remove reviewboardrc

We don't use the review board anymore.

.reviewboardrc

@@ -1,2 +0,0 @@
-REVIEWBOARD_URL = 'http:///'
-REPOSITORY = 'PrimitiveCollections'

README.md

@@ -1,19 +1,11 @@
 Java collections for primitives (currently only int) released under [MIT](https://opensource.org/licenses/MIT) license.
 
-*IntList* and *LongList* are implementations of lists that store primitive integers/longs. The ints/longs are stored in an int/long array and the class takes care of growing the array as needed. You can trim the list to reduce the memory overhead. No dependencies.
+*IntList* and *LongList* are implementations of lists that store primitive integers/longs. The ints/longs are stored in an int/long array and the class takes care of growing the array as needed. You can trim the list to reduce the memory overhead. The feature that separates this implementation from others is that the lists keep track of whether they are sorted. This enables powerfull optimizations for searching, union or retain operations.
 
-The lists support the following operations: 
+*LongLongHashMap* and *LongObjHashMap* are maps that use primitive longs as keys.
+
+*Sparse2DLongArray* is a memory efficient alternative to *long[][]*. In contrast to *long[][]* the indices are signed longs, which allows you to have negative keys and keys > 2^31.
 
-* add/remove elements via single and bulk operations
-* replace elements
-* sort and shuffle
-* the lists know whether or not they are sorted and can leverage that knowledge for searching (binary search), union and intersection
-* search for elements
-* union, intersection, retainIf, retainAll removeIf, removeAll
-* clear and trim are separate methods, so that the list can be re-used without having to re-allocate memory
-* stream support
-* the lists are serializable and cloneable
-* the lists are **not** thread-safe
 
 # How to use
 The library is still considered beta. There no pre-build artifacts on Maven Central or JCenter, but you can download them from repo.lucares.org.
@@ -21,32 +13,35 @@ The library is still considered beta. There no pre-build artifacts on Maven Cent
 Example for Gradle:
 
 ```groovy
-apply plugin: 'maven'
 repositories {
-	maven { url 'https://repo.lucares.org/' }
+	maven { url 'https://repo.lucares.de/' }
 }
 dependencies {
-	compile 'org.lucares:primitiveCollections:0.1.20181120195412'
+	compile 'org.lucares:primitiveCollections:0.3'
 }
 ```
 
 # Examples
 
+## IntList / LongList
+An alternative to `int[]`/`long[]` that grows dynamically. The list supports a few features that are either not supported
+by arrays or that would be expensive to implement. The most unique feature is that the list knows if it is sorted.
+
+### isSorted()
+The lists keep track of whether they are sorted or not. This makes the call to `isSorted()` very cheap, because we only have to return the value of a field. The drawback is that some operations are much more expensive. This affects `shuffle()`,
+as well as `remove(int, int)`, `removeIf()`, `removeAll(IntList)` and 'retainAll()' if the list was not sorted before. 
+
+The fact that we know if a list is sorted allows us to use more efficient algorithms for `union(IntList, IntList)`, `intersection(IntList, IntList)`, `indexOf(int)`, `lastIndexOf()` and `uniq()`.
+
 ```java
-import org.lucares.collections.IntList;
+final IntList list = IntList.of(1, 3, 5);
+System.out.println(list + " is sorted: " + list.isSorted());
 
-public class Example {
-	public static void main(final String[] args) {
-		final IntList list = IntList.of(1, 3, 5);
-		System.out.println(list + " is sorted: " + list.isSorted());
+list.insert(2, 7);
+System.out.println(list + " is sorted: " + list.isSorted());
 
-		list.insert(2, 7);
-		System.out.println(list + " is sorted: " + list.isSorted());
-
-		list.sort();
-		System.out.println(list + " is sorted: " + list.isSorted());
-	}
-}
+list.sort();
+System.out.println(list + " is sorted: " + list.isSorted());
 
 ```
 Running this program gives the following output:
@@ -56,3 +51,6 @@ Running this program gives the following output:
 [1, 3, 7, 5] is sorted: false
 [1, 3, 5, 7] is sorted: true
 ```
+
+
+

build.gradle

@@ -1,51 +1,53 @@
-
+/*
 buildscript {
   repositories {
     maven {
       url "https://plugins.gradle.org/m2/"
     }
-    jcenter()
   }
   dependencies {
     // run with Java 11 and ./gradlew --no-daemon clean jmh
-    classpath "me.champeau.gradle:jmh-gradle-plugin:0.5.2"
+    classpath "me.champeau.gradle:jmh-gradle-plugin:0.7.2"
   }
 }
+*/
 
 plugins {
   // usage: gradle dependencyUpdates -Drevision=release
-  id "com.github.ben-manes.versions" version "0.36.0"
+  id "com.github.ben-manes.versions" version "0.45.0"
+ 
 }
 
 apply plugin: 'java'
 apply plugin: 'eclipse'
 
+ext {
+  javaVersion=17
+  version_junit = '5.9.2'
+  version_junit_platform = '1.9.2'
+}
+
+
 // java compatibility version
-sourceCompatibility = 11
+sourceCompatibility = javaVersion
 
 /*
  * The shared configuration for all sub-projects:
  */
 subprojects {
-	apply plugin: 'java'
+	apply plugin: 'java-library'
 	apply plugin: 'eclipse'
-	apply plugin: 'maven'
+	//apply plugin: 'maven'
 	apply plugin: 'maven-publish'
-	apply plugin: 'me.champeau.gradle.jmh'
+	apply plugin: 'me.champeau.jmh'
 
 	// java compatibility version
-	sourceCompatibility = 11
+	sourceCompatibility = 17
 	
 	configurations {
 		tests
 	}
-	
-	// the repositories for external depenencies
-	repositories {
-		mavenCentral()
-		jcenter()
-	}
-		
+			
 	/**
 	 * Publish the to a local repository.
 	 * Use 'gradlew publishToMavenLocal' to publish to the local maven repo.
@@ -71,14 +73,20 @@ subprojects {
 	
 	java {
 		withSourcesJar()
+		
+		// Gradle 7.0 put half the dependencies on the module path. But without a module-info.java file 
+		// JUnit didn't want to run because of a class not found error. By disabling modules we ensure
+		// all jars are put on the classpath.
+		modularity.inferModulePath.set(false)
 	}
 
 		
 	// dependencies that all sub-projects have 
 	dependencies {
-		testImplementation 'org.junit.jupiter:junit-jupiter-api:5.7.0'
-    	testRuntime 'org.junit.jupiter:junit-jupiter-engine:5.7.0'
-    	testRuntime 'org.junit.platform:junit-platform-launcher:1.7.0' // needed by eclipse
+		testImplementation "org.junit.jupiter:junit-jupiter-api:${version_junit}"
+		testImplementation "org.junit.jupiter:junit-jupiter-params:${version_junit}"  // for @ParameterizedTest
+    	testRuntimeOnly "org.junit.jupiter:junit-jupiter-engine:${version_junit}"
+    	testRuntimeOnly "org.junit.platform:junit-platform-launcher:${version_junit_platform}" // needed by eclipse
 	}
 	
 	test {
@@ -88,11 +96,12 @@ subprojects {
 	jmh {
 		//jvmArgsAppend = ""
 		resultFormat = "JSON"
-		include = ['.*BenchmarkMultiwayMerge.*'] // include pattern (regular expression) for benchmarks to be executed
+		includes = ['.*BenchmarkMultiwayMerge.*'] // include pattern (regular expression) for benchmarks to be executed
+		//includes = ['.*']
 		//exclude = ['some regular expression'] // exclude pattern (regular expression) for benchmarks to be executed
 	}
 }
 
 wrapper {
-	gradleVersion = '6.8.3'
+	gradleVersion = '8.6'
 }

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.6-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradlew

@@ -1,7 +1,7 @@
-#!/usr/bin/env sh
+#!/bin/sh
 
 #
-# Copyright 2015 the original author or authors.
+# Copyright © 2015-2021 the original authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -17,67 +17,99 @@
 #
 
 ##############################################################################
-##
-##  Gradle start up script for UN*X
-##
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
 ##############################################################################
 
 # 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
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
 done
-SAVED="`pwd`"
-cd "`dirname \"$PRG\"`/" >/dev/null
-APP_HOME="`pwd -P`"
-cd "$SAVED" >/dev/null
 
-APP_NAME="Gradle"
-APP_BASE_NAME=`basename "$0"`
-
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD="maximum"
+MAX_FD=maximum
 
 warn () {
     echo "$*"
-}
+} >&2
 
 die () {
     echo
     echo "$*"
     echo
     exit 1
-}
+} >&2
 
 # 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
-    ;;
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
 esac
 
 CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
@@ -87,9 +119,9 @@ CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 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="$JAVA_HOME/jre/sh/java"
+        JAVACMD=$JAVA_HOME/jre/sh/java
     else
-        JAVACMD="$JAVA_HOME/bin/java"
+        JAVACMD=$JAVA_HOME/bin/java
     fi
     if [ ! -x "$JAVACMD" ] ; then
         die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
@@ -98,88 +130,120 @@ 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.
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        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
 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=`expr $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" ;;
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
     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, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
 
-# 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"
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# 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"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
 
 exec "$JAVACMD" "$@"

gradlew.bat

@@ -14,7 +14,7 @@
 @rem limitations under the License.
 @rem
 
-@if "%DEBUG%" == "" @echo off
+@if "%DEBUG%"=="" @echo off
 @rem ##########################################################################
 @rem
 @rem  Gradle startup script for Windows
@@ -25,7 +25,8 @@
 if "%OS%"=="Windows_NT" setlocal
 
 set DIRNAME=%~dp0
-if "%DIRNAME%" == "" set DIRNAME=.
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
@@ -40,13 +41,13 @@ if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto execute
+if %ERRORLEVEL% equ 0 goto execute
 
-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.
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
@@ -56,11 +57,11 @@ set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
 if exist "%JAVA_EXE%" goto execute
 
-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.
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
@@ -75,13 +76,15 @@ set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
 :end
 @rem End local scope for the variables with windows NT shell
-if "%ERRORLEVEL%"=="0" goto mainEnd
+if %ERRORLEVEL% equ 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
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
 
 :mainEnd
 if "%OS%"=="Windows_NT" endlocal

primitiveCollections/build.gradle

@@ -1,8 +1,8 @@
 
 group='org.lucares'
-version = '0.2'
+version = '0.3'
 
 dependencies {
-	jmh 'org.eclipse.collections:eclipse-collections:10.2.0'
+	jmh 'org.eclipse.collections:eclipse-collections:11.1.0'
 }
 

primitiveCollections/src/main/java/org/lucares/collections/BiLongFunction.java

@@ -0,0 +1,6 @@
+package org.lucares.collections;
+
+@FunctionalInterface
+public interface BiLongFunction {
+	long apply(long key, long value);
+}

primitiveCollections/src/main/java/org/lucares/collections/LongFunction.java

@@ -1,6 +0,0 @@
-package org.lucares.collections;
-
-@FunctionalInterface
-public interface LongFunction {
-	long apply(long value);
-}

primitiveCollections/src/main/java/org/lucares/collections/LongLongHashMap.java

@@ -1,5 +1,6 @@
 package org.lucares.collections;
 
+
 import java.util.Arrays;
 
 /**
@@ -12,7 +13,13 @@ public class LongLongHashMap {
 	// There is no equivalent to null for primitive values. Therefore we have to add
 	// special handling for one long value. Otherwise we couldn't tell if a key is
 	// in the map or not. We chose 0L, because LongList is initially all 0L.
-	private static final long NULL_KEY = 0L;
+	static final long NULL_KEY = 0L;
+	
+	// Needed when checking for the existence of a key. Without it we would be forced to
+	// iterate over all keys. This is caused by the fact that we search for the next free
+	// slot when adding new keys. 
+	// We rely on the fact that the value is -1!
+	static final long REMOVED_KEY = -1L;
 
 	private static final long EMPTY_SLOT = 0L;
 
@@ -27,14 +34,26 @@ public class LongLongHashMap {
 	private long[] values;
 	private int size = 0;
 
+	/**
+	 *  sentinel for the key {@value #NULL_KEY} ({@link #NULL_KEY}). 
+	 *  If this field is not null, then the map contains the key {@value #NULL_KEY} 
+	 */
 	private Long zeroValue = null;
+	
+	/**
+	 *  sentinel for the key {@value #REMOVED_KEY} ({@link #REMOVED_KEY}). 
+	 *  If this field is not null, then the map contains the key {@value #REMOVED_KEY} 
+	 */
+	private Long removedKeyValue = null;
+
+	private int maxCapacity = MAX_ARRAY_SIZE;
 
 	/**
 	 * Create a new {@link LongLongHashMap} with the given initial capacity and load
 	 * factor.
 	 *
 	 * @param initialCapacity the initial capacity
-	 * @param loadFactor      the load factor
+	 * @param loadFactor      the load factor between 0 and 1
 	 */
 	public LongLongHashMap(final int initialCapacity, final double loadFactor) {
 
@@ -44,8 +63,9 @@ public class LongLongHashMap {
 		if (initialCapacity > MAX_ARRAY_SIZE) {
 			throw new IllegalArgumentException("initial capacity must be smaller or equal to " + MAX_ARRAY_SIZE);
 		}
-		if (loadFactor <= 0 || Double.isNaN(loadFactor))
-			throw new IllegalArgumentException("Illegal load factor: " + loadFactor);
+		if (loadFactor <= 0 || Double.isNaN(loadFactor) || loadFactor >= 1.0) {
+			throw new IllegalArgumentException("Illegal load factor, must be between 0 and 1: " + loadFactor);
+		}
 
 		this.fillFactor = loadFactor;
 		keys = new long[initialCapacity];
@@ -60,6 +80,30 @@ public class LongLongHashMap {
 		this(8, 0.75);
 	}
 
+
+	/**
+	 * Sets the maximum capacity.<p>
+	 * This restricts the maximum memory used by this map. The memory consumption can be twice as much during grow or shrink phases.
+	 * <p>
+	 * Note that the performance can suffer if the map contains more keys than capacity time loadFactor.
+	 * <p>
+	 * Note an automatic {@link #rehash()} is triggered if the new maxCapacity is smaller than the current capacity. 
+	 * But there is not automatic rehash when the new maxCapacity is greater than the current capacity. 
+	 * 
+	 * @param maxCapacity new maximum capacity
+	 * @throws IllegalArgumentException if {@code maxCapacity} is smaller than {@link #size()}
+	 */
+	public void setMaxCapacity(int maxCapacity) {
+		if (maxCapacity < size) {
+			throw new IllegalArgumentException("maxCapacity must equal or larger than current size of the map");
+		}
+		this.maxCapacity = maxCapacity;
+		
+		if (maxCapacity < keys.length) {			
+			rehash(maxCapacity);
+		}
+	}
+
 	/**
 	 * The number of entries in this map.
 	 *
@@ -68,6 +112,49 @@ public class LongLongHashMap {
 	public int size() {
 		return size;
 	}
+	
+	@Override
+	public String toString() {
+		
+		StringBuilder s = new StringBuilder();
+		
+		if (zeroValue != null) {
+			s.append(NULL_KEY);
+			s.append("=");
+			s.append(zeroValue);
+		}
+		if (removedKeyValue != null) {
+			if (s.length() > 0) {
+				s.append(", ");
+			}
+			s.append(REMOVED_KEY);
+			s.append("=");
+			s.append(removedKeyValue);
+		}
+
+		int values = 0;
+		
+		for (int i = 0; i < keys.length; i++) {
+			if (keys[i] != EMPTY_SLOT && keys[i] != REMOVED_KEY) {
+				if (s.length() > 0) {
+					s.append(", ");
+				}
+				s.append(keys[i]);
+				s.append("=");
+				s.append(this.values[i]);
+				
+				values++;
+				if (values > 10) {
+					s.append(", ...");
+					break;
+				}
+			}
+		}
+		
+		
+		
+		return s.toString();
+	}
 
 	/**
 	 * The capacity of this map.
@@ -83,14 +170,25 @@ public class LongLongHashMap {
 	 *
 	 * @param key   the key
 	 * @param value the value
+	 * @throws IllegalStateException if the map is full, see {@link #setMaxCapacity(int)}
 	 */
 	public void put(final long key, final long value) {
 
+		if (size == maxCapacity) {
+			throw new IllegalStateException("map is full");
+		}
+		
 		if (key == NULL_KEY) {
 			size += zeroValue == null ? 1 : 0;
 			zeroValue = value;
 			return;
 		}
+		
+		if (key == REMOVED_KEY) {
+			size += removedKeyValue == null ? 1 : 0;
+			removedKeyValue = value;
+			return;
+		}
 
 		if ((keys.length * fillFactor) < size) {
 			growAndRehash();
@@ -122,7 +220,13 @@ public class LongLongHashMap {
 			currentPosition = (currentPosition + 1) % keys.length;
 		} while (currentPosition != searchStart);
 
-		throw new IllegalStateException("map is full");
+		// Can happen when all slots where occupied at some time in the past.
+		// Easy to reproduce by adding and immediately removing all keys from 1 to n.
+		// All slots will be marked with REMOVED_KEY.
+		// We fix this by calling rehash(), which will effectively replace all REMOVED_KEY 
+		// with EMPTY_SLOT.
+		rehash();
+		return putInternal(key, value);
 	}
 
 	/**
@@ -140,16 +244,24 @@ public class LongLongHashMap {
 			}
 			return defaultValue;
 		}
+		if (key == REMOVED_KEY) {
+			if (removedKeyValue != null) {
+				return removedKeyValue;
+			}
+			return defaultValue;
+		}
 
 		final int searchStart = spread(key);
 		int currentPosition = searchStart;
 		do {
 			if (keys[currentPosition] == key) {
 				return values[currentPosition];
+			} else if (keys[currentPosition] == EMPTY_SLOT) {
+				return defaultValue;
 			}
 			currentPosition = (currentPosition + 1) % keys.length;
 		} while (currentPosition != searchStart);
-		return defaultValue;
+		return defaultValue;// should never be reached unless the map is full at 100%, which should be impossible with loadFactor < 1.0
 	}
 
 	/**
@@ -163,16 +275,21 @@ public class LongLongHashMap {
 		if (key == NULL_KEY) {
 			return zeroValue != null;
 		}
+		if (key == REMOVED_KEY) {
+			return removedKeyValue != null;
+		}
 
 		final int searchStart = spread(key);
 		int currentPosition = searchStart;
 		do {
 			if (keys[currentPosition] == key) {
 				return true;
+			} else if (keys[currentPosition] == EMPTY_SLOT) {
+				return false;
 			}
 			currentPosition = (currentPosition + 1) % keys.length;
-		} while (currentPosition != searchStart);
-		return false;
+		} while (currentPosition != searchStart); 
+		return false;// should never be reached unless the map is full at 100%, which should be impossible with loadFactor < 1.0
 	}
 
 	/**
@@ -187,17 +304,25 @@ public class LongLongHashMap {
 			zeroValue = null;
 			return;
 		}
+		if (key == REMOVED_KEY) {
+			size -= removedKeyValue != null ? 1 : 0;
+			removedKeyValue = null;
+			return;
+		}
 
 		final int searchStart = spread(key);
 		int currentPosition = searchStart;
 		do {
 			if (keys[currentPosition] == key) {
-				keys[currentPosition] = EMPTY_SLOT;
+				keys[currentPosition] = REMOVED_KEY;
 				size--;
 				return;
+			}else if (keys[currentPosition] == EMPTY_SLOT) {
+				// key didn't exists
+				return;
 			}
 			currentPosition = (currentPosition + 1) % keys.length;
-		} while (currentPosition != searchStart);
+		} while (currentPosition != searchStart); // run around should never happen unless the map is full at 100%
 	}
 
 	/**
@@ -213,13 +338,21 @@ public class LongLongHashMap {
 	 *                             key
 	 * @param function             called to update an existing value
 	 */
-	public void compute(final long key, final long initialValueIfAbsent, final LongFunction function) {
+	public void compute(final long key, final long initialValueIfAbsent, final BiLongFunction function) {
 		if (key == NULL_KEY) {
 			if (zeroValue != null) {
-				zeroValue = function.apply(zeroValue);
+				zeroValue = function.apply(NULL_KEY,zeroValue);
 				return;
 			}
-			zeroValue = function.apply(initialValueIfAbsent);
+			zeroValue = function.apply(NULL_KEY,initialValueIfAbsent);
+			return;
+		}
+		if (key == REMOVED_KEY) {
+			if (removedKeyValue != null) {
+				removedKeyValue = function.apply(REMOVED_KEY, removedKeyValue);
+				return;
+			}
+			removedKeyValue = function.apply(REMOVED_KEY, initialValueIfAbsent);
 			return;
 		}
 
@@ -227,15 +360,19 @@ public class LongLongHashMap {
 		int currentPosition = searchStart;
 		do {
 			if (keys[currentPosition] == key) {
-				final long updatedValue = function.apply(values[currentPosition]);
+				final long updatedValue = function.apply(key, values[currentPosition]);
 				values[currentPosition] = updatedValue;
 				return;
 			}
+			else if (keys[currentPosition] == EMPTY_SLOT) {
+				// key not found
+				break;
+			}
 			currentPosition = (currentPosition + 1) % keys.length;
 		} while (currentPosition != searchStart);
 
 		// key not found -> add it
-		final long newZeroValue = function.apply(initialValueIfAbsent);
+		final long newZeroValue = function.apply(key, initialValueIfAbsent);
 		put(key, newZeroValue);
 	}
 
@@ -249,11 +386,14 @@ public class LongLongHashMap {
 	public void forEach(final LongLongConsumer consumer) {
 
 		if (zeroValue != null) {
-			consumer.accept(0, zeroValue);
+			consumer.accept(NULL_KEY, zeroValue);
+		}
+		if (removedKeyValue != null) {
+			consumer.accept(REMOVED_KEY, removedKeyValue);
 		}
 
 		for (int i = 0; i < keys.length; i++) {
-			if (keys[i] != EMPTY_SLOT) {
+			if (keys[i] != EMPTY_SLOT && keys[i] != REMOVED_KEY) {
 				consumer.accept(keys[i], values[i]);
 			}
 		}
@@ -268,26 +408,36 @@ public class LongLongHashMap {
 	 * @param consumer the consumer
 	 */
 	public void forEachOrdered(final LongLongConsumer consumer) {
-
-		if (zeroValue != null) {
-			consumer.accept(0, zeroValue);
-		}
-
 		final long[] sortedKeys = Arrays.copyOf(keys, keys.length);
 		Arrays.parallelSort(sortedKeys);
 
+		// handle negative keys
 		for (int i = 0; i < sortedKeys.length; i++) {
 			final long key = sortedKeys[i];
-			if (key != EMPTY_SLOT) {
+			if (key < REMOVED_KEY) {
 				consumer.accept(key, get(key, 0)); // the default value of 'get' will not be used, because the key exists
-			} else if (key == EMPTY_SLOT) {
-				final int posFirstKey = findPosOfFirstPositiveKey(sortedKeys);
-				if (posFirstKey < 0) {
-					return;
-				}
-				i = posFirstKey - 1;
+			} else {
+				break;
 			}
 		}
+		
+		// handle the special keys
+		if (removedKeyValue != null) {
+			consumer.accept(REMOVED_KEY, removedKeyValue);
+		}
+		if (zeroValue != null) {
+			consumer.accept(NULL_KEY, zeroValue);
+		}
+		
+		// handle positive keys
+		final int posFirstKey = findPosOfFirstPositiveKey(sortedKeys);
+		if (posFirstKey < 0) {
+			return;
+		}
+		for (int i = posFirstKey; i < sortedKeys.length; i++) {
+			final long key = sortedKeys[i];
+			consumer.accept(key, get(key, 0)); // the default value of 'get' will not be used, because the key exists
+		}
 	}
 
 	static int findPosOfFirstPositiveKey(final long[] sortedKeys) {
@@ -318,19 +468,32 @@ public class LongLongHashMap {
 
 		return low < sortedKeys.length && sortedKeys[low] > EMPTY_SLOT ? low : -1;
 	}
+	
+	/**
+	 * Rehashes all elements of this map.
+	 * <p>
+	 * This is a maintenance operation that should be executed periodically after removing elements.
+	 */
+	public void rehash() {
+		rehash(keys.length);
+	}
 
 	private void growAndRehash() {
+		final int newSize = Math.min(keys.length * 2, maxCapacity);
+		if(newSize != keys.length) {
+			rehash(newSize);
+		}
+	}
+
+	private void rehash(int newSize) {
 		final long[] oldKeys = keys;
 		final long[] oldValues = values;
-
-		final int newSize = Math.min(keys.length * 2, MAX_ARRAY_SIZE);
-
 		keys = new long[newSize];
 		values = new long[newSize];
 
 		for (int i = 0; i < oldKeys.length; i++) {
 			final long key = oldKeys[i];
-			if (key != EMPTY_SLOT) {
+			if (key != EMPTY_SLOT && key != REMOVED_KEY) {
 				final long value = oldValues[i];
 				putInternal(key, value);
 			}

primitiveCollections/src/main/java/org/lucares/collections/LongObjHashMap.java

@@ -14,7 +14,12 @@ public class LongObjHashMap<V> {
 	// There is no equivalent to null for primitive values. Therefore we have to add
 	// special handling for one long value. Otherwise we couldn't tell if a key is
 	// in the map or not. We chose 0L, because LongList is initially all 0L.
-	private static final long NULL_KEY = 0L;
+	static final long NULL_KEY = 0L;
+	
+	// Needed when checking for the existence of a key. Without it we would be forced to
+	// iterate over all keys. This is caused by the fact that we search for the next free
+	// slot when adding new keys. 
+	static final long REMOVED_KEY = -1L;
 
 	private static final long EMPTY_SLOT = 0L;
 
@@ -30,6 +35,7 @@ public class LongObjHashMap<V> {
 	private int size = 0;
 
 	private V zeroValue = null;
+	private V removedValue = null;
 
 	/**
 	 * Create a new {@link LongLongHashMap} with the given initial capacity and load
@@ -47,7 +53,7 @@ public class LongObjHashMap<V> {
 		if (initialCapacity > MAX_ARRAY_SIZE) {
 			throw new IllegalArgumentException("initial capacity must be smaller or equal to " + MAX_ARRAY_SIZE);
 		}
-		if (loadFactor <= 0 || Double.isNaN(loadFactor))
+		if (loadFactor <= 0 || Double.isNaN(loadFactor) || loadFactor >= 1.0)
 			throw new IllegalArgumentException("Illegal load factor: " + loadFactor);
 
 		this.fillFactor = loadFactor;
@@ -94,6 +100,11 @@ public class LongObjHashMap<V> {
 			zeroValue = value;
 			return;
 		}
+		if (key == REMOVED_KEY) {
+			size += removedValue == null ? 1 : 0;
+			removedValue = value;
+			return;
+		}
 
 		if ((keys.length * fillFactor) < size) {
 			growAndRehash();
@@ -125,7 +136,13 @@ public class LongObjHashMap<V> {
 			currentPosition = (currentPosition + 1) % keys.length;
 		} while (currentPosition != searchStart);
 
-		throw new IllegalStateException("map is full");
+		// Can happen when all slots where occupied at some time in the past.
+		// Easy to reproduce by adding and immediately removing all keys from 1 to n.
+		// All slots will be marked with REMOVED_KEY.
+		// We fix this by calling rehash(), which will effectively replace all REMOVED_KEY 
+		// with EMPTY_SLOT.
+		rehash();
+		return putInternal(key, value);
 	}
 
 	/**
@@ -144,6 +161,13 @@ public class LongObjHashMap<V> {
 			}
 			return null;
 		}
+		
+		if (key == REMOVED_KEY) {
+			if (removedValue != null) {
+				return removedValue;
+			}
+			return null;
+		}
 
 		final int searchStart = spread(key);
 		int currentPosition = searchStart;
@@ -167,6 +191,10 @@ public class LongObjHashMap<V> {
 		if (key == NULL_KEY) {
 			return zeroValue != null;
 		}
+		
+		if (key == REMOVED_KEY) {
+			return zeroValue != null;
+		}
 
 		final int searchStart = spread(key);
 		int currentPosition = searchStart;
@@ -176,6 +204,14 @@ public class LongObjHashMap<V> {
 			}
 			currentPosition = (currentPosition + 1) % keys.length;
 		} while (currentPosition != searchStart);
+		
+		// Can happen when all slots where occupied at some time in the past.
+		// Easy to reproduce by adding and immediately removing all keys from 1 to n.
+		// All slots will be marked with REMOVED_KEY.
+		// We fix this by calling rehash(), which will effectively replace all REMOVED_KEY 
+		// with EMPTY_SLOT.
+		rehash();
+		
 		return false;
 	}
 
@@ -191,17 +227,36 @@ public class LongObjHashMap<V> {
 			zeroValue = null;
 			return;
 		}
+		
+		if (key == REMOVED_KEY) {
+			size -= removedValue != null ? 1 : 0;
+			removedValue = null;
+			return;
+		}
 
 		final int searchStart = spread(key);
 		int currentPosition = searchStart;
 		do {
 			if (keys[currentPosition] == key) {
-				keys[currentPosition] = EMPTY_SLOT;
+				keys[currentPosition] = REMOVED_KEY;
 				size--;
 				return;
 			}
+			
+			if (keys[currentPosition] == EMPTY_SLOT) {
+				// key does not exist
+				return;
+			}
+			
 			currentPosition = (currentPosition + 1) % keys.length;
 		} while (currentPosition != searchStart);
+
+		// Can happen when all slots where occupied at some time in the past.
+		// Easy to reproduce by adding and immediately removing all keys from 1 to n.
+		// All slots will be marked with REMOVED_KEY.
+		// We fix this by calling rehash(), which will effectively replace all REMOVED_KEY 
+		// with EMPTY_SLOT.
+		rehash();
 	}
 
 	/**
@@ -226,6 +281,15 @@ public class LongObjHashMap<V> {
 			zeroValue = function.apply(NULL_KEY, initialValueIfAbsent.get());
 			return;
 		}
+		
+		if (key == REMOVED_KEY) {
+			if (removedValue != null) {
+				removedValue = function.apply(REMOVED_KEY, removedValue);
+				return;
+			}
+			removedValue = function.apply(REMOVED_KEY, initialValueIfAbsent.get());
+			return;
+		}
 
 		final int searchStart = spread(key);
 		int currentPosition = searchStart;
@@ -235,6 +299,10 @@ public class LongObjHashMap<V> {
 				values[currentPosition] = updatedValue;
 				return;
 			}
+			if (keys[currentPosition] == EMPTY_SLOT) {
+				// key does not exist
+				break;
+			}
 			currentPosition = (currentPosition + 1) % keys.length;
 		} while (currentPosition != searchStart);
 
@@ -253,11 +321,15 @@ public class LongObjHashMap<V> {
 	public void forEach(final LongObjConsumer<V> consumer) {
 
 		if (zeroValue != null) {
-			consumer.accept(0, zeroValue);
+			consumer.accept(NULL_KEY, zeroValue);
+		}
+		
+		if (removedValue != null) {
+			consumer.accept(REMOVED_KEY, removedValue);
 		}
 
 		for (int i = 0; i < keys.length; i++) {
-			if (keys[i] != EMPTY_SLOT) {
+			if (keys[i] != EMPTY_SLOT && keys[i] != REMOVED_KEY) {
 				consumer.accept(keys[i], values[i]);
 			}
 		}
@@ -272,26 +344,36 @@ public class LongObjHashMap<V> {
 	 * @param consumer the consumer
 	 */
 	public void forEachOrdered(final LongObjConsumer<V> consumer) {
-
-		if (zeroValue != null) {
-			consumer.accept(0, zeroValue);
-		}
-
 		final long[] sortedKeys = Arrays.copyOf(keys, keys.length);
 		Arrays.parallelSort(sortedKeys);
 
+		// handle negative keys
 		for (int i = 0; i < sortedKeys.length; i++) {
 			final long key = sortedKeys[i];
-			if (key != EMPTY_SLOT) {
+			if (key < REMOVED_KEY) {
 				consumer.accept(key, get(key));
-			} else if (key == EMPTY_SLOT) {
-				final int posFirstKey = findPosOfFirstPositiveKey(sortedKeys);
-				if (posFirstKey < 0) {
-					return;
-				}
-				i = posFirstKey - 1;
+			} else {
+				break;
 			}
 		}
+		
+		// handle the special keys
+		if (removedValue != null) {
+			consumer.accept(REMOVED_KEY, removedValue);
+		}
+		if (zeroValue != null) {
+			consumer.accept(NULL_KEY, zeroValue);
+		}
+		
+		// handle positive keys
+		final int posFirstKey = findPosOfFirstPositiveKey(sortedKeys);
+		if (posFirstKey < 0) {
+			return;
+		}
+		for (int i = posFirstKey; i < sortedKeys.length; i++) {
+			final long key = sortedKeys[i];
+			consumer.accept(key, get(key));
+		}
 	}
 
 	static int findPosOfFirstPositiveKey(final long[] sortedKeys) {
@@ -322,20 +404,32 @@ public class LongObjHashMap<V> {
 
 		return low < sortedKeys.length && sortedKeys[low] > EMPTY_SLOT ? low : -1;
 	}
+	
+	/**
+	 * Rehashes all elements of this map.
+	 * <p>
+	 * This is a maintenance operation that should be executed periodically after removing elements.
+	 */
+	public void rehash() {
+		rehash(keys.length);
+	} 
 
-	@SuppressWarnings("unchecked")
 	private void growAndRehash() {
+		final int newSize = Math.min(keys.length * 2, MAX_ARRAY_SIZE);
+		rehash(newSize);
+	}
+	
+	@SuppressWarnings("unchecked")
+	private void rehash(int newSize) {
 		final long[] oldKeys = keys;
 		final V[] oldValues = values;
 
-		final int newSize = Math.min(keys.length * 2, MAX_ARRAY_SIZE);
-
 		keys = new long[newSize];
 		values = (V[]) new Object[newSize];
 
 		for (int i = 0; i < oldKeys.length; i++) {
 			final long key = oldKeys[i];
-			if (key != EMPTY_SLOT) {
+			if (key != EMPTY_SLOT && key != REMOVED_KEY) {
 				final V value = oldValues[i];
 				putInternal(key, value);
 			}

primitiveCollections/src/main/java/org/lucares/collections/MultiwayLongMerger.java

@@ -106,6 +106,12 @@ class MultiwayLongMerger {
 		}
 	}
 
+	/**
+	 * Returns the next power of two that is equal or larger than i.
+	 * or more formally: x where x = 2^n and x >= i for n ∈ ℕ and n minimal
+	 * @param i some positive integer
+	 * @return smallest integer that is a power of two and equal or larger than i
+	 */
 	private static int nextPowOfTwo(int i) {
 		return Integer.highestOneBit(i - 1) << 1;
 	}
@@ -164,22 +170,32 @@ class MultiwayLongMerger {
 		}
 
 		/**
+		 * A heap is a tree where the value of the parent is smaller than the value of its children.
 		 * <pre>
-		 *               7
-		 *           3  
-		 *               8
-		 *       1   
-		 *               9
-		 *           4
-		 *               10
-		 *   0
-		 *               11
-		 *           5
-		 *               12
-		 *       2
-		 *               13
-		 *           6 
+		 *               23
+		 *           13  
 		 *               14
+		 *       9   
+		 *               37
+		 *           24
+		 *               77
+		 *   5
+		 *               44
+		 *           35
+		 *               93
+		 *       7
+		 *               29
+		 *           27 
+		 *               31       ┌────────────────────────┬────┐
+		 *                   ┌────┼──────────────┬────┐    │    │
+		 *    ┌────┬────┐    │    │              │    │    │    │
+		 * ┏━━┷━┳━━━━┳━━━━┳━━┷━┳━━┷━┳━━━━┳━━━━┳━━━━┳━━━━┳━━━━┳━━━━┳━━━━┳━━━━┳━━━━┓
+		 * ┃  5 ┃  9 ┃  7 ┃ 13 ┃ 24 ┃ 35 ┃ 27 ┃ 23 ┃ 14 ┃ 37 ┃ 77 ┃ 93 ┃ 29 ┃ 31 ┃
+		 * ┗━━━━┻━━━━┻━━━━┻━━━━┻━━━━┻━━━━┻━━━━┻━━━━┻━━━━┻━━━━┻━━━━┻━━━━┻━━━━┻━━━━┛
+		 *    0    1    2    3    4    5    6    7    8    9   10   11   12   13  (array indices)
+		 *         │    │    │    │    │    │
+		 *         └────┼────┴────┘    │    │
+		 *              └──────────────┴────┘           
 		 * </pre>
 		 */
 		private void init() {

primitiveCollections/src/test/java/org/lucares/collections/LongLongHashMapTest.java

@@ -1,5 +1,7 @@
 package org.lucares.collections;
 
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
 import java.util.Random;
 import java.util.stream.LongStream;
 
@@ -16,6 +18,11 @@ public class LongLongHashMapTest {
 	public void testNullValue() {
 		putGetRemove(0);
 	}
+	
+	@Test
+	public void testRemovedValue() {
+		putGetRemove(-1);
+	}
 
 	private void putGetRemove(final long key) {
 		final LongLongHashMap map = new LongLongHashMap();
@@ -45,26 +52,121 @@ public class LongLongHashMapTest {
 	}
 
 	@Test
-	public void testComputeZeroKey() {
+	public void testRemoveNonExistingKey() {
 		final LongLongHashMap map = new LongLongHashMap();
+		final int values = 100;
 
-		final long key = 1;
-		map.compute(key, 6, l -> l + 1);
-		Assertions.assertEquals(7, map.get(key, Long.MIN_VALUE), "initialValueIfAbsent is used when there is no mapping for the key");
+		 // fill with keys 0...99
+		for (int i = 0; i < values; i++) {
+			map.put(i, i);
+		}
 
-		map.compute(key, 6, l -> l + 1);
-		Assertions.assertEquals(8, map.get(key, Long.MIN_VALUE), "update function is called when 'zeroKey' is set");
+		map.remove(values); // key does not exist
+		Assertions.assertEquals(values, map.size(), "size after removing non existing key 100");
+
+		// -1 is a sentinel key and has special handling
+		map.remove(-1); // key does not exist
+		Assertions.assertEquals(values, map.size(), "size after removing non existing key -1");
+		
+		map.put(-1, -1);
+		Assertions.assertEquals(values+1, map.size(), "size after adding key -1");
+		
+		map.remove(-1); // key exists
+		Assertions.assertEquals(values, map.size(), "size after removing key -1");
+
+		// 0 is a sentinel key and has special handling
+		map.remove(0); // key exists
+		Assertions.assertEquals(values - 1, map.size(), "size after removing existing key 0");
+
+		map.remove(0); // key does not exist
+		Assertions.assertEquals(values - 1, map.size(), "size after removing non existing key 0 (2nd removal of 0)");
+
+		for (int i = 1; i < 100; i++) {
+			map.remove(i);
+			Assertions.assertEquals(values-i-1, map.size(), "size after removing key "+i);
+		}
+		Assertions.assertEquals(0, map.size(), "size after removing all keys");
 	}
 
 	@Test
-	public void testCompute() {
+	public void testRemoveAllValuesOneByOne() {
+		int values = 20;
 		final LongLongHashMap map = new LongLongHashMap();
-		final long key = 1;
-		map.compute(key, 6, l -> l + 1);
-		Assertions.assertEquals(7, map.get(key, Long.MIN_VALUE), "initialValueIfAbsent is used when there is no mapping for the key");
+		Random r = new Random(123);
 
-		map.compute(key, 6, l -> l + 1);
-		Assertions.assertEquals(8, map.get(key, Long.MIN_VALUE), "update function is called when key is set");
+		LongList keys = new LongList();
+
+		for (int round = 0; round < 5; round++) {
+			values *= 2;
+			keys.clear();
+			keys.addAll(r.longs(values).toArray());
+			keys.shuffle(r);
+			keys.stream().forEach(l -> map.put(l, 2));
+
+			for (int i = values - 1; i >= 0; i--) {
+				long key = keys.get(i);
+
+				map.compute(key, 2, (k,v) -> v * 2);
+				Assertions.assertEquals(4, map.get(key, -1), "value for key " + key + "=4 - map=" + map);
+
+				Assertions.assertTrue(map.containsKey(key), "map contains key " + key);
+				map.remove(key);
+				Assertions.assertEquals(i, map.size(), "size after removing key " + key);
+			}
+		}
+	}
+
+
+	@Test
+	public void testCompute() {		
+		final LongLongHashMap map = new LongLongHashMap();
+		
+		// initialize values
+		map.compute(LongLongHashMap.REMOVED_KEY, 11L, (k,v) -> {
+			Assertions.assertEquals(LongLongHashMap.REMOVED_KEY, k);
+			Assertions.assertEquals(11, v);
+			return 12L;
+		});
+		Assertions.assertEquals(12, map.get(LongLongHashMap.REMOVED_KEY, -111),
+				"initialValueIfAbsent is used when there is no mapping for the key");
+		
+		map.compute(LongLongHashMap.NULL_KEY, 21L, (k,v) -> {
+			Assertions.assertEquals(LongLongHashMap.NULL_KEY, k);
+			Assertions.assertEquals(21, v);
+			return 22L;
+		});
+		Assertions.assertEquals(22, map.get(LongLongHashMap.NULL_KEY, -111),
+				"initialValueIfAbsent is used when there is no mapping for the key");
+		
+		map.compute(1, 31L, (k,v) -> {
+			Assertions.assertEquals(1, k);
+			Assertions.assertEquals(31, v);
+			return 32L;
+		});
+		Assertions.assertEquals(32, map.get(1, -111),
+				"initialValueIfAbsent is used when there is no mapping for the key");
+		
+		// update the value
+		map.compute(LongLongHashMap.REMOVED_KEY, -123L, (k,v) -> {
+			Assertions.assertEquals(LongLongHashMap.REMOVED_KEY, k);
+			Assertions.assertEquals(12, v);
+			return 13L;
+		});
+		Assertions.assertEquals(13, map.get(LongLongHashMap.REMOVED_KEY, -111), "update function is called when key is set");
+		
+		map.compute(LongLongHashMap.NULL_KEY, -123L, (k,v) -> {
+			Assertions.assertEquals(LongLongHashMap.NULL_KEY, k);
+			Assertions.assertEquals(22, v);
+			return 23L;
+		});
+		Assertions.assertEquals(23, map.get(LongLongHashMap.NULL_KEY, -111), "update function is called when key is set");
+		
+		map.compute(1, -123L, (k,v) -> {
+			Assertions.assertEquals(1, k);
+			Assertions.assertEquals(32, v);
+			return 33L;
+		});
+		Assertions.assertEquals(33, map.get(1, -111), "update function is called when key is set");
 	}
 
 	@Test
@@ -96,7 +198,41 @@ public class LongLongHashMapTest {
 		keysWithSameSpread.stream().forEach(l -> map.put(l, l));
 		Assertions.assertEquals(keysWithSameSpread.size(), map.size());
 		keysWithSameSpread.stream().forEach(l -> Assertions.assertEquals(l, map.get(l, Long.MIN_VALUE)));
+
+		// remove the keys
+		keysWithSameSpread.shuffle();
+		keysWithSameSpread.stream().forEach(k -> {
+			int sizeBefore = map.size();
+			Assertions.assertTrue(map.containsKey(k));
+			map.remove(k);
+			Assertions.assertFalse(map.containsKey(k));
+			Assertions.assertEquals(Long.MIN_VALUE, map.get(k, Long.MIN_VALUE));
+			Assertions.assertEquals(sizeBefore - 1, map.size());
+		});
 	}
+	
+	@Test
+	public void testMultipleValuesOnSamePosition2() {
+		final LongLongHashMap map = new LongLongHashMap();
+		// find to values that yield the same 'spread' (position in the table)
+		final LongList keys = findKeysWithSameSpread(map);
+		Assertions.assertTrue(keys.size() > 5);
+
+		map.put(keys.get(0), 1);
+		map.put(keys.get(1), 1);
+		map.put(keys.get(2), 1);
+		
+		// creates a section of the array that looks like this: k0,-1,k2, where -1 marks a previously occupied slot
+		map.remove(keys.get(1));
+		
+		// should overwrite the existing value which is after a slot that is marked as previously occupied
+		map.put(keys.get(2), 2); 
+		
+		final LongList values=new LongList();
+		map.forEach((k,v) -> values.add(v));
+		Assertions.assertEquals(LongList.of(1,2), values);
+	}
+	
 
 	@Test
 	public void testForEach() {
@@ -104,7 +240,7 @@ public class LongLongHashMapTest {
 		final Random rand = new Random(6789);
 		final LongList entries = LongList.of(LongStream.generate(rand::nextLong).limit(15).toArray());
 
-		entries.stream().forEachOrdered(l -> {
+		entries.stream().forEach(l -> {
 			map.put(l, 2 * l);
 		});
 
@@ -115,10 +251,29 @@ public class LongLongHashMapTest {
 	}
 
 	@Test
-	public void testForEachOrdered() {
+	public void testForEachWithSpecialValues() {
 		final LongLongHashMap map = new LongLongHashMap();
 		final Random rand = new Random(6789);
 		final LongList entries = LongList.of(LongStream.generate(rand::nextLong).limit(15).toArray());
+		entries.add(0); // special key that is internally used to mark unset slots
+		entries.add(-1);// special key that is internally used to mark slots with removed values
+		entries.add(123); // value that will be removed later
+
+		entries.stream().forEach(l -> {
+			map.put(l, 2 * l);
+		});
+		map.remove(123);
+
+		map.forEach((k, v) -> {
+			Assertions.assertEquals(k * 2, v, "value is key*2");
+			Assertions.assertTrue(entries.indexOf(k) >= 0, "value " + k + " in entries: " + entries);
+		});
+	}
+
+	@Test
+	public void testForEachOrdered() {
+		final LongLongHashMap map = new LongLongHashMap();
+		final LongList entries = LongList.of(-10, -9, -1, 0, 1, 2, 10);
 
 		entries.stream().forEachOrdered(l -> {
 			map.put(l, 2 * l);
@@ -212,6 +367,42 @@ public class LongLongHashMapTest {
 		Assertions.assertEquals(5, LongLongHashMap.findPosOfFirstPositiveKey(new long[] { -1, 0, 0, 0, 0, 1, 1 }));
 		Assertions.assertEquals(6, LongLongHashMap.findPosOfFirstPositiveKey(new long[] { -1, 0, 0, 0, 0, 0, 1 }));
 	}
+	
+	@Test
+	public void testMaxCapacity() {
+		LongLongHashMap map = new LongLongHashMap(6,0.75);
+		Assertions.assertEquals(6, map.getCapacity());
+		
+		// capacity is reduced to 5 - possible, because map is empty 
+		map.setMaxCapacity(5);
+		Assertions.assertEquals(5, map.getCapacity());
+		
+		map.put(1, 0); 
+		map.put(2, 0);
+		map.put(3, 0);
+		map.put(4, 0);
+		map.put(5, 0);
+		Assertions.assertEquals(5, map.getCapacity());
+		Assertions.assertEquals(5, map.size());
+		
+		// ensure we cannot add more values than the capacity allows
+		// 0 and -1 are sentinels, we have to check them separately
+		assertThrows(IllegalStateException.class, () -> map.put(0, 55));
+		assertThrows(IllegalStateException.class, () -> map.put(-1, 55));
+		assertThrows(IllegalStateException.class, () -> map.put(6, 55));// key is negative to ensure we actually could add it if the capacity restriction was not there
+		
+		Assertions.assertEquals(5, map.size()); // we still have only 5 keys in the map
+		
+		// check that we can increase the maxCapacity
+		map.setMaxCapacity(map.getCapacity()+1);
+		Assertions.assertEquals(5, map.getCapacity()); // capacity was not updated, because there was not need - you would have to manually call rehash()
+		Assertions.assertEquals(5, map.size());
+		map.put(6, 0); 
+		assertThrows(IllegalStateException.class, () -> map.put(7, 55));
+		
+		// check we cannot make the capacity smaller than the current size
+		assertThrows(IllegalArgumentException.class, ()->map.setMaxCapacity(map.size()-1));
+	}
 
 	private LongList findKeysWithSameSpread(final LongLongHashMap map) {
 		final LongList result = new LongList();

primitiveCollections/src/test/java/org/lucares/collections/LongObjHashMapTest.java

@@ -1,7 +1,6 @@
 package org.lucares.collections;
 
 import java.util.Random;
-import java.util.function.Supplier;
 import java.util.stream.LongStream;
 
 import org.junit.jupiter.api.Assertions;
@@ -9,19 +8,6 @@ import org.junit.jupiter.api.Test;
 
 public class LongObjHashMapTest {
 	
-	private static final class LongSupplier implements Supplier<Long>{
-
-		private final Long value ;
-		
-		public LongSupplier(Long value) {
-			this.value = value;
-		}
-
-		@Override
-		public Long get() {
-			return value;
-		}
-	}
 	
 	@Test
 	public void testPutRemove() {
@@ -59,28 +45,86 @@ public class LongObjHashMapTest {
 		Assertions.assertFalse(map.containsKey(key));
 		Assertions.assertEquals(0, map.size());
 	}
-
+	
 	@Test
-	public void testComputeZeroKey() {
+	public void testRemoveAllValuesOneByOne() {
+		int values = 20;
 		final LongObjHashMap<Long> map = new LongObjHashMap<>();
+		Random r = new Random(123);
 
-		final long key = 1;
-		map.compute(key, new LongSupplier(6L), (k,l) -> l + 1);
-		Assertions.assertEquals(7, map.get(key), "initialValueIfAbsent is used when there is no mapping for the key");
+		LongList keys = new LongList();
 
-		map.compute(key, new LongSupplier(6L), (k,l) -> l + 1);
-		Assertions.assertEquals(8, map.get(key), "update function is called when 'zeroKey' is set");
+		for (int round = 0; round < 5; round++) {
+			values *= 2;
+			keys.clear();
+			keys.addAll(r.longs(values).toArray());
+			keys.shuffle(r);
+			keys.stream().forEach(l -> map.put(l, 2L));
+
+			for (int i = values - 1; i >= 0; i--) {
+				long key = keys.get(i);
+
+				map.compute(key, () -> 2L, (k,l) -> l * 2);
+				Assertions.assertEquals(4, map.get(key), "value for key " + key + "=4 - map=" + map);
+
+				Assertions.assertTrue(map.containsKey(key), "map contains key " + key);
+				map.remove(key);
+				Assertions.assertEquals(i, map.size(), "size after removing key " + key);
+			}
+		}
 	}
 
-	@Test
-	public void testCompute() {
-		final LongObjHashMap<Long> map = new LongObjHashMap<>();
-		final long key = 1;
-		map.compute(key, new LongSupplier(6L), (k,l) -> l + 1);
-		Assertions.assertEquals(7, map.get(key), "initialValueIfAbsent is used when there is no mapping for the key");
 
-		map.compute(key, new LongSupplier(6L), (k,l) -> l + 1);
-		Assertions.assertEquals(8, map.get(key), "update function is called when key is set");
+	@Test
+	public void testCompute() {		
+		final LongObjHashMap<Long> map = new LongObjHashMap<>();
+		
+		// initialize values
+		map.compute(LongObjHashMap.REMOVED_KEY, ()->11L, (k,v) -> {
+			Assertions.assertEquals(LongObjHashMap.REMOVED_KEY, k);
+			Assertions.assertEquals(11, v);
+			return 12L;
+		});
+		Assertions.assertEquals(12, map.get(LongObjHashMap.REMOVED_KEY),
+				"initialValueIfAbsent is used when there is no mapping for the key");
+		
+		map.compute(LongObjHashMap.NULL_KEY, ()->21L, (k,v) -> {
+			Assertions.assertEquals(LongObjHashMap.NULL_KEY, k);
+			Assertions.assertEquals(21, v);
+			return 22L;
+		});
+		Assertions.assertEquals(22, map.get(LongObjHashMap.NULL_KEY),
+				"initialValueIfAbsent is used when there is no mapping for the key");
+		
+		map.compute(1, ()->31L, (k,v) -> {
+			Assertions.assertEquals(1, k);
+			Assertions.assertEquals(31, v);
+			return 32L;
+		});
+		Assertions.assertEquals(32, map.get(1),
+				"initialValueIfAbsent is used when there is no mapping for the key");
+		
+		// update the value
+		map.compute(LongObjHashMap.REMOVED_KEY, ()->-123L, (k,v) -> {
+			Assertions.assertEquals(LongObjHashMap.REMOVED_KEY, k);
+			Assertions.assertEquals(12, v);
+			return 13L;
+		});
+		Assertions.assertEquals(13, map.get(LongObjHashMap.REMOVED_KEY), "update function is called when key is set");
+		
+		map.compute(LongObjHashMap.NULL_KEY, ()->-123L, (k,v) -> {
+			Assertions.assertEquals(LongObjHashMap.NULL_KEY, k);
+			Assertions.assertEquals(22, v);
+			return 23L;
+		});
+		Assertions.assertEquals(23, map.get(LongObjHashMap.NULL_KEY), "update function is called when key is set");
+		
+		map.compute(1, ()->-123L, (k,v) -> {
+			Assertions.assertEquals(1, k);
+			Assertions.assertEquals(32, v);
+			return 33L;
+		});
+		Assertions.assertEquals(33, map.get(1), "update function is called when key is set");
 	}
 
 	@Test
@@ -113,6 +157,28 @@ public class LongObjHashMapTest {
 		Assertions.assertEquals(keysWithSameSpread.size(), map.size());
 		keysWithSameSpread.stream().forEach(l -> Assertions.assertEquals(l, map.get(l)));
 	}
+	
+	@Test
+	public void testMultipleValuesOnSamePosition2() {
+		final LongObjHashMap<Long> map = new LongObjHashMap<>();
+		// find to values that yield the same 'spread' (position in the table)
+		final LongList keys = findKeysWithSameSpread(map);
+		Assertions.assertTrue(keys.size() > 5);
+
+		map.put(keys.get(0), 1L);
+		map.put(keys.get(1), 1L);
+		map.put(keys.get(2), 1L);
+		
+		// creates a section of the array that looks like this: k0,-1,k2, where -1 marks a previously occupied slot
+		map.remove(keys.get(1));
+		
+		// should overwrite the existing value which is after a slot that is marked as previously occupied
+		map.put(keys.get(2), 2L); 
+		
+		final LongList values=new LongList();
+		map.forEach((k,v) -> values.add(v));
+		Assertions.assertEquals(LongList.of(1,2), values);
+	}
 
 	@Test
 	public void testForEach() {
@@ -133,8 +199,7 @@ public class LongObjHashMapTest {
 	@Test
 	public void testForEachOrdered() {
 		final LongObjHashMap<Long> map = new LongObjHashMap<>();
-		final Random rand = new Random(6789);
-		final LongList entries = LongList.of(LongStream.generate(rand::nextLong).limit(15).toArray());
+		final LongList entries = LongList.of(-10, -9, -1, 0, 1, 2, 10);
 
 		entries.stream().forEachOrdered(l -> {
 			map.put(l, 2 * l);
@@ -197,6 +262,26 @@ public class LongObjHashMapTest {
 
 		Assertions.assertTrue(actualOrderOfKeys.isSorted(), "keys are sorted");
 	}
+	
+	@Test
+	public void testForEachWithSpecialValues() {
+		final LongObjHashMap<Long> map = new LongObjHashMap<>();
+		final Random rand = new Random(6789);
+		final LongList entries = LongList.of(LongStream.generate(rand::nextLong).limit(15).toArray());
+		entries.add(0); // special key that is internally used to mark unset slots
+		entries.add(-1);// special key that is internally used to mark slots with removed values
+		entries.add(123); // value that will be removed later
+
+		entries.stream().forEach(l -> {
+			map.put(l, 2 * l);
+		});
+		map.remove(123);
+
+		map.forEach((k, v) -> {
+			Assertions.assertEquals(k * 2, v, "value is key*2");
+			Assertions.assertTrue(entries.indexOf(k) >= 0, "value " + k + " in entries: " + entries);
+		});
+	}
 
 	@Test
 	public void testFindPositionOfFirstPositiveKey() {

settings.gradle

@@ -1 +1,25 @@
+pluginManagement {
+	repositories {
+		maven {
+			url "http://localhost:8081/repository/maven-public/"
+			allowInsecureProtocol true
+		}
+	}
+}
+
+plugins {
+	id("me.champeau.jmh") version "0.7.2" apply false
+}
+
+dependencyResolutionManagement {
+    repositories {
+		maven {
+			url "http://localhost:8081/repository/maven-public/"
+			allowInsecureProtocol true
+		}
+    }
+}
+
+
+
 include "primitiveCollections"