Add export_zip support

tasks/export_zip.ts

@@ -0,0 +1,61 @@
+import { join } from "std/path/mod.ts";
+import { Uint8ArrayReader, ZipWriter } from "zipjs/index.js";
+import { EhDb } from "../db.ts";
+import { addZero, asyncForEach } from "../utils.ts";
+import { Config } from "../config.ts";
+import { Task } from "../task.ts";
+
+export type ExportZipConfig = {
+    output?: string;
+};
+
+export const DEFAULT_EXPORT_ZIP_CONFIG: ExportZipConfig = {};
+
+export async function export_zip(
+    task: Task,
+    db: EhDb,
+    cfg: Config,
+    signal: AbortSignal,
+    ecfg: ExportZipConfig,
+) {
+    const gid = task.gid;
+    const g = db.get_gmeta_by_gid(gid);
+    if (!g) throw Error("Gallery not found in database.");
+    const output = ecfg.output === undefined
+        ? join(cfg.base, g.title + ".zip")
+        : ecfg.output;
+    const f = await Deno.open(output, {
+        create: true,
+        write: true,
+        truncate: true,
+    });
+    try {
+        const z = new ZipWriter(f.writable, {
+            signal,
+            level: 0,
+        });
+        const l = g.filecount.toString().length;
+        await asyncForEach(
+            db.get_pmeta(gid).sort((a, b) => a.index - b.index),
+            async (p) => {
+                const f = db.get_files(gid, p.token);
+                if (f.length) {
+                    const r = await Deno.readFile(f[0].path, { signal });
+                    await z.add(
+                        `${addZero(p.index, l)}_${p.name}`,
+                        new Uint8ArrayReader(r),
+                        { signal },
+                    );
+                }
+            },
+        );
+        await z.close();
+    } finally {
+        try {
+            f.close();
+        } catch (_) {
+            null;
+        }
+    }
+    return task;
+}