From 279d7291b8234075a1776532c122f3ce0070f172 Mon Sep 17 00:00:00 2001
From: Spencer T Brody <spencer@3box.io>
Date: Thu, 29 Apr 2021 13:30:45 -0400
Subject: [PATCH] fix(core): Add 2 retries when loading CIDs from IPFS (#1334)

---
 packages/core/src/dispatcher.ts | 48 +++++++++++++++++----------------
 1 file changed, 25 insertions(+), 23 deletions(-)

diff --git a/packages/core/src/dispatcher.ts b/packages/core/src/dispatcher.ts
index 415154b038..8fbacdcbc8 100644
--- a/packages/core/src/dispatcher.ts
+++ b/packages/core/src/dispatcher.ts
@@ -16,7 +16,7 @@ import { Subscription } from 'rxjs';
 import { MessageBus } from './pubsub/message-bus';
 
 const IPFS_GET_TIMEOUT = 60000 // 1 minute
-const IPFS_MAX_RECORD_SIZE = 256000 // 256 KB
+const IPFS_MAX_COMMIT_SIZE = 256000 // 256 KB
 const IPFS_RESUBSCRIBE_INTERVAL_DELAY = 1000 * 15 // 15 sec
 
 function messageTypeToString(type: MsgType): string {
@@ -32,6 +32,8 @@ function messageTypeToString(type: MsgType): string {
   }
 }
 
+const IPFS_RETRIES = 2
+
 /**
  * Ceramic core Dispatcher used for handling messages from pub/sub topic.
  */
@@ -57,12 +59,12 @@ export class Dispatcher {
       const cid = await this._ipfs.dag.put(jws, { format: 'dag-jose', hashAlg: 'sha2-256' })
       // put the payload into the ipfs dag
       await this._ipfs.block.put(linkedBlock, { cid: jws.link.toString() })
-      await this._restrictRecordSize(jws.link.toString())
-      await this._restrictRecordSize(cid)
+      await this._restrictCommitSize(jws.link.toString())
+      await this._restrictCommitSize(cid)
       return cid
     }
     const cid = await this._ipfs.dag.put(data)
-    await this._restrictRecordSize(cid)
+    await this._restrictCommitSize(cid)
     return cid
   }
 
@@ -74,14 +76,9 @@ export class Dispatcher {
    * @param cid - Commit CID
    */
   async retrieveCommit (cid: CID | string): Promise<any> {
-    try {
-      const record = await this._ipfs.dag.get(cid, {timeout: IPFS_GET_TIMEOUT})
-      await this._restrictRecordSize(cid)
-      return cloneDeep(record.value)
-    } catch (e) {
-      this._logger.err(`Error while loading commit CID ${cid.toString()} from IPFS: ${e}`)
-      throw e
-    }
+      const commit = await this.retrieveFromIPFS(cid)
+      await this._restrictCommitSize(cid)
+      return commit
   }
 
   /**
@@ -90,24 +87,29 @@ export class Dispatcher {
    * @param path - optional IPLD path to load, starting from the object represented by `cid`
    */
   async retrieveFromIPFS (cid: CID | string, path?: string): Promise<any> {
-    try {
-      const record = await this._ipfs.dag.get(cid, {timeout: IPFS_GET_TIMEOUT, path})
-      return cloneDeep(record.value)
-    } catch (e) {
-      this._logger.err(`Error while loading CID ${cid.toString()} from IPFS: ${e}`)
-      throw e
+    for (let i = 0; i <= IPFS_RETRIES; i++) {
+        try {
+            const record = await this._ipfs.dag.get(cid, {timeout: IPFS_GET_TIMEOUT, path})
+            return cloneDeep(record.value)
+        } catch (e) {
+            this._logger.err(`Error while loading CID ${cid.toString()} from IPFS: ${e}. Retries remaining: ${IPFS_RETRIES - i}`)
+            if (i < IPFS_RETRIES) {
+                continue
+            }
+            throw e
+        }
     }
   }
 
   /**
-   * Restricts record size to IPFS_MAX_RECORD_SIZE
-   * @param cid - Record CID
+   * Restricts commit size to IPFS_MAX_COMMIT_SIZE
+   * @param cid - Commit CID
    * @private
    */
-  async _restrictRecordSize(cid: CID | string): Promise<void> {
+  async _restrictCommitSize(cid: CID | string): Promise<void> {
     const stat = await this._ipfs.block.stat(cid, { timeout: IPFS_GET_TIMEOUT })
-    if (stat.size > IPFS_MAX_RECORD_SIZE) {
-      throw new Error(`${cid.toString()} record size ${stat.size} exceeds the maximum block size of ${IPFS_MAX_RECORD_SIZE}`)
+    if (stat.size > IPFS_MAX_COMMIT_SIZE) {
+      throw new Error(`${cid.toString()} record size ${stat.size} exceeds the maximum block size of ${IPFS_MAX_COMMIT_SIZE}`)
     }
   }