move dictionary files to dictionary folder (#429)

1 files changed, 661 insertions, 0 deletions

diff --git a/ext/js/dictionary/dictionary-database.js b/ext/js/dictionary/dictionary-database.js
new file mode 100644
index 00000000..45c5c6fd
--- /dev/null
+++ b/ext/js/dictionary/dictionary-database.js
@@ -0,0 +1,661 @@
+/*
+ * Copyright (C) 2023  Yomitan Authors
+ * Copyright (C) 2016-2022  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/>.
+ */
+
+import {log, stringReverse} from '../core.js';
+import {Database} from '../data/database.js';
+
+export class DictionaryDatabase {
+    constructor() {
+        /** @type {Database<import('dictionary-database').ObjectStoreName>} */
+        this._db = new Database();
+        /** @type {string} */
+        this._dbName = 'dict';
+        /** @type {import('dictionary-database').CreateQuery<string>} */
+        this._createOnlyQuery1 = (item) => IDBKeyRange.only(item);
+        /** @type {import('dictionary-database').CreateQuery<import('dictionary-database').DictionaryAndQueryRequest>} */
+        this._createOnlyQuery2 = (item) => IDBKeyRange.only(item.query);
+        /** @type {import('dictionary-database').CreateQuery<import('dictionary-database').TermExactRequest>} */
+        this._createOnlyQuery3 = (item) => IDBKeyRange.only(item.term);
+        /** @type {import('dictionary-database').CreateQuery<import('dictionary-database').MediaRequest>} */
+        this._createOnlyQuery4 = (item) => IDBKeyRange.only(item.path);
+        /** @type {import('dictionary-database').CreateQuery<string>} */
+        this._createBoundQuery1 = (item) => IDBKeyRange.bound(item, `${item}\uffff`, false, false);
+        /** @type {import('dictionary-database').CreateQuery<string>} */
+        this._createBoundQuery2 = (item) => { item = stringReverse(item); return IDBKeyRange.bound(item, `${item}\uffff`, false, false); };
+        /** @type {import('dictionary-database').CreateResult<import('dictionary-database').TermExactRequest, import('dictionary-database').DatabaseTermEntryWithId, import('dictionary-database').TermEntry>} */
+        this._createTermBind1 = this._createTermExact.bind(this);
+        /** @type {import('dictionary-database').CreateResult<import('dictionary-database').DictionaryAndQueryRequest, import('dictionary-database').DatabaseTermEntryWithId, import('dictionary-database').TermEntry>} */
+        this._createTermBind2 = this._createTermSequenceExact.bind(this);
+        /** @type {import('dictionary-database').CreateResult<string, import('dictionary-database').DatabaseTermMeta, import('dictionary-database').TermMeta>} */
+        this._createTermMetaBind = this._createTermMeta.bind(this);
+        /** @type {import('dictionary-database').CreateResult<string, import('dictionary-database').DatabaseKanjiEntry, import('dictionary-database').KanjiEntry>} */
+        this._createKanjiBind = this._createKanji.bind(this);
+        /** @type {import('dictionary-database').CreateResult<string, import('dictionary-database').DatabaseKanjiMeta, import('dictionary-database').KanjiMeta>} */
+        this._createKanjiMetaBind = this._createKanjiMeta.bind(this);
+        /** @type {import('dictionary-database').CreateResult<import('dictionary-database').MediaRequest, import('dictionary-database').MediaDataArrayBufferContent, import('dictionary-database').Media>} */
+        this._createMediaBind = this._createMedia.bind(this);
+    }
+
+    /** */
+    async prepare() {
+        await this._db.open(
+            this._dbName,
+            60,
+            /** @type {import('database').StructureDefinition<import('dictionary-database').ObjectStoreName>[]} */
+            ([
+                /** @type {import('database').StructureDefinition<import('dictionary-database').ObjectStoreName>} */
+                ({
+                    version: 20,
+                    stores: {
+                        terms: {
+                            primaryKey: {keyPath: 'id', autoIncrement: true},
+                            indices: ['dictionary', 'expression', 'reading']
+                        },
+                        kanji: {
+                            primaryKey: {autoIncrement: true},
+                            indices: ['dictionary', 'character']
+                        },
+                        tagMeta: {
+                            primaryKey: {autoIncrement: true},
+                            indices: ['dictionary']
+                        },
+                        dictionaries: {
+                            primaryKey: {autoIncrement: true},
+                            indices: ['title', 'version']
+                        }
+                    }
+                }),
+                {
+                    version: 30,
+                    stores: {
+                        termMeta: {
+                            primaryKey: {autoIncrement: true},
+                            indices: ['dictionary', 'expression']
+                        },
+                        kanjiMeta: {
+                            primaryKey: {autoIncrement: true},
+                            indices: ['dictionary', 'character']
+                        },
+                        tagMeta: {
+                            primaryKey: {autoIncrement: true},
+                            indices: ['dictionary', 'name']
+                        }
+                    }
+                },
+                {
+                    version: 40,
+                    stores: {
+                        terms: {
+                            primaryKey: {keyPath: 'id', autoIncrement: true},
+                            indices: ['dictionary', 'expression', 'reading', 'sequence']
+                        }
+                    }
+                },
+                {
+                    version: 50,
+                    stores: {
+                        terms: {
+                            primaryKey: {keyPath: 'id', autoIncrement: true},
+                            indices: ['dictionary', 'expression', 'reading', 'sequence', 'expressionReverse', 'readingReverse']
+                        }
+                    }
+                },
+                {
+                    version: 60,
+                    stores: {
+                        media: {
+                            primaryKey: {keyPath: 'id', autoIncrement: true},
+                            indices: ['dictionary', 'path']
+                        }
+                    }
+                }
+            ])
+        );
+    }
+
+    /** */
+    async close() {
+        this._db.close();
+    }
+
+    /**
+     * @returns {boolean}
+     */
+    isPrepared() {
+        return this._db.isOpen();
+    }
+
+    /**
+     * @returns {Promise<boolean>}
+     */
+    async purge() {
+        if (this._db.isOpening()) {
+            throw new Error('Cannot purge database while opening');
+        }
+        if (this._db.isOpen()) {
+            this._db.close();
+        }
+        let result = false;
+        try {
+            await Database.deleteDatabase(this._dbName);
+            result = true;
+        } catch (e) {
+            log.error(e);
+        }
+        await this.prepare();
+        return result;
+    }
+
+    /**
+     * @param {string} dictionaryName
+     * @param {number} progressRate
+     * @param {import('dictionary-database').DeleteDictionaryProgressCallback} onProgress
+     */
+    async deleteDictionary(dictionaryName, progressRate, onProgress) {
+        /** @type {[objectStoreName: import('dictionary-database').ObjectStoreName, key: string][][]} */
+        const targetGroups = [
+            [
+                ['kanji', 'dictionary'],
+                ['kanjiMeta', 'dictionary'],
+                ['terms', 'dictionary'],
+                ['termMeta', 'dictionary'],
+                ['tagMeta', 'dictionary'],
+                ['media', 'dictionary']
+            ],
+            [
+                ['dictionaries', 'title']
+            ]
+        ];
+
+        let storeCount = 0;
+        for (const targets of targetGroups) {
+            storeCount += targets.length;
+        }
+
+        /** @type {import('dictionary-database').DeleteDictionaryProgressData} */
+        const progressData = {
+            count: 0,
+            processed: 0,
+            storeCount,
+            storesProcesed: 0
+        };
+
+        /**
+         * @param {IDBValidKey[]} keys
+         * @returns {IDBValidKey[]}
+         */
+        const filterKeys = (keys) => {
+            ++progressData.storesProcesed;
+            progressData.count += keys.length;
+            onProgress(progressData);
+            return keys;
+        };
+        const onProgressWrapper = () => {
+            const processed = progressData.processed + 1;
+            progressData.processed = processed;
+            if ((processed % progressRate) === 0 || processed === progressData.count) {
+                onProgress(progressData);
+            }
+        };
+
+        for (const targets of targetGroups) {
+            const promises = [];
+            for (const [objectStoreName, indexName] of targets) {
+                const query = IDBKeyRange.only(dictionaryName);
+                const promise = this._db.bulkDelete(objectStoreName, indexName, query, filterKeys, onProgressWrapper);
+                promises.push(promise);
+            }
+            await Promise.all(promises);
+        }
+    }
+
+    /**
+     * @param {string[]} termList
+     * @param {import('dictionary-database').DictionarySet} dictionaries
+     * @param {import('dictionary-database').MatchType} matchType
+     * @returns {Promise<import('dictionary-database').TermEntry[]>}
+     */
+    findTermsBulk(termList, dictionaries, matchType) {
+        const visited = new Set();
+        /** @type {import('dictionary-database').FindPredicate<string, import('dictionary-database').DatabaseTermEntryWithId>} */
+        const predicate = (row) => {
+            if (!dictionaries.has(row.dictionary)) { return false; }
+            const {id} = row;
+            if (visited.has(id)) { return false; }
+            visited.add(id);
+            return true;
+        };
+
+        const indexNames = (matchType === 'suffix') ? ['expressionReverse', 'readingReverse'] : ['expression', 'reading'];
+
+        let createQuery = this._createOnlyQuery1;
+        switch (matchType) {
+            case 'prefix':
+                createQuery = this._createBoundQuery1;
+                break;
+            case 'suffix':
+                createQuery = this._createBoundQuery2;
+                break;
+        }
+
+        const createResult = this._createTermGeneric.bind(this, matchType);
+
+        return this._findMultiBulk('terms', indexNames, termList, createQuery, predicate, createResult);
+    }
+
+    /**
+     * @param {import('dictionary-database').TermExactRequest[]} termList
+     * @param {import('dictionary-database').DictionarySet} dictionaries
+     * @returns {Promise<import('dictionary-database').TermEntry[]>}
+     */
+    findTermsExactBulk(termList, dictionaries) {
+        /** @type {import('dictionary-database').FindPredicate<import('dictionary-database').TermExactRequest, import('dictionary-database').DatabaseTermEntry>} */
+        const predicate = (row, item) => (row.reading === item.reading && dictionaries.has(row.dictionary));
+        return this._findMultiBulk('terms', ['expression'], termList, this._createOnlyQuery3, predicate, this._createTermBind1);
+    }
+
+    /**
+     * @param {import('dictionary-database').DictionaryAndQueryRequest[]} items
+     * @returns {Promise<import('dictionary-database').TermEntry[]>}
+     */
+    findTermsBySequenceBulk(items) {
+        /** @type {import('dictionary-database').FindPredicate<import('dictionary-database').DictionaryAndQueryRequest, import('dictionary-database').DatabaseTermEntry>} */
+        const predicate = (row, item) => (row.dictionary === item.dictionary);
+        return this._findMultiBulk('terms', ['sequence'], items, this._createOnlyQuery2, predicate, this._createTermBind2);
+    }
+
+    /**
+     * @param {string[]} termList
+     * @param {import('dictionary-database').DictionarySet} dictionaries
+     * @returns {Promise<import('dictionary-database').TermMeta[]>}
+     */
+    findTermMetaBulk(termList, dictionaries) {
+        /** @type {import('dictionary-database').FindPredicate<string, import('dictionary-database').DatabaseTermMeta>} */
+        const predicate = (row) => dictionaries.has(row.dictionary);
+        return this._findMultiBulk('termMeta', ['expression'], termList, this._createOnlyQuery1, predicate, this._createTermMetaBind);
+    }
+
+    /**
+     * @param {string[]} kanjiList
+     * @param {import('dictionary-database').DictionarySet} dictionaries
+     * @returns {Promise<import('dictionary-database').KanjiEntry[]>}
+     */
+    findKanjiBulk(kanjiList, dictionaries) {
+        /** @type {import('dictionary-database').FindPredicate<string, import('dictionary-database').DatabaseKanjiEntry>} */
+        const predicate = (row) => dictionaries.has(row.dictionary);
+        return this._findMultiBulk('kanji', ['character'], kanjiList, this._createOnlyQuery1, predicate, this._createKanjiBind);
+    }
+
+    /**
+     * @param {string[]} kanjiList
+     * @param {import('dictionary-database').DictionarySet} dictionaries
+     * @returns {Promise<import('dictionary-database').KanjiMeta[]>}
+     */
+    findKanjiMetaBulk(kanjiList, dictionaries) {
+        /** @type {import('dictionary-database').FindPredicate<string, import('dictionary-database').DatabaseKanjiMeta>} */
+        const predicate = (row) => dictionaries.has(row.dictionary);
+        return this._findMultiBulk('kanjiMeta', ['character'], kanjiList, this._createOnlyQuery1, predicate, this._createKanjiMetaBind);
+    }
+
+    /**
+     * @param {import('dictionary-database').DictionaryAndQueryRequest[]} items
+     * @returns {Promise<(import('dictionary-database').Tag|undefined)[]>}
+     */
+    findTagMetaBulk(items) {
+        /** @type {import('dictionary-database').FindPredicate<import('dictionary-database').DictionaryAndQueryRequest, import('dictionary-database').Tag>} */
+        const predicate = (row, item) => (row.dictionary === item.dictionary);
+        return this._findFirstBulk('tagMeta', 'name', items, this._createOnlyQuery2, predicate);
+    }
+
+    /**
+     * @param {string} name
+     * @param {string} dictionary
+     * @returns {Promise<?import('dictionary-database').Tag>}
+     */
+    findTagForTitle(name, dictionary) {
+        const query = IDBKeyRange.only(name);
+        return this._db.find('tagMeta', 'name', query, (row) => (/** @type {import('dictionary-database').Tag} */ (row).dictionary === dictionary), null, null);
+    }
+
+    /**
+     * @param {import('dictionary-database').MediaRequest[]} items
+     * @returns {Promise<import('dictionary-database').Media[]>}
+     */
+    getMedia(items) {
+        /** @type {import('dictionary-database').FindPredicate<import('dictionary-database').MediaRequest, import('dictionary-database').MediaDataArrayBufferContent>} */
+        const predicate = (row, item) => (row.dictionary === item.dictionary);
+        return this._findMultiBulk('media', ['path'], items, this._createOnlyQuery4, predicate, this._createMediaBind);
+    }
+
+    /**
+     * @returns {Promise<import('dictionary-importer').Summary[]>}
+     */
+    getDictionaryInfo() {
+        return new Promise((resolve, reject) => {
+            const transaction = this._db.transaction(['dictionaries'], 'readonly');
+            const objectStore = transaction.objectStore('dictionaries');
+            this._db.getAll(objectStore, null, resolve, reject, null);
+        });
+    }
+
+    /**
+     * @param {string[]} dictionaryNames
+     * @param {boolean} getTotal
+     * @returns {Promise<import('dictionary-database').DictionaryCounts>}
+     */
+    getDictionaryCounts(dictionaryNames, getTotal) {
+        return new Promise((resolve, reject) => {
+            const targets = [
+                ['kanji', 'dictionary'],
+                ['kanjiMeta', 'dictionary'],
+                ['terms', 'dictionary'],
+                ['termMeta', 'dictionary'],
+                ['tagMeta', 'dictionary'],
+                ['media', 'dictionary']
+            ];
+            const objectStoreNames = targets.map(([objectStoreName]) => objectStoreName);
+            const transaction = this._db.transaction(objectStoreNames, 'readonly');
+            const databaseTargets = targets.map(([objectStoreName, indexName]) => {
+                const objectStore = transaction.objectStore(objectStoreName);
+                const index = objectStore.index(indexName);
+                return {objectStore, index};
+            });
+
+            /** @type {import('database').CountTarget[]} */
+            const countTargets = [];
+            if (getTotal) {
+                for (const {objectStore} of databaseTargets) {
+                    countTargets.push([objectStore, void 0]);
+                }
+            }
+            for (const dictionaryName of dictionaryNames) {
+                const query = IDBKeyRange.only(dictionaryName);
+                for (const {index} of databaseTargets) {
+                    countTargets.push([index, query]);
+                }
+            }
+
+            /**
+             * @param {number[]} results
+             */
+            const onCountComplete = (results) => {
+                const resultCount = results.length;
+                const targetCount = targets.length;
+                /** @type {import('dictionary-database').DictionaryCountGroup[]} */
+                const counts = [];
+                for (let i = 0; i < resultCount; i += targetCount) {
+                    /** @type {import('dictionary-database').DictionaryCountGroup} */
+                    const countGroup = {};
+                    for (let j = 0; j < targetCount; ++j) {
+                        countGroup[targets[j][0]] = results[i + j];
+                    }
+                    counts.push(countGroup);
+                }
+                const total = getTotal ? /** @type {import('dictionary-database').DictionaryCountGroup} */ (counts.shift()) : null;
+                resolve({total, counts});
+            };
+
+            this._db.bulkCount(countTargets, onCountComplete, reject);
+        });
+    }
+
+    /**
+     * @param {string} title
+     * @returns {Promise<boolean>}
+     */
+    async dictionaryExists(title) {
+        const query = IDBKeyRange.only(title);
+        const result = await this._db.find('dictionaries', 'title', query, null, null, void 0);
+        return typeof result !== 'undefined';
+    }
+
+    /**
+     * @template {import('dictionary-database').ObjectStoreName} T
+     * @param {T} objectStoreName
+     * @param {import('dictionary-database').ObjectStoreData<T>[]} items
+     * @param {number} start
+     * @param {number} count
+     * @returns {Promise<void>}
+     */
+    bulkAdd(objectStoreName, items, start, count) {
+        return this._db.bulkAdd(objectStoreName, items, start, count);
+    }
+
+    // Private
+
+    /**
+     * @template [TRow=unknown]
+     * @template [TItem=unknown]
+     * @template [TResult=unknown]
+     * @param {import('dictionary-database').ObjectStoreName} objectStoreName
+     * @param {string[]} indexNames
+     * @param {TItem[]} items
+     * @param {import('dictionary-database').CreateQuery<TItem>} createQuery
+     * @param {import('dictionary-database').FindPredicate<TItem, TRow>} predicate
+     * @param {import('dictionary-database').CreateResult<TItem, TRow, TResult>} createResult
+     * @returns {Promise<TResult[]>}
+     */
+    _findMultiBulk(objectStoreName, indexNames, items, createQuery, predicate, createResult) {
+        return new Promise((resolve, reject) => {
+            const itemCount = items.length;
+            const indexCount = indexNames.length;
+            /** @type {TResult[]} */
+            const results = [];
+            if (itemCount === 0 || indexCount === 0) {
+                resolve(results);
+                return;
+            }
+
+            const transaction = this._db.transaction([objectStoreName], 'readonly');
+            const objectStore = transaction.objectStore(objectStoreName);
+            const indexList = [];
+            for (const indexName of indexNames) {
+                indexList.push(objectStore.index(indexName));
+            }
+            let completeCount = 0;
+            const requiredCompleteCount = itemCount * indexCount;
+            /**
+             * @param {TRow[]} rows
+             * @param {import('dictionary-database').FindMultiBulkData<TItem>} data
+             */
+            const onGetAll = (rows, data) => {
+                for (const row of rows) {
+                    if (predicate(row, data.item)) {
+                        results.push(createResult(row, data));
+                    }
+                }
+                if (++completeCount >= requiredCompleteCount) {
+                    resolve(results);
+                }
+            };
+            for (let i = 0; i < itemCount; ++i) {
+                const item = items[i];
+                const query = createQuery(item);
+                for (let j = 0; j < indexCount; ++j) {
+                    /** @type {import('dictionary-database').FindMultiBulkData<TItem>} */
+                    const data = {item, itemIndex: i, indexIndex: j};
+                    this._db.getAll(indexList[j], query, onGetAll, reject, data);
+                }
+            }
+        });
+    }
+
+    /**
+     * @template [TRow=unknown]
+     * @template [TItem=unknown]
+     * @param {import('dictionary-database').ObjectStoreName} objectStoreName
+     * @param {string} indexName
+     * @param {TItem[]} items
+     * @param {import('dictionary-database').CreateQuery<TItem>} createQuery
+     * @param {import('dictionary-database').FindPredicate<TItem, TRow>} predicate
+     * @returns {Promise<(TRow|undefined)[]>}
+     */
+    _findFirstBulk(objectStoreName, indexName, items, createQuery, predicate) {
+        return new Promise((resolve, reject) => {
+            const itemCount = items.length;
+            /** @type {(TRow|undefined)[]} */
+            const results = new Array(itemCount);
+            if (itemCount === 0) {
+                resolve(results);
+                return;
+            }
+
+            const transaction = this._db.transaction([objectStoreName], 'readonly');
+            const objectStore = transaction.objectStore(objectStoreName);
+            const index = objectStore.index(indexName);
+            let completeCount = 0;
+            /**
+             * @param {TRow|undefined} row
+             * @param {number} itemIndex
+             */
+            const onFind = (row, itemIndex) => {
+                results[itemIndex] = row;
+                if (++completeCount >= itemCount) {
+                    resolve(results);
+                }
+            };
+            for (let i = 0; i < itemCount; ++i) {
+                const item = items[i];
+                const query = createQuery(item);
+                this._db.findFirst(index, query, onFind, reject, i, predicate, item, void 0);
+            }
+        });
+    }
+
+    /**
+     * @param {import('dictionary-database').MatchType} matchType
+     * @param {import('dictionary-database').DatabaseTermEntryWithId} row
+     * @param {import('dictionary-database').FindMultiBulkData<string>} data
+     * @returns {import('dictionary-database').TermEntry}
+     */
+    _createTermGeneric(matchType, row, data) {
+        const matchSourceIsTerm = (data.indexIndex === 0);
+        const matchSource = (matchSourceIsTerm ? 'term' : 'reading');
+        if ((matchSourceIsTerm ? row.expression : row.reading) === data.item) {
+            matchType = 'exact';
+        }
+        return this._createTerm(matchSource, matchType, row, data.itemIndex);
+    }
+
+    /**
+     * @param {import('dictionary-database').DatabaseTermEntryWithId} row
+     * @param {import('dictionary-database').FindMultiBulkData<import('dictionary-database').TermExactRequest>} data
+     * @returns {import('dictionary-database').TermEntry}
+     */
+    _createTermExact(row, data) {
+        return this._createTerm('term', 'exact', row, data.itemIndex);
+    }
+
+    /**
+     * @param {import('dictionary-database').DatabaseTermEntryWithId} row
+     * @param {import('dictionary-database').FindMultiBulkData<import('dictionary-database').DictionaryAndQueryRequest>} data
+     * @returns {import('dictionary-database').TermEntry}
+     */
+    _createTermSequenceExact(row, data) {
+        return this._createTerm('sequence', 'exact', row, data.itemIndex);
+    }
+
+    /**
+     * @param {import('dictionary-database').MatchSource} matchSource
+     * @param {import('dictionary-database').MatchType} matchType
+     * @param {import('dictionary-database').DatabaseTermEntryWithId} row
+     * @param {number} index
+     * @returns {import('dictionary-database').TermEntry}
+     */
+    _createTerm(matchSource, matchType, row, index) {
+        const {sequence} = row;
+        return {
+            index,
+            matchType,
+            matchSource,
+            term: row.expression,
+            reading: row.reading,
+            definitionTags: this._splitField(row.definitionTags || row.tags),
+            termTags: this._splitField(row.termTags),
+            rules: this._splitField(row.rules),
+            definitions: row.glossary,
+            score: row.score,
+            dictionary: row.dictionary,
+            id: row.id,
+            sequence: typeof sequence === 'number' ? sequence : -1
+        };
+    }
+
+    /**
+     * @param {import('dictionary-database').DatabaseKanjiEntry} row
+     * @param {import('dictionary-database').FindMultiBulkData<string>} data
+     * @returns {import('dictionary-database').KanjiEntry}
+     */
+    _createKanji(row, {itemIndex: index}) {
+        const {stats} = row;
+        return {
+            index,
+            character: row.character,
+            onyomi: this._splitField(row.onyomi),
+            kunyomi: this._splitField(row.kunyomi),
+            tags: this._splitField(row.tags),
+            definitions: row.meanings,
+            stats: typeof stats === 'object' && stats !== null ? stats : {},
+            dictionary: row.dictionary
+        };
+    }
+
+    /**
+     * @param {import('dictionary-database').DatabaseTermMeta} row
+     * @param {import('dictionary-database').FindMultiBulkData<string>} data
+     * @returns {import('dictionary-database').TermMeta}
+     * @throws {Error}
+     */
+    _createTermMeta({expression: term, mode, data, dictionary}, {itemIndex: index}) {
+        switch (mode) {
+            case 'freq':
+                return {index, term, mode, data, dictionary};
+            case 'pitch':
+                return {index, term, mode, data, dictionary};
+            default:
+                throw new Error(`Unknown mode: ${mode}`);
+        }
+    }
+
+    /**
+     * @param {import('dictionary-database').DatabaseKanjiMeta} row
+     * @param {import('dictionary-database').FindMultiBulkData<string>} data
+     * @returns {import('dictionary-database').KanjiMeta}
+     */
+    _createKanjiMeta({character, mode, data, dictionary}, {itemIndex: index}) {
+        return {index, character, mode, data, dictionary};
+    }
+
+    /**
+     * @param {import('dictionary-database').MediaDataArrayBufferContent} row
+     * @param {import('dictionary-database').FindMultiBulkData<import('dictionary-database').MediaRequest>} data
+     * @returns {import('dictionary-database').Media}
+     */
+    _createMedia(row, {itemIndex: index}) {
+        const {dictionary, path, mediaType, width, height, content} = row;
+        return {index, dictionary, path, mediaType, width, height, content};
+    }
+
+    /**
+     * @param {unknown} field
+     * @returns {string[]}
+     */
+    _splitField(field) {
+        return typeof field === 'string' && field.length > 0 ? field.split(' ') : [];
+    }
+}