Vihren Atlas

prefixSumComputer.ts ×20

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unlabeled · c_b39c3ac3a985

156 tests · 3526 LOC · 20 files · introduces 0 tests · 103 LOC · 1 file

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Code
20 ranges103 lines · 1 files
Tests
0 tests

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503 ranges3526 lines · 20 files · Browse complete extent
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156 testsBrowse complete intent

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1 file ranked by introduced lines: 103 introduced LOC across 20 ranges. Expand a file to inspect source; the > gutter marks introduced lines.

src/vs/editor/common/model/prefixSumComputer.ts 103 introduced LOC · 20 ranges

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1 > /*--------------------------------------------------------------------------------------------- prefixSumComputer.ts
2 > * Copyright (c) Microsoft Corporation. All rights reserved.
3 > * Licensed under the MIT License. See License.txt in the project root for license information.
4 > *--------------------------------------------------------------------------------------------*/
5 >
6 > import { arrayInsert } from '../../../base/common/arrays.js';
7 > import { toUint32 } from '../../../base/common/uint.js';
8 >
9 > export class PrefixSumComputer {
10 >
11 > /**
12 > * values[i] is the value at index i
13 > */
14 > private values: Uint32Array;
15 >
16 > /**
17 > * prefixSum[i] = SUM(heights[j]), 0 <= j <= i
18 > */
19 > private prefixSum: Uint32Array;
20 >
21 > /**
22 > * prefixSum[i], 0 <= i <= prefixSumValidIndex can be trusted
23 > */
24 > private readonly prefixSumValidIndex: Int32Array;
25 >
26 > constructor(values: Uint32Array) {
27 this.values = values;
28 this.prefixSum = new Uint32Array(values.length);
30 this.prefixSumValidIndex[0] = -1;
31 }
32 > prefixSumComputer.ts
33 > public getCount(): number {
34 return this.values.length;
35 }
36 > prefixSumComputer.ts
37 > public insertValues(insertIndex: number, insertValues: Uint32Array): boolean {
38 insertIndex = toUint32(insertIndex);
39 const oldValues = this.values;
60 return true;
61 }
62 > prefixSumComputer.ts
63 > public setValue(index: number, value: number): boolean {
64 index = toUint32(index);
65 value = toUint32(value);
74 return true;
75 }
76 > prefixSumComputer.ts
77 > public removeValues(startIndex: number, count: number): boolean {
78 startIndex = toUint32(startIndex);
79 count = toUint32(count);
108 return true;
109 }
110 > prefixSumComputer.ts
111 > public getTotalSum(): number {
112 if (this.values.length === 0) {
113 return 0;
115 return this._getPrefixSum(this.values.length - 1);
116 }
117 > prefixSumComputer.ts
118 > /**
119 > * Returns the sum of the first `index + 1` many items.
120 > * @returns `SUM(0 <= j <= index, values[j])`.
121 > */
122 > public getPrefixSum(index: number): number {
123 if (index < 0) {
124 return 0;
128 return this._getPrefixSum(index);
129 }
130 > prefixSumComputer.ts
131 > private _getPrefixSum(index: number): number {
132 if (index <= this.prefixSumValidIndex[0]) {
133 return this.prefixSum[index];
150 return this.prefixSum[index];
151 }
152 > prefixSumComputer.ts
153 > public getIndexOf(sum: number): PrefixSumIndexOfResult {
154 sum = Math.floor(sum);
155
180 return new PrefixSumIndexOfResult(mid, sum - midStart);
181 }
182 > } prefixSumComputer.ts
183 >
184 > /**
185 > * {@link getIndexOf} has an amortized runtime complexity of O(1).
186 > *
187 > * ({@link PrefixSumComputer.getIndexOf} is just O(log n))
188 > */
189 > export class ConstantTimePrefixSumComputer {
190 > private _values: number[];
191 > private _isValid: boolean;
192 > private _validEndIndex: number;
193 >
194 > /**
195 > * _prefixSum[i] = SUM(values[j]), 0 <= j <= i
196 > */
197 > private _prefixSum: number[];
198 >
199 > /**
200 > * _indexBySum[sum] = idx => _prefixSum[idx - 1] <= sum < _prefixSum[idx]
201 > */
202 > private _indexBySum: number[];
203 >
204 > constructor(values: number[]) {
205 this._values = values;
206 this._isValid = false;
209 this._indexBySum = [];
210 }
211 > prefixSumComputer.ts
212 > /**
213 > * @returns SUM(0 <= j < values.length, values[j])
214 > */
215 > public getTotalSum(): number {
216 this._ensureValid();
217 return this._indexBySum.length;
218 }
219 > prefixSumComputer.ts
220 > /**
221 > * Returns the sum of the first `count` many items.
222 > * @returns `SUM(0 <= j < count, values[j])`.
223 > */
224 > public getPrefixSum(count: number): number {
225 this._ensureValid();
226 if (count === 0) {
229 return this._prefixSum[count - 1];
230 }
231 > prefixSumComputer.ts
232 > /**
233 > * @returns `result`, such that `getPrefixSum(result.index) + result.remainder = sum`
234 > */
235 > public getIndexOf(sum: number): PrefixSumIndexOfResult {
236 this._ensureValid();
237 const idx = this._indexBySum[sum];
245 return new PrefixSumIndexOfResult(idx, sum - viewLinesAbove);
246 }
247 > prefixSumComputer.ts
248 > public removeValues(start: number, deleteCount: number): void {
249 this._values.splice(start, deleteCount);
250 this._invalidate(start);
251 }
252 > prefixSumComputer.ts
253 > public insertValues(insertIndex: number, insertArr: number[]): void {
254 this._values = arrayInsert(this._values, insertIndex, insertArr);
255 this._invalidate(insertIndex);
256 }
257 > prefixSumComputer.ts
258 > private _invalidate(index: number): void {
259 this._isValid = false;
260 this._validEndIndex = Math.min(this._validEndIndex, index - 1);
261 }
262 > prefixSumComputer.ts
263 > private _ensureValid(): void {
264 if (this._isValid) {
265 return;
284 this._validEndIndex = this._values.length - 1;
285 }
286 > prefixSumComputer.ts
287 > public setValue(index: number, value: number): void {
288 if (this._values[index] === value) {
289 // no change
293 this._invalidate(index);
294 }
295 > } prefixSumComputer.ts
296 >
297 >
298 > export class PrefixSumIndexOfResult {
299 > _prefixSumIndexOfResultBrand: void = undefined;
300 >
301 > constructor(
302 public readonly index: number,
303 public readonly remainder: number

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