fix: address review

packages/api/package.json

@@ -23,6 +23,7 @@
   },
   "dependencies": {
     "@supabase/postgrest-js": "^0.37.2",
+    "http-range-parse": "^1.0.0",
     "itty-router": "^2.4.5",
     "multiformats": "^9.6.4",
     "nanoid": "^3.1.30",

packages/api/src/env.js

@@ -126,16 +126,16 @@ function getSentry(request, env, ctx) {
  * @property {Headers} [httpMetadata]
  * @property {Record<string, string>} [customMetadata]
  *
- * @typedef {Object} R2Range
- * @property {number} [offset]
- * @property {number} [length]
+ * @typedef {{ offset: number, length?: number } | { offset?: number, length: number } | { suffix: number }} R2Range
  *
  * @typedef {Object} R2GetOptions
  * @property {R2Range} [range]
  *
  * @typedef {Object} R2Object
  * @property {Date} uploaded
  * @property {number} size
+ * @property {string} httpEtag
+ * @property {(headers: Headers) => void} writeHttpMetadata
  * @property {Headers} [httpMetadata]
  * @property {Record<string, string>} [customMetadata]
  *

packages/api/src/perma-cache/get.js

@@ -1,6 +1,8 @@
 /* eslint-env serviceworker, browser */
 /* global Response */
 
+import parseRange from 'http-range-parse'
+
 import { getSourceUrl, getNormalizedUrl } from '../utils/url.js'
 import { UrlNotFoundError, InvalidRangeError } from '../errors.js'
 
@@ -21,38 +23,59 @@ export async function permaCacheGet(request, env) {
   const r2Key = normalizedUrl.toString()
 
   // Get range header
-  const range = parseRange(request.headers.get('range'))
+  const range = toR2Range(request.headers.get('range'))
   const r2Object = await env.SUPERHOT.get(r2Key, {
     range,
   })
-  if (r2Object) {
-    return new Response(r2Object.body, {
-      status: range ? 206 : 200,
-    })
+
+  if (!r2Object || !r2Object.body) {
+    throw new UrlNotFoundError()
+  }
+
+  const headers = new Headers()
+  headers.set('etag', r2Object.httpEtag)
+  r2Object.writeHttpMetadata(headers)
+
+  if (range) {
+    headers.set('status', '206')
+    let first, last
+    if (range.suffix != null) {
+      first = r2Object.size - range.suffix
+      last = r2Object.size - 1
+    } else {
+      first = range.offset || 0
+      last = range.length != null ? first + range.length - 1 : r2Object.size - 1
+    }
+    headers.set('content-range', `bytes ${first}-${last}/${r2Object.size}`)
+    headers.set('content-length', `${last - first + 1}`)
+  } else {
+    headers.set('status', '200')
+    headers.set('content-length', `${r2Object.size}`)
   }
 
-  throw new UrlNotFoundError()
+  return new Response(r2Object.body, {
+    status: range ? 206 : 200,
+  })
 }
 
 /**
+ * Convert a HTTP Range header to an R2 range object.
  *
  * @param {string|null} encoded
- * @returns {R2Range}
+ * @returns {R2Range|undefined}
  */
-function parseRange(encoded) {
+function toR2Range(encoded) {
   if (encoded === null) {
     return
   }
 
-  const parts = encoded.split('bytes=')[1]?.split('-') ?? []
-  if (parts.length !== 2) {
-    throw new InvalidRangeError(
-      'Not supported to skip specifying the beginning/ending byte at this time'
-    )
-  }
-
-  return {
-    offset: Number(parts[0]),
-    length: Number(parts[1]) + 1 - Number(parts[0]),
-  }
+  const result = parseRange(encoded)
+  if (result.ranges)
+    throw new InvalidRangeError('Multiple ranges not supported')
+  const { unit, first, last, suffix } = result
+  if (unit !== 'bytes')
+    throw new InvalidRangeError(`Unsupported range unit: ${unit}`)
+  return suffix != null
+    ? { suffix }
+    : { offset: first, length: last != null ? last - first + 1 : undefined }
 }