1 files changed, 126 insertions, 0 deletions
diff --git a/java/com/google/gerrit/httpd/raw/RecompileGwtUiFilter.java b/java/com/google/gerrit/httpd/raw/RecompileGwtUiFilter.java
new file mode 100644
index 0000000000..c6c336707b
--- /dev/null
+++ b/java/com/google/gerrit/httpd/raw/RecompileGwtUiFilter.java
@@ -0,0 +1,126 @@
+// Copyright (C) 2015 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.gerrit.httpd.raw;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Enumeration;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+class RecompileGwtUiFilter implements Filter {
+  private final boolean gwtuiRecompile =
+      System.getProperty("gerrit.disable-gwtui-recompile") == null;
+  private final UserAgentRule rule = new UserAgentRule();
+  private final Set<String> uaInitialized = new HashSet<>();
+  private final Path unpackedWar;
+  private final BazelBuild builder;
+
+  private String lastAgent;
+  private long lastTime;
+
+  RecompileGwtUiFilter(BazelBuild builder, Path unpackedWar) {
+    this.builder = builder;
+    this.unpackedWar = unpackedWar;
+  }
+
+  @Override
+  public void doFilter(ServletRequest request, ServletResponse res, FilterChain chain)
+      throws IOException, ServletException {
+    String agent = rule.select((HttpServletRequest) request);
+    if (unpackedWar != null && (gwtuiRecompile || !uaInitialized.contains(agent))) {
+      BazelBuild.Label label = builder.gwtZipLabel(agent);
+      File zip = builder.targetPath(label).toFile();
+
+      synchronized (this) {
+        try {
+          builder.build(label);
+        } catch (BazelBuild.BuildFailureException e) {
+          e.display(label.toString(), (HttpServletResponse) res);
+          return;
+        }
+
+        if (!agent.equals(lastAgent) || lastTime != zip.lastModified()) {
+          lastAgent = agent;
+          lastTime = zip.lastModified();
+          unpack(zip, unpackedWar.toFile());
+        }
+      }
+      uaInitialized.add(agent);
+    }
+    chain.doFilter(request, res);
+  }
+
+  @Override
+  public void init(FilterConfig config) {}
+
+  @Override
+  public void destroy() {}
+
+  private static void unpack(File srcwar, File dstwar) throws IOException {
+    try (ZipFile zf = new ZipFile(srcwar)) {
+      final Enumeration<? extends ZipEntry> e = zf.entries();
+      while (e.hasMoreElements()) {
+        final ZipEntry ze = e.nextElement();
+        final String name = ze.getName();
+
+        if (ze.isDirectory()
+            || name.startsWith("WEB-INF/")
+            || name.startsWith("META-INF/")
+            || name.startsWith("com/google/gerrit/launcher/")
+            || name.equals("Main.class")) {
+          continue;
+        }
+
+        final File rawtmp = new File(dstwar, name);
+        mkdir(rawtmp.getParentFile());
+        rawtmp.deleteOnExit();
+
+        try (OutputStream rawout = Files.newOutputStream(rawtmp.toPath());
+            InputStream in = zf.getInputStream(ze)) {
+          final byte[] buf = new byte[4096];
+          int n;
+          while ((n = in.read(buf, 0, buf.length)) > 0) {
+            rawout.write(buf, 0, n);
+          }
+        }
+      }
+    }
+  }
+
+  private static void mkdir(File dir) throws IOException {
+    if (!dir.isDirectory()) {
+      mkdir(dir.getParentFile());
+      if (!dir.mkdir()) {
+        throw new IOException("Cannot mkdir " + dir.getAbsolutePath());
+      }
+      dir.deleteOnExit();
+    }
+  }
+}