From fe811c78bda8f626a0a2e0f39e8a90e156c916f5 Mon Sep 17 00:00:00 2001
From: Chris Pacia <chris@ob1.io>
Date: Thu, 19 Jul 2018 18:30:20 -0400
Subject: [PATCH] Add optional asyncID query param to async API calls

This commit adds an optional query parameter allowing clients to pass in an
ID used for async requests where the response is returned over websockets.

The current approach of generating and returning a random ID may create a race
condition causing the client to miss the response.

closes #925
---
 api/jsonapi.go | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/api/jsonapi.go b/api/jsonapi.go
index 056ba1a54e..255b71a797 100644
--- a/api/jsonapi.go
+++ b/api/jsonapi.go
@@ -1803,9 +1803,12 @@ func (i *jsonAPIHandler) GETModerators(w http.ResponseWriter, r *http.Request) {
 		}
 		SanitizedResponse(w, resp)
 	} else {
-		idBytes := make([]byte, 16)
-		rand.Read(idBytes)
-		id := base58.Encode(idBytes)
+		id := r.URL.Query().Get("asyncID")
+		if id == "" {
+			idBytes := make([]byte, 16)
+			rand.Read(idBytes)
+			id = base58.Encode(idBytes)
+		}
 
 		type resp struct {
 			Id string `json:"id"`
@@ -2623,9 +2626,12 @@ func (i *jsonAPIHandler) POSTFetchProfiles(w http.ResponseWriter, r *http.Reques
 		resp += "\n]"
 		SanitizedResponse(w, resp)
 	} else {
-		idBytes := make([]byte, 16)
-		rand.Read(idBytes)
-		id := base58.Encode(idBytes)
+		id := r.URL.Query().Get("asyncID")
+		if id == "" {
+			idBytes := make([]byte, 16)
+			rand.Read(idBytes)
+			id = base58.Encode(idBytes)
+		}
 
 		type resp struct {
 			Id string `json:"id"`
@@ -3366,9 +3372,12 @@ func (i *jsonAPIHandler) POSTFetchRatings(w http.ResponseWriter, r *http.Request
 		resp += "\n]"
 		SanitizedResponse(w, resp)
 	} else {
-		idBytes := make([]byte, 16)
-		rand.Read(idBytes)
-		id := base58.Encode(idBytes)
+		id := r.URL.Query().Get("asyncID")
+		if id == "" {
+			idBytes := make([]byte, 16)
+			rand.Read(idBytes)
+			id = base58.Encode(idBytes)
+		}
 
 		type resp struct {
 			Id string `json:"id"`