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-rw-r--r--ext/mixed/js/cache-map.js177
-rw-r--r--package.json2
-rw-r--r--test/test-cache-map.js168
3 files changed, 346 insertions, 1 deletions
diff --git a/ext/mixed/js/cache-map.js b/ext/mixed/js/cache-map.js
new file mode 100644
index 00000000..7953e2cc
--- /dev/null
+++ b/ext/mixed/js/cache-map.js
@@ -0,0 +1,177 @@
+/*
+ * Copyright (C) 2020 Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Class which caches a map of values using an arbitrary length path,
+ * keeping the most recently accessed values.
+ */
+class CacheMap {
+ /**
+ * Creates a new CacheMap.
+ * @param maxCount The maximum number of entries able to be stored in the cache.
+ * @param create A function to create a value for the corresponding path.
+ * The signature is: create(...path)
+ */
+ constructor(maxCount, create) {
+ if (!(
+ typeof maxCount === 'number' &&
+ Number.isFinite(maxCount) &&
+ maxCount >= 0 &&
+ Math.floor(maxCount) === maxCount
+ )) {
+ throw new Error('Invalid maxCount');
+ }
+
+ this._maxCount = maxCount;
+ this._create = create;
+ this._count = 0;
+ this._map = new Map();
+ this._listFirst = this._createNode(null, null);
+ this._listLast = this._createNode(null, null);
+ this._resetEndNodes();
+ }
+
+ /**
+ * Returns the number of items in the cache.
+ */
+ get count() {
+ return this._count;
+ }
+
+ /**
+ * Returns the maximum number of items that can be added to the cache.
+ */
+ get maxCount() {
+ return this._maxCount;
+ }
+
+ /**
+ * Gets an item at the given path, if it exists. Otherwise, creates a new item
+ * and adds it to the cache. If the count exceeds the maximum count, items will be removed.
+ * @param path Arguments corresponding to the key of the cache.
+ */
+ get(...path) {
+ let ii = path.length;
+ if (ii === 0) { throw new Error('Invalid path'); }
+
+ let map = this._map;
+ let i = 0;
+ for (; i < ii; ++i) {
+ const map2 = map.get(path[i]);
+ if (typeof map2 === 'undefined') { break; }
+ map = map2;
+ }
+
+ if (i === ii) {
+ // Found (map is now a node)
+ this._updateRecency(map);
+ return map.value;
+ }
+
+ // Create new
+ const value = this._create(...path);
+
+ // Create mapping
+ --ii;
+ for (; i < ii; ++i) {
+ const map2 = new Map();
+ map.set(path[i], map2);
+ map = map2;
+ }
+
+ // Assign
+ const node = this._createNode(value, path);
+ this._addNode(node, this._listFirst);
+ map.set(path[ii], node);
+ ++this._count;
+
+ this._updateCount();
+
+ return value;
+ }
+
+ /**
+ * Clears the cache.
+ */
+ clear() {
+ this._map.clear();
+ this._count = 0;
+ this._resetEndNodes();
+ }
+
+ // Private
+
+ _updateRecency(node) {
+ this._removeNode(node);
+ this._addNode(node, this._listFirst);
+ }
+
+ _updateCount() {
+ for (let removeCount = this._count - this._maxCount; removeCount > 0; --removeCount) {
+ const node = this._listLast.previous;
+ this._removeNode(node);
+ this._removeMapping(node.path);
+ --this._count;
+ }
+ }
+
+ _createNode(value, path) {
+ return {value, path, previous: null, next: null};
+ }
+
+ _addNode(node, previous) {
+ const next = previous.next;
+ node.next = next;
+ node.previous = previous;
+ previous.next = node;
+ next.previous = node;
+ }
+
+ _removeNode(node) {
+ node.next.previous = node.previous;
+ node.previous.next = node.next;
+ }
+
+ _removeMapping(path) {
+ const ii = path.length - 1;
+ let i = 0;
+ const maps = [];
+ let map = this._map;
+ for (; i < ii; ++i) {
+ const map2 = map.get(path[i]);
+ if (typeof map2 === 'undefined') { return; }
+ maps.push([map, map2]);
+ map = map2;
+ }
+
+ // Delete node
+ map.delete(path[ii]);
+
+ // Clear empty paths
+ for (i = ii - 1; i >= 0; --i) {
+ let map2;
+ [map, map2] = maps[i];
+ if (map2.size > 0) { return; }
+ map.delete(path[i]);
+ }
+ }
+
+ _resetEndNodes() {
+ this._listFirst.next = this._listLast;
+ this._listLast.previous = this._listFirst;
+ }
+}
diff --git a/package.json b/package.json
index aaa7087e..5704ddb3 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,7 @@
"build": "node ./dev/build.js",
"test": "npm run test-lint && npm run test-code && npm run test-manifest",
"test-lint": "eslint . && node ./test/lint/global-declarations.js",
- "test-code": "node ./test/test-schema.js && node ./test/test-dictionary.js && node ./test/test-database.js && node ./test/test-document.js && node ./test/test-object-property-accessor.js && node ./test/test-japanese.js && node ./test/test-text-source-map.js && node ./test/test-dom-text-scanner.js",
+ "test-code": "node ./test/test-schema.js && node ./test/test-dictionary.js && node ./test/test-database.js && node ./test/test-document.js && node ./test/test-object-property-accessor.js && node ./test/test-japanese.js && node ./test/test-text-source-map.js && node ./test/test-dom-text-scanner.js && node ./test/test-cache-map.js",
"test-manifest": "node ./test/test-manifest.js"
},
"repository": {
diff --git a/test/test-cache-map.js b/test/test-cache-map.js
new file mode 100644
index 00000000..00383e65
--- /dev/null
+++ b/test/test-cache-map.js
@@ -0,0 +1,168 @@
+/*
+ * Copyright (C) 2020 Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+const assert = require('assert');
+const {VM} = require('./yomichan-vm');
+
+const vm = new VM({console});
+vm.execute([
+ 'mixed/js/cache-map.js'
+]);
+const CacheMap = vm.get('CacheMap');
+
+
+function testConstructor() {
+ const data = [
+ [false, () => new CacheMap(0, () => null)],
+ [false, () => new CacheMap(1, () => null)],
+ [false, () => new CacheMap(Number.MAX_VALUE, () => null)],
+ [true, () => new CacheMap(-1, () => null)],
+ [true, () => new CacheMap(1.5, () => null)],
+ [true, () => new CacheMap(Number.NaN, () => null)],
+ [true, () => new CacheMap(Number.POSITIVE_INFINITY, () => null)],
+ [true, () => new CacheMap('a', () => null)]
+ ];
+
+ for (const [throws, create] of data) {
+ if (throws) {
+ assert.throws(create);
+ } else {
+ assert.doesNotThrow(create);
+ }
+ }
+}
+
+function testApi() {
+ const data = [
+ {
+ maxCount: 1,
+ expectedCount: 0,
+ calls: []
+ },
+ {
+ maxCount: 1,
+ expectedCount: 1,
+ calls: [
+ ['get', 'a', 'b', 'c']
+ ]
+ },
+ {
+ maxCount: 10,
+ expectedCount: 1,
+ calls: [
+ ['get', 'a', 'b', 'c'],
+ ['get', 'a', 'b', 'c'],
+ ['get', 'a', 'b', 'c']
+ ]
+ },
+ {
+ maxCount: 10,
+ expectedCount: 3,
+ calls: [
+ ['get', 'a1', 'b', 'c'],
+ ['get', 'a2', 'b', 'c'],
+ ['get', 'a3', 'b', 'c']
+ ]
+ },
+ {
+ maxCount: 10,
+ expectedCount: 3,
+ calls: [
+ ['get', 'a', 'b1', 'c'],
+ ['get', 'a', 'b2', 'c'],
+ ['get', 'a', 'b3', 'c']
+ ]
+ },
+ {
+ maxCount: 10,
+ expectedCount: 3,
+ calls: [
+ ['get', 'a', 'b', 'c1'],
+ ['get', 'a', 'b', 'c2'],
+ ['get', 'a', 'b', 'c3']
+ ]
+ },
+ {
+ maxCount: 1,
+ expectedCount: 1,
+ calls: [
+ ['get', 'a1', 'b', 'c'],
+ ['get', 'a2', 'b', 'c'],
+ ['get', 'a3', 'b', 'c']
+ ]
+ },
+ {
+ maxCount: 1,
+ expectedCount: 1,
+ calls: [
+ ['get', 'a', 'b1', 'c'],
+ ['get', 'a', 'b2', 'c'],
+ ['get', 'a', 'b3', 'c']
+ ]
+ },
+ {
+ maxCount: 1,
+ expectedCount: 1,
+ calls: [
+ ['get', 'a', 'b', 'c1'],
+ ['get', 'a', 'b', 'c2'],
+ ['get', 'a', 'b', 'c3']
+ ]
+ },
+ {
+ maxCount: 10,
+ expectedCount: 0,
+ calls: [
+ ['get', 'a', 'b', 'c1'],
+ ['get', 'a', 'b', 'c2'],
+ ['get', 'a', 'b', 'c3'],
+ ['clear']
+ ]
+ },
+ {
+ maxCount: 0,
+ expectedCount: 0,
+ calls: [
+ ['get', 'a1', 'b', 'c'],
+ ['get', 'a', 'b2', 'c'],
+ ['get', 'a', 'b', 'c3']
+ ]
+ }
+ ];
+
+ const create = (...args) => args.join(',');
+ for (const {maxCount, expectedCount, calls} of data) {
+ const cache = new CacheMap(maxCount, create);
+ assert.strictEqual(cache.maxCount, maxCount);
+ for (const [name, ...args] of calls) {
+ switch (name) {
+ case 'get': cache.get(...args); break;
+ case 'clear': cache.clear(); break;
+ }
+ }
+ assert.strictEqual(cache.count, expectedCount);
+ }
+}
+
+
+function main() {
+ testConstructor();
+ testApi();
+}
+
+
+if (require.main === module) { main(); }