]> git.lizzy.rs Git - dragonfireclient.git/blobdiff - src/log.h
Merge pull request #59 from PrairieAstronomer/readme_irrlicht_change
[dragonfireclient.git] / src / log.h
index 952ebadb1959a8544ea2b1f1a139e33007136c9f..0a84332e70b80416fcff76f500556b053a63e6e1 100644 (file)
--- a/src/log.h
+++ b/src/log.h
@@ -19,6 +19,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #pragma once
 
+#include <atomic>
 #include <map>
 #include <queue>
 #include <string>
@@ -28,6 +29,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #if !defined(_WIN32)  // POSIX
        #include <unistd.h>
 #endif
+#include "threading/mutex_auto_lock.h"
+#include "util/basic_macros.h"
+#include "util/stream.h"
 #include "irrlichttypes.h"
 
 class ILogOutput;
@@ -39,6 +43,7 @@ enum LogLevel {
        LL_ACTION,  // In-game actions
        LL_INFO,
        LL_VERBOSE,
+       LL_TRACE,
        LL_MAX,
 };
 
@@ -67,12 +72,13 @@ class Logger {
        // Logs without a prefix
        void logRaw(LogLevel lev, const std::string &text);
 
-       void setTraceEnabled(bool enable) { m_trace_enabled = enable; }
-       bool getTraceEnabled() { return m_trace_enabled; }
-
        static LogLevel stringToLevel(const std::string &name);
        static const std::string getLevelLabel(LogLevel lev);
 
+       bool hasOutput(LogLevel level) {
+               return m_has_outputs[level].load(std::memory_order_relaxed);
+       }
+
        static LogColor color_mode;
 
 private:
@@ -84,6 +90,7 @@ class Logger {
        const std::string getThreadName();
 
        std::vector<ILogOutput *> m_outputs[LL_MAX];
+       std::atomic<bool> m_has_outputs[LL_MAX];
 
        // Should implement atomic loads and stores (even though it's only
        // written to when one thread has access currently).
@@ -91,7 +98,6 @@ class Logger {
        volatile bool m_silenced_levels[LL_MAX];
        std::map<std::thread::id, std::string> m_thread_names;
        mutable std::mutex m_mutex;
-       bool m_trace_enabled;
 };
 
 class ILogOutput {
@@ -118,54 +124,22 @@ class StreamLogOutput : public ICombinedLogOutput {
                m_stream(stream)
        {
 #if !defined(_WIN32)
-               colored = (Logger::color_mode == LOG_COLOR_ALWAYS) ||
-                       (Logger::color_mode == LOG_COLOR_AUTO && isatty(fileno(stdout)));
+               is_tty = isatty(fileno(stdout));
 #else
-               colored = Logger::color_mode == LOG_COLOR_ALWAYS;
+               is_tty = false;
 #endif
        }
 
-       void logRaw(LogLevel lev, const std::string &line)
-       {
-               bool colored_message = colored;
-               if (colored_message)
-                       switch (lev) {
-                       case LL_ERROR:
-                               // error is red
-                               m_stream << "\033[91m";
-                               break;
-                       case LL_WARNING:
-                               // warning is yellow
-                               m_stream << "\033[93m";
-                               break;
-                       case LL_INFO:
-                               // info is a bit dark
-                               m_stream << "\033[37m";
-                               break;
-                       case LL_VERBOSE:
-                               // verbose is darker than info
-                               m_stream << "\033[2m";
-                               break;
-                       default:
-                               // action is white
-                               colored_message = false;
-                       }
-
-               m_stream << line << std::endl;
-
-               if (colored_message)
-                       // reset to white color
-                       m_stream << "\033[0m";
-       }
+       void logRaw(LogLevel lev, const std::string &line);
 
 private:
        std::ostream &m_stream;
-       bool colored;
+       bool is_tty;
 };
 
 class FileLogOutput : public ICombinedLogOutput {
 public:
-       void open(const std::string &filename);
+       void setFile(const std::string &filename, s64 file_size_max);
 
        void logRaw(LogLevel lev, const std::string &line)
        {
@@ -178,80 +152,224 @@ class FileLogOutput : public ICombinedLogOutput {
 
 class LogOutputBuffer : public ICombinedLogOutput {
 public:
-       LogOutputBuffer(Logger &logger, LogLevel lev) :
+       LogOutputBuffer(Logger &logger) :
                m_logger(logger)
        {
-               m_logger.addOutput(this, lev);
-       }
+               updateLogLevel();
+       };
 
-       ~LogOutputBuffer()
+       virtual ~LogOutputBuffer()
        {
                m_logger.removeOutput(this);
        }
 
-       void logRaw(LogLevel lev, const std::string &line)
+       void updateLogLevel();
+
+       void logRaw(LogLevel lev, const std::string &line);
+
+       void clear()
        {
-               m_buffer.push(line);
+               MutexAutoLock lock(m_buffer_mutex);
+               m_buffer = std::queue<std::string>();
        }
 
-       bool empty()
+       bool empty() const
        {
+               MutexAutoLock lock(m_buffer_mutex);
                return m_buffer.empty();
        }
 
        std::string get()
        {
-               if (empty())
+               MutexAutoLock lock(m_buffer_mutex);
+               if (m_buffer.empty())
                        return "";
-               std::string s = m_buffer.front();
+               std::string s = std::move(m_buffer.front());
                m_buffer.pop();
                return s;
        }
 
 private:
+       // g_logger serializes calls to logRaw() with a mutex, but that
+       // doesn't prevent get() / clear() from being called on top of it.
+       // This mutex prevents that.
+       mutable std::mutex m_buffer_mutex;
        std::queue<std::string> m_buffer;
        Logger &m_logger;
 };
 
+#ifdef __ANDROID__
+class AndroidLogOutput : public ICombinedLogOutput {
+public:
+       void logRaw(LogLevel lev, const std::string &line);
+};
+#endif
 
-extern StreamLogOutput stdout_output;
-extern StreamLogOutput stderr_output;
-extern std::ostream null_stream;
+/*
+ * LogTarget
+ *
+ * This is the interface that sits between the LogStreams and the global logger.
+ * Primarily used to route streams to log levels, but could also enable other
+ * custom behavior.
+ *
+ */
+class LogTarget {
+public:
+       // Must be thread-safe. These can be called from any thread.
+       virtual bool hasOutput() = 0;
+       virtual void log(const std::string &buf) = 0;
+};
 
-extern std::ostream *dout_con_ptr;
-extern std::ostream *derr_con_ptr;
-extern std::ostream *dout_server_ptr;
-extern std::ostream *derr_server_ptr;
 
-#ifndef SERVER
-extern std::ostream *dout_client_ptr;
-extern std::ostream *derr_client_ptr;
-#endif
+/*
+ * StreamProxy
+ *
+ * An ostream-like object that can proxy to a real ostream or do nothing,
+ * depending on how it is configured. See LogStream below.
+ *
+ */
+class StreamProxy {
+public:
+       StreamProxy(std::ostream *os) : m_os(os) { }
+
+       template<typename T>
+       StreamProxy& operator<<(T&& arg) {
+               if (m_os) {
+                       *m_os << std::forward<T>(arg);
+               }
+               return *this;
+       }
 
-extern Logger g_logger;
+       StreamProxy& operator<<(std::ostream& (*manip)(std::ostream&)) {
+               if (m_os) {
+                       *m_os << manip;
+               }
+               return *this;
+       }
 
-// Writes directly to all LL_NONE log outputs for g_logger with no prefix.
-extern std::ostream rawstream;
+private:
+       std::ostream *m_os;
+};
 
-extern std::ostream errorstream;
-extern std::ostream warningstream;
-extern std::ostream actionstream;
-extern std::ostream infostream;
-extern std::ostream verbosestream;
-extern std::ostream dstream;
 
-#define TRACEDO(x) do {               \
-       if (g_logger.getTraceEnabled()) { \
-               x;                            \
-       }                                 \
-} while (0)
+/*
+ * LogStream
+ *
+ * The public interface for log streams (infostream, verbosestream, etc).
+ *
+ * LogStream minimizes the work done when a given stream is off. (meaning
+ * it has no output targets, so it goes to /dev/null)
+ *
+ * For example, consider:
+ *
+ *     verbosestream << "hello world" << 123 << std::endl;
+ *
+ * The compiler evaluates this as:
+ *
+ *   (((verbosestream << "hello world") << 123) << std::endl)
+ *      ^                            ^
+ *
+ * If `verbosestream` is on, the innermost expression (marked by ^) will return
+ * a StreamProxy that forwards to a real ostream, that feeds into the logger.
+ * However, if `verbosestream` is off, it will return a StreamProxy that does
+ * nothing on all later operations. Specifically, CPU time won't be wasted
+ * writing "hello world" and 123 into a buffer, or formatting the log entry.
+ *
+ * It is also possible to directly check if the stream is on/off:
+ *
+ *   if (verbosestream) {
+ *       auto data = ComputeExpensiveDataForTheLog();
+ *       verbosestream << data << endl;
+ *   }
+ *
+*/
+
+class LogStream {
+public:
+       LogStream() = delete;
+       DISABLE_CLASS_COPY(LogStream);
+
+       LogStream(LogTarget &target) :
+               m_target(target),
+               m_buffer(std::bind(&LogStream::internalFlush, this, std::placeholders::_1)),
+               m_dummy_buffer(),
+               m_stream(&m_buffer),
+               m_dummy_stream(&m_dummy_buffer),
+               m_proxy(&m_stream),
+               m_dummy_proxy(nullptr) { }
+
+       template<typename T>
+       StreamProxy& operator<<(T&& arg) {
+               StreamProxy& sp = m_target.hasOutput() ? m_proxy : m_dummy_proxy;
+               sp << std::forward<T>(arg);
+               return sp;
+       }
 
-#define TRACESTREAM(x) TRACEDO(verbosestream x)
+       StreamProxy& operator<<(std::ostream& (*manip)(std::ostream&)) {
+               StreamProxy& sp = m_target.hasOutput() ? m_proxy : m_dummy_proxy;
+               sp << manip;
+               return sp;
+       }
+
+       operator bool() {
+               return m_target.hasOutput();
+       }
 
-#define dout_con (*dout_con_ptr)
-#define derr_con (*derr_con_ptr)
-#define dout_server (*dout_server_ptr)
+       void internalFlush(const std::string &buf) {
+               m_target.log(buf);
+       }
 
-#ifndef SERVER
-       #define dout_client (*dout_client_ptr)
+       operator std::ostream&() {
+               return m_target.hasOutput() ? m_stream : m_dummy_stream;
+       }
+
+private:
+       // 10 streams per thread x (256 + overhead) ~ 3K per thread
+       static const int BUFFER_LENGTH = 256;
+       LogTarget &m_target;
+       StringStreamBuffer<BUFFER_LENGTH> m_buffer;
+       DummyStreamBuffer m_dummy_buffer;
+       std::ostream m_stream;
+       std::ostream m_dummy_stream;
+       StreamProxy m_proxy;
+       StreamProxy m_dummy_proxy;
+
+};
+
+#ifdef __ANDROID__
+extern AndroidLogOutput stdout_output;
+extern AndroidLogOutput stderr_output;
+#else
+extern StreamLogOutput stdout_output;
+extern StreamLogOutput stderr_output;
 #endif
+
+extern Logger g_logger;
+
+/*
+ * By making the streams thread_local, each thread has its own
+ * private buffer. Two or more threads can write to the same stream
+ * simultaneously (lock-free), and there won't be any interference.
+ *
+ * The finished lines are sent to a LogTarget which is a global (not thread-local)
+ * object, and from there relayed to g_logger. The final writes are serialized
+ * by the mutex in g_logger.
+*/
+
+extern thread_local LogStream dstream;
+extern thread_local LogStream rawstream;  // Writes directly to all LL_NONE log outputs with no prefix.
+extern thread_local LogStream errorstream;
+extern thread_local LogStream warningstream;
+extern thread_local LogStream actionstream;
+extern thread_local LogStream infostream;
+extern thread_local LogStream verbosestream;
+extern thread_local LogStream tracestream;
+// TODO: Search/replace these with verbose/tracestream
+extern thread_local LogStream derr_con;
+extern thread_local LogStream dout_con;
+
+#define TRACESTREAM(x) do {    \
+       if (tracestream) {      \
+               tracestream x;  \
+       }                       \
+} while (0)