1 files changed, 122 insertions, 0 deletions
diff --git a/compiler/exo/src/Knob.cpp b/compiler/exo/src/Knob.cpp
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+++ b/compiler/exo/src/Knob.cpp
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+/*
+ * Copyright (c) 2019 Samsung Electronics Co., Ltd. All Rights Reserved
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "Knob.h"
+
+#include <pepper/strcast.h>
+
+#include <iostream>
+#include <string>
+#include <map>
+
+// Basic Infrastructure to declare and access Knob values
+namespace
+{
+
+using KnobName = std::string;
+
+/**
+ * @brief Load configuration (from somewhere)
+ */
+struct KnobLoader
+{
+  virtual ~KnobLoader() = default;
+
+  virtual bool load(const KnobName &name, bool default_value) const = 0;
+};
+
+/**
+ * @brief Load configuration from environment variables
+ *
+ * Given a prefix P, EnvKnobLoader reads a configuration K from concat(P, K).
+ *
+ * For example, let us assume that P is "MY_" and K is "CONFIG".
+ *
+ * Then, EnvKnobLoader reads configuration CONFIG from environment variable MY_CONFIG.
+ */
+class EnvKnobLoader final : public KnobLoader
+{
+public:
+  EnvKnobLoader() = default;
+
+public:
+  bool load(const KnobName &knob_name, bool default_value) const override
+  {
+    auto envvar = _prefix + knob_name;
+    auto s = std::getenv(envvar.c_str());
+
+    return pepper::safe_strcast<int>(s, default_value ? 1 : 0) != 0;
+  }
+  void knob_set(const KnobName &knob_name, bool value) { _knob[knob_name] = value; }
+  void dialect_set(const exo::Dialect &dialect_name) { _prefix = _label[dialect_name]; }
+  bool knob_get(const KnobName &knob_name) { return load(knob_name, _knob[knob_name]); }
+
+private:
+  /// @brief Environment variable prefix
+  std::string _prefix;
+  std::map<KnobName, bool> _knob;
+  std::map<exo::Dialect, KnobName> _label = {{exo::Dialect::TFLITE, "TFL_"},
+                                             {exo::Dialect::CIRCLE, "CIRCLE_"}};
+};
+
+} // namespace
+
+namespace
+{
+
+EnvKnobLoader &knob_loader(void)
+{
+  // TODO separate "EXOTFLITE_" and "EXOCIRCLE_" when necessary
+  static EnvKnobLoader loader;
+  return loader;
+}
+
+} // namespace
+
+namespace exo
+{
+
+#define KNOB_BOOL(NAME, TFL_DEFAULT, CIRCLE_DEFAULT, DESC)                    \
+  template <> typename KnobTrait<Knob::NAME>::ValueType get<Knob::NAME>(void) \
+  {                                                                           \
+    return ::knob_loader().knob_get(#NAME);                                   \
+  }
+#include "Knob.lst"
+#undef KNOB_BOOL
+
+void set(Dialect d)
+{
+  ::knob_loader().dialect_set(d);
+  switch (d)
+  {
+    case Dialect::TFLITE:
+#define KNOB_BOOL(NAME, TFL_DEFAULT, CIRCLE_DEFAULT, DESC) \
+  ::knob_loader().knob_set(#NAME, TFL_DEFAULT);
+#include "Knob.lst"
+#undef KNOB_BOOL
+      break;
+    case Dialect::CIRCLE:
+#define KNOB_BOOL(NAME, TFL_DEFAULT, CIRCLE_DEFAULT, DESC) \
+  ::knob_loader().knob_set(#NAME, CIRCLE_DEFAULT);
+#include "Knob.lst"
+#undef KNOB_BOOL
+      break;
+    default:
+      std::runtime_error("UnKnown dialect");
+  }
+}
+
+} // namespace exo