reduce image compression memory pressure

src/lib/api/index.ts

@@ -10,11 +10,12 @@ import {t} from '@lingui/core/macro'
 import {type QueryClient} from '@tanstack/react-query'
 
 import {type LinkResolvers} from '#/lib/api/resolve'
+import {mapWithSerialRetry} from '#/lib/async/map-with-serial-retry'
 import {IMAGE_SIZE_CONFIG_POSTS} from '#/lib/constants'
 import {isNetworkError} from '#/lib/strings/errors'
 import {shortenLinks, stripInvalidMentions} from '#/lib/strings/rich-text-manip'
 import {logger} from '#/logger'
-import {compressImage} from '#/state/gallery'
+import {type ComposerImage, compressImage} from '#/state/gallery'
 import {
   fetchResolveGifQuery,
   fetchResolveLinkQuery,
@@ -334,18 +335,15 @@ async function resolveMedia(
       count: imagesDraft.length,
     })
     onStateChange?.(t`Uploading images...`)
+    const compressedImages = await compressImages(imagesDraft)
     const images: app.bsky.embed.images.Image[] = await Promise.all(
-      imagesDraft.map(async (image, i) => {
-        logger.debug(`Compressing image #${i}`)
-        const {path, width, height, mime} = await compressImage(
-          image,
-          IMAGE_SIZE_CONFIG_POSTS,
-        )
+      compressedImages.map(async (compressedImage, i) => {
+        const {path, width, height, mime} = compressedImage
         logger.debug(`Uploading image #${i}`)
         const res = await uploadBlob(pdsClient, path, mime)
         return {
           image: res.blob,
-          alt: image.alt,
+          alt: imagesDraft[i].alt,
           aspectRatio: {width, height},
         }
       }),
@@ -361,19 +359,16 @@ async function resolveMedia(
       count: imagesDraft.length,
     })
     onStateChange?.(t`Uploading images...`)
+    const compressedImages = await compressImages(imagesDraft)
     const items: $Typed<app.bsky.embed.gallery.Image>[] = await Promise.all(
-      imagesDraft.map(async (image, i) => {
-        logger.debug(`Compressing image #${i}`)
-        const {path, width, height, mime} = await compressImage(
-          image,
-          IMAGE_SIZE_CONFIG_POSTS,
-        )
+      compressedImages.map(async (compressedImage, i) => {
+        const {path, width, height, mime} = compressedImage
         logger.debug(`Uploading image #${i}`)
         const res = await uploadBlob(pdsClient, path, mime)
         return {
           $type: 'app.bsky.embed.gallery#image' as const,
           image: res.blob,
-          alt: image.alt,
+          alt: imagesDraft[i].alt,
           aspectRatio: {width, height},
         }
       }),
@@ -490,6 +485,28 @@ async function resolveMedia(
   return undefined
 }
 
+type CompressedImage = Awaited<ReturnType<typeof compressImage>>
+
+async function compressImages(
+  images: ComposerImage[],
+): Promise<CompressedImage[]> {
+  return mapWithSerialRetry(
+    images,
+    (image, i) => {
+      logger.debug(`Compressing image #${i}`)
+      return compressImage(image, IMAGE_SIZE_CONFIG_POSTS)
+    },
+    isBitmapLoadingError,
+    (_error, i) => {
+      logger.info(`Retrying image compression serially`, {index: i})
+    },
+  )
+}
+
+function isBitmapLoadingError(error: unknown): boolean {
+  return String(error).includes('Loading bitmap failed')
+}
+
 async function resolveRecord(
   clients: LinkResolvers,
   queryClient: QueryClient,

src/lib/async/map-with-serial-retry.test.ts

@@ -0,0 +1,52 @@
+import {mapWithSerialRetry} from './map-with-serial-retry'
+
+describe('mapWithSerialRetry', () => {
+  it('reuses successes and retries failures serially', async () => {
+    const attempts = new Map<number, number>()
+    let retriesInFlight = 0
+    let maxRetriesInFlight = 0
+
+    const result = await mapWithSerialRetry(
+      [1, 2, 3],
+      async value => {
+        const attempt = (attempts.get(value) ?? 0) + 1
+        attempts.set(value, attempt)
+
+        if (value !== 1 && attempt === 1) {
+          throw new Error('retryable')
+        }
+
+        if (attempt > 1) {
+          retriesInFlight++
+          maxRetriesInFlight = Math.max(maxRetriesInFlight, retriesInFlight)
+          await Promise.resolve()
+          retriesInFlight--
+        }
+
+        return value * 2
+      },
+      error => String(error).includes('retryable'),
+    )
+
+    expect(result).toEqual([2, 4, 6])
+    expect(attempts).toEqual(
+      new Map([
+        [1, 1],
+        [2, 2],
+        [3, 2],
+      ]),
+    )
+    expect(maxRetriesInFlight).toBe(1)
+  })
+
+  it('does not retry when any concurrent attempt fails permanently', async () => {
+    const mapper = jest.fn((value: string) => Promise.reject(new Error(value)))
+
+    await expect(
+      mapWithSerialRetry(['retryable', 'permanent'], mapper, error =>
+        String(error).includes('retryable'),
+      ),
+    ).rejects.toThrow('permanent')
+    expect(mapper).toHaveBeenCalledTimes(2)
+  })
+})

src/lib/async/map-with-serial-retry.ts

@@ -0,0 +1,32 @@
+/**
+ * Maps all values concurrently, then retries eligible failures one at a time.
+ * Successful results from the concurrent attempt are reused.
+ */
+export async function mapWithSerialRetry<T, U>(
+  values: T[],
+  mapper: (value: T, index: number) => Promise<U>,
+  shouldRetry: (error: unknown) => boolean,
+  onRetry?: (error: unknown, index: number) => void,
+): Promise<U[]> {
+  const settled = await Promise.allSettled(values.map(mapper))
+
+  const nonRetryableFailure = settled.find(
+    result => result.status === 'rejected' && !shouldRetry(result.reason),
+  )
+  if (nonRetryableFailure?.status === 'rejected') {
+    throw nonRetryableFailure.reason
+  }
+
+  const results: U[] = []
+  for (let i = 0; i < settled.length; i++) {
+    const result = settled[i]
+    if (result.status === 'fulfilled') {
+      results.push(result.value)
+    } else {
+      onRetry?.(result.reason, i)
+      results.push(await mapper(values[i], i))
+    }
+  }
+
+  return results
+}

src/state/gallery.ts

@@ -12,7 +12,7 @@ import {renderImage} from '#/lib/media/image-manipulator'
 import {getImageDim} from '#/lib/media/manip'
 import {openCropper} from '#/lib/media/picker'
 import {type PickerImage} from '#/lib/media/picker.shared'
-import {getDataUriSize} from '#/lib/media/util'
+import {getUriSize} from '#/lib/media/uriSize'
 import {isCancelledError} from '#/lib/strings/errors'
 import {logger} from '#/logger'
 import {IS_NATIVE, IS_WEB} from '#/env'
@@ -241,15 +241,16 @@ export async function compressImage(
       source.path,
       context => context.resize({width: w, height: h}),
       {
+        // Requesting base64 makes Android encode the bitmap a second time and
+        // retain the encoded bytes and string in memory. Measure the URI instead.
+        base64: false,
         compress: qualityPercentage / 100,
         format: SaveFormat.JPEG,
-        base64: true,
       },
     )
 
-    const base64 = res.base64
-    const size = base64 ? getDataUriSize(base64) : 0
-    if (base64 && size <= maxBytes) {
+    const size = await getUriSize(res.uri)
+    if (size <= maxBytes) {
       minQualityPercentage = qualityPercentage
       newDataUri = {
         path: await moveIfNecessary(res.uri),