Rename the PolicyManager to UpdateManager.
This change renames the PolicyManager class, directory, tests, etc,
to avoid confusion with libpolicy and its classes.
BUG=chromium:373551
TEST=emerged on link.
CQ-DEPEND=CL:I43081673c7ba409f02273197da7915537bde39c6
Change-Id: Iffa76caa3b95ecbbdba87ab01006d1d8ce35a27f
Reviewed-on: https://chromium-review.googlesource.com/201876
Tested-by: Alex Deymo <deymo@chromium.org>
Reviewed-by: David Zeuthen <zeuthen@chromium.org>
Commit-Queue: Alex Deymo <deymo@chromium.org>
diff --git a/update_manager/generic_variables.h b/update_manager/generic_variables.h
new file mode 100644
index 0000000..5831463
--- /dev/null
+++ b/update_manager/generic_variables.h
@@ -0,0 +1,206 @@
+// Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Generic and provider-independent Variable subclasses. These variables can be
+// used by any state provider to implement simple variables to avoid repeat the
+// same common code on different state providers.
+
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_MANAGER_GENERIC_VARIABLES_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_MANAGER_GENERIC_VARIABLES_H_
+
+#include <string>
+
+#include <base/callback.h>
+
+#include "update_engine/update_manager/variable.h"
+
+namespace chromeos_update_manager {
+
+// Variable class returning a copy of a given object using the copy constructor.
+// This template class can be used to define variables that expose as a variable
+// any fixed object, such as the a provider's private member. The variable will
+// create copies of the provided object using the copy constructor of that
+// class.
+//
+// For example, a state provider exposing a private member as a variable can
+// implement this as follows:
+//
+// class SomethingProvider {
+// public:
+// SomethingProvider(...) {
+// var_something_foo = new PollCopyVariable<MyType>(foo_);
+// }
+// ...
+// private:
+// MyType foo_;
+// };
+template<typename T>
+class PollCopyVariable : public Variable<T> {
+ public:
+ // Creates the variable returning copies of the passed |ref|. The reference to
+ // this object is kept and it should be available whenever the GetValue()
+ // method is called. If |is_set_p| is not null, then this flag will be
+ // consulted prior to returning the value, and an |errmsg| will be returned if
+ // it is not set.
+ PollCopyVariable(const std::string& name, const T& ref, const bool* is_set_p,
+ const std::string& errmsg)
+ : Variable<T>(name, kVariableModePoll), ref_(ref), is_set_p_(is_set_p),
+ errmsg_(errmsg) {}
+ PollCopyVariable(const std::string& name, const T& ref, const bool* is_set_p)
+ : PollCopyVariable(name, ref, is_set_p, std::string()) {}
+ PollCopyVariable(const std::string& name, const T& ref)
+ : PollCopyVariable(name, ref, nullptr) {}
+
+ PollCopyVariable(const std::string& name, const base::TimeDelta poll_interval,
+ const T& ref, const bool* is_set_p,
+ const std::string& errmsg)
+ : Variable<T>(name, poll_interval), ref_(ref), is_set_p_(is_set_p),
+ errmsg_(errmsg) {}
+ PollCopyVariable(const std::string& name, const base::TimeDelta poll_interval,
+ const T& ref, const bool* is_set_p)
+ : PollCopyVariable(name, poll_interval, ref, is_set_p, std::string()) {}
+ PollCopyVariable(const std::string& name, const base::TimeDelta poll_interval,
+ const T& ref)
+ : PollCopyVariable(name, poll_interval, ref, nullptr) {}
+
+ protected:
+ FRIEND_TEST(UmPollCopyVariableTest, SimpleTest);
+ FRIEND_TEST(UmPollCopyVariableTest, UseCopyConstructorTest);
+
+ // Variable override.
+ virtual inline const T* GetValue(base::TimeDelta /* timeout */,
+ std::string* errmsg) {
+ if (is_set_p_ && !(*is_set_p_)) {
+ if (errmsg) {
+ if (errmsg_.empty())
+ *errmsg = "No value set for " + this->GetName();
+ else
+ *errmsg = errmsg_;
+ }
+ return nullptr;
+ }
+ return new T(ref_);
+ }
+
+ private:
+ // Reference to the object to be copied by GetValue().
+ const T& ref_;
+
+ // A pointer to a flag indicating whether the value is set. If null, then the
+ // value is assumed to be set.
+ const bool* const is_set_p_;
+
+ // An error message to be returned when attempting to get an unset value.
+ const std::string errmsg_;
+};
+
+// Variable class returning a constant value that is cached on the variable when
+// it is created.
+template<typename T>
+class ConstCopyVariable : public Variable<T> {
+ public:
+ // Creates the variable returning copies of the passed |obj|. The value passed
+ // is copied in this variable, and new copies of it will be returned by
+ // GetValue().
+ ConstCopyVariable(const std::string& name, const T& obj)
+ : Variable<T>(name, kVariableModeConst), obj_(obj) {}
+
+ protected:
+ // Variable override.
+ virtual const T* GetValue(base::TimeDelta /* timeout */,
+ std::string* /* errmsg */) {
+ return new T(obj_);
+ }
+
+ private:
+ // Value to be copied by GetValue().
+ const T obj_;
+};
+
+// Variable class returning a copy of a value returned by a given function. The
+// function is called every time the variable is being polled.
+template<typename T>
+class CallCopyVariable : public Variable<T> {
+ public:
+ CallCopyVariable(const std::string& name, base::Callback<T(void)> func)
+ : Variable<T>(name, kVariableModePoll), func_(func) {}
+ CallCopyVariable(const std::string& name,
+ const base::TimeDelta poll_interval,
+ base::Callback<T(void)> func)
+ : Variable<T>(name, poll_interval), func_(func) {}
+
+ protected:
+ // Variable override.
+ virtual const T* GetValue(base::TimeDelta /* timeout */,
+ std::string* /* errmsg */) {
+ if (func_.is_null())
+ return nullptr;
+ return new T(func_.Run());
+ }
+
+ private:
+ FRIEND_TEST(UmCallCopyVariableTest, SimpleTest);
+
+ // The function to be called, stored as a base::Callback.
+ base::Callback<T(void)> func_;
+
+ DISALLOW_COPY_AND_ASSIGN(CallCopyVariable);
+};
+
+
+// A Variable class to implement simple Async variables. It provides two methods
+// SetValue and UnsetValue to modify the current value of the variable and
+// notify the registered observers whenever the value changed.
+//
+// The type T needs to be copy-constructable, default-constructable and have an
+// operator== (to determine if the value changed), which makes this class
+// suitable for basic types.
+template<typename T>
+class AsyncCopyVariable : public Variable<T> {
+ public:
+ explicit AsyncCopyVariable(const std::string& name)
+ : Variable<T>(name, kVariableModeAsync), has_value_(false) {}
+
+ AsyncCopyVariable(const std::string& name, const T value)
+ : Variable<T>(name, kVariableModeAsync),
+ has_value_(true), value_(value) {}
+
+ void SetValue(const T& new_value) {
+ bool should_notify = !(has_value_ && new_value == value_);
+ value_ = new_value;
+ has_value_ = true;
+ if (should_notify)
+ this->NotifyValueChanged();
+ }
+
+ void UnsetValue() {
+ if (has_value_) {
+ has_value_ = false;
+ this->NotifyValueChanged();
+ }
+ }
+
+ protected:
+ // Variable override.
+ virtual const T* GetValue(base::TimeDelta /* timeout */,
+ std::string* errmsg) {
+ if (!has_value_) {
+ if (errmsg)
+ *errmsg = "No value set for " + this->GetName();
+ return nullptr;
+ }
+ return new T(value_);
+ }
+
+ private:
+ // Whether the variable has a value set.
+ bool has_value_;
+
+ // Copy of the object to be returned by GetValue().
+ T value_;
+};
+
+} // namespace chromeos_update_manager
+
+#endif // CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_MANAGER_GENERIC_VARIABLES_H_