COMPMID-619: Logging interface

Change-Id: I73d1433ee7a682aeabb7540aa2ea1f6564f90aae
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/91775
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
diff --git a/src/core/utils/logging/FilePrinter.cpp b/src/core/utils/logging/FilePrinter.cpp
new file mode 100644
index 0000000..b699afc
--- /dev/null
+++ b/src/core/utils/logging/FilePrinter.cpp
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2017 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "arm_compute/core/utils/logging/FilePrinter.h"
+
+using namespace arm_compute::logging;
+
+FilePrinter::FilePrinter(const std::string &filename)
+    : _handler()
+{
+    _handler.open(filename, std::fstream::out | std::fstream::trunc);
+}
+
+void FilePrinter::print_internal(const std::string &msg)
+{
+    _handler.stream() << msg << std::endl;
+}
\ No newline at end of file
diff --git a/src/core/utils/logging/Helpers.cpp b/src/core/utils/logging/Helpers.cpp
new file mode 100644
index 0000000..f5ab608
--- /dev/null
+++ b/src/core/utils/logging/Helpers.cpp
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2017 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "arm_compute/core/utils/logging/Helpers.h"
+
+#include <map>
+#include <string>
+
+using namespace arm_compute::logging;
+
+const std::string &arm_compute::logging::string_from_log_level(LogLevel log_level)
+{
+    static std::map<LogLevel, const std::string> log_level_map =
+    {
+        { LogLevel::VERBOSE, "VERBOSE" },
+        { LogLevel::INFO, "INFO" },
+        { LogLevel::WARN, "WARN" },
+        { LogLevel::OFF, "OFF" },
+    };
+
+    return log_level_map[log_level];
+}
\ No newline at end of file
diff --git a/src/core/utils/logging/Logger.cpp b/src/core/utils/logging/Logger.cpp
new file mode 100644
index 0000000..b025ca8
--- /dev/null
+++ b/src/core/utils/logging/Logger.cpp
@@ -0,0 +1,154 @@
+/*
+ * Copyright (c) 2017 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "arm_compute/core/utils/logging/Logger.h"
+
+#include "arm_compute/core/Error.h"
+#include "support/ToolchainSupport.h"
+
+using namespace arm_compute::logging;
+
+Logger::Logger(std::string name, LogLevel log_level, std::shared_ptr<Printer> printer)
+    : _name(std::move(name)), _log_level(log_level), _printers(
+{
+    std::move(printer)
+}), _decorators()
+{
+    // Check printer
+    ARM_COMPUTE_ERROR_ON(printer == nullptr);
+
+    // Set default message decorators
+    set_default_decorators();
+}
+
+Logger::Logger(std::string name, LogLevel log_level, std::vector<std::shared_ptr<Printer>> printers)
+    : _name(std::move(name)), _log_level(log_level), _printers(std::move(printers)), _decorators()
+{
+    // Check printers
+    for(const auto &p : _printers)
+    {
+        ARM_COMPUTE_UNUSED(p);
+        ARM_COMPUTE_ERROR_ON(p == nullptr);
+    }
+    // Set default message decorators
+    set_default_decorators();
+}
+
+Logger::Logger(std::string                              name,
+               LogLevel                                 log_level,
+               std::vector<std::shared_ptr<Printer>>    printers,
+               std::vector<std::unique_ptr<IDecorator>> decorators)
+    : _name(std::move(name)), _log_level(log_level), _printers(std::move(printers)), _decorators(std::move(decorators))
+{
+    // Check printers
+    for(const auto &p : _printers)
+    {
+        ARM_COMPUTE_UNUSED(p);
+        ARM_COMPUTE_ERROR_ON(p == nullptr);
+    }
+    // Check decorators
+    for(const auto &d : _decorators)
+    {
+        ARM_COMPUTE_UNUSED(d);
+        ARM_COMPUTE_ERROR_ON(d == nullptr);
+    }
+}
+
+void Logger::log(LogLevel log_level, const std::string &msg)
+{
+    // Return if message shouldn't be logged
+    // i.e. if log level does not match the logger's
+    if(!is_loggable(log_level))
+    {
+        return;
+    }
+
+    // Print message to all printers
+    print_all(create_log_msg(msg, log_level));
+}
+
+void Logger::set_log_level(LogLevel log_level)
+{
+    _log_level = log_level;
+}
+
+LogLevel Logger::log_level() const
+{
+    return _log_level;
+}
+
+std::string Logger::name() const
+{
+    return _name;
+}
+
+void Logger::add_printer(std::shared_ptr<Printer> printer)
+{
+    ARM_COMPUTE_ERROR_ON(printer == nullptr);
+    _printers.push_back(std::move(printer));
+}
+
+void Logger::add_decorator(std::unique_ptr<IDecorator> decorator)
+{
+    ARM_COMPUTE_ERROR_ON(decorator == nullptr);
+    _decorators.push_back(std::move(decorator));
+}
+
+void Logger::set_default_decorators()
+{
+    _decorators.emplace_back(support::cpp14::make_unique<StringDecorator>(_name));
+    _decorators.emplace_back(support::cpp14::make_unique<DateDecorator>());
+    _decorators.emplace_back(support::cpp14::make_unique<LogLevelDecorator>());
+}
+
+bool Logger::is_loggable(LogLevel log_level)
+{
+    return (log_level >= _log_level);
+}
+
+void Logger::decorate_log_msg(LogMsg &msg)
+{
+    for(const auto &d : _decorators)
+    {
+        d->decorate(msg);
+    }
+    msg.raw_ += std::string(" ");
+}
+
+std::string Logger::create_log_msg(const std::string &str, LogLevel log_level)
+{
+    // Adding space string to avoid Android failures
+    LogMsg log_msg(" ", log_level);
+    decorate_log_msg(log_msg);
+    std::ostringstream ss;
+    ss << log_msg.raw_ << " " << str;
+    return ss.str();
+}
+
+void Logger::print_all(const std::string &msg)
+{
+    for(auto &p : _printers)
+    {
+        p->print(msg);
+    }
+}
\ No newline at end of file
diff --git a/src/core/utils/logging/LoggerRegistry.cpp b/src/core/utils/logging/LoggerRegistry.cpp
new file mode 100644
index 0000000..99236d2
--- /dev/null
+++ b/src/core/utils/logging/LoggerRegistry.cpp
@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2017 ARM Limited.
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include "arm_compute/core/utils/logging/LoggerRegistry.h"
+
+#include "arm_compute/core/Error.h"
+#include "support/ToolchainSupport.h"
+
+using namespace arm_compute::logging;
+
+/** Reserved logger used by the library */
+std::set<std::string> LoggerRegistry::_reserved_loggers = { "CORE", "RUNTIME", "GRAPH" };
+
+LoggerRegistry::LoggerRegistry()
+    : _mtx(), _loggers()
+{
+}
+
+LoggerRegistry &LoggerRegistry::get()
+{
+    static LoggerRegistry _instance;
+    return _instance;
+}
+
+void LoggerRegistry::create_logger(const std::string &name, LogLevel log_level, std::vector<std::shared_ptr<Printer>> printers)
+{
+    std::lock_guard<arm_compute::Mutex> lock(_mtx);
+    if((_loggers.find(name) == _loggers.end()) && (_reserved_loggers.find(name) == _reserved_loggers.end()))
+    {
+        _loggers[name] = std::make_shared<Logger>(name, log_level, std::move(printers));
+    }
+}
+
+void LoggerRegistry::remove_logger(const std::string &name)
+{
+    std::lock_guard<arm_compute::Mutex> lock(_mtx);
+    if(_loggers.find(name) != _loggers.end())
+    {
+        _loggers.erase(name);
+    }
+}
+
+std::shared_ptr<Logger> LoggerRegistry::logger(const std::string &name)
+{
+    std::lock_guard<arm_compute::Mutex> lock(_mtx);
+    return (_loggers.find(name) != _loggers.end()) ? _loggers[name] : nullptr;
+}
+
+void LoggerRegistry::create_reserved_loggers(LogLevel log_level, std::vector<std::shared_ptr<Printer>> printers)
+{
+    std::lock_guard<arm_compute::Mutex> lock(_mtx);
+    for(const auto &r : _reserved_loggers)
+    {
+        if(_loggers.find(r) == _loggers.end())
+        {
+            _loggers[r] = std::make_shared<Logger>(r, log_level, printers);
+        }
+    }
+}