upload android base code part6

android/system/core/init/action.cpp

@@ -0,0 +1,364 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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 "action.h"
+
+#include <android-base/chrono_utils.h>
+#include <android-base/logging.h>
+#include <android-base/properties.h>
+#include <android-base/strings.h>
+
+#include "util.h"
+
+using android::base::Join;
+
+namespace android {
+namespace init {
+
+Command::Command(BuiltinFunction f, const std::vector<std::string>& args, int line)
+    : func_(f), args_(args), line_(line) {}
+
+int Command::InvokeFunc() const {
+    std::vector<std::string> expanded_args;
+    expanded_args.resize(args_.size());
+    expanded_args[0] = args_[0];
+    for (std::size_t i = 1; i < args_.size(); ++i) {
+        if (!expand_props(args_[i], &expanded_args[i])) {
+            LOG(ERROR) << args_[0] << ": cannot expand '" << args_[i] << "'";
+            return -EINVAL;
+        }
+    }
+
+    return func_(expanded_args);
+}
+
+std::string Command::BuildCommandString() const {
+    return Join(args_, ' ');
+}
+
+Action::Action(bool oneshot, const std::string& filename, int line)
+    : oneshot_(oneshot), filename_(filename), line_(line) {}
+
+const KeywordMap<BuiltinFunction>* Action::function_map_ = nullptr;
+
+bool Action::AddCommand(const std::vector<std::string>& args, int line, std::string* err) {
+    if (!function_map_) {
+        *err = "no function map available";
+        return false;
+    }
+
+    auto function = function_map_->FindFunction(args, err);
+    if (!function) {
+        return false;
+    }
+
+    AddCommand(function, args, line);
+    return true;
+}
+
+void Action::AddCommand(BuiltinFunction f, const std::vector<std::string>& args, int line) {
+    commands_.emplace_back(f, args, line);
+}
+
+std::size_t Action::NumCommands() const {
+    return commands_.size();
+}
+
+void Action::ExecuteOneCommand(std::size_t command) const {
+    // We need a copy here since some Command execution may result in
+    // changing commands_ vector by importing .rc files through parser
+    Command cmd = commands_[command];
+    ExecuteCommand(cmd);
+}
+
+void Action::ExecuteAllCommands() const {
+    for (const auto& c : commands_) {
+        ExecuteCommand(c);
+    }
+}
+
+void Action::ExecuteCommand(const Command& command) const {
+    android::base::Timer t;
+    int result = command.InvokeFunc();
+
+    auto duration = t.duration();
+    // Any action longer than 50ms will be warned to user as slow operation
+    if (duration > 50ms || android::base::GetMinimumLogSeverity() <= android::base::DEBUG) {
+        std::string trigger_name = BuildTriggersString();
+        std::string cmd_str = command.BuildCommandString();
+
+        LOG(INFO) << "Command '" << cmd_str << "' action=" << trigger_name << " (" << filename_
+                  << ":" << command.line() << ") returned " << result << " took "
+                  << duration.count() << "ms.";
+    }
+}
+
+bool Action::ParsePropertyTrigger(const std::string& trigger, std::string* err) {
+    const static std::string prop_str("property:");
+    std::string prop_name(trigger.substr(prop_str.length()));
+    size_t equal_pos = prop_name.find('=');
+    if (equal_pos == std::string::npos) {
+        *err = "property trigger found without matching '='";
+        return false;
+    }
+
+    std::string prop_value(prop_name.substr(equal_pos + 1));
+    prop_name.erase(equal_pos);
+
+    if (auto [it, inserted] = property_triggers_.emplace(prop_name, prop_value); !inserted) {
+        *err = "multiple property triggers found for same property";
+        return false;
+    }
+    return true;
+}
+
+bool Action::InitTriggers(const std::vector<std::string>& args, std::string* err) {
+    const static std::string prop_str("property:");
+    for (std::size_t i = 0; i < args.size(); ++i) {
+        if (args[i].empty()) {
+            *err = "empty trigger is not valid";
+            return false;
+        }
+
+        if (i % 2) {
+            if (args[i] != "&&") {
+                *err = "&& is the only symbol allowed to concatenate actions";
+                return false;
+            } else {
+                continue;
+            }
+        }
+
+        if (!args[i].compare(0, prop_str.length(), prop_str)) {
+            if (!ParsePropertyTrigger(args[i], err)) {
+                return false;
+            }
+        } else {
+            if (!event_trigger_.empty()) {
+                *err = "multiple event triggers are not allowed";
+                return false;
+            }
+
+            event_trigger_ = args[i];
+        }
+    }
+
+    return true;
+}
+
+bool Action::InitSingleTrigger(const std::string& trigger) {
+    std::vector<std::string> name_vector{trigger};
+    std::string err;
+    bool ret = InitTriggers(name_vector, &err);
+    if (!ret) {
+        LOG(ERROR) << "InitSingleTrigger failed due to: " << err;
+    }
+    return ret;
+}
+
+// This function checks that all property triggers are satisfied, that is
+// for each (name, value) in property_triggers_, check that the current
+// value of the property 'name' == value.
+//
+// It takes an optional (name, value) pair, which if provided must
+// be present in property_triggers_; it skips the check of the current
+// property value for this pair.
+bool Action::CheckPropertyTriggers(const std::string& name,
+                                   const std::string& value) const {
+    if (property_triggers_.empty()) {
+        return true;
+    }
+
+    bool found = name.empty();
+    for (const auto& [trigger_name, trigger_value] : property_triggers_) {
+        if (trigger_name == name) {
+            if (trigger_value != "*" && trigger_value != value) {
+                return false;
+            } else {
+                found = true;
+            }
+        } else {
+            std::string prop_val = android::base::GetProperty(trigger_name, "");
+            if (prop_val.empty() || (trigger_value != "*" && trigger_value != prop_val)) {
+                return false;
+            }
+        }
+    }
+    return found;
+}
+
+bool Action::CheckEvent(const EventTrigger& event_trigger) const {
+    return event_trigger == event_trigger_ && CheckPropertyTriggers();
+}
+
+bool Action::CheckEvent(const PropertyChange& property_change) const {
+    const auto& [name, value] = property_change;
+    return event_trigger_.empty() && CheckPropertyTriggers(name, value);
+}
+
+bool Action::CheckEvent(const BuiltinAction& builtin_action) const {
+    return this == builtin_action;
+}
+
+std::string Action::BuildTriggersString() const {
+    std::vector<std::string> triggers;
+
+    for (const auto& [trigger_name, trigger_value] : property_triggers_) {
+        triggers.emplace_back(trigger_name + '=' + trigger_value);
+    }
+    if (!event_trigger_.empty()) {
+        triggers.emplace_back(event_trigger_);
+    }
+
+    return Join(triggers, " && ");
+}
+
+void Action::DumpState() const {
+    std::string trigger_name = BuildTriggersString();
+    LOG(INFO) << "on " << trigger_name;
+
+    for (const auto& c : commands_) {
+        std::string cmd_str = c.BuildCommandString();
+        LOG(INFO) << "  " << cmd_str;
+    }
+}
+
+ActionManager::ActionManager() : current_command_(0) {
+}
+
+ActionManager& ActionManager::GetInstance() {
+    static ActionManager instance;
+    return instance;
+}
+
+void ActionManager::AddAction(std::unique_ptr<Action> action) {
+    actions_.emplace_back(std::move(action));
+}
+
+void ActionManager::QueueEventTrigger(const std::string& trigger) {
+    event_queue_.emplace(trigger);
+}
+
+void ActionManager::QueuePropertyChange(const std::string& name, const std::string& value) {
+    event_queue_.emplace(std::make_pair(name, value));
+}
+
+void ActionManager::QueueAllPropertyActions() {
+    QueuePropertyChange("", "");
+}
+
+void ActionManager::QueueBuiltinAction(BuiltinFunction func, const std::string& name) {
+    auto action = std::make_unique<Action>(true, "<Builtin Action>", 0);
+    std::vector<std::string> name_vector{name};
+
+    if (!action->InitSingleTrigger(name)) {
+        return;
+    }
+
+    action->AddCommand(func, name_vector, 0);
+
+    event_queue_.emplace(action.get());
+    actions_.emplace_back(std::move(action));
+}
+
+void ActionManager::ExecuteOneCommand() {
+    // Loop through the event queue until we have an action to execute
+    while (current_executing_actions_.empty() && !event_queue_.empty()) {
+        for (const auto& action : actions_) {
+            if (std::visit([&action](const auto& event) { return action->CheckEvent(event); },
+                           event_queue_.front())) {
+                current_executing_actions_.emplace(action.get());
+            }
+        }
+        event_queue_.pop();
+    }
+
+    if (current_executing_actions_.empty()) {
+        return;
+    }
+
+    auto action = current_executing_actions_.front();
+
+    if (current_command_ == 0) {
+        std::string trigger_name = action->BuildTriggersString();
+        LOG(INFO) << "processing action (" << trigger_name << ") from (" << action->filename()
+                  << ":" << action->line() << ")";
+    }
+
+    action->ExecuteOneCommand(current_command_);
+
+    // If this was the last command in the current action, then remove
+    // the action from the executing list.
+    // If this action was oneshot, then also remove it from actions_.
+    ++current_command_;
+    if (current_command_ == action->NumCommands()) {
+        current_executing_actions_.pop();
+        current_command_ = 0;
+        if (action->oneshot()) {
+            auto eraser = [&action] (std::unique_ptr<Action>& a) {
+                return a.get() == action;
+            };
+            actions_.erase(std::remove_if(actions_.begin(), actions_.end(), eraser));
+        }
+    }
+}
+
+bool ActionManager::HasMoreCommands() const {
+    return !current_executing_actions_.empty() || !event_queue_.empty();
+}
+
+void ActionManager::DumpState() const {
+    for (const auto& a : actions_) {
+        a->DumpState();
+    }
+}
+
+void ActionManager::ClearQueue() {
+    // We are shutting down so don't claim the oneshot builtin actions back
+    current_executing_actions_ = {};
+    event_queue_ = {};
+    current_command_ = 0;
+}
+
+bool ActionParser::ParseSection(std::vector<std::string>&& args, const std::string& filename,
+                                int line, std::string* err) {
+    std::vector<std::string> triggers(args.begin() + 1, args.end());
+    if (triggers.size() < 1) {
+        *err = "actions must have a trigger";
+        return false;
+    }
+
+    auto action = std::make_unique<Action>(false, filename, line);
+    if (!action->InitTriggers(triggers, err)) {
+        return false;
+    }
+
+    action_ = std::move(action);
+    return true;
+}
+
+bool ActionParser::ParseLineSection(std::vector<std::string>&& args, int line, std::string* err) {
+    return action_ ? action_->AddCommand(std::move(args), line, err) : false;
+}
+
+void ActionParser::EndSection() {
+    if (action_ && action_->NumCommands() > 0) {
+        action_manager_->AddAction(std::move(action_));
+    }
+}
+
+}  // namespace init
+}  // namespace android