52 lines
1.7 KiB
TypeScript
52 lines
1.7 KiB
TypeScript
/*
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Copyright 2020 Bruno Windels <bruno@windels.cloud>
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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//entries can be sorted, first by fragment, then by entry index.
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import {EventKey} from "../EventKey.js";
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export const PENDING_FRAGMENT_ID = Number.MAX_SAFE_INTEGER;
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interface FragmentIdComparer {
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compare: (a: number, b: number) => number
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}
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export abstract class BaseEntry {
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constructor(
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protected readonly _fragmentIdComparer: FragmentIdComparer
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) {
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}
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abstract get fragmentId(): number;
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abstract get entryIndex(): number;
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abstract updateFrom(other: BaseEntry): void;
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compare(otherEntry: BaseEntry): number {
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if (this.fragmentId === otherEntry.fragmentId) {
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return this.entryIndex - otherEntry.entryIndex;
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} else if (this.fragmentId === PENDING_FRAGMENT_ID) {
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return 1;
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} else if (otherEntry.fragmentId === PENDING_FRAGMENT_ID) {
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return -1;
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} else {
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// This might throw if the relation of two fragments is unknown.
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return this._fragmentIdComparer.compare(this.fragmentId, otherEntry.fragmentId);
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}
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}
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asEventKey(): EventKey {
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return new EventKey(this.fragmentId, this.entryIndex);
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}
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}
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