commit 8060ded9475664981f08a2a5eae3de04d14027df Author: FyloZ Date: Sat Jan 29 12:18:28 2022 -0500 Add default cache implementation (BasicMemoryCache) diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..ef96df8 --- /dev/null +++ b/.gitignore @@ -0,0 +1,17 @@ +### IntelliJ IDEA ### +.idea +*.iws +*.iml +*.ipr + +## Other directories +.gradle/ +build/ +logs/ +data/ +dokka/ +dist/ +out/ + +## Prevent ignoring the gradle wrapper +!gradle-wrapper.jar \ No newline at end of file diff --git a/build.gradle.kts b/build.gradle.kts new file mode 100644 index 0000000..691808c --- /dev/null +++ b/build.gradle.kts @@ -0,0 +1,26 @@ +group = "dev.fyloz" +version = "1.0" + +plugins { + id("org.jetbrains.kotlin.jvm") version "1.6.10" +} + +repositories { + mavenCentral() + + maven { + url = uri("https://archiva.fyloz.dev/repository/internal") + } +} + +dependencies { + implementation("org.jetbrains.kotlin:kotlin-stdlib:1.6.10") + + testImplementation("io.kotest:kotest-runner-junit5:5.1.0") + testImplementation("io.kotest:kotest-assertions-core:5.1.0") + testImplementation("io.mockk:mockk:1.12.2") +} + +tasks.withType { + useJUnitPlatform() +} \ No newline at end of file diff --git a/gradle.properties b/gradle.properties new file mode 100644 index 0000000..29e08e8 --- /dev/null +++ b/gradle.properties @@ -0,0 +1 @@ +kotlin.code.style=official \ No newline at end of file diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar new file mode 100644 index 0000000..7454180 Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties new file mode 100644 index 0000000..ffed3a2 --- /dev/null +++ b/gradle/wrapper/gradle-wrapper.properties @@ -0,0 +1,5 @@ +distributionBase=GRADLE_USER_HOME +distributionPath=wrapper/dists +distributionUrl=https\://services.gradle.org/distributions/gradle-7.2-bin.zip +zipStoreBase=GRADLE_USER_HOME +zipStorePath=wrapper/dists diff --git a/gradlew b/gradlew new file mode 100755 index 0000000..744e882 --- /dev/null +++ b/gradlew @@ -0,0 +1,185 @@ +#!/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 "$*" + echo + exit 1 +} + +# OS specific support (must be 'true' or 'false'). +cygwin=false +msys=false +darwin=false +nonstop=false +case "`uname`" in + CYGWIN* ) + cygwin=true + ;; + Darwin* ) + darwin=true + ;; + MSYS* | MINGW* ) + msys=true + ;; + NONSTOP* ) + nonstop=true + ;; +esac + +CLASSPATH=$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=`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" ;; + 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" + +exec "$JAVACMD" "$@" diff --git a/gradlew.bat b/gradlew.bat new file mode 100644 index 0000000..107acd3 --- /dev/null +++ b/gradlew.bat @@ -0,0 +1,89 @@ +@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 Resolve any "." and ".." in APP_HOME to make it shorter. +for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi + +@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 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. + +goto fail + +:findJavaFromJavaHome +set JAVA_HOME=%JAVA_HOME:"=% +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. + +goto fail + +: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 %* + +: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.kts b/settings.gradle.kts new file mode 100644 index 0000000..5d3e179 --- /dev/null +++ b/settings.gradle.kts @@ -0,0 +1,2 @@ +rootProject.name = "memorycache" + diff --git a/src/main/kotlin/dev/fyloz/memorycache/BaseMemoryCache.kt b/src/main/kotlin/dev/fyloz/memorycache/BaseMemoryCache.kt new file mode 100644 index 0000000..d5cdcec --- /dev/null +++ b/src/main/kotlin/dev/fyloz/memorycache/BaseMemoryCache.kt @@ -0,0 +1,34 @@ +package dev.fyloz.memorycache + +abstract class BaseMemoryCache( + protected val map: MutableMap = hashMapOf() +) : MemoryCache { + override fun contains(key: K) = + key in map + + override fun get(key: K): V? = + map[key] + + override fun getNotNull(key: K): V { + if (key !in this) { + throw KeyNotFoundException(key) + } + + return get(key)!! + } + + override fun set(key: K, value: V) { + map[key] = value + } + + override fun remove(key: K) { + map.remove(key) + } + + override fun clear() { + map.clear() + } +} + +internal class KeyNotFoundException(val key: Any?) : + RuntimeException("The cache doesn't contains the requested key '$key'") \ No newline at end of file diff --git a/src/main/kotlin/dev/fyloz/memorycache/BasicMemoryCache.kt b/src/main/kotlin/dev/fyloz/memorycache/BasicMemoryCache.kt new file mode 100644 index 0000000..d64b2a3 --- /dev/null +++ b/src/main/kotlin/dev/fyloz/memorycache/BasicMemoryCache.kt @@ -0,0 +1,50 @@ +package dev.fyloz.memorycache + +import java.util.* + +private const val defaultCacheCapacity = 1000 + +/** + * A basic key-value memory cache with a limited size. + * + * When full, the oldest key-value pair will be removed from the cache. + * + * @param K The type of the keys. + * @param V The type of the values. + * @property capacity The capacity of the cache, which is 1000 by default. + */ +class BasicMemoryCache( + private val capacity: Int = defaultCacheCapacity, +) : BaseMemoryCache() { + private val keys = LinkedList() + + override fun contains(key: K) = + key in keys + + override fun set(key: K, value: V) { + cleanup() + + super.set(key, value) + keys.add(key) + } + + override fun remove(key: K) { + super.remove(key) + keys.remove(key) + } + + override fun clear() { + super.clear() + keys.clear() + } + + private fun cleanup() { + if (keys.size < capacity) { + return + } + + // Remove the oldest key when the capacity is exceeded, aka the first in the keys linked list + val oldestKey = keys.pop() + remove(oldestKey) + } +} \ No newline at end of file diff --git a/src/main/kotlin/dev/fyloz/memorycache/MemoryCache.kt b/src/main/kotlin/dev/fyloz/memorycache/MemoryCache.kt new file mode 100644 index 0000000..bbda9fa --- /dev/null +++ b/src/main/kotlin/dev/fyloz/memorycache/MemoryCache.kt @@ -0,0 +1,27 @@ +package dev.fyloz.memorycache + +/** + * Represents a key-value cache whose data is stored in memory. + * + * @param K The type of the keys. + * @param V The type of the values. + */ +interface MemoryCache { + /** Checks if a value correspond to the given [key]. */ + operator fun contains(key: K): Boolean + + /** Gets the value corresponding to the given [key], or null if there is none. */ + operator fun get(key: K): V? + + /** Gets the value corresponding to the given [key]. */ + fun getNotNull(key: K): V + + /** Associates the [value] with the given [key]. The previous value associated with the [key] will be replaced. */ + operator fun set(key: K, value: V) + + /** Removes the value corresponding to the given [key]. */ + fun remove(key: K) + + /** Removes all the cached data. */ + fun clear() +} \ No newline at end of file diff --git a/src/test/kotlin/dev/fyloz/memorycache/BaseMemoryCacheTest.kt b/src/test/kotlin/dev/fyloz/memorycache/BaseMemoryCacheTest.kt new file mode 100644 index 0000000..1a0790a --- /dev/null +++ b/src/test/kotlin/dev/fyloz/memorycache/BaseMemoryCacheTest.kt @@ -0,0 +1,162 @@ +package dev.fyloz.memorycache + +import io.kotest.assertions.throwables.shouldThrow +import io.kotest.core.spec.style.ShouldSpec +import io.kotest.matchers.shouldBe +import io.mockk.* + +internal class BaseMemoryCacheTest : ShouldSpec({ + val cacheMap = mockk>() + val cache = TestBaseMemoryCache(cacheMap) + + val key = Int.MAX_VALUE + val value = "unit test value" + + fun setup_cacheMap_contains(exists: Boolean) { + every { any() in cacheMap } returns exists + } + + fun setup_cacheMap_get(value: String?) { + every { cacheMap[any()] } returns value + } + + afterEach { + clearMocks(cacheMap) + } + + context("contains") { + should("return false when key not in cache") { + // Arrange + setup_cacheMap_contains(false) + + // Act + val contains = key in cache + + // Assert + contains shouldBe false + } + + should("return true when key in cache") { + // Arrange + setup_cacheMap_contains(true) + + // Act + val contains = key in cache + + // Assert + contains shouldBe true + } + } + + context("get") { + should("return value corresponding to key") { + // Arrange + val expectedValue = "unit test value" + + setup_cacheMap_get(expectedValue) + + // Act + val actualValue = cache[key] + + // Assert + actualValue shouldBe expectedValue + } + + should("return null when no value corresponding to key") { + // Arrange + setup_cacheMap_get(null) + + // Act + val actualValue = cache[key] + + // Assert + actualValue shouldBe null + } + } + + context("getNotNull") { + should("return value corresponding to key") { + // Arrange + setup_cacheMap_contains(true) + setup_cacheMap_get(value) + + // Act + val actualValue = cache.getNotNull(key) + + // Assert + actualValue shouldBe value + } + + should("throw NullPointerException when no value corresponding to key") { + // Arrange + setup_cacheMap_contains(false) + setup_cacheMap_get(null) + + // Act + // Assert + shouldThrow { cache.getNotNull(key) } + } + + should("throw NullPointerException with given key when no value corresponding to key") { + // Arrange + setup_cacheMap_contains(false) + setup_cacheMap_get(null) + + // Act + val exception = shouldThrow { cache.getNotNull(key) } + + // Assert + exception.key shouldBe key + } + } + + context("set") { + should("associates value to key in internal map") { + // Arrange + every { cacheMap[any()] = any() } just runs + + // Act + cache[key] = value + + // Assert + verify { + cacheMap[key] = value + } + confirmVerified(cacheMap) + } + } + + context("remove") { + should("removes key-value pair from internal map") { + // Arrange + every { cacheMap.remove(any()) } returns value + + // Act + cache.remove(key) + + // Assert + verify { + cacheMap.remove(key) + } + confirmVerified(cacheMap) + } + } + + context("clear") { + should("clears internal map") { + // Arrange + every { cacheMap.clear() } just runs + + // Act + cache.clear() + + // Assert + verify { + cacheMap.clear() + } + confirmVerified(cacheMap) + } + } +}) + +private class TestBaseMemoryCache(map: MutableMap) : BaseMemoryCache(map) \ No newline at end of file diff --git a/src/test/kotlin/dev/fyloz/memorycache/BasicMemoryCacheTest.kt b/src/test/kotlin/dev/fyloz/memorycache/BasicMemoryCacheTest.kt new file mode 100644 index 0000000..6b27dff --- /dev/null +++ b/src/test/kotlin/dev/fyloz/memorycache/BasicMemoryCacheTest.kt @@ -0,0 +1,72 @@ +package dev.fyloz.memorycache + +import io.kotest.core.spec.style.ShouldSpec +import io.kotest.matchers.shouldBe + +class BasicMemoryCacheTest : ShouldSpec({ + val cacheCapacity = 20 + val cache = BasicMemoryCache(cacheCapacity) + + val key = Int.MAX_VALUE + val value = "unit test value" + + afterEach { + cache.clear() + } + + context("set") { + should("add key to internal key list") { + // Arrange + // Act + cache[key] = value + + // Assert + val contains = key in cache + contains shouldBe true + } + + should("remove oldest key-value pair when full") { + // Arrange + val firstKey = 0 + val lastKey = firstKey + cacheCapacity + + for (currentKey in firstKey..lastKey) { + cache[currentKey] = currentKey.toString() + } + + // Act + val containsFirstKey = firstKey in cache + + // Assert + containsFirstKey shouldBe false + } + } + + context("remove") { + should("remove key from internal key list") { + // Arrange + cache[key] = value + + // Act + cache.remove(key) + + // Assert + val contains = key in cache + contains shouldBe false + } + } + + context("clear") { + should("remove all keys from internal key list") { + // Arrange + cache[key] = value + + // Act + cache.clear() + + // Assert + val contains = key in cache + contains shouldBe false + } + } +}) \ No newline at end of file