added client for experimentation system

clients/dart/dart_cac_client/test/dart_cac_client_test.dart

@@ -1,5 +1,3 @@
-import 'dart:isolate';
-
 import 'package:flutter_test/flutter_test.dart';
 
 import 'package:dart_cac_client/dart_cac_client.dart';

clients/dart/dart_exp_client/.gitignore

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+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.buildlog/
+.history
+.svn/
+migrate_working_dir/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+# Libraries should not include pubspec.lock, per https://dart.dev/guides/libraries/private-files#pubspeclock.
+/pubspec.lock
+**/doc/api/
+.dart_tool/
+build/

clients/dart/dart_exp_client/.metadata

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+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: "ba393198430278b6595976de84fe170f553cc728"
+  channel: "stable"
+
+project_type: package

clients/dart/dart_exp_client/CHANGELOG.md

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+## 0.0.1
+
+* TODO: Describe initial release.

clients/dart/dart_exp_client/LICENSE

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+TODO: Add your license here.

clients/dart/dart_exp_client/README.md

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+# Dart Experimentation Client
+
+This package provides a Dart interface for the Experimentation client, allowing you to interact with the experimentation server to retrieve and manage experiments.
+
+## Table of Contents
+- [Dart Experimentation Client](#dart-experimentation-client)
+  - [Table of Contents](#table-of-contents)
+  - [Usage](#usage)
+    - [Creating a Client](#creating-a-client)
+    - [Starting Polling for Updates](#starting-polling-for-updates)
+    - [Retrieving Configurations](#retrieving-configurations)
+    - [Getting Default Configurations](#getting-default-configurations)
+    - [Getting Resolved Configurations](#getting-resolved-configurations)
+    - [Getting Last Modified Timestamp](#getting-last-modified-timestamp)
+    - [Disposing the Client](#disposing-the-client)
+
+## Usage
+
+### Creating a Client
+To create a new DartExptClient client, instantiate the DartCacClient class with the tenant name, update frequency (in seconds), and host URL
+
+```dart
+final client = To create a new DartExptClient client, instantiate the DartCacClient class with the tenant name, update frequency (in seconds), and host URL
+('dev', 60, 'http://localhost:8080');
+```
+
+### Starting Polling for Updates
+Use the exptStartPolling method to start polling for configuration updates for the specified tenant:
+
+```dart
+client.exptStartPolling("<tenant name>");
+```
+
+### Retrieving Configurations
+Use the getConfigs method to retrieve configurations based on a filter query and filter prefix:
+```dart
+String configs = client.getConfigs('{"country": "India"}', 'country');
+```
+
+### Getting Default Configurations
+Use the getDefaultConfig method to retrieve the default configurations for the specified keys:
+
+```dart
+String defaultConfigs = client.getDefaultConfig("india");
+```
+
+### Getting Resolved Configurations
+Use the getResolvedConfig method to retrieve resolved configurations based on the provided query, keys, and merge strategy:
+
+
+```dart
+String resolvedConfigs = client.getResolvedConfig(
+    '{"query": "example"}', "key1, key2", MergeStrategy.MERGE/MergeStrategy.REPLACE);
+```
+
+
+### Getting Last Modified Timestamp
+Use the getCacLastModified method to get the last modified timestamp of the configurations:
+
+```dart
+String lastModified = client.getCacLastModified();
+```
+
+### Disposing the Client
+Ensure that you dispose of the client properly to free up resources:
+```dart
+client.dispose();
+```

clients/dart/dart_exp_client/analysis_options.yaml

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+include: package:flutter_lints/flutter.yaml
+
+# Additional information about this file can be found at
+# https://dart.dev/guides/language/analysis-options

clients/dart/dart_exp_client/lib/client.dart

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+import 'dart:ffi' as ffi;
+import 'package:dart_cac_client/types/types.dart';
+import 'package:ffi/ffi.dart';
+import 'dart:io' show Platform;
+import 'package:path/path.dart' as path;
+
+// Define the library
+final ffi.DynamicLibrary _lib = ffi.DynamicLibrary.open(_libName);
+
+// Helper to get the correct library name based on the platform
+String get _libName {
+  if (Platform.isWindows) {
+    return path.join(
+        '/Users/subhash/working-repos/github/superposition/target/debug/',
+        'libexperimentation_client.dll');
+  }
+  if (Platform.isMacOS) {
+    return path.join(
+        '/Users/subhash/working-repos/github/superposition/target/debug/',
+        'libexperimentation_client.dylib');
+  }
+  return path.join(
+      '/Users/subhash/working-repos/github/superposition/target/debug/',
+      'libexperimentation_client.so');
+}
+
+// Bind the C functions
+final ExptNewClientDart _exptNewClient = _lib
+    .lookup<ffi.NativeFunction<ExptNewClientNative>>('expt_new_client')
+    .asFunction();
+
+final ExptGetClientDart _exptGetClient = _lib
+    .lookup<ffi.NativeFunction<ExptGetClientNative>>('expt_get_client')
+    .asFunction();
+
+final ExptLastErrorLengthDart _exptLastErrorLength = _lib
+    .lookup<ffi.NativeFunction<ExptLastErrorLengthNative>>(
+        'expt_last_error_length')
+    .asFunction();
+
+final ExptLastErrorMessageDart _exptLastErrorMessage = _lib
+    .lookup<ffi.NativeFunction<ExptLastErrorMessageNative>>(
+        'expt_last_error_message')
+    .asFunction();
+
+final ExptFreeStringDart _exptFreeString = _lib
+    .lookup<ffi.NativeFunction<ExptFreeStringNative>>('expt_free_string')
+    .asFunction();
+
+final ExpStartPollingUpdateDart _exptStartPollingUpdate = _lib
+    .lookup<ffi.NativeFunction<ExpStartPollingUpdateNative>>(
+        'expt_start_polling_update')
+    .asFunction();
+
+final ExptFreeClientDart _exptFreeClient = _lib
+    .lookup<ffi.NativeFunction<ExptFreeClientNative>>('expt_free_client')
+    .asFunction();
+
+final ExptGetApplicableVariantDart _exptGetApplicableVariant = _lib
+    .lookup<ffi.NativeFunction<ExptGetApplicableVariantNative>>(
+        'expt_get_applicable_variant')
+    .asFunction();
+
+final ExptGetSatisfiedExperimentsDart _exptGetSatisfiedExperiments = _lib
+    .lookup<ffi.NativeFunction<ExptGetSatisfiedExperimentsNative>>(
+        'expt_get_satisfied_experiments')
+    .asFunction();
+
+final ExptGetFilteredSatisfiedExperimentsDart
+    _exptGetFilteredSatisfiedExperiments = _lib
+        .lookup<ffi.NativeFunction<ExptGetFilteredSatisfiedExperimentsNative>>(
+            'expt_get_filtered_satisfied_experiments')
+        .asFunction();
+
+final ExptGetRunningExperimentsDart _exptGetRunningExperiments = _lib
+    .lookup<ffi.NativeFunction<ExptGetRunningExperimentsNative>>(
+        'expt_get_running_experiments')
+    .asFunction();
+
+// Dart wrapper class
+class ExptClient {
+  late ffi.Pointer<ffi.Void> _clientPtr;
+
+  ExptClient(String tenant, int updateFrequency, String hostname) {
+    final tenantPtr = tenant.toNativeUtf8();
+    final hostnamePtr = hostname.toNativeUtf8();
+
+    final result = _exptNewClient(tenantPtr, updateFrequency, hostnamePtr);
+    print("Expt Client result: $result");
+
+    _exptFreeString(tenantPtr);
+    _exptFreeString(hostnamePtr);
+
+    if (result != 0) {
+      final errorPtr = _exptLastErrorMessage();
+      final errorMessage = errorPtr.toDartString();
+      print("Error message: $errorMessage");
+      _exptFreeString(errorPtr);
+      throw Exception("Failed to create Experimentation client: $errorMessage");
+    }
+
+    _clientPtr = _exptGetClient(tenant.toNativeUtf8());
+    if (_clientPtr == ffi.nullptr) {
+      final errorPtr = _exptLastErrorMessage();
+      final errorMessage = errorPtr.toDartString();
+      print("Error getting client pointer: $errorMessage");
+      _exptFreeString(errorPtr);
+      throw Exception("Failed to get Experimentation client: $errorMessage");
+    }
+    print("Client pointer obtained successfully");
+  }
+
+  String getApplicableVariants(String context, int toss) {
+    final clientPtr = context.toNativeUtf8();
+    final tossPtr = malloc.allocate<ffi.Int16>(ffi.sizeOf<ffi.Int16>());
+    tossPtr.value = toss;
+    final applicableVariantPtr =
+        _exptGetApplicableVariant(_clientPtr, clientPtr, tossPtr);
+
+    _exptFreeString(clientPtr);
+    malloc.free(tossPtr);
+
+    if (applicableVariantPtr == ffi.nullptr) {
+      final errorPtr = _exptLastErrorMessage();
+      final errorMessage = errorPtr.toDartString();
+      print("Error getting Applicable Variant: $errorMessage");
+      _exptFreeString(errorPtr);
+      throw Exception("Failed to get config: $errorMessage");
+    }
+    final applicableVariant = applicableVariantPtr.toDartString();
+    print("Received Applicable Variant: $applicableVariant");
+    _exptFreeString(applicableVariantPtr);
+
+    return applicableVariant;
+  }
+
+  String getSatisfiedExperiments(String context, String filterPrefix) {
+    final contextPtr = context.toNativeUtf8();
+    final filterPrefixPtr = filterPrefix.toNativeUtf8();
+
+    final satisfiedExperimentsPtr =
+        _exptGetSatisfiedExperiments(_clientPtr, contextPtr, filterPrefixPtr);
+
+    _exptFreeString(contextPtr);
+    _exptFreeString(filterPrefixPtr);
+
+    if (satisfiedExperimentsPtr == ffi.nullptr) {
+      final errorPtr = _exptLastErrorMessage();
+      final errorMessage = errorPtr.toDartString();
+      print("Error getting satisfied experiments: $errorMessage");
+      _exptFreeString(errorPtr);
+      throw Exception("Failed to get satisfied experiments: $errorMessage");
+    }
+
+    final satisfiedExperiments = satisfiedExperimentsPtr.toDartString();
+    print("Received satisfied experiments: $satisfiedExperiments");
+    _exptFreeString(satisfiedExperimentsPtr);
+
+    return satisfiedExperiments;
+  }
+
+  String getFilteredSatisfiedExperiments(String context, String filterPrefix) {
+    if (_clientPtr == ffi.nullptr) {
+      throw Exception("Failed to get Experimentation client!");
+    }
+    final contextPtr = context.toNativeUtf8();
+    final filterPrefixPtr = filterPrefix.toNativeUtf8();
+
+    final fltSatisfiedExperimentsPtr = _exptGetFilteredSatisfiedExperiments(
+        _clientPtr, contextPtr, filterPrefixPtr);
+
+    _exptFreeString(contextPtr);
+    _exptFreeString(filterPrefixPtr);
+
+    if (fltSatisfiedExperimentsPtr == ffi.nullptr) {
+      final errorPtr = _exptLastErrorMessage();
+      final errorMessage = errorPtr.toDartString();
+      print("Error getting filtered satisfied experiments : $errorMessage");
+      _exptFreeString(errorPtr);
+      throw Exception(
+          "Failed to get filtered satisfied experiments: $errorMessage");
+    }
+    var fltSatisfiedExperiments = fltSatisfiedExperimentsPtr.toDartString();
+    _exptFreeString(fltSatisfiedExperimentsPtr);
+
+    return fltSatisfiedExperiments;
+  }
+
+  String getRunningExperiments() {
+    if (_clientPtr == ffi.nullptr) {
+      throw Exception("Failed to get Experimentation client!");
+    }
+    final runningExprsPtr = _exptGetRunningExperiments(_clientPtr);
+    if (runningExprsPtr == ffi.nullptr) {
+      final errorPtr = _exptLastErrorMessage();
+      final errorMessage = errorPtr.toDartString();
+      print("Error getting filtered running experiments : $errorMessage");
+      _exptFreeString(errorPtr);
+      throw Exception(
+          "Failed to get filtered running experiments: $errorMessage");
+    }
+    var runningExprs = runningExprsPtr.toDartString();
+    _exptFreeString(runningExprsPtr);
+    return runningExprs;
+  }
+
+  void startPollingUpdate(String tenant) {
+    if (_clientPtr == ffi.nullptr) {
+      throw Exception("Failed to get Experimentation client!");
+    }
+    final tenantPtr = tenant.toNativeUtf8();
+    _exptStartPollingUpdate(tenantPtr);
+    _exptFreeString(tenantPtr);
+    print("finish polling");
+  }
+
+  void dispose() {
+    if (_clientPtr != ffi.nullptr) {
+      _exptFreeClient(_clientPtr);
+      _clientPtr = ffi.nullptr;
+    }
+  }
+}