scope-impl

doc/design/scope.md

@@ -41,7 +41,7 @@ class Scope {
   const Variable* GetVariable(const std::string& name) const;
 
  private:
-    std::unordered_map<std::string, std::unique_ptr<Vairable>> vars_;
+    std::unordered_map<std::string, std::unique_ptr<Variable>> vars_;
 };
 ```
 

paddle/framework/CMakeLists.txt

@@ -1,6 +1,11 @@
+# ddim lib
 cc_library(ddim SRCS ddim.cc)
 cc_test(ddim_test SRCS ddim_test.cc DEPS ddim)
 
 nv_test(dim_test SRCS dim_test.cu DEPS ddim)
 
 cc_test(variable_test SRCS variable_test.cc)
+
+# scope lib
+cc_library(scope SRCS scope.cc)
+cc_test(scope_test SRCS scope_test.cc DEPS scope)

paddle/framework/scope.cc

@@ -0,0 +1,54 @@
+#include "paddle/framework/scope.h"
+
+namespace paddle {
+namespace framework {
+
+Error Scope::CreateVariable(const std::string &name) {
+  if (name == "") {
+    return Error("Variable name should not be empty");
+  }
+
+  if (HaveVariable(name)) {
+    return AlreadyCreated;
+  }
+  vars_[name] = std::unique_ptr<Variable>(new Variable());
+  return Error();
+}
+
+Variable* Scope::GetVarLocally(const std::string& name) const {
+  if (vars_.count(name)) {
+    return vars_.at(name).get();
+  }
+  return nullptr;
+}
+
+Variable* Scope::GetVariable(const std::string &name) const {
+  Variable* var = GetVarLocally(name);
+  if (var != nullptr) {
+    return var;
+  } else if (parent_ != nullptr) {
+    return parent_->GetVariable(name);
+  } else {
+    return nullptr;
+  }
+}
+
+Variable* Scope::GetOrCreateVariable(const std::string &name) {
+  Variable* var;
+  var = GetVariable(name);
+  if (var == nullptr) {
+    auto err = CreateVariable(name);
+    if (!err.isOK()) {
+      return nullptr;
+    }
+  }
+  return GetVariable(name);
+}
+
+bool Scope::HaveVariable(const std::string &name) {
+  return vars_.count(name) != 0;
+}
+
+}  // namespace framework
+}  // namespace paddle
+

paddle/framework/scope.h

@@ -0,0 +1,51 @@
+#pragma once
+
+#include <vector>
+#include <unordered_map>
+#include "paddle/framework/variable.h"
+#include "paddle/utils/Error.h"
+
+namespace paddle {
+namespace framework {
+
+const static Error AlreadyCreated("Variable has already been created");
+
+/**
+ * Scope is an association of a name to Variable. All variables belong to `Scope`.
+ * You need to specify a scope to run a Net, i.e., `net.Run(&scope)`. One net can
+ * run in different scopes and update different variable in the scope.
+ */
+class Scope {
+ public:
+  Scope() {}
+
+  explicit Scope(const std::shared_ptr<Scope> &scope):
+          parent_(scope) {}
+
+  ~Scope() {}
+
+  // Create Variable in this Scope. Return error if Variable already been
+  // created.
+  Error __must_check CreateVariable(const std::string& name);
+
+  // Get Variable from this Scope, this function will recursive find Variable
+  // from it's parent scope.
+  // Return nullptr if not found.
+  Variable* GetVariable(const std::string& name) const;
+
+  // find and return Variables in the scope it self.
+  Variable* GetVarLocally(const std::string& name) const;
+
+  // Get a Variable from Scope, if the Variable is not exist then create it.
+  // User should call this function most of time.
+  Variable* GetOrCreateVariable(const std::string& name);
+
+  bool HaveVariable(const std::string& name);
+
+ private:
+  std::unordered_map<std::string, std::unique_ptr<Variable>> vars_;
+  std::shared_ptr<Scope> parent_ {nullptr};
+};
+
+}  // namespace framework
+}  // namespace paddle

paddle/framework/scope_test.cc

@@ -0,0 +1,47 @@
+#include "paddle/framework/scope.h"
+#include "gtest/gtest.h"
+
+TEST(Scope, Create) {
+  using paddle::framework::Scope;
+  using paddle::Error;
+  using paddle::framework::Variable;
+  using paddle::framework::AlreadyCreated;
+
+  Scope* scope = new Scope();
+
+  Error err = scope->CreateVariable("");
+  EXPECT_FALSE(err.isOK());
+
+  Variable* var1 = scope->GetVariable("a");
+  EXPECT_EQ(var1, nullptr);
+
+  Error err1 = scope->CreateVariable("a");
+  EXPECT_TRUE(err1.isOK());
+
+  Error err2 = scope->CreateVariable("a");
+  EXPECT_EQ(err2, AlreadyCreated);
+
+  Variable* var2 = scope->GetVariable("a");
+  EXPECT_NE(var2, nullptr);
+
+  Variable* var3 = scope->GetOrCreateVariable("b");
+  EXPECT_NE(var3, nullptr);
+}
+
+TEST(Scope, Parent) {
+  using paddle::framework::Scope;
+  using paddle::framework::Variable;
+  using paddle::Error;
+
+  const auto parent_scope_ptr = std::shared_ptr<Scope>(new Scope());
+  Scope* scope = new Scope(parent_scope_ptr);
+
+  Error err = parent_scope_ptr->CreateVariable("a");
+  EXPECT_TRUE(err.isOK());
+
+  Variable* var1 = scope->GetVarLocally("a");
+  EXPECT_EQ(var1, nullptr);
+
+  Variable* var2 = scope->GetVariable("a");
+  EXPECT_NE(var2, nullptr);
+}