1 files changed, 153 insertions, 0 deletions
diff --git a/src/proguard/UpToDateChecker.java b/src/proguard/UpToDateChecker.java
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+++ b/src/proguard/UpToDateChecker.java
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+/*
+ * ProGuard -- shrinking, optimization, obfuscation, and preverification
+ *             of Java bytecode.
+ *
+ * Copyright (c) 2002-2009 Eric Lafortune (eric@graphics.cornell.edu)
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+package proguard;
+
+import java.io.File;
+
+/**
+ * This class checks whether the output is up to date.
+ *
+ * @author Eric Lafortune
+ */
+public class UpToDateChecker
+{
+    private final Configuration configuration;
+
+
+    /**
+     * Creates a new UpToDateChecker with the given configuration.
+     */
+    public UpToDateChecker(Configuration configuration)
+    {
+        this.configuration = configuration;
+    }
+
+
+    /**
+     * Returns whether the output is up to date, based on the modification times
+     * of the input jars, output jars, and library jars (or directories).
+     */
+    public boolean check()
+    {
+        long inputLastModified  = configuration.lastModified;
+        long outputLastModified = Long.MAX_VALUE;
+
+        ClassPath programJars = configuration.programJars;
+        ClassPath libraryJars = configuration.libraryJars;
+
+        // Check the dates of the program jars, if any.
+        if (programJars != null)
+        {
+            for (int index = 0; index < programJars.size(); index++)
+            {
+                // Break early, if possible.
+                if (inputLastModified >= outputLastModified)
+                {
+                    break;
+                }
+
+                // Update the input and output modification times.
+                ClassPathEntry classPathEntry = programJars.get(index);
+                if (classPathEntry.isOutput())
+                {
+                    long lastModified = lastModified(classPathEntry.getFile(), true);
+                    if (outputLastModified > lastModified)
+                    {
+                        outputLastModified = lastModified;
+                    }
+                }
+                else
+                {
+                    long lastModified = lastModified(classPathEntry.getFile(), false);
+                    if (inputLastModified < lastModified)
+                    {
+                        inputLastModified = lastModified;
+                    }
+                }
+            }
+        }
+
+        // Check the dates of the library jars, if any.
+        if (libraryJars != null)
+        {
+            for (int index = 0; index < libraryJars.size(); index++)
+            {
+                // Break early, if possible.
+                if (inputLastModified >= outputLastModified)
+                {
+                    break;
+                }
+
+                // Update the input modification time.
+                ClassPathEntry classPathEntry = libraryJars.get(index);
+                long lastModified = lastModified(classPathEntry.getFile(), false);
+                if (inputLastModified < lastModified)
+                {
+                    inputLastModified = lastModified;
+                }
+            }
+        }
+
+        boolean outputUpToDate = inputLastModified < outputLastModified;
+        if (outputUpToDate)
+        {
+            System.out.println("The output is up to date");
+        }
+
+        return outputUpToDate;
+    }
+
+
+    /**
+     * Returns the minimum or maximum modification time of the given file or
+     * of the files in the given directory (recursively).
+     */
+    private long lastModified(File file, boolean minimum)
+    {
+        // Is it a directory?
+        if (file.isDirectory())
+        {
+            // Ignore the directory's modification time; just recurse on its files.
+            File[] files = file.listFiles();
+
+            // Still, an empty output directory is probably a sign that it is
+            // not up to date.
+            long lastModified = files.length != 0 && minimum ?
+                Long.MAX_VALUE : 0L;
+
+            for (int index = 0; index < files.length; index++)
+            {
+                long fileLastModified = lastModified(files[index], minimum);
+                if ((lastModified < fileLastModified) ^ minimum)
+                {
+                    lastModified = fileLastModified;
+                }
+            }
+
+            return lastModified;
+        }
+        else
+        {
+            // Return the file's modification time.
+            return file.lastModified();
+        }
+    }
+}