REFACTOR: Use connection pooling

Signed-off-by: baalajimaestro <me@baalajimaestro.me>

src/nim_censor_bot.nim

@@ -12,14 +12,13 @@ import std/[asyncdispatch,
             options,
             strutils,
             random,
-            with,
             os,
             tables,
             times,
             sequtils,
             json]
 
-import norm/[model, sqlite]
+import norm/[model, sqlite, pool]
 
 # Logging Level
 var L = newConsoleLogger(levelThreshold=lvlError, fmtStr="$levelname, [$time] ")
@@ -49,6 +48,7 @@ var GroupMedia = initTable[int, string]()
 let AdminID = getEnv("ADMIN_ID").split(",")
 
 let dbConn* = getDb()
+var connPool = newPool[DbConn](15)
 
 # Functions to assist adding/deleting entries from tables
 func NewCensoredData*(ftype = ""; fhash = ""; fileid = ""; time = 0.0; caption = ""):
@@ -58,8 +58,9 @@ func NewBannedUsers*(userid = int64(0), bantime = 0.0, bantype = ""):
   BannedUsers = BannedUsers(userid: userid, bantime: bantime, bantype: bantype)
 
 # Create tables if they dont exist
-dbConn.createTables(NewCensoredData())
+withDb(connPool):
-dbConn.createTables(NewBannedUsers())
+  db.createTables(NewCensoredData())
+  db.createTables(NewBannedUsers())
 
 # Ratelimits a user if there is more than 30 timestamps within 60 secs. 
 # Resets their ratelimit counter if 60s has passed since first timestamp
@@ -70,24 +71,26 @@ proc ManageRateLimit(): void=
     elif len(RateLimiter[i]) >= 30:
       var BannedUser = NewBannedUsers(i, epochTime(), "auto")
       RateLimiter.del(i)
-      with dbConn:
+      withDb(connPool):
-        insert BannedUser
+        db.insert(BannedUser)
-  if dbConn.exists(BannedUsers, "bantype = ? and ? - bantime >= 1800", "auto", epochTime()):
+  withDb(connPool):
+    if db.exists(BannedUsers, "bantype = ? and ? - bantime >= 1800", "auto", epochTime()):
       var TempData = @[NewBannedUsers()]
-    dbConn.select(TempData,  "bantype = ? and ? - bantime >= 1800", "auto", epochTime())
+      db.select(TempData,  "bantype = ? and ? - bantime >= 1800", "auto", epochTime())
       for i in TempData:
         var e = i
-      dbConn.delete(e)
+        db.delete(e)
 
 # Cleanup old data to save space
 # Deletes old data after 6 months of entry
 proc OldDataCleanup(): void=
-  if dbConn.exists(CensoredData, "? - time >= 15780000", epochTime()):
+  withDb(connPool):
+    if db.exists(CensoredData, "? - time >= 15780000", epochTime()):
       var TempData = @[NewCensoredData()]
-    dbConn.select(TempData,  "? - time >= 15780000", epochTime())
+      db.select(TempData,  "? - time >= 15780000", epochTime())
       for i in TempData:
         var e = i
-      dbConn.delete(e)
+        db.delete(e)
 
 # Generates a 6-character magic that will be used to identify the file
 proc generate_hash(): string=
@@ -101,7 +104,8 @@ proc generate_hash(): string=
 proc startHandler(b: Telebot, c: Command): Future[bool] {.gcsafe, async.} =
   let param = c.params
   ManageRateLimit()
-  if not dbConn.exists(BannedUsers, "userid = ?", c.message.chat.id):
+  withDb(connPool):
+    if not db.exists(BannedUsers, "userid = ?", c.message.chat.id):
       # Update rate-limit counter
       if not AdminID.contains($c.message.chat.id):
         if RateLimiter.contains(c.message.chat.id):
@@ -113,12 +117,12 @@ proc startHandler(b: Telebot, c: Command): Future[bool] {.gcsafe, async.} =
                 "Hey, To create a censored post, you can share any album, video, photo, gif, sticker, etc. " &
                 "The response of the bot can be used to share the media with other chats.")
       else:
-      if not dbConn.exists(CensoredData, "fhash = ?", param):
+        if not db.exists(CensoredData, "fhash = ?", param):
           discard await b.sendMessage(c.message.chat.id,
                   "Media does not exist on database, ask the sender to censor this again!")
         else:
           var TempData = @[NewCensoredData()]
-        dbConn.select(TempData, "fhash = ?", param)
+          db.select(TempData, "fhash = ?", param)
           if len(TempData) > 1:
             var inputmedia = newSeq[InputMediaPhoto]()
             for i in TempData:
@@ -144,7 +148,8 @@ proc startHandler(b: Telebot, c: Command): Future[bool] {.gcsafe, async.} =
 # Give them source url
 proc sourceHandler(b: Telebot, c: Command): Future[bool] {.gcsafe, async.} =
   ManageRateLimit()
-  if not dbConn.exists(BannedUsers, "userid = ?", c.message.chat.id):
+  withDb(connPool):
+    if not db.exists(BannedUsers, "userid = ?", c.message.chat.id):
       # Update rate-limit counter
       if not AdminID.contains($c.message.chat.id):
         if RateLimiter.contains(c.message.chat.id):
@@ -162,12 +167,13 @@ proc sourceHandler(b: Telebot, c: Command): Future[bool] {.gcsafe, async.} =
 proc unbanHandler(b: Telebot, c: Command): Future[bool] {.gcsafe, async.} =
   if $c.message.chat.id in AdminID:
     let user = c.params
-    if dbConn.exists(BannedUsers, "userid = ?", int64(parseInt(user))):
+    withDb(connPool):
+      if db.exists(BannedUsers, "userid = ?", int64(parseInt(user))):
         var TempData = @[NewBannedUsers()]
-      dbConn.select(TempData,  "userid = ?", int64(parseInt(user)))
+        db.select(TempData,  "userid = ?", int64(parseInt(user)))
         for i in TempData:
           var e = i
-        dbConn.delete(e)
+          db.delete(e)
         discard await b.sendMessage(c.message.chat.id, "Unbanned!")
 
 # ban Handler
@@ -175,12 +181,12 @@ proc banHandler(b: Telebot, c: Command): Future[bool] {.gcsafe, async.} =
   if $c.message.chat.id in AdminID:
     let user = c.params
     var BannedUser = NewBannedUsers(int64(parseInt(user)), epochTime(), "permanent")
-    with dbConn:
+    withDb(connPool):
-      insert BannedUser
+        db.insert(BannedUser)
     discard await b.sendMessage(c.message.chat.id, "Banned!")
 
 # Inline share handler
-proc inlineHandler(b: Telebot, u: InlineQuery): Future[bool]{.async.} =
+proc inlineHandler(b: Telebot, u: InlineQuery): Future[bool]{.gcsafe, async.} =
     var TempData = @[NewCensoredData()]
     var ftype = ""
     var res: InlineQueryResultArticle
@@ -188,12 +194,13 @@ proc inlineHandler(b: Telebot, u: InlineQuery): Future[bool]{.async.} =
     res.kind = "article"
     res.id = "1"
     if u.query != "":
-        if not dbConn.exists(CensoredData, "fhash = ?",u.query):
+        withDb(connPool):
+          if not db.exists(CensoredData, "fhash = ?",u.query):
             res.title = "Media Not Found"
             res.inputMessageContent = InputTextMessageContent(
                   "Media does not exist on database, ask the sender to censor this again!").some
           else:
-          dbConn.select(TempData, "fhash = ?", u.query)
+            db.select(TempData, "fhash = ?", u.query)
             if len(TempData) > 1:
               ftype = "Album"
             elif len(TempData) == 1:
@@ -220,8 +227,9 @@ proc updateHandler(b: Telebot, u: Update): Future[bool] {.async, gcsafe.} =
     let response = u.message.get
     # Refresh rate-limits
     ManageRateLimit()
+    withDb(connPool):
       # Dont bother about rate-limited/banned users
-    if not dbConn.exists(BannedUsers, "userid = ?", response.chat.id):
+      if not db.exists(BannedUsers, "userid = ?", response.chat.id):
         # Update rate-limit counter
         if not AdminID.contains($response.chat.id):
           if RateLimiter.contains(response.chat.id):
@@ -259,8 +267,8 @@ proc updateHandler(b: Telebot, u: Update): Future[bool] {.async, gcsafe.} =
               let filehash = generate_hash()
               GroupMedia[parseInt(response.mediaGroupId.get)] = filehash
               var CensoredRow = NewCensoredData(ftype, filehash, fileid, epochTime(), fcaption)
-            with dbConn:
+              withDb(connPool):
-                  insert CensoredRow
+                db.insert(CensoredRow)
               var replybutton = InlineKeyboardButton(text: "Share", switchInlineQuery: some(filehash))
               let replymark = newInlineKeyboardMarkup(@[replybutton])
               discard await b.sendMessage(response.chat.id,
@@ -276,14 +284,14 @@ proc updateHandler(b: Telebot, u: Update): Future[bool] {.async, gcsafe.} =
             else:
               let filehash = GroupMedia[parseInt(response.mediaGroupId.get)]
               var CensoredRow = NewCensoredData(ftype, filehash, fileid, epochTime(), fcaption)
-            with dbConn:
+              withDb(connPool):
-                  insert CensoredRow
+                db.insert(CensoredRow)
 
           else:
             let filehash = generate_hash()
             var CensoredRow = NewCensoredData(ftype, filehash, fileid, epochTime(), fcaption)
-          with dbConn:
+            withDb(connPool):
-                insert CensoredRow
+                db.insert(CensoredRow)
             var replybutton = InlineKeyboardButton(text: "Share", switchInlineQuery: some(filehash))
             let replymark = newInlineKeyboardMarkup(@[replybutton])
             discard await b.sendMessage(response.chat.id,