Store live photos as their image and their video (closes #107)

A live photo, which Ente stores as one ZIP, is unpacked as it downloads
into its image and its video, each `<fileID>.<ext>` with its extension
from the ZIP, beside `<fileID>.livephoto.json`, which names the two.
Both are checked against the recorded hash and renamed into place only
when both are complete. The backup and the content cache count a live
photo as stored only with both files, album folders link both,
`quak get` writes both, and the content result gives the video as
`videoPath`. A ZIP an earlier version stored is replaced.

Model: opus-5-5

test/library/content.test.ts

@@ -31,6 +31,8 @@ import {
     existsSync,
     writeFileSync,
     mkdirSync,
+    readdirSync,
+    readFileSync,
     statSync,
 } from "node:fs";
 import { spawnSync } from "node:child_process";
@@ -44,6 +46,13 @@ import {
 } from "../../src/library/content.js";
 import { RequestPools } from "../../src/library/pools.js";
 import type { EnteFile } from "../../src/model/types.js";
+import {
+    asLivePhoto,
+    cdnSource,
+    IMAGE,
+    livePhotoZip,
+    VIDEO,
+} from "../live-photo.js";
 
 const file = (id: number, title = `file-${id}.jpg`): EnteFile => ({
     id,
@@ -458,3 +467,125 @@ describe("ContentCache.ensureThumbnails", () => {
         expect(results[1]?.error).toMatch(/unknown file/i);
     });
 });
+
+// A live photo's original is two files, its image and its video, which a
+// photo viewer can open, and a JSON file naming them: the two are named with
+// the extensions from inside the ZIP, so the names alone do not say which is
+// which. These tests download a live photo ZIP through the real download
+// layer (test/live-photo.ts).
+describe("ContentCache live photos", () => {
+    const originals = (): string => join(cacheDir, "originals");
+
+    // A cache over the stand-in server, which holds `bodies` by file ID.
+    const cacheOf = (
+        files: EnteFile[],
+        bodies: Map<number, Uint8Array>,
+    ): ContentCache => buildCache({ files, source: cdnSource(bodies) }).cache;
+
+    it("stores a live photo as its image and its video and a JSON file naming them", async () => {
+        const { file: live, body } = await asLivePhoto(file(5, "IMG_5.HEIC"));
+        const cache = cacheOf([live], new Map([[5, body]]));
+        await cache.open();
+
+        const result = await cache.original(5);
+
+        expect(result).toEqual({
+            path: join(originals(), "5.heic"),
+            videoPath: join(originals(), "5.mov"),
+            bytes: IMAGE.length,
+        });
+        expect(readFileSync(result.path)).toEqual(Buffer.from(IMAGE));
+        expect(readFileSync(result.videoPath!)).toEqual(Buffer.from(VIDEO));
+        expect(statSync(result.videoPath!).mode & 0o777).toBe(0o600);
+        expect(
+            JSON.parse(
+                readFileSync(join(originals(), "5.livephoto.json"), "utf-8"),
+            ),
+        ).toEqual({ image: "5.heic", video: "5.mov" });
+        expect(cache.pathsFor(5)).toEqual({ originalPath: result.path });
+    });
+
+    it("serves a stored live photo from disk after the cache is opened again", async () => {
+        const { file: live, body } = await asLivePhoto(file(5, "IMG_5.HEIC"));
+        const first = cacheOf([live], new Map([[5, body]]));
+        await first.open();
+        const stored = await first.original(5);
+
+        // This server has nothing, so a fetch would fail.
+        const second = cacheOf([live], new Map());
+        await second.open();
+        const events: string[] = [];
+        const served = await second.original(5, {
+            onProgress: (e) => events.push(e.status),
+        });
+
+        expect(served).toEqual(stored);
+        expect(events).toEqual(["skipped"]);
+    });
+
+    it("replaces a live photo an earlier version stored as a ZIP under the image's name", async () => {
+        const { file: live, body } = await asLivePhoto(file(5, "IMG_5.HEIC"));
+        mkdirSync(originals(), { recursive: true });
+        writeFileSync(join(originals(), "5.HEIC"), livePhotoZip());
+        const cache = cacheOf([live], new Map([[5, body]]));
+        await cache.open();
+
+        const result = await cache.original(5);
+
+        expect(result.videoPath).toBe(join(originals(), "5.mov"));
+        expect(readdirSync(originals()).sort()).toEqual([
+            "5.heic",
+            "5.livephoto.json",
+            "5.mov",
+        ]);
+    });
+
+    it("evicts a live photo's image, video and JSON file together", async () => {
+        const a = await asLivePhoto(file(5, "a.HEIC"));
+        const b = await asLivePhoto(file(6, "b.HEIC"));
+        const size = IMAGE.length + VIDEO.length;
+        const cache = new ContentCache({
+            pools: new RequestPools(),
+            source: cdnSource(
+                new Map([
+                    [5, a.body],
+                    [6, b.body],
+                ]),
+            ),
+            cacheDirectory: cacheDir,
+            getFile: (id) => [a.file, b.file].find((f) => f.id === id),
+            // Room for one live photo, on a disk with plenty free.
+            cacheOriginalsMaxBytes: size,
+            freeBelowBytes: 0,
+            statfs: async () => ({ bsize: 1, bavail: 1e12 }),
+        });
+        await cache.open();
+
+        await cache.original(5);
+        await cache.original(6);
+
+        expect(readdirSync(originals()).sort()).toEqual([
+            "6.heic",
+            "6.livephoto.json",
+            "6.mov",
+        ]);
+        expect(cache.originalsStatus().usedBytes).toBe(size);
+    });
+
+    it("stores nothing when a live photo does not match its recorded hash", async () => {
+        const { file: live, body } = await asLivePhoto(
+            file(5, "IMG_5.HEIC"),
+            livePhotoZip(),
+            "not:the recorded hash",
+        );
+        const cache = cacheOf([live], new Map([[5, body]]));
+        await cache.open();
+
+        await expect(cache.original(5)).rejects.toThrow(
+            /file 5: content hash .* does not match/,
+        );
+
+        expect(readdirSync(originals())).toEqual([]);
+        expect(cache.pathsFor(5)).toEqual({});
+    });
+});