Provision -> UpdateTableIfRequired refactor

Author: bartelink

README.md

@@ -120,7 +120,7 @@ type Counter private (table : TableContext<CounterEntry>, key : TableKey) =
     static member Create(client : IAmazonDynamoDB, tableName : string) = async {
         let table = TableContext<CounterEntry>(client, tableName)
         let throughput = ProvisionedThroughput(readCapacityUnits = 10L, writeCapacityUnits = 10L)        
-        do! table.CreateTableIfNotExistsAsync(Throughput.Provisioned throughput)
+        do! table.VerifyOrCreateTableAsync(Throughput.Provisioned throughput)
         let initialEntry = { Id = Guid.NewGuid() ; Value = 0L }
         let! key = table.PutItemAsync(initialEntry)
         return Counter(table, key)

RELEASE_NOTES.md

@@ -5,15 +5,15 @@
 * Added `TryGetItemAsync` (same as `GetItemAsync`, but returns `None`, instead of throwing, if an item is not present)
 * Switched test framework to Xunit, assertions to Unquote, runner to `dotnet test` 
 * Clarified Creation/Verification APIs:
-  * Obsoleted `TableContext.Create` (replace with `TableContext.Scripting.Initialize`, `TableContext.CreateTableIfNotExistsAsync`, `TableContext.VerifyTableAsync`)
+  * Obsoleted `TableContext.Create` (replace with `TableContext.Scripting.Initialize`, `TableContext.VerifyOrCreateTableAsync`, `TableContext.VerifyTableAsync`)
   * Added `TableContext` constructor (replaces `TableContext.Create(verifyTable = false)`)
   * Added `TableContext.Scripting.Initialize` (replaces `TableContext.Create()`)
   * Added `TableContext.VerifyTableAsync` overload that only performs verification but never creates a Table
-  * Added `TableContext.CreateTableIfNotExistsAsync` (replaces `TableContext.VerifyTableAsync(createIfNotExists = true)`)
-  * Added `TableContext.ProvisionTableAsync` (as per `CreateTableIfNotExistsAsync` but does an `UpdateTableAsync` if `throughput` or `streaming` has changed)
-  * Added Support for `Throughput.OnDemand` mode (sets `BillingMode` to `PAY_PER_REQUEST` rather than attempting to configure a `ProvisionedThroughput`)
-  * Added ability to configure DynamoDB streaming (via `Streaming` DU) to `CreateTableIfNotExistsAsync` and `ProvisionTableAsync` 
-  * Removed `TableContext.CreateAsync` (replace with `TableContext.VerifyTableAsync` or `CreateTableIfNotExistsAsync`)
+  * Added `TableContext.VerifyOrCreateTableAsync` (replaces `TableContext.VerifyTableAsync(createIfNotExists = true)`)
+  * Added `TableContext.UpdateTableIfRequiredAsync` (conditional `UpdateTableAsync` to establish specified `throughput` or `streaming` only if required)
+  * Added `Throughput.OnDemand` mode (sets `BillingMode` to `PAY_PER_REQUEST` rather than attempting to configure a `ProvisionedThroughput`)
+  * Added ability to configure DynamoDB streaming (via `Streaming` DU) to `VerifyOrCreateTableAsync` and `UpdateTableIfRequiredAsync` 
+  * Removed `TableContext.CreateAsync` (replace with `TableContext.VerifyTableAsync` or `VerifyOrCreateTableAsync`)
   * Replaced `TableKeySchemata.CreateCreateTableRequest` with `ApplyToCreateTableRequest`
 
 ### 0.9.3-beta

src/FSharp.AWS.DynamoDB/Script.fsx

@@ -128,7 +128,7 @@ type EasyCounters private (table : TableContext<CounterEntry>) =
         // Create the table if necessary. Verifies schema is correct if it has already been created
         // NOTE the hard coded initial throughput provisioning - arguably this belongs outside of your application logic
         let throughput = ProvisionedThroughput(readCapacityUnits = 10L, writeCapacityUnits = 10L)
-        do! table.CreateTableIfNotExistsAsync(Throughput.Provisioned throughput)
+        do! table.VerifyOrCreateTableAsync(Throughput.Provisioned throughput)
         return EasyCounters(table)
     }
 
@@ -138,16 +138,21 @@ type EasyCounters private (table : TableContext<CounterEntry>) =
 /// Variant of EasyCounters that splits the provisioning step from the (optional) validation that the table is present
 type SimpleCounters private (table : TableContext<CounterEntry>) =
 
-    static member Provision(client : IAmazonDynamoDB, tableName : string, readCapacityUnits, writeCapacityUnits) : Async<unit> =
+    static member Provision(client : IAmazonDynamoDB, tableName : string, readCapacityUnits, writeCapacityUnits) : Async<unit> = async {
         let table = TableContext<CounterEntry>(client, tableName)
-        // normally, RCU/WCU provisioning only happens first time the Table is created and is then considered an external concern
-        // here we use `ProvisionTableAsync` instead of `CreateTableIfNotExistsAsync` to reset it each time we deploy the app
         let provisionedThroughput = ProvisionedThroughput(readCapacityUnits, writeCapacityUnits)
-        table.ProvisionTableAsync(Throughput.Provisioned provisionedThroughput)
+        let throughput = Throughput.Provisioned provisionedThroughput
+        // normally, RCU/WCU provisioning only happens first time the Table is created and is then considered an external concern
+        // here we use `UpdateTableIfRequiredAsync` to reset it each time we deploy the app
+        do! table.VerifyOrCreateTableAsync(throughput)
+        do! table.UpdateTableIfRequiredAsync(throughput) }
 
-    static member ProvisionOnDemand(client : IAmazonDynamoDB, tableName : string) : Async<unit> =
+    static member ProvisionOnDemand(client : IAmazonDynamoDB, tableName : string) : Async<unit> = async {
         let table = TableContext<CounterEntry>(client, tableName)
-        table.ProvisionTableAsync(Throughput.OnDemand)
+        let throughput = Throughput.OnDemand
+        do! table.VerifyOrCreateTableAsync(throughput)
+        // as per the Provision, above, we reset to OnDemand, if it got reconfigured since it was originally created
+        do! table.UpdateTableIfRequiredAsync(throughput) }
 
     /// We only want to do the initialization bit once per instance of our application
     /// Similar to EasyCounters.Create in that it ensures the table is provisioned correctly