chore: apply suggestions from code review

Co-authored-by: Alan Shaw <[email protected]>

src/bindings.d.ts

@@ -9,7 +9,7 @@ export interface Environment {
   CARPARK: R2Bucket
   DUDEWHERE: R2Bucket
   SATNAV: R2Bucket
-  MAX_CAR_CIDS_TO_RESOLVE: string
+  MAX_SHARDS: string
 }
 
 export interface CarCidsContext extends Context {

src/middleware.js

@@ -40,6 +40,11 @@ export function withCarCids (handler) {
     if (!ctx.dataCid) throw new Error('missing data CID')
     if (!ctx.searchParams) throw new Error('missing URL search params')
 
+    // Cloudflare currently sets a limit of 1000 sub-requests within the worker context
+    // If we have a given root CID splitted across hundreds of CARs, freeway will hit
+    // the sub-requests limit and not serve content anyway
+    const maxShards = env.MAX_SHARDS ? parseInt(env.MAX_SHARDS) : 250
+
     const carCids = ctx.searchParams.getAll('origin').flatMap(str => {
       return str.split(',')
         .reduce((/** @type {import('multiformats').CID[]} */cids, str) => {
@@ -62,23 +67,25 @@ export function withCarCids (handler) {
         const results = await env.DUDEWHERE.list({ prefix: `${ctx.dataCid}/`, cursor })
         if (!results || !results.objects.length) break
         carCids.push(...results.objects.map(o => parseCid(o.key.split('/')[1])))
+
+        if (carCids.length > maxShards) {
+          throw new HttpError('request exceeds maximum DAG shards', { status: 501 })
+        }
+
         if (!results.truncated) break
         cursor = results.cursor
       }
       console.log(`dude where's my CAR? ${ctx.dataCid} => ${carCids}`)
+    } else {
+      if (carCids.length > maxShards) {
+        throw new HttpError('request exceeds maximum DAG shards', { status: 501 })
+      }
     }
 
     if (!carCids.length) {
       throw new HttpError('missing origin CAR CID(s)', { status: 400 })
     }
 
-    // Cloudflare currently sets a limit of 1000 sub-requests within the worker context
-    // If we have a given root CID splitted across hundreds of CARs, freeway will hit
-    // the sub-requests limit and not serve content anyway
-    if (carCids.length > Number(env.MAX_CAR_CIDS_TO_RESOLVE)) {
-      throw new HttpError('number CAR CIDs is too large to resolve', { status: 501 })
-    }
-
     return handler(request, env, { ...ctx, carCids })
   }
 }

wrangler.toml

@@ -28,7 +28,7 @@ r2_buckets = [
 command = "npm run build"
 
 [env.production.vars]
-MAX_CAR_CIDS_TO_RESOLVE = "250"
+MAX_SHARDS = "250"
 
 # Staging!
 [env.staging]
@@ -44,7 +44,7 @@ r2_buckets = [
 command = "npm run build"
 
 [env.staging.vars]
-MAX_CAR_CIDS_TO_RESOLVE = "250"
+MAX_SHARDS = "250"
 
 # Test!
 [env.test]
@@ -57,7 +57,7 @@ r2_buckets = [
 
 [env.test.vars]
 DEBUG = "true"
-MAX_CAR_CIDS_TO_RESOLVE = "120"
+MAX_SHARDS = "120"
 
 [env.alanshaw]
 workers_dev = true