Initial cut of zero GC logging lib

Cheated by not offloading to async thread yet

9 files changed, 603 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..6873309
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,32 @@
+target
+prop
+out
+
+# OS X
+.DS_Store
+
+# intellij
+.idea
+*.iml
+
+# eclipse
+.project
+.classpath
+.settings
+
+# editors
+*.sublime-project
+*.sublime-workspace
+*~
+
+# the build
+build-local.properties
+.gradle
+build
+
+# Benchmark timings
+timings.log
+
+# JVM crash reports
+hs_err_pid*
+/bin/
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 0000000..6676a6b
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,37 @@
+/*
+ * This file was generated by the Gradle 'init' task.
+ *
+ * This generated file contains a sample Java Library project to get you started.
+ * For more details take a look at the Java Libraries chapter in the Gradle
+ * User Manual available at https://docs.gradle.org/5.6.1/userguide/java_library_plugin.html
+ */
+
+plugins {
+    // Apply the java-library plugin to add support for Java Library
+    id 'java-library'
+}
+
+repositories {
+    // Use jcenter for resolving dependencies.
+    // You can declare any Maven/Ivy/file repository here.
+    mavenCentral()
+}
+
+dependencies {
+    // This dependency is exported to consumers, that is to say found on their compile classpath.
+    api 'org.agrona:agrona:1.0.7'
+
+    // This dependency is used internally, and not exposed to consumers on their own compile classpath.
+//    implementation 'com.google.guava:guava:28.0-jre'
+
+    // Use JUnit Jupiter API for testing.
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.4.2'
+
+    // Use JUnit Jupiter Engine for testing.
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.4.2'
+}
+
+test {
+    // Use junit platform for unit tests
+    useJUnitPlatform()
+}
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..5c2d1cf
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.jar
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..c8e083c
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Sun Sep 08 05:36:33 BST 2019
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.1-all.zip
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStorePath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
diff --git a/gradlew b/gradlew
new file mode 100755
index 0000000..83f2acf
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,188 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# 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
+#
+#      https://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.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+  cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..24467a1
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,100 @@
+@rem

+@rem Copyright 2015 the original author or authors.

+@rem

+@rem Licensed under the Apache License, Version 2.0 (the "License");

+@rem you may not use this file except in compliance with the License.

+@rem You may obtain a copy of the License at

+@rem

+@rem      https://www.apache.org/licenses/LICENSE-2.0

+@rem

+@rem Unless required by applicable law or agreed to in writing, software

+@rem distributed under the License is distributed on an "AS IS" BASIS,

+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

+@rem See the License for the specific language governing permissions and

+@rem limitations under the License.

+@rem

+

+@if "%DEBUG%" == "" @echo off

+@rem ##########################################################################

+@rem

+@rem  Gradle startup script for Windows

+@rem

+@rem ##########################################################################

+

+@rem Set local scope for the variables with windows NT shell

+if "%OS%"=="Windows_NT" setlocal

+

+set DIRNAME=%~dp0

+if "%DIRNAME%" == "" set DIRNAME=.

+set APP_BASE_NAME=%~n0

+set APP_HOME=%DIRNAME%

+

+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.

+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"

+

+@rem Find java.exe

+if defined JAVA_HOME goto findJavaFromJavaHome

+

+set JAVA_EXE=java.exe

+%JAVA_EXE% -version >NUL 2>&1

+if "%ERRORLEVEL%" == "0" goto init

+

+echo.

+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.

+echo.

+echo Please set the JAVA_HOME variable in your environment to match the

+echo location of your Java installation.

+

+goto fail

+

+:findJavaFromJavaHome

+set JAVA_HOME=%JAVA_HOME:"=%

+set JAVA_EXE=%JAVA_HOME%/bin/java.exe

+

+if exist "%JAVA_EXE%" goto init

+

+echo.

+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%

+echo.

+echo Please set the JAVA_HOME variable in your environment to match the

+echo location of your Java installation.

+

+goto fail

+

+:init

+@rem Get command-line arguments, handling Windows variants

+

+if not "%OS%" == "Windows_NT" goto win9xME_args

+

+:win9xME_args

+@rem Slurp the command line arguments.

+set CMD_LINE_ARGS=

+set _SKIP=2

+

+:win9xME_args_slurp

+if "x%~1" == "x" goto execute

+

+set CMD_LINE_ARGS=%*

+

+:execute

+@rem Setup the command line

+

+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar

+

+@rem Execute Gradle

+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%

+

+:end

+@rem End local scope for the variables with windows NT shell

+if "%ERRORLEVEL%"=="0" goto mainEnd

+

+:fail

+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of

+rem the _cmd.exe /c_ return code!

+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1

+exit /b 1

+

+:mainEnd

+if "%OS%"=="Windows_NT" endlocal

+

+:omega

diff --git a/settings.gradle b/settings.gradle
new file mode 100644
index 0000000..34460eb
--- /dev/null
+++ b/settings.gradle
@@ -0,0 +1,10 @@
+/*
+ * This file was generated by the Gradle 'init' task.
+ *
+ * The settings file is used to specify which projects to include in your build.
+ *
+ * Detailed information about configuring a multi-project build in Gradle can be found
+ * in the user manual at https://docs.gradle.org/5.6.1/userguide/multi_project_builds.html
+ */
+
+rootProject.name = 'logging'
diff --git a/src/main/java/org/mamago/logging/Logger.java b/src/main/java/org/mamago/logging/Logger.java
new file mode 100644
index 0000000..6610da8
--- /dev/null
+++ b/src/main/java/org/mamago/logging/Logger.java
@@ -0,0 +1,213 @@
+package org.mamago.logging;
+
+import sun.misc.HexDumpEncoder;
+
+import java.nio.ByteBuffer;
+
+import static java.lang.Math.min;
+
+public class Logger {
+    public enum Level {TRACE, DEBUG, INFO, WARN, ERROR}
+    private enum TypeMarker {BYTE, CHAR, SHORT, INT, LONG, FLOAT, DOUBLE, CHAR_SEQUENCE, FORMATTABLE}
+
+    private final LogBuilder builder;
+
+    // Factory methods  ------------------------------------
+
+    public static Logger createLogger() {
+        return new Logger(getCallerClass());
+    }
+
+    public static Logger createLogger(CharSequence name) {
+        return new Logger(name);
+    }
+
+    // Instance methods  -----------------------------------
+
+    private Logger(CharSequence name) {
+        builder = new LogBuilder(name.toString());
+    }
+
+    public LogBuilder log(Level level, CharSequence formatSpec) {
+        return builder.reset(level, formatSpec);
+    }
+
+    // Helper methods --------------------------------------
+
+    private static String getCallerClass() {
+        return Thread.currentThread().getStackTrace()[3].getClassName();
+    }
+
+    private static byte b(int i) {
+        // @Fixme[MA]: check whether casting give out-of-bounds check, otherwise add in for safety
+        return (byte) i;
+    }
+
+    // Helper classes --------------------------------------
+
+    public interface Formattable {
+        void formatTo(ByteBuffer b);
+    }
+
+    public static class LogBuilder implements Appendable {
+        // @Fixme[MA]: buffer needs to be auto-expandable
+        private final ByteBuffer headerBuf = ByteBuffer.allocate(256);
+        private final Header header;
+        // @Fixme[MA]: buffer needs to be auto-expandable
+        private final ByteBuffer buffer = ByteBuffer.allocate(256);
+        private Level level;
+
+        private LogBuilder(CharSequence loggerName) {
+            // @Optimisation[MA]: Write logger name to the header buffer once. Should never have to be written again,
+            // as LogBuilders are not shareable between loggers. In the event of seeing corruption of header buffer
+            // data in the wild can remove this mini-optimisation and just write logger name every time in log() call.
+            // (Though the real question would be: how if the buffer getting corrupted?)
+            header = new Header(loggerName);
+        }
+
+        @Override
+        public LogBuilder append(CharSequence csq) {
+            append(csq, 0, csq.length());
+            return this;
+        }
+
+        @Override
+        public LogBuilder append(CharSequence csq, int start, int end) {
+            buffer.put(b(TypeMarker.CHAR_SEQUENCE.ordinal()));
+            buffer.putInt(end - start); // length
+            for (int i = start; i < end; i++) {
+                append(csq.charAt(i));
+            }
+            return this;
+        }
+
+        @Override
+        public LogBuilder append(char c) {
+            buffer.put(b(TypeMarker.CHAR.ordinal()));
+            buffer.put(b(c));
+            return this;
+        }
+
+        @Deprecated // @Fixme[MA]: really want an annotation to create a compiler warning.
+        public LogBuilder append(String s) {
+            append((CharSequence) s);
+            return this;
+        }
+
+        public LogBuilder append(Formattable f) {
+            buffer.put(b(TypeMarker.FORMATTABLE.ordinal()));
+            // @Fixme[MA]: Implement this!
+            throw new RuntimeException("Not yet implemented");
+//            return this;
+        }
+
+        public LogBuilder append(byte b) {
+            buffer.put(b(TypeMarker.BYTE.ordinal()));
+            buffer.put(b);
+            return this;
+        }
+
+        public LogBuilder append(short s) {
+            buffer.put(b(TypeMarker.SHORT.ordinal()));
+            buffer.putShort(s);
+            return this;
+        }
+
+        public LogBuilder append(int i) {
+            buffer.put(b(TypeMarker.INT.ordinal()));
+            buffer.putInt(i);
+            return this;
+        }
+
+        public LogBuilder append(long l) {
+            buffer.put(b(TypeMarker.LONG.ordinal()));
+            buffer.putLong(l);
+            return this;
+        }
+
+        public LogBuilder append(float f) {
+            buffer.put(b(TypeMarker.FLOAT.ordinal()));
+            buffer.putFloat(f);
+            return this;
+        }
+
+        public LogBuilder append(double d) {
+            buffer.put(b(TypeMarker.DOUBLE.ordinal()));
+            buffer.putDouble(d);
+            return this;
+        }
+
+        // @Fixme[MA]: should generate a compiler warning if a log statement is missing the .log() call
+        public void log() {
+            Thread ct = Thread.currentThread();
+            header.timestamp(System.currentTimeMillis()) // @Fixme[MA] Use high precision wall clock
+                    .level(level)
+                    .threadId(ct.getId()).threadName(ct.getName());
+//            logRingBuffer.write(headerBuf, buffer);
+            HexDumpEncoder encoder = new HexDumpEncoder();
+            System.out.println("Header:");
+            headerBuf.position(0).limit(headerBuf.get(0));
+            System.out.println(encoder.encodeBuffer(headerBuf));
+            System.out.println("Args:");
+            System.out.println(encoder.encodeBuffer((ByteBuffer) buffer.flip()));
+        }
+
+        public LogBuilder reset(Level level, CharSequence formatSpec) {
+            this.level = level;
+            buffer.clear();
+            append(formatSpec);
+            return this;
+        }
+
+        // Helper classes ----------------------------------
+
+        // @Speedup[MA]: this implementation just packs everything tight in the header.
+        // It is possible that alignment optimisations may make this faster.
+        private class Header {
+            private final int tsOffset;
+            private final int levelOffset;
+            private final int tidOffset;
+            private final int tNameOffset;
+
+            Header(CharSequence loggerName) {
+                tsOffset = put(1, loggerName);
+                levelOffset = tsOffset + 8;
+                tidOffset = levelOffset + 1;
+                tNameOffset = tidOffset + 8;
+            }
+
+            Header timestamp(long ts) {
+                System.out.println("ts = " + ts);
+                headerBuf.putLong(tsOffset, ts);
+                return this;
+            }
+
+            Header level(Level level) {
+                headerBuf.put(levelOffset, b(level.ordinal()));
+                return this;
+            }
+
+            Header threadId(long tid) {
+                headerBuf.putLong(tidOffset, tid);
+                return this;
+            }
+
+            // Does not return this reference, as this is the terminator for building the header buffer
+            void threadName(CharSequence tName) {
+                // Write header size to first byte
+                headerBuf.put(0, b(put(tNameOffset, tName)));
+            }
+
+            private int put(int offset, CharSequence csq) {
+                // @Optimisation[MA]: CharSequence length as a byte, as we chop header char sequences short (we don't
+                // expect long thread or logger names).
+                int length = min(csq.length(), 50);
+                headerBuf.put(offset++, b(length));
+                for (int i = 0; i < length; i++) {
+                    headerBuf.put(offset++, (byte) csq.charAt(i));
+                }
+                return offset;
+            }
+        }
+    }
+}
diff --git a/src/test/java/org/mamago/logging/LoggerTest.java b/src/test/java/org/mamago/logging/LoggerTest.java
new file mode 100644
index 0000000..3a1efbd
--- /dev/null
+++ b/src/test/java/org/mamago/logging/LoggerTest.java
@@ -0,0 +1,17 @@
+package org.mamago.logging;
+
+import org.junit.jupiter.api.Test;
+
+public class LoggerTest {
+    final static Logger LOG = Logger.createLogger();
+
+    @Test
+    public void testLogger() {
+        System.out.println("header length = " +
+                ( 1 // Header length
+                + 1 // Thread name length
+                + LoggerTest.class.getName().length()
+                + 8 + 8 + 1 + "main".length() + 1));
+        LOG.log(Logger.Level.INFO, "Log this {}").append(3).log();
+    }
+}