Update protocol for PSS

Author: radeksimko

docs/plugin-protocol/tfplugin6.proto

@@ -375,6 +375,19 @@ service Provider {
     //////// Provider-contributed Functions
     rpc CallFunction(CallFunction.Request) returns (CallFunction.Response);
 
+    // ValidateStateStoreConfig fills in any default values and performs configuration validation
+    rpc ValidateStateStoreConfig(ValidateStateStore.Request) returns (ValidateStateStore.Response);
+    // ConfigureStateStore configures the Statestore, such as S3 connection in the context of already configured provider
+    rpc ConfigureStateStore(ConfigureStateStore.Request) returns (ConfigureStateStore.Response);
+
+    rpc ReadState(ReadState.Request) returns (stream ReadState.ResponseChunk);
+    rpc WriteState(stream WriteState.RequestChunk) returns (stream WriteState.Response);
+
+    rpc LockState(LockState.Request) returns (LockState.Response);
+    rpc UnlockState(UnlockState.Request) returns (UnlockState.Response);
+    rpc GetStates(GetStates.Request) returns (GetStates.Response);
+    rpc DeleteState(DeleteState.Request) returns (DeleteState.Response);
+
     //////// Graceful Shutdown
     rpc StopProvider(StopProvider.Request) returns (StopProvider.Response);
 }
@@ -426,6 +439,7 @@ message GetProviderSchema {
         map<string, Function> functions = 7;
         map<string, Schema> ephemeral_resource_schemas = 8;
         map<string, Schema> list_resource_schemas = 9;
+        map<string, Schema> state_store_schemas = 10;
         repeated Diagnostic diagnostics = 4;
         Schema provider_meta = 5;
         ServerCapabilities server_capabilities = 6;
@@ -839,3 +853,95 @@ message ValidateListResourceConfig {
         repeated Diagnostic diagnostics = 1;
     }
 }
+
+
+message ValidateStateStore {
+    message Request {
+        string type_name = 1;
+        DynamicValue config = 2;
+    }
+    message Response {
+        repeated Diagnostic diagnostics = 1;
+    }
+}
+
+message ConfigureStateStore {
+    message Request {
+        string type_name = 1;
+        DynamicValue prepared_config = 2;
+    }
+    message Response {
+        repeated Diagnostic diagnostics = 1;
+    }
+}
+
+message ReadState {
+    message Request {
+        string type_name = 1;
+        string state_id = 2;
+    }
+    message ResponseChunk {
+        bytes data = 1;
+        // supplied with the first chunk
+        optional StateMeta meta = 2;
+    }
+}
+
+message WriteState {
+    message RequestChunk {
+        bytes data = 1;
+        string state_id = 2;
+        // supplied with the first chunk
+        optional StateMeta meta = 3;
+    }
+    message Response {
+        repeated Diagnostic diagnostics = 1;
+    }
+}
+
+message StateMeta {
+	bytes checksum = 1;
+    int64 number_of_chunks = 2;
+}
+
+message LockState {
+    message Request {
+        string type_name = 1;
+        string state_id = 2;
+        string operation = 3;
+    }
+    message Response {
+        string id = 1;
+        repeated Diagnostic diagnostics = 2;
+    }
+}
+
+message UnlockState {
+    message Request {
+        string type_name = 1;
+        string state_id = 2;
+        string lock_id = 3;
+    }
+    message Response {
+        repeated Diagnostic diagnostics = 1;
+    }
+}
+
+message GetStates {
+	message Request {
+		string type_name = 1;
+    }
+    message Response {
+        repeated string state_id = 1;
+    }
+}
+
+message DeleteState {
+	message Request {
+		string type_name = 1;
+		string state_id = 2;
+    }
+	message Response {
+        repeated Diagnostic diagnostics = 1;
+    }
+}