Treat ABORTED writes as retryable

This corresponds to a server-side change that will be released for the v1 protocol only (see b/119437764).

This is a port of firebase/firebase-js-sdk#1456.

Author: wilhuff

firebase-firestore/src/main/java/com/google/firebase/firestore/remote/Datastore.java

@@ -219,7 +219,13 @@ public Task<List<MaybeDocument>> lookup(List<DocumentKey> keys) {
             });
   }
 
-  public static boolean isPermanentWriteError(Status status) {
+  /**
+   * Determines whether the given status has an error code that represents a permanent error when
+   * received in response to a non-write operation.
+   *
+   * @see #isPermanentWriteError for classifying write errors.
+   */
+  public static boolean isPermanentError(Status status) {
     // See go/firestore-client-errors
     switch (status.getCode()) {
       case OK:
@@ -251,4 +257,19 @@ public static boolean isPermanentWriteError(Status status) {
         throw new IllegalArgumentException("Unknown gRPC status code: " + status.getCode());
     }
   }
+
+  /**
+   * Determines whether the given status has an error code represents a permanent error when
+   * received in response to a write operation.
+   *
+   * <p>Write operations must be handled specially because as of b/119437764, ABORTED errors on the
+   * write stream should be retried too (even though ABORTED errors are not generally retryable).
+   *
+   * <p>Note that during the initial handshake on the write stream an ABORTED error signals that we
+   * should discard our stream token (i.e. it is permanent). This means a handshake error should be
+   * classified with isPermanentError, above.
+   */
+  public static boolean isPermanentWriteError(Status status) {
+    return isPermanentError(status) && !status.getCode().equals(Status.Code.ABORTED);
+  }
 }

firebase-firestore/src/main/java/com/google/firebase/firestore/remote/RemoteStore.java

@@ -37,7 +37,6 @@
 import com.google.firebase.firestore.util.Util;
 import com.google.protobuf.ByteString;
 import io.grpc.Status;
-import io.grpc.Status.Code;
 import java.util.ArrayDeque;
 import java.util.Deque;
 import java.util.HashMap;
@@ -642,9 +641,10 @@ private void handleWriteStreamClose(Status status) {
 
   private void handleWriteHandshakeError(Status status) {
     hardAssert(!status.isOk(), "Handling write error with status OK.");
-    // Reset the token if it's a permanent error or the error code is ABORTED, signaling the write
-    // stream is no longer valid.
-    if (Datastore.isPermanentWriteError(status) || status.getCode().equals(Code.ABORTED)) {
+    // Reset the token if it's a permanent error, signaling the write stream is no longer valid.
+    // Note that the handshake does not count as a write: see comments on isPermanentWriteError for
+    // details.
+    if (Datastore.isPermanentError(status)) {
       String token = Util.toDebugString(writeStream.getLastStreamToken());
       Logger.debug(
           LOG_TAG,
@@ -658,7 +658,7 @@ private void handleWriteHandshakeError(Status status) {
 
   private void handleWriteError(Status status) {
     hardAssert(!status.isOk(), "Handling write error with status OK.");
-    // Only handle permanent error, if it's transient just let the retry logic kick in.
+    // Only handle permanent errors here. If it's transient, just let the retry logic kick in.
     if (Datastore.isPermanentWriteError(status)) {
       // If this was a permanent error, the request itself was the problem so it's not going
       // to succeed if we resend it.