From 61d27efd69985debe2d1dfd0ae438688e15f6150 Mon Sep 17 00:00:00 2001
From: Zed <zedeus@pm.me>
Date: Tue, 9 Jun 2020 18:19:20 +0200
Subject: [PATCH] Optimize profile caching strategy

---
 src/redis_cache.nim     |  4 +++-
 src/routes/timeline.nim | 24 +++++++++++++++++-------
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/src/redis_cache.nim b/src/redis_cache.nim
index fafd2eb..660b0e3 100644
--- a/src/redis_cache.nim
+++ b/src/redis_cache.nim
@@ -85,12 +85,14 @@ proc getProfileId*(username: string): Future[string] {.async.} =
     if result == redisNil:
       result.setLen(0)
 
-proc getCachedProfile*(username: string; fetch=true): Future[Profile] {.async.} =
+proc getCachedProfile*(username: string; fetch=true;
+                       cache=false): Future[Profile] {.async.} =
   let prof = await get("p:" & toLower(username))
   if prof != redisNil:
     uncompress(prof).thaw(result)
   elif fetch:
     result = await getProfile(username)
+    if cache: await cache(result)
 
 proc getCachedPhotoRail*(id: string): Future[PhotoRail] {.async.} =
   if id.len == 0: return
diff --git a/src/routes/timeline.nim b/src/routes/timeline.nim
index 2d415f3..ff08ee6 100644
--- a/src/routes/timeline.nim
+++ b/src/routes/timeline.nim
@@ -23,17 +23,23 @@ proc fetchSingleTimeline*(after: string; query: Query; skipRail=false):
   let name = query.fromUser[0]
 
   var
-    profile = await getCachedProfile(name, fetch=false)
+    profile: Profile
     profileId = await getProfileId(name)
+    fetched = false
 
-  if profile.username.len == 0 and profileId.len == 0:
-    profile = await getProfile(name)
-    profileId = profile.id
-    await cacheProfileId(profile.username, profile.id)
+  if profileId.len == 0:
+    profile = await getCachedProfile(name)
+    profileId = if profile.suspended: "s"
+                else: profile.id
+    await cacheProfileId(profile.username, profileId)
+    fetched = true
 
-  if profile.suspended or profile.protected or profileId.len == 0:
+  if profileId.len == 0 or profile.protected:
     result[0] = profile
     return
+  elif profileId == "s":
+    result[0] = Profile(username: name, suspended: true)
+    return
 
   var rail: Future[PhotoRail]
   if skipRail or query.kind == media:
@@ -51,14 +57,18 @@ proc fetchSingleTimeline*(after: string; query: Query; skipRail=false):
 
   timeline.query = query
 
+  var found = false
   for tweet in timeline.content.mitems:
     if tweet.profile.id == profileId or
        tweet.profile.username.cmpIgnoreCase(name) == 0:
       profile = tweet.profile
+      found = true
       break
 
   if profile.username.len == 0:
-    profile = await getCachedProfile(name)
+    profile = await getCachedProfile(name, cache=true)
+
+  if fetched and not found:
     await cache(profile)
 
   return (profile, timeline, await rail)