// Copyright 2018 Google LLC
//
// 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.firebase.firestore.core;

/** Implements a monotonic sequence starting after an initial value. */
public class ListenSequence {
  public static final long INVALID = -1;

  private long previousSequenceNumber;

  public ListenSequence(long startAfter) {
    this.previousSequenceNumber = startAfter;
  }

  public long next() {
    return ++previousSequenceNumber;
  }
}
