream.newOutputStream(tempTarget, options.date, options.compressLevel))
             {
                 jf.stream().forEach(e -> {
                     try (InputStream in = jf.getInputStream(e.section(), e.name())) {
@@ -1179,6 +1181,33 @@ public LocalDateTime convert(String value) {
         @Override public String valuePattern() { return "date"; }
     }
 
+    static class CompLevelConverter implements ValueConverter<Integer> {
+        @Override
+        public Integer convert(String value) {
+            int idx = value.indexOf("-");
+            int lastIdx = value.lastIndexOf("-");
+            if (idx == -1 || idx != lastIdx) {
+                throw new CommandException("err.compress.incorrect", value);
+            }
+            if (!value.substring(0, idx).equals("zip")) {
+                throw new CommandException("err.compress.incorrect", value);
+            }
+            try {
+                int level = Integer.parseInt(value.substring(idx + 1));
+                if (level < 0 || level > 9) {
+                    throw new CommandException("err.compress.incorrect", value);
+                }
+                return level;
+            } catch (NumberFormatException x) {
+                throw new CommandException("err.compress.incorrect", value);
+            }
+        }
+
+        @Override public Class<Integer> valueType() { return Integer.class; }
+
+        @Override public String valuePattern() { return "compress"; }
+    }
+
     static class WarnIfResolvedReasonConverter
         implements ValueConverter<ModuleResolution>
     {
@@ -1419,6 +1448,11 @@ private void handleOptions(String[] args) {
                         .withRequiredArg()
                         .withValuesConvertedBy(new DateConverter());
 
+        OptionSpec<Integer> compress
+                = parser.accepts("compress", getMessage("main.opt.compress"))
+                        .withRequiredArg()
+                        .withValuesConvertedBy(new CompLevelConverter());
+
         NonOptionArgumentSpec<String> nonOptions
                 = parser.nonOptions();
 
@@ -1488,6 +1522,16 @@ private void handleOptions(String[] args) {
                     throw new CommandException("err.modulepath.must.be.specified")
                             .showUsage(true);
             }
+            if (opts.has(compress)) {
+                if (!options.mode.equals(Mode.CREATE)) {
+                    throw new CommandException("err.compress.wrong.mode")
+                            .showUsage(true);
+                }
+                options.compressLevel = getLastElement(opts.valuesOf(compress));
+            } else {
+                // Default to fast compression.
+                options.compressLevel = Deflater.DEFAULT_COMPRESSION;
+            }
 
             if (options.mode.equals(Mode.HASH)) {
                 if (options.moduleFinder == null || options.modulesToHash == null)

src/jdk.jlink/share/classes/jdk/tools/jmod/resources/jmod.properties

@@ -82,6 +82,10 @@ main.opt.date=Date and time for the timestamps of entries, specified in ISO-8601
 
 main.opt.cmdfile=Read options from the specified file
 
+main.opt.compress=Compression to use when creating the JMOD archive.\
+\ Accepted values are: zip-[0-9], where zip-0 provides no compression, and zip-9\
+\ provides the best compression.
+
 module.hashes.recorded=Hashes are recorded in module {0}
 
 err.missing.mode=one of create, extract, list, describe, or hash must be specified
@@ -113,6 +117,8 @@ err.module.resolution.fail=Resolution failed: {0}
 err.no.moduleToHash=No hashes recorded: no module matching {0} found to record hashes
 err.invalid.date=--date {0} is not a valid ISO-8601 extended offset date-time with optional time-zone format: {1}
 err.date.out.of.range=--date {0} is out of the valid range 1980-01-01T00:00:02Z to 2099-12-31T23:59:59Z
+err.compress.incorrect=--compress value is invalid: {0}
+err.compress.wrong.mode=--compress is only accepted with create mode
 warn.invalid.arg=Invalid classname or pathname not exist: {0}
 warn.no.module.hashes=No hashes recorded: no module specified for hashing depends on {0}
 warn.ignore.entry=ignoring entry {0}, in section {1}

test/jdk/tools/jmod/JmodTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2022, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -739,6 +739,90 @@ public void testTmpFileRemoved() throws IOException {
             });
     }
 
+    @Test
+    public void testCompressionLevel() throws IOException {
+        String cp = EXPLODED_DIR.resolve("foo").resolve("classes").toString();
+        Path jmod = MODS_DIR.resolve("foo.jmod");
+        FileUtils.deleteFileIfExistsWithRetry(jmod);
+
+        jmod("create",
+             "--class-path", cp,
+             "--compress", "zip-0",
+             jmod.toString())
+            .assertSuccess();
+
+        jmod("list",
+             "--compress", "zip-0",
+             jmod.toString())
+            .assertFailure()
+            .resultChecker(r -> {
+                assertTrue(r.output.contains("--compress is only accepted with create mode"), "Error message printed");
+            });
+
+        FileUtils.deleteFileIfExistsWithRetry(jmod);
+
+        jmod("create",
+             "--class-path", cp,
+             "--compress", "zip-9",
+             jmod.toString())
+            .assertSuccess();
+
+        FileUtils.deleteFileIfExistsWithRetry(jmod);
+
+        jmod("create",
+             "--class-path", cp,
+             "--compress", "zip--1",
+             jmod.toString())
+            .assertFailure()
+            .resultChecker(r -> {
+                assertTrue(r.output.contains("--compress value is invalid"), "Error message printed");
+            });
+
+        FileUtils.deleteFileIfExistsWithRetry(jmod);
+
+        jmod("create",
+             "--class-path", cp,
+             "--compress", "zip-1-something",
+             jmod.toString())
+            .assertFailure()
+            .resultChecker(r -> {
+                assertTrue(r.output.contains("--compress value is invalid"), "Error message printed");
+            });
+
+        FileUtils.deleteFileIfExistsWithRetry(jmod);
+
+        jmod("create",
+             "--class-path", cp,
+             "--compress", "zip-10",
+             jmod.toString())
+            .assertFailure()
+            .resultChecker(r -> {
+                assertTrue(r.output.contains("--compress value is invalid"), "Error message printed");
+            });
+
+        FileUtils.deleteFileIfExistsWithRetry(jmod);
+
+        jmod("create",
+             "--class-path", cp,
+             "--compress", "test",
+             jmod.toString())
+            .assertFailure()
+            .resultChecker(r -> {
+                assertTrue(r.output.contains("--compress value is invalid"), "Error message printed");
+            });
+
+        FileUtils.deleteFileIfExistsWithRetry(jmod);
+
+        jmod("create",
+             "--class-path", cp,
+             "--compress", "test-0",
+             jmod.toString())
+            .assertFailure()
+            .resultChecker(r -> {
+                assertTrue(r.output.contains("--compress value is invalid"), "Error message printed");
+            });
+    }
+
     // ---
 
     static boolean compileModule(String name, Path dest) throws IOException {