jet · bartelink · Aug 9, 2023 · Aug 9, 2023 · Aug 9, 2023 · Aug 9, 2023
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -13,10 +13,10 @@ The `Unreleased` section name is replaced by the expected version of next releas
 - `Equinox`: `Decider.Transact`, `TransactAsync`, `TransactExAsync` overloads [#325](https://github.com/jet/equinox/pull/325)
 - `Equinox.LoadOption.RequireLeader`: support for requesting a consistent read of a stream [#341](https://github.com/jet/equinox/pull/341)
 - `Equinox.LoadOption.AllowStale`: Read mode that limits reads to a maximum of one retrieval per the defined time window [#386](https://github.com/jet/equinox/pull/386)
-- `Equinox.Core`: `Category` base class, with `Decider` and `Stream` helper `module`s [#337](https://github.com/jet/equinox/pull/337)
-- `Equinox.Batching`: `BatcherDictionary`, `BatcherCache` to host concurrent `Batchers` [#390](https://github.com/jet/equinox/pull/390)
+- `Equinox.Category` base class, with `Decider` and `Stream` helper `module`s [#337](https://github.com/jet/equinox/pull/337)
 - `Equinox.DeciderCore`: C# friendly equivalent of `Decider` (i.e. `Func` and `Task`) [#338](https://github.com/jet/equinox/pull/338)
 - `Equinox.ISyncContext.StreamEventBytes`: Exposes stored size of events in the stream (initial impl provides it for `DynamoStore` only) [#326](https://github.com/jet/equinox/pull/326)
+- `Equinox.Core.Batching`: `BatcherDictionary`, `BatcherCache` to host concurrent `Batchers` [#390](https://github.com/jet/equinox/pull/390)
 - `CosmosStore.Exceptions`: Active patterns to simplify classification in the context of Propulsion handlers [#416](https://github.com/jet/equinox/pull/416)
 - `CosmosStore.Prometheus`: Add `rut` tag to enable filtering/grouping by Read vs Write activity as per `DynamoStore` [#321](https://github.com/jet/equinox/pull/321)
 - `DynamoStore`/`DynamoStore.Prometheus`: Implements the majority of the `CosmosStore` functionality via `FSharp.AWS.DynamoDB` [#321](https://github.com/jet/equinox/pull/321)
@@ -37,8 +37,8 @@ The `Unreleased` section name is replaced by the expected version of next releas
 - `Equinox.LoadOption`: Rename `AllowStale` to `AnyCachedValue` [#386](https://github.com/jet/equinox/pull/386)
 - `Equinox.Decider`: Replace `'event list` with `'event[]` [#411](https://github.com/jet/equinox/pull/411)
 - `Equinox.Decider`: Replace `maxAttempts` with a default policy and an optional argument on `Transact*` APIs [#337](https://github.com/jet/equinox/pull/337)
-- `Equinox.Core`: push `FsCodec` dependency out to concrete stores [#337](https://github.com/jet/equinox/pull/337)
 - `Equinox.Core.AsyncBatchingGate`: renamed to `Batching.Batcher` [#390](https://github.com/jet/equinox/pull/390)
+- `Equinox.Core`: Now a free-standing library that a) does not depend on `Equinox` b) is not depended on by the Stores (though `CosmosStore` inlines `AsyncCacheCell`) [#420](https://github.com/jet/equinox/pull/420)
 - Stores: Change Event Body types, requiring `FsCodec` v `3.0.0`, with [`EventBody` types switching from `byte[]` to `ReadOnlyMemory<byte>` and/or `JsonElement` see FsCodec#75](https://github.com/jet/FsCodec/pull/75) [#323](https://github.com/jet/equinox/pull/323)
 - Stores: `*Category.Resolve`: Replace `Resolve(sn, ?ResolveOption, ?context)` with `?load = LoadOption` parameter on all `Transact` and `Query` methods, and `Decider.forStream`/`Decider.forContext` to convey context [#308](https://github.com/jet/equinox/pull/308)
 - Stores: `*Category` ctor: Add mandatory `name` argument, and `Name` property [#410](https://github.com/jet/equinox/pull/410)
@@ -57,6 +57,7 @@ The `Unreleased` section name is replaced by the expected version of next releas
 
 - `Equinox.ISyncContext.CreateMemento` [#413](https://github.com/jet/equinox/pull/413)
 - Stores: `*StoreCategory.FromMemento` [#413](https://github.com/jet/equinox/pull/413)
+- Stores: Removed `Equinox.Core` dependency; everything a store needs is either inlined privately, or lives in `Equinox` [#420](https://github.com/jet/equinox/pull/420)
 - Remove explicit `net461` handling; minimum target now `net6.0` / `FSharp.Core` v `6.0.0` [#310](https://github.com/jet/equinox/pull/310) [#323](https://github.com/jet/equinox/pull/323) [#354](https://github.com/jet/equinox/pull/354)
 - Remove `Equinox.Core.ICache` (there is/was only one impl, and the interface has changed as part of [#386](https://github.com/jet/equinox/pull/386)) [#389](https://github.com/jet/equinox/pull/389)
 

diff --git a/Equinox.sln b/Equinox.sln
@@ -109,6 +109,8 @@ Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "Equinox.MessageDb.Integrati
 EndProject
 Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "Equinox.Core.Tests", "tests\Equinox.Core.Tests\Equinox.Core.Tests.fsproj", "{FB376808-7B32-4724-98BE-D9458EB0F68B}"
 EndProject
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "Equinox.Tests", "src\Equinox.Tests\Equinox.Tests.fsproj", "{D8677ABB-1D7C-4FC3-ABF9-5A49AF377372}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -247,6 +249,10 @@ Global
 		{FB376808-7B32-4724-98BE-D9458EB0F68B}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{FB376808-7B32-4724-98BE-D9458EB0F68B}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{FB376808-7B32-4724-98BE-D9458EB0F68B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D8677ABB-1D7C-4FC3-ABF9-5A49AF377372}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D8677ABB-1D7C-4FC3-ABF9-5A49AF377372}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D8677ABB-1D7C-4FC3-ABF9-5A49AF377372}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D8677ABB-1D7C-4FC3-ABF9-5A49AF377372}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

diff --git a/README.md b/README.md
@@ -151,7 +151,7 @@ The components within this repository are delivered as multi-targeted Nuget pack
 
 ## Core library
 
-- `Equinox` [![NuGet](https://img.shields.io/nuget/v/Equinox.svg)](https://www.nuget.org/packages/Equinox/): Store-agnostic decision flow runner that manages the optimistic concurrency protocol and application-level API surface. ([depends](https://www.fuget.org/packages/Equinox) only on `FSharp.Core` v `6.0.7`, `FsCodec` v `3.0.0`, `Serilog` (but not specific Serilog sinks, i.e. you configure to emit to `NLog` etc)
+- `Equinox` [![NuGet](https://img.shields.io/nuget/v/Equinox.svg)](https://www.nuget.org/packages/Equinox/): Store-agnostic decision flow runner that manages the optimistic concurrency protocol and application-level API surface, together with the default [`System.Runtime.Caching.MemoryCache`-based] `Cache` implementation. ([depends](https://www.fuget.org/packages/Equinox) only on `FSharp.Core` v `6.0.7`, `FsCodec` v `3.0.0`, `System.Runtime.Caching`, `Serilog` (but not specific Serilog sinks, i.e. you configure to emit to `NLog` etc)
 
 ## Serialization support
 
@@ -168,16 +168,16 @@ The components within this repository are delivered as multi-targeted Nuget pack
 
 ## Data Store libraries
 
-- `Equinox.Core` [![NuGet](https://img.shields.io/nuget/v/Equinox.Core.svg)](https://www.nuget.org/packages/Equinox.Core/): Interfaces and helpers used in the concrete Store implementations, together with the default [`System.Runtime.Caching.MemoryCache`-based] `Cache` implementation. Hosts generic utility types frequently useful alongside Equinox: [`AsyncCacheCell`](https://github.com/jet/equinox/blob/master/src/Equinox.Core/AsyncCacheCell.fs#L36), [`Batcher`, `BatcherCache`, `BatcherDictionary`](https://github.com/jet/equinox/blob/master/src/Equinox.Core/Batching.fs#L44). ([depends](https://www.fuget.org/packages/Equinox.Core) on `Equinox`, `System.Runtime.Caching`)
-- `Equinox.MemoryStore` [![MemoryStore NuGet](https://img.shields.io/nuget/v/Equinox.MemoryStore.svg)](https://www.nuget.org/packages/Equinox.MemoryStore/): In-memory store for integration testing/performance base-lining/providing out-of-the-box zero dependency storage for examples. ([depends](https://www.fuget.org/packages/Equinox.MemoryStore) on `Equinox.Core`, `FsCodec`)
-- `Equinox.CosmosStore` [![CosmosStore NuGet](https://img.shields.io/nuget/v/Equinox.CosmosStore.svg)](https://www.nuget.org/packages/Equinox.CosmosStore/): Azure CosmosDB Adapter with integrated 'unfolds' feature, facilitating optimal read performance in terms of latency and RU costs, instrumented to meet Jet's production monitoring requirements. ([depends](https://www.fuget.org/packages/Equinox.CosmosStore) on `Equinox.Core`, `Microsoft.Azure.Cosmos` >= `3.27`, `FsCodec`, `System.Text.Json`, `FSharp.Control.TaskSeq`)
+- `Equinox.Core` [![NuGet](https://img.shields.io/nuget/v/Equinox.Core.svg)](https://www.nuget.org/packages/Equinox.Core/): Hosts generic utility types frequently useful alongside Equinox: [`AsyncCacheCell`](https://github.com/jet/equinox/blob/master/src/Equinox.Core/AsyncCacheCell.fs#L36), [`Batcher`, `BatcherCache`, `BatcherDictionary`](https://github.com/jet/equinox/blob/master/src/Equinox.Core/Batching.fs#L44). ([depends](https://www.fuget.org/packages/Equinox.Core) on `System.Runtime.Caching`)
+- `Equinox.MemoryStore` [![MemoryStore NuGet](https://img.shields.io/nuget/v/Equinox.MemoryStore.svg)](https://www.nuget.org/packages/Equinox.MemoryStore/): In-memory store for integration testing/performance base-lining/providing out-of-the-box zero dependency storage for examples. ([depends](https://www.fuget.org/packages/Equinox.MemoryStore) on `Equinox`)
+- `Equinox.CosmosStore` [![CosmosStore NuGet](https://img.shields.io/nuget/v/Equinox.CosmosStore.svg)](https://www.nuget.org/packages/Equinox.CosmosStore/): Azure CosmosDB Adapter with integrated 'unfolds' feature, facilitating optimal read performance in terms of latency and RU costs, instrumented to meet Jet's production monitoring requirements. ([depends](https://www.fuget.org/packages/Equinox.CosmosStore) on `Equinox`, `Equinox`, `Microsoft.Azure.Cosmos` >= `3.27`, `System.Text.Json`, `FSharp.Control.TaskSeq`)
 - `Equinox.CosmosStore.Prometheus` [![CosmosStore.Prometheus NuGet](https://img.shields.io/nuget/v/Equinox.CosmosStore.Prometheus.svg)](https://www.nuget.org/packages/Equinox.CosmosStore.Prometheus/): Integration package providing a `Serilog.Core.ILogEventSink` that extracts detailed metrics information attached to the `LogEvent`s and feeds them to the `prometheus-net`'s `Prometheus.Metrics` static instance. ([depends](https://www.fuget.org/packages/Equinox.CosmosStore.Prometheus) on `Equinox.CosmosStore`, `prometheus-net >= 3.6.0`)
-- `Equinox.DynamoStore` [![DynamoStore NuGet](https://img.shields.io/nuget/v/Equinox.DynamoStore.svg)](https://www.nuget.org/packages/Equinox.DynamoStore/): Amazon DynamoDB Adapter with integrated 'unfolds' feature, facilitating optimal read performance in terms of latency and RC costs, patterned after `Equinox.CosmosStore`. ([depends](https://www.fuget.org/packages/Equinox.DynamoStore) on `Equinox.Core`, `FSharp.AWS.DynamoDB` >= `0.11.2-beta`, `FsCodec`, `FSharp.Control.TaskSeq`)
+- `Equinox.DynamoStore` [![DynamoStore NuGet](https://img.shields.io/nuget/v/Equinox.DynamoStore.svg)](https://www.nuget.org/packages/Equinox.DynamoStore/): Amazon DynamoDB Adapter with integrated 'unfolds' feature, facilitating optimal read performance in terms of latency and RC costs, patterned after `Equinox.CosmosStore`. ([depends](https://www.fuget.org/packages/Equinox.DynamoStore) on `Equinox`, `FSharp.AWS.DynamoDB` >= `0.11.2-beta`, `FSharp.Control.TaskSeq`)
 - `Equinox.DynamoStore.Prometheus` [![DynamoStore.Prometheus NuGet](https://img.shields.io/nuget/v/Equinox.DynamoStore.Prometheus.svg)](https://www.nuget.org/packages/Equinox.DynamoStore.Prometheus/): Integration package providing a `Serilog.Core.ILogEventSink` that extracts detailed metrics information attached to the `LogEvent`s and feeds them to the `prometheus-net`'s `Prometheus.Metrics` static instance. ([depends](https://www.fuget.org/packages/Equinox.CosmosStore.Prometheus) on `Equinox.DynamoStore`, `prometheus-net >= 3.6.0`)
-- `Equinox.EventStore` [![EventStore NuGet](https://img.shields.io/nuget/v/Equinox.EventStore.svg)](https://www.nuget.org/packages/Equinox.EventStore/): [EventStoreDB](https://eventstore.org/) Adapter designed to meet Jet's production monitoring requirements. ([depends](https://www.fuget.org/packages/Equinox.EventStore) on `Equinox.Core`, `EventStore.Client >= 22.0.0-preview`, `FSharp.Control.TaskSeq`), EventStore Server version `21.10` or later). **NO NOT use for new projects - the TCP interface to EventStoreDB has long been deprecated, this package is only provided to ease migration scenarios and will be removed in due course**
-- `Equinox.EventStoreDb` [![EventStoreDb NuGet](https://img.shields.io/nuget/v/Equinox.EventStoreDb.svg)](https://www.nuget.org/packages/Equinox.EventStoreDb/): Production-strength [EventStoreDB](https://eventstore.org/) Adapter. ([depends](https://www.fuget.org/packages/Equinox.EventStoreDb) on `Equinox.Core`, `EventStore.Client.Grpc.Streams` >= `22.0.0`, `FSharp.Control.TaskSeq`, EventStore Server version `21.10` or later)
-- `Equinox.MessageDb` [![MessageDb NuGet](https://img.shields.io/nuget/v/Equinox.MessageDb.svg)](https://www.nuget.org/packages/Equinox.MessageDb/): [MessageDb](http://docs.eventide-project.org/user-guide/message-db/) Adapter. ([depends](https://www.fuget.org/packages/Equinox.MessageDb) on `Equinox.Core`, `Npgsql` >= `7.0.0`, `FSharp.Control.TaskSeq`))
-- `Equinox.SqlStreamStore` [![SqlStreamStore NuGet](https://img.shields.io/nuget/v/Equinox.SqlStreamStore.svg)](https://www.nuget.org/packages/Equinox.SqlStreamStore/): [SqlStreamStore](https://github.com/SQLStreamStore/SQLStreamStore) Adapter derived from `Equinox.EventStore` - provides core facilities (but does not connect to a specific database; see sibling `SqlStreamStore`.* packages). ([depends](https://www.fuget.org/packages/Equinox.SqlStreamStore) on `Equinox.Core`, `FsCodec`, `SqlStreamStore >= 1.2.0-beta.8`, `FSharp.Control.TaskSeq`)
+- `Equinox.EventStore` [![EventStore NuGet](https://img.shields.io/nuget/v/Equinox.EventStore.svg)](https://www.nuget.org/packages/Equinox.EventStore/): [EventStoreDB](https://eventstore.org/) Adapter designed to meet Jet's production monitoring requirements. ([depends](https://www.fuget.org/packages/Equinox.EventStore) on `Equinox`, `EventStore.Client >= 22.0.0-preview`, `FSharp.Control.TaskSeq`), EventStore Server version `21.10` or later). **NO NOT use for new projects - the TCP interface to EventStoreDB has long been deprecated, this package is only provided to ease migration scenarios and will be removed in due course**
+- `Equinox.EventStoreDb` [![EventStoreDb NuGet](https://img.shields.io/nuget/v/Equinox.EventStoreDb.svg)](https://www.nuget.org/packages/Equinox.EventStoreDb/): Production-strength [EventStoreDB](https://eventstore.org/) Adapter. ([depends](https://www.fuget.org/packages/Equinox.EventStoreDb) on `Equinox`, `EventStore.Client.Grpc.Streams` >= `22.0.0`, `FSharp.Control.TaskSeq`, EventStore Server version `21.10` or later)
+- `Equinox.MessageDb` [![MessageDb NuGet](https://img.shields.io/nuget/v/Equinox.MessageDb.svg)](https://www.nuget.org/packages/Equinox.MessageDb/): [MessageDb](http://docs.eventide-project.org/user-guide/message-db/) Adapter. ([depends](https://www.fuget.org/packages/Equinox.MessageDb) on `Equinox`, `Npgsql` >= `7.0.0`, `FSharp.Control.TaskSeq`))
+- `Equinox.SqlStreamStore` [![SqlStreamStore NuGet](https://img.shields.io/nuget/v/Equinox.SqlStreamStore.svg)](https://www.nuget.org/packages/Equinox.SqlStreamStore/): [SqlStreamStore](https://github.com/SQLStreamStore/SQLStreamStore) Adapter derived from `Equinox.EventStore` - provides core facilities (but does not connect to a specific database; see sibling `SqlStreamStore`.* packages). ([depends](https://www.fuget.org/packages/Equinox.SqlStreamStore) on `Equinox`, `SqlStreamStore >= 1.2.0-beta.8`, `FSharp.Control.TaskSeq`)
 - `Equinox.SqlStreamStore.MsSql` [![MsSql NuGet](https://img.shields.io/nuget/v/Equinox.SqlStreamStore.MsSql.svg)](https://www.nuget.org/packages/Equinox.SqlStreamStore.MsSql/): [SqlStreamStore.MsSql](https://sqlstreamstore.readthedocs.io/en/latest/sqlserver) Sql Server `Connector` implementation for `Equinox.SqlStreamStore` package). ([depends](https://www.fuget.org/packages/Equinox.SqlStreamStore.MsSql) on `Equinox.SqlStreamStore`, `SqlStreamStore.MsSql >= 1.2.0-beta.8`)
 - `Equinox.SqlStreamStore.MySql` [![MySql NuGet](https://img.shields.io/nuget/v/Equinox.SqlStreamStore.MySql.svg)](https://www.nuget.org/packages/Equinox.SqlStreamStore.MySql/): `SqlStreamStore.MySql` MySQL `Connector` implementation for `Equinox.SqlStreamStore` package). ([depends](https://www.fuget.org/packages/Equinox.SqlStreamStore.MySql) on `Equinox.SqlStreamStore`, `SqlStreamStore.MySql >= 1.2.0-beta.8`)
 - `Equinox.SqlStreamStore.Postgres` [![Postgres NuGet](https://img.shields.io/nuget/v/Equinox.SqlStreamStore.Postgres.svg)](https://www.nuget.org/packages/Equinox.SqlStreamStore.Postgres/): [SqlStreamStore.Postgres](https://sqlstreamstore.readthedocs.io/en/latest/postgres) PostgreSQL `Connector` implementation for `Equinox.SqlStreamStore` package). ([depends](https://www.fuget.org/packages/Equinox.SqlStreamStore.Postgres) on `Equinox.SqlStreamStore`, `SqlStreamStore.Postgres >= 1.2.0-beta.8`)

diff --git a/src/Equinox.Core/AsyncCacheCell.fs b/src/Equinox.Core/AsyncCacheCell.fs
@@ -1,41 +1,15 @@
 namespace Equinox.Core
 
-open System
-
-/// Asynchronous Lazy<'T> used to gate a workflow to ensure at most once execution of a computation.
-type AsyncLazy<'T>(startTask: Func<Task<'T>>) =
-
-    // NOTE due to `Lazy<T>` semantics, failed attempts will cache any exception; AsyncCacheCell compensates for this by rolling over to a new instance
-    let workflow = lazy startTask.Invoke()
-
-    /// Synchronously peek at what's been previously computed (if it's not Empty, or the last attempt Faulted).
-    member _.TryCompleted() =
-        if not workflow.IsValueCreated then ValueNone else
-
-        let t = workflow.Value
-        if t.Status <> System.Threading.Tasks.TaskStatus.RanToCompletion then ValueNone
-        else ValueSome t.Result
-
-    /// Used to rule out values where the computation yielded an exception or the result has now expired
-    member _.TryAwaitValid() = task {
-        let t = workflow.Value
-
-        // Determines if the last attempt completed, but failed; For TMI see https://stackoverflow.com/a/33946166/11635
-        if t.IsFaulted then return ValueNone
-        else
-            let! res = t
-            return ValueSome res }
-
-    /// Await the outcome of the computation.
-    member _.Await() = workflow.Value
-
-    /// Singleton Empty value
-    static member val Empty = AsyncLazy(fun () -> Task.FromException<'T>(InvalidOperationException "Uninitialized AsyncLazy"))
-
 /// Generic async lazy caching implementation that admits expiration/recomputation/retry on exception semantics.
 /// If `workflow` fails, all readers entering while the load/refresh is in progress will share the failure
 /// The first caller through the gate triggers a recomputation attempt if the previous attempt ended in failure
-type AsyncCacheCell<'T>(startWorkflow : Func<CancellationToken, Task<'T>>, [<O; D null>]?isExpired: Func<'T, bool>) =
+type
+#if !EQUINOX_CORE
+    // NOT PUBLIC in Equinox.CosmosStore library - used internally to ensure the stored proc init is checked on first append once per container per process
+    // PUBLIC in Equinox.Core (it can also be used independent of Equinox)
+    internal
+#endif
+    AsyncCacheCell<'T>(startWorkflow : System.Func<CancellationToken, Task<'T>>, [<O; D null>]?isExpired: System.Func<'T, bool>) =
 
     let isValid = match isExpired with Some f -> not << f.Invoke | None -> fun _ -> true
     let mutable cell = AsyncLazy<'T>.Empty