🚤 TLDR for @fluxlife

jet · Mar 23, 2020 · 338012e · 338012e
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diff --git a/README.md b/README.md
@@ -15,6 +15,11 @@ Some aspects of the implementation are distilled from [`Jet.com` systems dating
 - `MemoryStore`: In-memory store (volatile, for unit or integration test purposes). Fulfils the full contract Equinox imposes on a store, but without I/O costs [(it's ~100 LOC wrapping a `ConcurrentDictionary`)](https://github.com/jet/equinox/blob/master/src/Equinox.MemoryStore/MemoryStore.fs), and the ability to [take serialization/deserialization cost out of the picture](https://github.com/jet/FsCodec#boxcodec).
 - [SqlStreamStore](https://github.com/SQLStreamStore/SQLStreamStore): Bindings for the powerful and widely used SQL-backed Event Storage system. [See SqlStreamStore docs](https://sqlstreamstore.readthedocs.io/en/latest/#introduction). :pray: [@rajivhost](https://github.com/rajivhost)
 
+<a name="tldr"></a>
+# TL;DR :fast_forward:
+
+- **Dev that wants a slab of code instead of a wall of text and will guess the rest** ? :point_right: <100 LOC end to end 'tutorial' using CosmosDB: https://github.com/jet/equinox/blob/master/samples/Tutorial/Cosmos.fsx#L36 
+
 # Features
 
 - Designed not to invade application code; Domain tests can be written directly against your models without any need to involve or understand Equinox assemblies or constructs as part of writing those tests.

diff --git a/samples/Tutorial/Cosmos.fsx b/samples/Tutorial/Cosmos.fsx
@@ -19,87 +19,120 @@
 #r "Serilog.Sinks.Seq.dll"
 #r "Equinox.Cosmos.dll"
 
-let Category = "Favorites"
-let streamName clientId = FsCodec.StreamName.create Category clientId
+module Log =
+
+    open Serilog
+    open Serilog.Events
+    let verbose = true // false will remove lots of noise
+    let log =
+        let c = LoggerConfiguration()
+        let c = if verbose then c.MinimumLevel.Debug() else c
+        let c = c.WriteTo.Sink(Equinox.Cosmos.Store.Log.InternalMetrics.Stats.LogSink()) // to power Log.InternalMetrics.dump
+        let c = c.WriteTo.Seq("http://localhost:5341") // https://getseq.net
+        let c = c.WriteTo.Console(if verbose then LogEventLevel.Debug else LogEventLevel.Information)
+        c.CreateLogger()
+    let dumpMetrics () = Equinox.Cosmos.Store.Log.InternalMetrics.dump log
 
 module Favorites =
 
-    type Item = { sku : string }
-    type Event =
-        | Added of Item
-        | Removed of Item
-        interface TypeShape.UnionContract.IUnionContract
-    let codec = FsCodec.NewtonsoftJson.Codec.Create<Event>()
-    type State = string list
-    let initial : State = []
-    let evolve state = function
-        | Added {sku = sku } -> sku :: state
-        | Removed {sku = sku } -> state |> List.filter (fun x -> x <> sku)
-    let fold s xs = Seq.fold evolve s xs
+    let Category = "Favorites"
+    let streamName clientId = FsCodec.StreamName.create Category clientId
+
+    module Events =
+
+        type Item = { sku : string }
+        type Event =
+            | Added of Item
+            | Removed of Item
+            interface TypeShape.UnionContract.IUnionContract
+        let codec = FsCodec.NewtonsoftJson.Codec.Create<Event>() // Coming soon, replace Newtonsoft with SystemTextJson and works same
+
+    module Fold =
+
+        type State = string list
+        let initial : State = []
+        let evolve state = function
+            | Events.Added {sku = sku } -> sku :: state
+            | Events.Removed {sku = sku } -> state |> List.filter (fun x -> x <> sku)
+        let fold s xs = Seq.fold evolve s xs
 
     type Command =
         | Add of string
         | Remove of string
     let interpret command state =
         match command with
-        | Add sku -> if state |> List.contains sku then [] else [Added {sku = sku}]
-        | Remove sku -> if state |> List.contains sku then [Removed {sku = sku}] else []
+        | Add sku -> if state |> List.contains sku then [] else [ Events.Added {sku = sku}]
+        | Remove sku -> if state |> List.contains sku then [ Events.Removed {sku = sku}] else []
 
-    type Service internal (resolve : string -> Equinox.Stream<Event, State>) =
+    type Service internal (resolve : string -> Equinox.Stream<Events.Event, Fold.State>) =
 
-        let execute clientId command : Async<unit> =
+        member __.Favorite(clientId, sku) =
             let stream = resolve clientId
-            stream.Transact(interpret command)
-
-        member __.Favorite(clientId, sku) = execute clientId (Add sku)
-        member __.Unfavorite(clientId, skus) = execute clientId (Remove skus)
+            stream.Transact(interpret (Add sku))
+        member __.Unfavorite(clientId, skus) =
+            let stream = resolve clientId
+            stream.Transact(interpret (Remove skus))
         member __.List clientId: Async<string list> =
             let stream = resolve clientId
             stream.Query id
 
-module Log =
-    open Serilog
-    open Serilog.Events
-    let verbose = true // false will remove lots of noise
-    let log =
-        let c = LoggerConfiguration()
-        let c = if verbose then c.MinimumLevel.Debug() else c
-        let c = c.WriteTo.Sink(Equinox.Cosmos.Store.Log.InternalMetrics.Stats.LogSink()) // to power Log.InternalMetrics.dump
-        let c = c.WriteTo.Seq("http://localhost:5341") // https://getseq.net
-        let c = c.WriteTo.Console(if verbose then LogEventLevel.Debug else LogEventLevel.Information)
-        c.CreateLogger()
-    let dumpMetrics () = Equinox.Cosmos.Store.Log.InternalMetrics.dump log
+    let create resolve =
+        let resolve clientId = Equinox.Stream(Log.log, resolve (streamName clientId), maxAttempts = 3)
+        Service(resolve)
+
+    module Cosmos =
+
+        open Equinox.Cosmos // Everything outside of this module is completely storage agnostic so can be unit tested simply and/or bound to any store
+        let accessStrategy = AccessStrategy.Unoptimized // Or Snapshot etc https://github.com/jet/equinox/blob/master/DOCUMENTATION.md#access-strategies
+        let create (context, cache) =
+            let cacheStrategy = CachingStrategy.SlidingWindow (cache, System.TimeSpan.FromMinutes 20.) // OR CachingStrategy.NoCaching
+            let resolver = Resolver(context, Events.codec, Fold.fold, Fold.initial, cacheStrategy, accessStrategy)
+            create resolver.Resolve
 
 let [<Literal>] appName = "equinox-tutorial"
-let cache = Equinox.Cache(appName, 20)
 
-open Equinox.Cosmos
-open System
 module Store =
     let read key = System.Environment.GetEnvironmentVariable key |> Option.ofObj |> Option.get
 
-    let connector = Connector(TimeSpan.FromSeconds 5., 2, TimeSpan.FromSeconds 5., log=Log.log)
-    let conn = connector.Connect(appName, Discovery.FromConnectionString (read "EQUINOX_COSMOS_CONNECTION")) |> Async.RunSynchronously
-    let gateway = Gateway(conn, BatchingPolicy())
+    let connector = Equinox.Cosmos.Connector(System.TimeSpan.FromSeconds 5., 2, System.TimeSpan.FromSeconds 5., log=Log.log)
+    let conn = connector.Connect(appName, Equinox.Cosmos.Discovery.FromConnectionString (read "EQUINOX_COSMOS_CONNECTION")) |> Async.RunSynchronously
+    let createContext () = Equinox.Cosmos.Context(conn, read "EQUINOX_COSMOS_DATABASE", read "EQUINOX_COSMOS_CONTAINER")
 
-    let context = Context(gateway, read "EQUINOX_COSMOS_DATABASE", read "EQUINOX_COSMOS_CONTAINER")
-    let cacheStrategy = CachingStrategy.SlidingWindow (cache, TimeSpan.FromMinutes 20.) // OR CachingStrategy.NoCaching
-
-module FavoritesCategory = 
-    let resolver = Resolver(Store.context, Favorites.codec, Favorites.fold, Favorites.initial, Store.cacheStrategy, AccessStrategy.Unoptimized)
-    let resolve clientId =
-        let streamName = streamName clientId
-        Equinox.Stream(Log.log, resolver.Resolve streamName, maxAttempts = 3)
-
-let service =
-    Favorites.Service(FavoritesCategory.resolve)
+let context = Store.createContext ()
+let cache = Equinox.Cache(appName, 20)
+let service = Favorites.Cosmos.create (context, cache)
 
 let client = "ClientJ"
+
 service.Favorite(client, "a") |> Async.RunSynchronously
 service.Favorite(client, "b") |> Async.RunSynchronously 
 service.List(client) |> Async.RunSynchronously 
 
 service.Unfavorite(client, "b") |> Async.RunSynchronously 
 service.List(client) |> Async.RunSynchronously 
 
-Log.dumpMetrics ()
+Log.dumpMetrics ()
+
+(* EXAMPLE OUTPUT
+
+[13:48:33 INF] EqxCosmos Response 5/5 Backward 189ms i=0 rc=3.43
+[13:48:33 INF] EqxCosmos QueryB Favorites-ClientJ v5 5/1 190ms rc=3.43
+[13:48:33 DBG] No events generated
+[13:48:33 INF] EqxCosmos Tip 200 90ms rc=1
+[13:48:33 INF] EqxCosmos Response 0/0 Forward 179ms i=null rc=3.62
+[13:48:33 INF] EqxCosmos QueryF Favorites-ClientJ v0 0/1 179ms rc=3.62
+[13:48:33 INF] EqxCosmos Sync: Conflict writing ["Added"]
+[13:48:33 INF] EqxCosmos Sync 1+0 90ms rc=5.4
+[13:48:33 INF] EqxCosmos Tip 200 86ms rc=1
+[13:48:33 INF] EqxCosmos Response 5/5 Forward 184ms i=0 rc=4.37
+[13:48:33 INF] EqxCosmos QueryF Favorites-ClientJ v5 5/1 185ms rc=4.37
+[13:48:33 DBG] Resyncing and retrying
+[13:48:33 INF] EqxCosmos Sync 1+0 96ms rc=37.67
+[13:48:34 INF] EqxCosmos Tip 302 90ms rc=1
+[13:48:34 INF] EqxCosmos Tip 302 92ms rc=1
+[13:48:34 INF] EqxCosmos Sync 1+0 96ms rc=37.33
+[13:48:34 INF] EqxCosmos Tip 302 87ms rc=1
+[13:48:34 INF] Read: 8 requests costing 16 RU (average: 2.05); Average latency: 125ms
+[13:48:34 INF] Write: 3 requests costing 80 RU (average: 26.80); Average latency: 94ms
+[13:48:34 INF] TOTAL: 11 requests costing 97 RU (average: 8.80); Average latency: 116ms
+[13:48:34 INF] rps 2 = ~21 RU *)