CacheSpan and Util.un/escapeFileName tests.

Fixed CacheSpan regexp for line breaks characters in key.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=129631446

library/src/androidTest/java/com/google/android/exoplayer2/upstream/cache/CacheSpanTest.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2016 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.android.exoplayer2.upstream.cache;
+
+import com.google.android.exoplayer2.testutil.TestUtil;
+import java.io.File;
+import java.util.Random;
+import junit.framework.TestCase;
+
+/**
+ * Unit tests for {@link CacheSpan}.
+ */
+public class CacheSpanTest extends TestCase {
+
+  public void testCacheFile() throws Exception {
+    assertCacheSpan(new File("parent"), "key", 0, 0);
+    assertCacheSpan(new File("parent/"), "key", 1, 2);
+    assertCacheSpan(new File("parent"), "<>:\"/\\|?*%", 1, 2);
+    assertCacheSpan(new File("/"), "key", 1, 2);
+
+    assertNullCacheSpan(new File("parent"), "", 1, 2);
+    assertNullCacheSpan(new File("parent"), "key", -1, 2);
+    assertNullCacheSpan(new File("parent"), "key", 1, -2);
+
+    assertNotNull(CacheSpan.createCacheEntry(new File("/asd%aa.1.2.v2.exo")));
+    assertNull(CacheSpan.createCacheEntry(new File("/asd%za.1.2.v2.exo")));
+
+    assertCacheSpan(new File("parent"),
+        "A newline (line feed) character \n"
+            + "A carriage-return character followed immediately by a newline character \r\n"
+            + "A standalone carriage-return character \r"
+            + "A next-line character \u0085"
+            + "A line-separator character \u2028"
+            + "A paragraph-separator character \u2029", 1, 2);
+  }
+
+  public void testCacheFileNameRandomData() throws Exception {
+    Random random = new Random(0);
+    File parent = new File("parent");
+    for (int i = 0; i < 1000; i++) {
+      String key = TestUtil.buildTestString(1000, random);
+      long offset = Math.abs(random.nextLong());
+      long lastAccessTimestamp = Math.abs(random.nextLong());
+      assertCacheSpan(parent, key, offset, lastAccessTimestamp);
+    }
+  }
+
+  private void assertCacheSpan(File parent, String key, long offset, long lastAccessTimestamp) {
+    File cacheFile = CacheSpan.getCacheFileName(parent, key, offset, lastAccessTimestamp);
+    CacheSpan cacheSpan = CacheSpan.createCacheEntry(cacheFile);
+    String message = cacheFile.toString();
+    assertNotNull(message, cacheSpan);
+    assertEquals(message, parent, cacheFile.getParentFile());
+    assertEquals(message, key, cacheSpan.key);
+    assertEquals(message, offset, cacheSpan.position);
+    assertEquals(message, lastAccessTimestamp, cacheSpan.lastAccessTimestamp);
+  }
+
+  private void assertNullCacheSpan(File parent, String key, long offset,
+      long lastAccessTimestamp) {
+    File cacheFile = CacheSpan.getCacheFileName(parent, key, offset, lastAccessTimestamp);
+    CacheSpan cacheSpan = CacheSpan.createCacheEntry(cacheFile);
+    assertNull(cacheFile.toString(), cacheSpan);
+  }
+
+}

library/src/androidTest/java/com/google/android/exoplayer2/util/UtilTest.java

@@ -15,9 +15,11 @@
  */
 package com.google.android.exoplayer2.util;
 
+import com.google.android.exoplayer2.testutil.TestUtil;
 import java.text.ParseException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Random;
 import junit.framework.TestCase;
 
 /**
@@ -152,6 +154,12 @@ public class UtilTest extends TestCase {
     assertEscapeUnescapeFileName("just+a regular+fileName", "just+a regular+fileName");
     assertEscapeUnescapeFileName("key:value", "key%3avalue");
     assertEscapeUnescapeFileName("<>:\"/\\|?*%", "%3c%3e%3a%22%2f%5c%7c%3f%2a%25");
+
+    Random random = new Random(0);
+    for (int i = 0; i < 1000; i++) {
+      String string = TestUtil.buildTestString(1000, random);
+      assertEscapeUnescapeFileName(string);
+    }
   }
 
   private static void assertEscapeUnescapeFileName(String fileName, String escapedFileName) {
@@ -159,4 +167,9 @@ public class UtilTest extends TestCase {
     assertEquals(fileName, Util.unescapeFileName(escapedFileName));
   }
 
+  private static void assertEscapeUnescapeFileName(String fileName) {
+    String escapedFileName = Util.escapeFileName(fileName);
+    assertEquals(fileName, Util.unescapeFileName(escapedFileName));
+  }
+
 }

library/src/main/java/com/google/android/exoplayer2/upstream/cache/CacheSpan.java

@@ -27,9 +27,9 @@ public final class CacheSpan implements Comparable<CacheSpan> {
 
   private static final String SUFFIX = ".v2.exo";
   private static final Pattern CACHE_FILE_PATTERN_V1 =
-      Pattern.compile("^(.+)\\.(\\d+)\\.(\\d+)\\.v1\\.exo$");
+      Pattern.compile("^(.+)\\.(\\d+)\\.(\\d+)\\.v1\\.exo$", Pattern.DOTALL);
   private static final Pattern CACHE_FILE_PATTERN_V2 =
-      Pattern.compile("^(.+)\\.(\\d+)\\.(\\d+)\\.v2\\.exo$");
+      Pattern.compile("^(.+)\\.(\\d+)\\.(\\d+)\\.v2\\.exo$", Pattern.DOTALL);
 
   /**
    * The cache key that uniquely identifies the original stream.

testutils/src/main/java/com/google/android/exoplayer2/testutil/TestUtil.java

@@ -131,6 +131,15 @@ public class TestUtil {
     return source;
   }
 
+  public static String buildTestString(int maxLength, Random random) {
+    int length = random.nextInt(maxLength);
+    StringBuilder builder = new StringBuilder(length);
+    for (int i = 0; i < length; i++) {
+      builder.append((char) random.nextInt());
+    }
+    return builder.toString();
+  }
+
   /**
    * Converts an array of integers in the range [0, 255] into an equivalent byte array.
    *