platform_system_core/init/action.cpp

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/*
* 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 <errno.h>
#include <android-base/strings.h>
#include <android-base/stringprintf.h>
#include "builtins.h"
#include "error.h"
#include "init_parser.h"
#include "log.h"
#include "property_service.h"
#include "util.h"
using android::base::Join;
using android::base::StringPrintf;
Command::Command(BuiltinFunction f, const std::vector<std::string>& args,
const std::string& filename, int line)
: func_(f), args_(args), filename_(filename), 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])) {
ERROR("%s: cannot expand '%s'\n", args_[0].c_str(), args_[i].c_str());
return -EINVAL;
}
}
return func_(expanded_args);
}
std::string Command::BuildCommandString() const {
return Join(args_, ' ');
}
std::string Command::BuildSourceString() const {
if (!filename_.empty()) {
return StringPrintf(" (%s:%d)", filename_.c_str(), line_);
} else {
return std::string();
}
}
Action::Action(bool oneshot) : oneshot_(oneshot) {
}
const KeywordMap<BuiltinFunction>* Action::function_map_ = nullptr;
bool Action::AddCommand(const std::vector<std::string>& args,
const std::string& filename, int line, std::string* err) {
if (!function_map_) {
*err = "no function map available";
return false;
}
if (args.empty()) {
*err = "command needed, but not provided";
return false;
}
auto function = function_map_->FindFunction(args[0], args.size() - 1, err);
if (!function) {
return false;
}
AddCommand(function, args, filename, line);
return true;
}
void Action::AddCommand(BuiltinFunction f,
const std::vector<std::string>& args,
const std::string& filename, int line) {
commands_.emplace_back(f, args, filename, line);
}
void Action::CombineAction(const Action& action) {
for (const auto& c : action.commands_) {
commands_.emplace_back(c);
}
}
std::size_t Action::NumCommands() const {
return commands_.size();
}
void Action::ExecuteOneCommand(std::size_t command) const {
ExecuteCommand(commands_[command]);
}
void Action::ExecuteAllCommands() const {
for (const auto& c : commands_) {
ExecuteCommand(c);
}
}
void Action::ExecuteCommand(const Command& command) const {
Timer t;
int result = command.InvokeFunc();
if (klog_get_level() >= KLOG_INFO_LEVEL) {
std::string trigger_name = BuildTriggersString();
std::string cmd_str = command.BuildCommandString();
std::string source = command.BuildSourceString();
INFO("Command '%s' action=%s%s returned %d took %.2fs\n",
cmd_str.c_str(), trigger_name.c_str(), source.c_str(),
result, t.duration());
}
}
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);
auto res = property_triggers_.emplace(prop_name, prop_value);
if (res.second == false) {
*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 (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;
return InitTriggers(name_vector, &err);
}
// 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& t : property_triggers_) {
const auto& trigger_name = t.first;
const auto& trigger_value = t.second;
if (trigger_name == name) {
if (trigger_value != "*" && trigger_value != value) {
return false;
} else {
found = true;
}
} else {
std::string prop_val = property_get(trigger_name.c_str());
if (prop_val.empty() || (trigger_value != "*" &&
trigger_value != prop_val)) {
return false;
}
}
}
return found;
}
bool Action::CheckEventTrigger(const std::string& trigger) const {
return !event_trigger_.empty() &&
trigger == event_trigger_ &&
CheckPropertyTriggers();
}
bool Action::CheckPropertyTrigger(const std::string& name,
const std::string& value) const {
return event_trigger_.empty() && CheckPropertyTriggers(name, value);
}
bool Action::TriggersEqual(const Action& other) const {
return property_triggers_ == other.property_triggers_ &&
event_trigger_ == other.event_trigger_;
}
std::string Action::BuildTriggersString() const {
std::string result;
for (const auto& t : property_triggers_) {
result += t.first;
result += '=';
result += t.second;
result += ' ';
}
if (!event_trigger_.empty()) {
result += event_trigger_;
result += ' ';
}
result.pop_back();
return result;
}
void Action::DumpState() const {
std::string trigger_name = BuildTriggersString();
INFO("on %s\n", trigger_name.c_str());
for (const auto& c : commands_) {
std::string cmd_str = c.BuildCommandString();
INFO(" %s\n", cmd_str.c_str());
}
INFO("\n");
}
class EventTrigger : public Trigger {
public:
EventTrigger(const std::string& trigger) : trigger_(trigger) {
}
bool CheckTriggers(const Action& action) const override {
return action.CheckEventTrigger(trigger_);
}
private:
const std::string trigger_;
};
class PropertyTrigger : public Trigger {
public:
PropertyTrigger(const std::string& name, const std::string& value)
: name_(name), value_(value) {
}
bool CheckTriggers(const Action& action) const override {
return action.CheckPropertyTrigger(name_, value_);
}
private:
const std::string name_;
const std::string value_;
};
class BuiltinTrigger : public Trigger {
public:
BuiltinTrigger(Action* action) : action_(action) {
}
bool CheckTriggers(const Action& action) const override {
return action_ == &action;
}
private:
const Action* action_;
};
ActionManager::ActionManager() : current_command_(0) {
}
ActionManager& ActionManager::GetInstance() {
static ActionManager instance;
return instance;
}
void ActionManager::AddAction(std::unique_ptr<Action> action) {
auto old_action_it =
std::find_if(actions_.begin(), actions_.end(),
[&action] (std::unique_ptr<Action>& a) {
return action->TriggersEqual(*a);
});
if (old_action_it != actions_.end()) {
(*old_action_it)->CombineAction(*action);
} else {
actions_.emplace_back(std::move(action));
}
}
void ActionManager::QueueEventTrigger(const std::string& trigger) {
trigger_queue_.push(std::make_unique<EventTrigger>(trigger));
}
void ActionManager::QueuePropertyTrigger(const std::string& name,
const std::string& value) {
trigger_queue_.push(std::make_unique<PropertyTrigger>(name, value));
}
void ActionManager::QueueAllPropertyTriggers() {
QueuePropertyTrigger("", "");
}
void ActionManager::QueueBuiltinAction(BuiltinFunction func,
const std::string& name) {
auto action = std::make_unique<Action>(true);
std::vector<std::string> name_vector{name};
if (!action->InitSingleTrigger(name)) {
return;
}
action->AddCommand(func, name_vector);
trigger_queue_.push(std::make_unique<BuiltinTrigger>(action.get()));
actions_.emplace_back(std::move(action));
}
void ActionManager::ExecuteOneCommand() {
// Loop through the trigger queue until we have an action to execute
while (current_executing_actions_.empty() && !trigger_queue_.empty()) {
for (const auto& action : actions_) {
if (trigger_queue_.front()->CheckTriggers(*action)) {
current_executing_actions_.emplace(action.get());
}
}
trigger_queue_.pop();
}
if (current_executing_actions_.empty()) {
return;
}
auto action = current_executing_actions_.front();
if (current_command_ == 0) {
std::string trigger_name = action->BuildTriggersString();
INFO("processing action (%s)\n", trigger_name.c_str());
}
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() || !trigger_queue_.empty();
}
void ActionManager::DumpState() const {
for (const auto& a : actions_) {
a->DumpState();
}
INFO("\n");
}
bool ActionParser::ParseSection(const std::vector<std::string>& args,
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);
if (!action->InitTriggers(triggers, err)) {
return false;
}
action_ = std::move(action);
return true;
}
bool ActionParser::ParseLineSection(const std::vector<std::string>& args,
const std::string& filename, int line,
std::string* err) const {
return action_ ? action_->AddCommand(args, filename, line, err) : false;
}
void ActionParser::EndSection() {
if (action_ && action_->NumCommands() > 0) {
ActionManager::GetInstance().AddAction(std::move(action_));
}
}