66 lines
1.6 KiB
JavaScript
66 lines
1.6 KiB
JavaScript
/*
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* keySelector.js
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*
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* This source file is part of the FoundationDB open source project
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*
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* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
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*
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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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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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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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"use strict";
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var fdbUtil = require('./fdbUtil');
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var KeySelector = function(key, orEqual, offset) {
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this.key = fdbUtil.keyToBuffer(key);
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this.orEqual = orEqual;
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this.offset = offset;
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};
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KeySelector.prototype.next = function() {
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return this.add(1);
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};
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KeySelector.prototype.prev = function() {
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return this.add(-1);
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};
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KeySelector.prototype.add = function(addOffset) {
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return new KeySelector(this.key, this.orEqual, this.offset + addOffset);
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};
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KeySelector.isKeySelector = function(sel) {
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return sel instanceof KeySelector;
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};
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KeySelector.lastLessThan = function(key) {
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return new KeySelector(key, false, 0);
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};
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KeySelector.lastLessOrEqual = function(key) {
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return new KeySelector(key, true, 0);
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};
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KeySelector.firstGreaterThan = function(key) {
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return new KeySelector(key, true, 1);
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};
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KeySelector.firstGreaterOrEqual = function(key) {
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return new KeySelector(key, false, 1);
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};
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module.exports = KeySelector;
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