com.google.gerrit.server.notedb.rebuild.EventList.java Source code

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Here is the source code for com.google.gerrit.server.notedb.rebuild.EventList.java

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// Copyright (C) 2016 The Android Open Source Project
//
// 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.gerrit.server.notedb.rebuild;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.base.Preconditions.checkState;

import com.google.common.collect.Lists;
import com.google.gerrit.reviewdb.client.Account;
import com.google.gerrit.reviewdb.client.PatchSet;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Objects;

class EventList<E extends Event> implements Iterable<E> {
    private final ArrayList<E> list = new ArrayList<>();
    private boolean isSubmit;

    @Override
    public Iterator<E> iterator() {
        return list.iterator();
    }

    void add(E e) {
        list.add(e);
        if (e.isSubmit()) {
            isSubmit = true;
        }
    }

    void clear() {
        list.clear();
        isSubmit = false;
    }

    boolean isEmpty() {
        return list.isEmpty();
    }

    boolean canAdd(E e) {
        if (isEmpty()) {
            return true;
        }
        if (e instanceof FinalUpdatesEvent) {
            return false; // FinalUpdatesEvent always gets its own update.
        }

        Event last = getLast();
        if (!Objects.equals(e.user, last.user) || !Objects.equals(e.realUser, last.realUser)
                || !e.psId.equals(last.psId)) {
            return false; // Different patch set or author.
        }
        if (e.canHaveTag() && canHaveTag() && !Objects.equals(e.tag, getTag())) {
            // We should trust the tag field, and it doesn't match.
            return false;
        }
        if (e.isPostSubmitApproval() && isSubmit) {
            // Post-submit approvals must come after the update that submits.
            return false;
        }

        long t = e.when.getTime();
        long tFirst = getFirstTime();
        long tLast = getLastTime();
        checkArgument(t >= tLast, "event %s is before previous event in list %s", e, last);
        if (t - tLast > ChangeRebuilderImpl.MAX_DELTA_MS || t - tFirst > ChangeRebuilderImpl.MAX_WINDOW_MS) {
            return false; // Too much time elapsed.
        }

        if (!e.uniquePerUpdate()) {
            return true;
        }
        for (Event o : this) {
            if (e.getClass() == o.getClass()) {
                return false; // Only one event of this type allowed per update.
            }
        }

        // TODO(dborowitz): Additional heuristics, like keeping events separate if
        // they affect overlapping fields within a single entity.

        return true;
    }

    Timestamp getWhen() {
        return get(0).when;
    }

    PatchSet.Id getPatchSetId() {
        PatchSet.Id id = checkNotNull(get(0).psId);
        for (int i = 1; i < size(); i++) {
            checkState(get(i).psId.equals(id), "mismatched patch sets in EventList: %s != %s", id, get(i).psId);
        }
        return id;
    }

    Account.Id getAccountId() {
        Account.Id id = get(0).user;
        for (int i = 1; i < size(); i++) {
            checkState(Objects.equals(id, get(i).user), "mismatched users in EventList: %s != %s", id, get(i).user);
        }
        return id;
    }

    Account.Id getRealAccountId() {
        Account.Id id = get(0).realUser;
        for (int i = 1; i < size(); i++) {
            checkState(Objects.equals(id, get(i).realUser), "mismatched real users in EventList: %s != %s", id,
                    get(i).realUser);
        }
        return id;
    }

    String getTag() {
        for (E e : Lists.reverse(list)) {
            if (e.tag != null) {
                return e.tag;
            }
        }
        return null;
    }

    private boolean canHaveTag() {
        return list.stream().anyMatch(Event::canHaveTag);
    }

    private E get(int i) {
        return list.get(i);
    }

    private int size() {
        return list.size();
    }

    private E getLast() {
        return list.get(list.size() - 1);
    }

    private long getLastTime() {
        return getLast().when.getTime();
    }

    private long getFirstTime() {
        return list.get(0).when.getTime();
    }
}