multipool (empty) → 0.1.0.0

raw patch · 7 files changed

+200/−0 lines, 7 filesdep +basedep +bytestringdep +hashablesetup-changed

Dependencies added: base, bytestring, hashable, hedis, mmorph, monad-logger, mtl, multipool, persistent, persistent-postgresql, postgresql-common-persistent, resource-pool, text, unordered-containers

Files

ChangeLog.md +3/−0
LICENSE +30/−0
README.md +1/−0
Setup.hs +2/−0
multipool.cabal +74/−0
src/Data/MultiPool.hs +88/−0
test/Spec.hs +2/−0

+ ChangeLog.md view

@@ -0,0 +1,3 @@+# Changelog for multipool++## Unreleased changes

+ LICENSE view

@@ -0,0 +1,30 @@+Copyright Author name here (c) 2018++All rights reserved.++Redistribution and use in source and binary forms, with or without+modification, are permitted provided that the following conditions are met:++    * Redistributions of source code must retain the above copyright+      notice, this list of conditions and the following disclaimer.++    * Redistributions in binary form must reproduce the above+      copyright notice, this list of conditions and the following+      disclaimer in the documentation and/or other materials provided+      with the distribution.++    * Neither the name of Author name here nor the names of other+      contributors may be used to endorse or promote products derived+      from this software without specific prior written permission.++THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

+ README.md view

@@ -0,0 +1,1 @@+# multipool

+ Setup.hs view

@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain

+ multipool.cabal view

@@ -0,0 +1,74 @@+-- This file has been generated from package.yaml by hpack version 0.28.2.+--+-- see: https://github.com/sol/hpack+--+-- hash: 94867a7572b048dffde7b9f36b385a6ca96a42467c6d513f22a25f60ed82c231++name:           multipool+version:        0.1.0.0+synopsis:       Generalized system for reading and writing to distributed systems that have primary/replica topologies.+description:    Please see the README on GitHub at <https://github.com/githubuser/multipool#readme>+homepage:       https://github.com/iand675/multipool#readme+bug-reports:    https://github.com/iand675/multipool/issues+author:         Ian Duncan+maintainer:     ian@iankduncan.com+copyright:      2018 Ian Duncan+license:        BSD3+license-file:   LICENSE+build-type:     Simple+cabal-version:  >= 1.10+extra-source-files:+    ChangeLog.md+    README.md++source-repository head+  type: git+  location: https://github.com/iand675/multipool++library+  exposed-modules:+      Data.MultiPool+  other-modules:+      Paths_multipool+  hs-source-dirs:+      src+  build-depends:+      base >=4.7 && <5+    , bytestring+    , hashable+    , hedis+    , mmorph+    , monad-logger+    , mtl+    , persistent+    , persistent-postgresql+    , postgresql-common-persistent+    , resource-pool+    , text+    , unordered-containers+  default-language: Haskell2010++test-suite multipool-test+  type: exitcode-stdio-1.0+  main-is: Spec.hs+  other-modules:+      Paths_multipool+  hs-source-dirs:+      test+  ghc-options: -threaded -rtsopts -with-rtsopts=-N+  build-depends:+      base >=4.7 && <5+    , bytestring+    , hashable+    , hedis+    , mmorph+    , monad-logger+    , mtl+    , multipool+    , persistent+    , persistent-postgresql+    , postgresql-common-persistent+    , resource-pool+    , text+    , unordered-containers+  default-language: Haskell2010

+ src/Data/MultiPool.hs view

@@ -0,0 +1,88 @@+{-# LANGUAGE AllowAmbiguousTypes #-}+{-# LANGUAGE DataKinds #-}+{-# LANGUAGE FlexibleInstances #-}+{-# LANGUAGE MultiParamTypeClasses #-}+{-# LANGUAGE OverloadedStrings #-}+{-# LANGUAGE RankNTypes #-}+{-# LANGUAGE TypeFamilies #-}+{-# LANGUAGE FlexibleInstances #-}+{-# LANGUAGE UndecidableInstances #-}+{-# LANGUAGE RecordWildCards #-}++module Data.MultiPool where++import Control.Exception+import Control.Monad.Reader+import Control.Monad.Logger+import Data.Hashable+import Data.HashMap.Strict (HashMap)+import qualified Data.HashMap.Strict as HM+import Data.Pool+import Data.Text (Text)+import Data.Text.Encoding+import Data.Typeable+import Data.IORef+-- Todo: separate out implementations+import Data.ByteString (ByteString)+import Database.Persist.Postgresql+import Database.Persist.Postgresql.Common++newtype InstanceName backend = InstanceName+  { rawInstanceName :: Hashed Text+  } deriving (Show, Eq, Ord)++mkInstanceName :: Text -> InstanceName backend+mkInstanceName = InstanceName . hashed++instance Hashable (InstanceName backend) where+  hashWithSalt s r = hashWithSalt s (rawInstanceName r)+  hash = hash . rawInstanceName++data InstanceDoesNotExist backend = InstanceDoesNotExist+  { instanceDoesNotExist :: InstanceName backend+  } deriving (Show, Eq, Typeable)++instance (Show (InstanceDoesNotExist backend), Typeable backend) => Exception (InstanceDoesNotExist backend)++class Monad m => MultiPoolBackend m backend where+  type Masters backend :: *+  type Masters backend = Pool (MasterConnection backend)+  type Replicas backend :: *+  type Replicas backend = HashMap (ReplicaIdentifier backend) (Pool (ReplicaConnection backend))++  type MasterConnection backend :: *+  type ReplicaConnection backend :: *++  type MasterIdentifier backend :: *+  type MasterIdentifier backend = ()+  type ReplicaIdentifier backend :: *+  type ReplicaIdentifier backend = InstanceName backend++  runWriteAny :: MultiPool backend -> ReaderT (MasterConnection backend) m a -> m a+  runWrite :: MultiPool backend -> MasterIdentifier backend -> ReaderT (MasterConnection backend) m a -> m a++  runReadMaster :: MultiPool backend -> MasterIdentifier backend -> ReaderT (ReplicaConnection backend) m a -> m a+  runReadAnyMaster :: MultiPool backend -> ReaderT (ReplicaConnection backend) m a -> m a+  runReadAny :: MultiPool backend -> ReaderT (ReplicaConnection backend) m a -> m a+  runRead :: MultiPool backend -> ReplicaIdentifier backend -> ReaderT (ReplicaConnection backend) m a -> m a+++-- Invariant: MultiPool should not be modified after creation?+data MultiPool backend = MultiPool+  { multiPoolMaster :: !(Masters backend)+  , multiPoolReplica :: !(Replicas backend)+  , multiPoolAnyMasterSelector :: MultiPool backend -> IO (MasterIdentifier backend)+  , multiPoolAnyReplicaSelector :: MultiPool backend -> IO (Maybe (ReplicaIdentifier backend))+  }++forReplicas :: (MultiPoolBackend m backend, Replicas backend ~ HashMap k v) => MultiPool backend -> (k -> v -> m a) -> m [a]+forReplicas pool f = forM (HM.toList (multiPoolReplica pool)) $ \(k, v) -> f k v++roundRobin :: MonadIO m => [choice] -> m (a -> IO (Maybe choice))+roundRobin [] = return $ const $ return Nothing+roundRobin choices = do+  let infiniteChoice = cycle choices+  picker <- liftIO $ newIORef infiniteChoice+  return $ const $ atomicModifyIORef' picker $ \l -> case l of+    (x:xs) -> (xs, Just x)+    [] -> error "roundRobin: should have matched empty list in first clause"

+ test/Spec.hs view

@@ -0,0 +1,2 @@+main :: IO ()+main = putStrLn "Test suite not yet implemented"