Revert https://codereview.chromium.org/1291903002 (protobuf roll).

third_party/protobuf/java/src/main/java/com/google/protobuf/LazyFieldLite.java

Index: third_party/protobuf/java/src/main/java/com/google/protobuf/LazyFieldLite.java
diff --git a/third_party/protobuf/java/src/main/java/com/google/protobuf/LazyFieldLite.java b/third_party/protobuf/java/src/main/java/com/google/protobuf/LazyFieldLite.java
deleted file mode 100644
index eea1fe3cdde1b3f395abb6664033f9207b2b13db..0000000000000000000000000000000000000000
--- a/third_party/protobuf/java/src/main/java/com/google/protobuf/LazyFieldLite.java
+++ /dev/null
@@ -1,339 +0,0 @@
-// Protocol Buffers - Google's data interchange format
-// Copyright 2008 Google Inc.  All rights reserved.
-// https://developers.google.com/protocol-buffers/
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-// copyright notice, this list of conditions and the following disclaimer
-// in the documentation and/or other materials provided with the
-// distribution.
-//     * Neither the name of Google Inc. nor the names of its
-// contributors may be used to endorse or promote products derived from
-// this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package com.google.protobuf;
-
-/**
- * LazyFieldLite encapsulates the logic of lazily parsing message fields. It stores
- * the message in a ByteString initially and then parse it on-demand.
- *
- * LazyField is thread-compatible e.g. concurrent read are safe, however,
- * synchronizations are needed under read/write situations.
- *
- * This class is internal implementation detail, so you don't need to use it directly.
- *
- * @author xiangl@google.com (Xiang Li)
- */
-public class LazyFieldLite {
-  private static final ExtensionRegistryLite EMPTY_REGISTRY =
-      ExtensionRegistryLite.getEmptyRegistry();
-
-  /**
-   * A delayed-parsed version of the bytes. When this is non-null then {@code extensionRegistry } is
-   * also non-null and {@code value} and {@code memoizedBytes} are null.
-   */
-  private ByteString delayedBytes;
-
-  /**
-   * An {@code ExtensionRegistryLite} for parsing bytes. It is non-null on a best-effort basis. It
-   * is only guaranteed to be non-null if this message was initialized using bytes and an
-   * {@code ExtensionRegistry}. If it directly had a value set then it will be null, unless it has
-   * been merged with another {@code LazyFieldLite} that had an {@code ExtensionRegistry}.
-   */
-  private ExtensionRegistryLite extensionRegistry;
-
-  /**
-   * The parsed value. When this is non-null then {@code delayedBytes} will be null.
-   */
-  protected volatile MessageLite value;
-
-  /**
-   * The memoized bytes for {@code value}. Will be null when {@code value} is null.
-   */
-  private volatile ByteString memoizedBytes;
-
-  /**
-   * Constructs a LazyFieldLite with bytes that will be parsed lazily.
-   */
-  public LazyFieldLite(ExtensionRegistryLite extensionRegistry, ByteString bytes) {
-    checkArguments(extensionRegistry, bytes);
-    this.extensionRegistry = extensionRegistry;
-    this.delayedBytes = bytes;
-  }
-
-  /**
-   * Constructs a LazyFieldLite with no contents, and no ability to parse extensions.
-   */
-  public LazyFieldLite() {
-  }
-
-  /**
-   * Constructs a LazyFieldLite instance with a value. The LazyFieldLite may not be able to parse
-   * the extensions in the value as it has no ExtensionRegistry.
-   */
-  public static LazyFieldLite fromValue(MessageLite value) {
-    LazyFieldLite lf = new LazyFieldLite();
-    lf.setValue(value);
-    return lf;
-  }
-
-  /**
-   * Determines whether this LazyFieldLite instance represents the default instance of this type.
-   */
-  public boolean containsDefaultInstance() {
-    return memoizedBytes == ByteString.EMPTY
-        || value == null && (delayedBytes == null || delayedBytes == ByteString.EMPTY);
-  }
-
-  /**
-   * Clears the value state of this instance.
-   *
-   * <p>LazyField is not thread-safe for write access. Synchronizations are needed
-   * under read/write situations.
-   */
-  public void clear() {
-    // Don't clear the ExtensionRegistry. It might prove useful later on when merging in another
-    // value, but there is no guarantee that it will contain all extensions that were directly set
-    // on the values that need to be merged.
-    delayedBytes = null;
-    value = null;
-    memoizedBytes = null;
-  }
-
-  /**
-   * Overrides the contents of this LazyField.
-   *
-   * <p>LazyField is not thread-safe for write access. Synchronizations are needed
-   * under read/write situations.
-   */
-  public void set(LazyFieldLite other) {
-    this.delayedBytes = other.delayedBytes;
-    this.value = other.value;
-    this.memoizedBytes = other.memoizedBytes;
-    // If the other LazyFieldLite was created by directly setting the value rather than first by
-    // parsing, then it will not have an extensionRegistry. In this case we hold on to the existing
-    // extensionRegistry, which has no guarantees that it has all the extensions that will be
-    // directly set on the value.
-    if (other.extensionRegistry != null) {
-      this.extensionRegistry = other.extensionRegistry;
-    }
-  }
-
-  /**
-   * Returns message instance. It may do some thread-safe delayed parsing of bytes.
-   *
-   * @param defaultInstance its message's default instance. It's also used to get parser for the
-   * message type.
-   */
-  public MessageLite getValue(MessageLite defaultInstance) {
-    ensureInitialized(defaultInstance);
-    return value;
-  }
-
-  /**
-   * Sets the value of the instance and returns the old value without delay parsing anything.
-   *
-   * <p>LazyField is not thread-safe for write access. Synchronizations are needed
-   * under read/write situations.
-   */
-  public MessageLite setValue(MessageLite value) {
-    MessageLite originalValue = this.value;
-    this.delayedBytes = null;
-    this.memoizedBytes = null;
-    this.value = value;
-    return originalValue;
-  }
-
-  /**
-   * Merges another instance's contents. In some cases may drop some extensions if both fields
-   * contain data. If the other field has an {@code ExtensionRegistry} but this does not, then this
-   * field will copy over that {@code ExtensionRegistry}.
-   *
-   * <p>LazyField is not thread-safe for write access. Synchronizations are needed
-   * under read/write situations.
-   */
-  public void merge(LazyFieldLite other) {
-    if (other.containsDefaultInstance()) {
-      return;
-    }
-
-    if (this.containsDefaultInstance()) {
-      set(other);
-      return;
-    }
-
-    // If the other field has an extension registry but this does not, copy over the other extension
-    // registry.
-    if (this.extensionRegistry == null) {
-      this.extensionRegistry = other.extensionRegistry;
-    }
-
-    // In the case that both of them are not parsed we simply concatenate the bytes to save time. In
-    // the (probably rare) case that they have different extension registries there is a chance that
-    // some of the extensions may be dropped, but the tradeoff of making this operation fast seems
-    // to outway the benefits of combining the extension registries, which is not normally done for
-    // lite protos anyways.
-    if (this.delayedBytes != null && other.delayedBytes != null) {
-      this.delayedBytes = this.delayedBytes.concat(other.delayedBytes);
-      return;
-    }
-
-    // At least one is parsed and both contain data. We won't drop any extensions here directly, but
-    // in the case that the extension registries are not the same then we might in the future if we
-    // need to serialze and parse a message again.
-    if (this.value == null && other.value != null) {
-      setValue(mergeValueAndBytes(other.value, this.delayedBytes, this.extensionRegistry));
-      return;
-    } else if (this.value != null && other.value == null) {
-      setValue(mergeValueAndBytes(this.value, other.delayedBytes, other.extensionRegistry));
-      return;
-    }
-
-    // At this point we have two fully parsed messages. We can't merge directly from one to the
-    // other because only generated builder code contains methods to mergeFrom another parsed
-    // message. We have to serialize one instance and then merge the bytes into the other. This may
-    // drop extensions from one of the messages if one of the values had an extension set on it
-    // directly.
-    //
-    // To mitigate this we prefer serializing a message that has an extension registry, and
-    // therefore a chance that all extensions set on it are in that registry.
-    //
-    // NOTE: The check for other.extensionRegistry not being null must come first because at this
-    // point in time if other.extensionRegistry is not null then this.extensionRegistry will not be
-    // null either.
-    if (other.extensionRegistry != null) {
-      setValue(mergeValueAndBytes(this.value, other.toByteString(), other.extensionRegistry));
-      return;
-    } else if (this.extensionRegistry != null) {
-      setValue(mergeValueAndBytes(other.value, this.toByteString(), this.extensionRegistry));
-      return;
-    } else {
-      // All extensions from the other message will be dropped because we have no registry.
-      setValue(mergeValueAndBytes(this.value, other.toByteString(), EMPTY_REGISTRY));
-      return;
-    }
-  }
-
-  private static MessageLite mergeValueAndBytes(
-      MessageLite value, ByteString otherBytes, ExtensionRegistryLite extensionRegistry) {
-    try {
-      return value.toBuilder().mergeFrom(otherBytes, extensionRegistry).build();
-    } catch (InvalidProtocolBufferException e) {
-      // Nothing is logged and no exceptions are thrown. Clients will be unaware that a proto
-      // was invalid.
-      return value;
-    }
-  }
-
-  /**
-   * Sets this field with bytes to delay-parse.
-   */
-  public void setByteString(ByteString bytes, ExtensionRegistryLite extensionRegistry) {
-    checkArguments(extensionRegistry, bytes);
-    this.delayedBytes = bytes;
-    this.extensionRegistry = extensionRegistry;
-    this.value = null;
-    this.memoizedBytes = null;
-  }
-
-  /**
-   * Due to the optional field can be duplicated at the end of serialized
-   * bytes, which will make the serialized size changed after LazyField
-   * parsed. Be careful when using this method.
-   */
-  public int getSerializedSize() {
-    if (delayedBytes != null) {
-      return delayedBytes.size();
-    } else if (memoizedBytes != null) {
-      return memoizedBytes.size();
-    } else if (value != null) {
-      return value.getSerializedSize();
-    } else {
-      return 0;
-    }
-  }
-
-  /**
-   * Returns a BytesString for this field in a thread-safe way.
-   */
-  public ByteString toByteString() {
-    if (delayedBytes != null) {
-      return delayedBytes;
-    }
-    if (memoizedBytes != null) {
-      return memoizedBytes;
-    }
-    synchronized (this) {
-      if (memoizedBytes != null) {
-        return memoizedBytes;
-      }
-      if (value == null) {
-        memoizedBytes = ByteString.EMPTY;
-      } else {
-        memoizedBytes = value.toByteString();
-      }
-      return memoizedBytes;
-    }
-  }
-
-  /**
-   * Might lazily parse the bytes that were previously passed in. Is thread-safe.
-   */
-  protected void ensureInitialized(MessageLite defaultInstance) {
-    if (value != null) {
-      return;
-    }
-    synchronized (this) {
-      if (value != null) {
-        return;
-      }
-      try {
-        if (delayedBytes != null) {
-          // The extensionRegistry shouldn't be null here since we have delayedBytes.
-          MessageLite parsedValue = defaultInstance.getParserForType()
-              .parseFrom(delayedBytes, extensionRegistry);
-          this.value = parsedValue;
-          this.memoizedBytes = delayedBytes;
-          this.delayedBytes = null;
-        } else {
-          this.value = defaultInstance;
-          this.memoizedBytes = ByteString.EMPTY;
-          this.delayedBytes = null;
-        }
-      } catch (InvalidProtocolBufferException e) {
-        // Nothing is logged and no exceptions are thrown. Clients will be unaware that this proto
-        // was invalid.
-        this.value = defaultInstance;
-        this.memoizedBytes = ByteString.EMPTY;
-        this.delayedBytes = null;
-      }
-    }
-  }
-
-
-  private static void checkArguments(ExtensionRegistryLite extensionRegistry, ByteString bytes) {
-    if (extensionRegistry == null) {
-      throw new NullPointerException("found null ExtensionRegistry");
-    }
-    if (bytes == null) {
-      throw new NullPointerException("found null ByteString");
-    }
-  }
-}