Fix streaming via /ipfs/<cid> and /content/<cid> (#3349)

creator-node/src/routes/files.js

@@ -111,6 +111,17 @@ const streamFromFileSystem = async (
       res.set('Content-Length', stat.size)
     }
 
+    // If client has provided filename, set filename in header to be auto-populated in download prompt.
+    if (req.query.filename) {
+      res.setHeader(
+        'Content-Disposition',
+        contentDisposition(req.query.filename)
+      )
+    }
+
+    // Set the CID cache-control so that client caches the response for 30 days
+    res.setHeader('cache-control', 'public, max-age=2592000, immutable')
+
     await new Promise((resolve, reject) => {
       fileStream
         .on('open', () => fileStream.pipe(res))
@@ -123,6 +134,9 @@ const streamFromFileSystem = async (
         })
     })
   } catch (e) {
+    // Unset the cache-control header so that a bad response is not cached
+    res.removeHeader('cache-control')
+
     // Unable to stream from file system. Throw a server error message
     throw e
   }
@@ -141,10 +155,10 @@ const logGetCIDDecisionTree = (decisionTree, req) => {
 /**
  * Given a CID, return the appropriate file
  * 1. Check if file exists at expected storage path (current and legacy)
- * 1. If found, stream from FS
- * 2. Else, check if CID exists in DB. If not, return 404 not found error
- * 3. If exists in DB, fetch file from CN network, save to FS, and stream from FS
- * 4. If not avail in CN network, respond with 400 server error
+ * 2. If found, stream from FS
+ * 3. Else, check if CID exists in DB. If not, return 404 not found error
+ * 4. If exists in DB, fetch file from CN network, save to FS, and stream from FS
+ * 5. If not avail in CN network, respond with 400 server error
  */
 const getCID = async (req, res) => {
   if (!(req.params && req.params.CID)) {
@@ -372,7 +386,6 @@ const getCID = async (req, res) => {
         stage: `STREAM_FROM_FILE_SYSTEM_COMPLETE`,
         time: `${Date.now() - startMs}ms`
       })
-      _setHeadersForStreaming(req, res)
       logGetCIDDecisionTree(decisionTree, req)
       return fsStream
     } catch (e) {
@@ -473,7 +486,6 @@ const getCID = async (req, res) => {
       time: `${Date.now() - startMs}ms`
     })
 
-    _setHeadersForStreaming()
     logGetCIDDecisionTree(decisionTree, req)
     return fsStream
   } catch (e) {
@@ -581,21 +593,6 @@ const _verifyContentMatchesHash = async function (req, resizeResp, dirCID) {
   }
 }
 
-/**
- * Sets headers for streaming
- * @param {Object} req
- * @param {Object} res
- */
-function _setHeadersForStreaming(req, res) {
-  // If client has provided filename, set filename in header to be auto-populated in download prompt.
-  if (req.query.filename) {
-    res.setHeader('Content-Disposition', contentDisposition(req.query.filename))
-  }
-
-  // Set the CID cache-control so that client caches the response for 30 days
-  res.setHeader('cache-control', 'public, max-age=2592000, immutable')
-}
-
 /**
  * Helper fn to generate the input for `generateImageCids()`
  * @param {File[]} resizeResp resizeImage.js response; should be a File[] of resized images