Add CSS linker module to create cacheable CSS references from modules
This linker module makes all CSS references within the entire
output module to be cached by a strongly computed name from
the CSS content. This covers not just application CSS code,
but also any CSS code imported by GWT or other modules that
the application module inherits from.
Signed-off-by: Shawn O. Pearce <sop@google.com>
diff --git a/src/main/java/com/google/gwtexpui/css/CSS.gwt.xml b/src/main/java/com/google/gwtexpui/css/CSS.gwt.xml
new file mode 100644
index 0000000..b385987
--- /dev/null
+++ b/src/main/java/com/google/gwtexpui/css/CSS.gwt.xml
@@ -0,0 +1,19 @@
+<!--
+ Copyright (C) 2009 The Android Open Source Project
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+-->
+<module>
+ <define-linker name='cachecss' class='com.google.gwtexpui.css.rebind.CssLinker'/>
+ <add-linker name='cachecss'/>
+</module>
diff --git a/src/main/java/com/google/gwtexpui/css/rebind/CssLinker.java b/src/main/java/com/google/gwtexpui/css/rebind/CssLinker.java
new file mode 100644
index 0000000..8ab34c4
--- /dev/null
+++ b/src/main/java/com/google/gwtexpui/css/rebind/CssLinker.java
@@ -0,0 +1,130 @@
+// Copyright (C) 2009 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gwtexpui.css.rebind;
+
+import com.google.gwt.core.ext.LinkerContext;
+import com.google.gwt.core.ext.TreeLogger;
+import com.google.gwt.core.ext.UnableToCompleteException;
+import com.google.gwt.core.ext.linker.AbstractLinker;
+import com.google.gwt.core.ext.linker.Artifact;
+import com.google.gwt.core.ext.linker.ArtifactSet;
+import com.google.gwt.core.ext.linker.LinkerOrder;
+import com.google.gwt.core.ext.linker.PublicResource;
+import com.google.gwt.core.ext.linker.impl.StandardLinkerContext;
+import com.google.gwt.core.ext.linker.impl.StandardStylesheetReference;
+import com.google.gwt.dev.util.Util;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.HashMap;
+
+@LinkerOrder(LinkerOrder.Order.PRE)
+public class CssLinker extends AbstractLinker {
+ @Override
+ public String getDescription() {
+ return "CssLinker";
+ }
+
+ @SuppressWarnings("unchecked")
+ @Override
+ public ArtifactSet link(final TreeLogger logger, final LinkerContext context,
+ final ArtifactSet artifacts) throws UnableToCompleteException {
+ final ArtifactSet returnTo = new ArtifactSet();
+ int index = 0;
+
+ final HashMap<String, PublicResource> css =
+ new HashMap<String, PublicResource>();
+
+ for (final StandardStylesheetReference ssr : artifacts
+ .<StandardStylesheetReference, StandardStylesheetReference> find(StandardStylesheetReference.class)) {
+ css.put(ssr.getSrc(), null);
+ }
+ for (final PublicResource pr : artifacts
+ .<PublicResource, PublicResource> find(PublicResource.class)) {
+ if (css.containsKey(pr.getPartialPath())) {
+ css.put(pr.getPartialPath(), new CssPubRsrc(name(logger, pr), pr));
+ }
+ }
+
+ for (Artifact a : artifacts) {
+ if (a instanceof PublicResource) {
+ final PublicResource r = (PublicResource) a;
+ if (css.containsKey(r.getPartialPath())) {
+ a = css.get(r.getPartialPath());
+ }
+ } else if (a instanceof StandardStylesheetReference) {
+ final StandardStylesheetReference r = (StandardStylesheetReference) a;
+ final PublicResource p = css.get(r.getSrc());
+ a = new StandardStylesheetReference(p.getPartialPath(), index);
+ }
+
+ returnTo.add(a);
+ index++;
+ }
+ return returnTo;
+ }
+
+ private String name(final TreeLogger logger, final PublicResource r)
+ throws UnableToCompleteException {
+ final InputStream in = r.getContents(logger);
+ final ByteArrayOutputStream tmp = new ByteArrayOutputStream();
+ try {
+ try {
+ final byte[] buf = new byte[2048];
+ int n;
+ while ((n = in.read(buf)) >= 0) {
+ tmp.write(buf, 0, n);
+ }
+ tmp.close();
+ } finally {
+ in.close();
+ }
+ } catch (IOException e) {
+ final UnableToCompleteException ute = new UnableToCompleteException();
+ ute.initCause(e);
+ throw ute;
+ }
+
+ String base = r.getPartialPath();
+ final int s = base.lastIndexOf('/');
+ if (0 < s) {
+ base = base.substring(0, s + 1);
+ } else {
+ base = "";
+ }
+ return base + Util.computeStrongName(tmp.toByteArray()) + ".cache.css";
+ }
+
+ private static class CssPubRsrc extends PublicResource {
+ private final PublicResource src;
+
+ CssPubRsrc(final String partialPath, final PublicResource r) {
+ super(StandardLinkerContext.class, partialPath);
+ src = r;
+ }
+
+ @Override
+ public InputStream getContents(final TreeLogger logger)
+ throws UnableToCompleteException {
+ return src.getContents(logger);
+ }
+
+ @Override
+ public long getLastModified() {
+ return src.getLastModified();
+ }
+ }
+}
