Files
notesnook/apps/web/src/common/sqlite/sqlite-export.ts
2024-03-21 11:13:46 +05:00

102 lines
3.0 KiB
TypeScript

/*
This file is part of the Notesnook project (https://notesnook.com/)
Copyright (C) 2023 Streetwriters (Private) Limited
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 <http://www.gnu.org/licenses/>.
*/
import * as VFS from "./VFS";
export class DatabaseSource {
isDone;
#vfs;
#path;
#fileId = Math.floor(Math.random() * 0x100000000);
#iOffset = 0;
#bytesRemaining = 0;
#onDone: (() => Promise<unknown> | unknown)[] = [];
#resolve!: (value: unknown) => void;
#reject!: (reason?: unknown) => void;
constructor(vfs: VFS.Base, path: string) {
this.#vfs = vfs;
this.#path = path;
this.isDone = new Promise((resolve, reject) => {
this.#resolve = resolve;
this.#reject = reject;
}).finally(async () => {
while (this.#onDone.length) {
await this.#onDone.pop()?.();
}
});
}
async start(controller: ReadableStreamDefaultController) {
try {
// Open the file for reading.
const flags = VFS.SQLITE_OPEN_MAIN_DB | VFS.SQLITE_OPEN_READONLY;
await check(
this.#vfs.xOpen(this.#path, this.#fileId, flags, {
setInt32() {}
} as unknown as DataView)
);
this.#onDone.push(() => this.#vfs.xClose(this.#fileId));
await check(this.#vfs.xLock(this.#fileId, VFS.SQLITE_LOCK_SHARED));
this.#onDone.push(() =>
this.#vfs.xUnlock(this.#fileId, VFS.SQLITE_LOCK_NONE)
);
// Get the file size.
const fileSize = new DataView(new ArrayBuffer(8));
await check(this.#vfs.xFileSize(this.#fileId, fileSize));
this.#bytesRemaining = Number(fileSize.getBigUint64(0, true));
} catch (e) {
controller.error(e);
this.#reject(e);
}
}
async pull(controller: ReadableStreamDefaultController) {
try {
const buffer = new Uint8Array(Math.min(this.#bytesRemaining, 65536));
await check(this.#vfs.xRead(this.#fileId, buffer, this.#iOffset));
console.log("reading", buffer);
controller.enqueue(buffer);
this.#iOffset += buffer.byteLength;
this.#bytesRemaining -= buffer.byteLength;
if (this.#bytesRemaining === 0) {
controller.close();
this.#resolve(undefined);
}
} catch (e) {
controller.error(e);
this.#reject(e);
}
}
cancel(reason?: any) {
this.#reject(new Error(reason));
}
}
async function check(code: Promise<number> | number) {
if ((await code) !== VFS.SQLITE_OK) {
throw new Error(`Error code: ${await code}`);
}
}