1 files changed, 237 insertions, 0 deletions
diff --git a/src/com/google/common/io/protocol/ProtoBufUtil.java b/src/com/google/common/io/protocol/ProtoBufUtil.java
new file mode 100644
index 0000000..72e1bca
--- /dev/null
+++ b/src/com/google/common/io/protocol/ProtoBufUtil.java
@@ -0,0 +1,237 @@
+// Copyright 2008 Google Inc. All Rights Reserved.
+
+package com.google.common.io.protocol;
+
+import java.io.*;
+
+/**
+ * Utility functions for dealing with ProtoBuf objects consolidated from
+ * previous spot implementations across the codebase.
+ *
+ */
+public final class ProtoBufUtil {
+  private ProtoBufUtil() {
+  }
+
+  /** Convenience method to return a string value from of a proto or "". */
+  public static String getProtoValueOrEmpty(ProtoBuf proto, int tag) {
+    try {
+      return (proto != null && proto.has(tag)) ? proto.getString(tag) : "";
+    } catch (ClassCastException e) {
+      return "";
+    }
+  }
+
+  /** Convenience method to return a string value from of a sub-proto or "". */
+  public static String getSubProtoValueOrEmpty(
+      ProtoBuf proto, int sub, int tag) {
+    try {
+      return getProtoValueOrEmpty(getSubProtoOrNull(proto, sub), tag);
+    } catch (ClassCastException e) {
+      return "";
+    }
+  }
+
+  /** Convenience method to get a subproto if the proto has it. */
+  public static ProtoBuf getSubProtoOrNull(ProtoBuf proto, int sub) {
+    return (proto != null && proto.has(sub)) ? proto.getProtoBuf(sub) : null;
+  }
+
+  /**
+   * Get an int with "tag" from the proto buffer. If the given field can't be
+   * retrieved, return the provided default value.
+   * 
+   * @param proto The proto buffer.
+   * @param tag The tag value that identifies which protocol buffer field to
+   *        retrieve.
+   * @param defaultValue The value to return if the field can't be retrieved.
+   * @return The result which should be an integer.
+   */
+  public static int getProtoValueOrDefault(ProtoBuf proto, int tag,
+      int defaultValue) {
+    try {
+      return (proto != null && proto.has(tag))
+          ? proto.getInt(tag) : defaultValue;
+    } catch (IllegalArgumentException e) {
+      return defaultValue;
+    } catch (ClassCastException e) {
+      return defaultValue;
+    }
+  }
+
+  /**
+   * Get an Int with "tag" from the proto buffer.
+   * If the given field can't be retrieved, return 0.
+   *
+   * @param proto The proto buffer.
+   * @param tag The tag value that identifies which protocol buffer field to
+   * retrieve.
+   * @return The result which should be an integer.
+   */
+  public static int getProtoValueOrZero(ProtoBuf proto, int tag) {
+    return getProtoValueOrDefault(proto, tag, 0);
+  }
+
+  /**
+   * Get an Long with "tag" from the proto buffer.
+   * If the given field can't be retrieved, return 0.
+   *
+   * @param proto The proto buffer.
+   * @param tag The tag value that identifies which protocol buffer field to
+   * retrieve.
+   * @return The result which should be an integer.
+   */
+  public static long getProtoLongValueOrZero(ProtoBuf proto, int tag) {
+    try {
+      return (proto != null && proto.has(tag)) ? proto.getLong(tag) : 0L;
+    } catch (IllegalArgumentException e) {
+      return 0L;
+    } catch (ClassCastException e) {
+      return 0L;
+    }
+  }
+
+  /**
+   * Get an Int with "tag" from the proto buffer.
+   * If the given field can't be retrieved, return -1.
+   *
+   * @param proto The proto buffer.
+   * @param tag The tag value that identifies which protocol buffer field to
+   * retrieve.
+   * @return The result which should be a long.
+   */
+  public static long getProtoValueOrNegativeOne(ProtoBuf proto, int tag) {
+    try {
+      return (proto != null && proto.has(tag)) ? proto.getLong(tag) : -1;
+    } catch (IllegalArgumentException e) {
+      return -1;
+    } catch (ClassCastException e) {
+      return -1;
+    }
+  }
+
+  /**
+   * Reads a single protocol buffer from the given input stream. This method is
+   * provided where the client needs incremental access to the contents of a 
+   * protocol buffer which contains a sequence of protocol buffers.  
+   * <p />
+   * Please use {@link #getInputStreamForProtoBufResponse} to obtain an input 
+   * stream suitable for this method.
+   * 
+   * @param umbrellaType the type of the "outer" protocol buffer containing
+   *                    the message to read
+   * @param is the stream to read the protocol buffer from
+   * @param result the result protocol buffer (must be empty, will be filled
+   *               with the data read and the type will be set)
+   * @return the tag id of the message, -1 at the end of the stream
+   */
+  public static int readNextProtoBuf(ProtoBufType umbrellaType, 
+      InputStream is, ProtoBuf result) throws IOException {
+    long tagAndType = ProtoBuf.readVarInt(is, true /* permits EOF */);
+    if (tagAndType == -1) {
+      return -1;
+    }
+    
+    if ((tagAndType & 7) != ProtoBuf.WIRETYPE_LENGTH_DELIMITED) {
+      throw new IOException("Message expected");
+    }
+    int tag = (int) (tagAndType >>> 3);
+    
+    result.setType((ProtoBufType) umbrellaType.getData(tag));
+    int length = (int) ProtoBuf.readVarInt(is, false);
+    result.parse(is, length);
+    return tag;
+  }
+  
+  /**
+   * A wrapper for <code> getProtoValueOrNegativeOne </code> that drills into
+   * a sub message returning the long value if it exists, returning -1 if it
+   * does not.
+   *
+   * @param proto The proto buffer.
+   * @param tag The tag value that identifies which protocol buffer field to
+   * retrieve.
+   * @param sub The sub tag value that identifies which protocol buffer
+   * sub-field to retrieve.n
+   * @return The result which should be a long.
+   */
+  public static long getSubProtoValueOrNegativeOne(
+      ProtoBuf proto, int sub, int tag) {
+    try {
+      return getProtoValueOrNegativeOne(getSubProtoOrNull(proto, sub), tag);
+    } catch (IllegalArgumentException e) {
+      return -1;
+    } catch (ClassCastException e) {
+      return -1; 
+    }
+  }
+
+  /**
+   * A wrapper for {@link #getProtoValueOrDefault(ProtoBuf, int, int)} that
+   * drills into a sub message returning the int value if it exists, returning
+   * the given default if it does not.
+   *
+   * @param proto The proto buffer.
+   * @param tag The tag value that identifies which protocol buffer field to
+   * retrieve.
+   * @param sub The sub tag value that identifies which protocol buffer
+   * sub-field to retrieve.
+   * @param defaultValue The value to return if the field is not present.
+   * @return The result which should be a long.
+   */
+  public static int getSubProtoValueOrDefault(ProtoBuf proto, int sub, int tag,
+      int defaultValue) {
+    try {
+      return getProtoValueOrDefault(getSubProtoOrNull(proto, sub), tag, 
+          defaultValue);
+    } catch (IllegalArgumentException e) {
+      return defaultValue;
+    } catch (ClassCastException e) {
+      return defaultValue; 
+    }
+  }
+
+  /**
+   * Creates a sub ProtoBuf of the given Protobuf and sets it.
+   *
+   * @param proto The proto buffer.
+   * @param tag The tag value that identifies which protocol buffer field to
+   * create.
+   * @return the sub ProtoBuf generated.
+   */
+  public static ProtoBuf createProtoBuf(ProtoBuf proto, int tag) {
+    ProtoBuf child = proto.createGroup(tag);
+    proto.setProtoBuf(tag, child);
+    return child;
+  }
+
+  /**
+   * Creates a sub ProtoBuf of the given Protobuf and adds it.
+   *
+   * @param proto The proto buffer.
+   * @param tag The tag value that identifies which protocol buffer field to
+   * add.
+   * @return the sub ProtoBuf generated.
+   */
+  public static ProtoBuf addProtoBuf(ProtoBuf proto, int tag) {
+    ProtoBuf child = proto.createGroup(tag);
+    proto.addProtoBuf(tag, child);
+    return child;
+  }
+
+  /**
+   * Writes the ProtoBuf to the given DataOutput.  This is useful for unit
+   * tests.
+   *
+   * @param output The data output to write to.
+   * @param protoBuf The proto buffer.
+   */
+  public static void writeProtoBufToOutput(DataOutput output, ProtoBuf protoBuf)
+      throws IOException {
+    ByteArrayOutputStream baos = new ByteArrayOutputStream();
+    protoBuf.outputTo(baos);
+    byte[] bytes = baos.toByteArray();
+    output.writeInt(bytes.length);
+    output.write(bytes);
+  }
+}