Pull cacheinvalidations code directory into chromium repo.

third_party/cacheinvalidation/src/java/com/google/ipc/invalidation/util/TextBuilder.java

+/*
+ * Copyright 2011 Google Inc.
+ *
+ * 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.ipc.invalidation.util;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+
+/**
+ * A {@link TextBuilder} is an abstraction that allows classes to efficiently append their string
+ * representations and then use them later for human consumption, e.g., for debugging or logging. It
+ * is currently a wrapper around {@link StringBuilder} and {@link Formatter} to give us format and
+ * append capabilities together. All append methods return this TextBuilder so that the method calls
+ * can be chained.
+ *
+ */
+public class TextBuilder {
+
+  private final StringBuilder builder;
+  private final UtilFormatter formatter;
+
+  /**
+   * Given an {@code object} that is an instance of {@code clazz}, outputs names and values of all
+   * member fields declared on {@code clazz}. This method should be used carefully:
+   * <ol>
+   * <li>This method is expensive. For frequently logged types, an ad hoc
+   *     {@link InternalBase#toCompactString} implementation is preferred.</li>
+   * <li>May overflow the stack if there is a cycle in an object graph.</li>
+   * <li>Custom formatters have been implemented for many protos. They will not be used by this
+   *     method.</li>
+   * </ol>
+   */
+  public static void outputFieldsToBuilder(TextBuilder builder, Object object, Class<?> clazz) {
+    Preconditions.checkArgument(clazz.isAssignableFrom(object.getClass()));
+
+    // Get all the fields and print them using toCompactString if possible;
+    // otherwise, via toString
+    Field[] fields = clazz.getDeclaredFields();
+    for (Field field : fields) {
+      try {
+        // Ignore static final fields, as they're uninteresting.
+        int modifiers = field.getModifiers();
+        if (Modifier.isStatic(modifiers) && Modifier.isFinal(modifiers)) {
+          continue;
+        }
+
+        field.setAccessible(true);
+        builder.append(field.getName() + " = ");
+        Object fieldValue = field.get(object);
+        if (fieldValue instanceof InternalBase) {
+          ((InternalBase) fieldValue).toCompactString(builder);
+        } else {
+          builder.append(fieldValue);
+        }
+        builder.append(", ");
+      } catch (IllegalArgumentException e) {
+        e.printStackTrace();
+      } catch (IllegalAccessException e) {
+        e.printStackTrace();
+      }
+    }
+  }
+
+  /**
+   * Returns an empty TextBuilder to which various objects' string
+   * representations can be added later.
+   */
+  public TextBuilder() {
+   builder = new StringBuilder();
+   formatter = new UtilFormatter(builder);
+  }
+
+  /**
+   * Appends the string representation of {@code c} to this builder.
+   *
+   * @param c the character being appended
+   */
+  public TextBuilder append(char c) {
+    builder.append(c);
+    return this;
+  }
+
+  /**
+   * Appends the string representation of {@code i} to this builder.
+   *
+   * @param i the integer being appended
+   */
+  public TextBuilder append(int i) {
+    builder.append(i);
+    return this;
+  }
+
+  /**
+   * Appends the toString representation of {@code object} to this builder.
+   */
+  public TextBuilder append(Object object) {
+    builder.append(object);
+    return this;
+  }
+
+  /**
+   * Appends the {@code InternalBase#toCompactString} representation of {@code object} to this
+   * builder.
+   */
+  public TextBuilder append(InternalBase object) {
+    if (object == null) {
+      return append("null");
+    }
+    object.toCompactString(this);
+    return this;
+  }
+
+  /**
+   * Appends the comma-separated {@code InternalBase#toCompactString} representations of
+   * {@code objects} to this builder.
+   */
+  public TextBuilder append(Iterable<? extends InternalBase> objects) {
+    if (objects == null) {
+      return this;
+    }
+    boolean first = true;
+    for (InternalBase object : objects) {
+      if (first) {
+        first = false;
+      } else {
+        builder.append(", ");
+      }
+      append(object);
+    }
+    return this;
+  }
+
+  /** Appends the {@link Bytes#toString} representation of {@code bytes} to this builder. */
+  public TextBuilder append(byte[] bytes) {
+    if (bytes == null) {
+      return append("null");
+    }
+    Bytes.toCompactString(this, bytes);
+    return this;
+  }
+
+  /**
+   * Appends the string representation of {@code l} to this builder.
+   *
+   * @param l the long being appended
+   */
+  public TextBuilder append(long l) {
+    builder.append(l);
+    return this;
+  }
+
+  /**
+   * Appends the string representation of {@code b} to this builder.
+   *
+   * @param b the boolean being appended
+   */
+  public TextBuilder append(boolean b) {
+    builder.append(b);
+    return this;
+  }
+
+  /**
+   * Appends {@code s} to this builder.
+   *
+   * @param s the string being appended
+   */
+  public TextBuilder append(String s) {
+    builder.append(s);
+    return this;
+  }
+
+  /**
+   * Writes a formatted string to this using the specified format string and
+   * arguments.
+   *
+   * @param format the format as used in {@link java.util.Formatter}
+   * @param args the arguments that are converted to their string form using
+   * {@code format}
+   */
+  public TextBuilder appendFormat(String format, Object... args) {
+    formatter.format(format, args);
+    return this;
+  }
+
+  @Override
+  public String toString() {
+    return builder.toString();
+  }
+}