import { Marshaller } from 'app/common/marshal'; import { OpenMode, quoteIdent } from 'app/server/lib/SQLiteDB'; /** * Code common to SQLite wrappers. */ /** * It is important that Statement exists - but we don't expect * anything of it. */ // eslint-disable-next-line @typescript-eslint/no-empty-interface export interface Statement {} export interface MinDB { exec(sql: string): Promise; run(sql: string, ...params: any[]): Promise; get(sql: string, ...params: any[]): Promise; all(sql: string, ...params: any[]): Promise; prepare(sql: string, ...params: any[]): Promise; runAndGetId(sql: string, ...params: any[]): Promise; close(): Promise; allMarshal(sql: string, ...params: any[]): Promise; /** * Limit the number of ATTACHed databases permitted. */ limitAttach(maxAttach: number): Promise; } export interface MinRunResult { changes: number; } // Describes the result of get() and all() database methods. export interface ResultRow { [column: string]: any; } export interface PreparedStatement { run(...params: any[]): Promise; finalize(): Promise; columns(): string[]; } export interface SqliteVariant { opener(dbPath: string, mode: OpenMode): Promise; } /** * A crude implementation of Grist marshalling. * There is a fork of node-sqlite3 that has Grist * marshalling built in, at: * https://github.com/gristlabs/node-sqlite3 * If using a version of SQLite without this built * in, another option is to add custom functions * to do it. This object has the initialize, step, * and finalize callbacks typically needed to add * a custom aggregration function. */ export const gristMarshal = { initialize(): GristMarshalIntermediateValue { return {}; }, step(accum: GristMarshalIntermediateValue, ...row: any[]) { if (!accum.names || !accum.values) { accum.names = row.map(value => String(value)); accum.values = row.map(() => []); } else { for (const [i, v] of row.entries()) { accum.values[i].push(v); } } return accum; }, finalize(accum: GristMarshalIntermediateValue) { const marshaller = new Marshaller({version: 2, keysAreBuffers: true}); const result: Record> = {}; if (accum.names && accum.values) { for (const [i, name] of accum.names.entries()) { result[name] = accum.values[i]; } } marshaller.marshal(result); return marshaller.dumpAsBuffer(); } }; /** * An intermediate value used during an aggregation. */ interface GristMarshalIntermediateValue { // The names of the columns, once known. names?: string[]; // Values stored in the columns. // There is one element in the outermost array per column. // That element contains a list of values stored in that column. values?: Array>; } /** * Run Grist marshalling as a SQLite query, assuming * a custom aggregation has been added as "grist_marshal". * The marshalled result needs to contain the column * identifiers embedded in it. This is a little awkward * to organize - hence the hacky UNION here. This is * for compatibility with the existing marshalling method, * which could be replaced instead. */ export async function allMarshalQuery(db: MinDB, sql: string, ...params: any[]): Promise { const statement = await db.prepare(sql); const columns = statement.columns(); const quotedColumnList = columns.map(quoteIdent).join(','); const query = await db.all(`select grist_marshal(${quotedColumnList}) as buf FROM ` + `(select ${quotedColumnList} UNION ALL select * from (` + sql + '))', ..._fixParameters(params)); return query[0].buf; } /** * Booleans need to be cast to 1 or 0 for SQLite. * The node-sqlite3 wrapper does this automatically, but other * wrappers do not. */ function _fixParameters(params: any[]) { return params.map(p => p === true ? 1 : (p === false ? 0 : p)); }