Memory interface in spi

client/build.gradle

@@ -14,6 +14,7 @@ plugins {
 }
 
 dependencies {
+    implementation project(path: ":${rootProject.name}-spi", configuration: 'shadow')
     implementation project(':opensearch-ml-common')
     compileOnly group: 'org.opensearch', name: 'opensearch', version: "${opensearch_version}"
     testImplementation group: 'junit', name: 'junit', version: '4.13.2'

ml-algorithms/build.gradle

@@ -18,6 +18,7 @@ repositories {
 
 dependencies {
     compileOnly group: 'org.opensearch', name: 'opensearch', version: "${opensearch_version}"
+    implementation project(path: ":${rootProject.name}-spi", configuration: 'shadow')
     implementation project(':opensearch-ml-common')
     implementation "org.opensearch.client:opensearch-rest-client:${opensearch_version}"
     testImplementation "org.opensearch.test:framework:${opensearch_version}"

plugin/build.gradle

@@ -46,6 +46,7 @@ opensearchplugin {
 }
 
 dependencies {
+    implementation project(path: ":${rootProject.name}-spi", configuration: 'shadow')
     implementation project(':opensearch-ml-common')
     implementation project(':opensearch-ml-algorithms')
     implementation project(':opensearch-ml-search-processors')

settings.gradle

@@ -7,6 +7,8 @@ rootProject.name = 'opensearch-ml'
 
 include 'client'
 project(":client").name = rootProject.name + "-client"
+include 'spi'
+project(":spi").name = rootProject.name + "-spi"
 include 'common'
 project(":common").name = rootProject.name + "-common"
 include 'plugin'

spi/build.gradle

@@ -0,0 +1,137 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import com.github.jengelman.gradle.plugins.shadow.ShadowBasePlugin
+import org.opensearch.gradle.test.RestIntegTestTask
+
+plugins {
+    id 'com.github.johnrengelman.shadow'
+    id 'jacoco'
+    id 'maven-publish'
+    id 'signing'
+}
+
+apply plugin: 'opensearch.java'
+
+repositories {
+    mavenLocal()
+    mavenCentral()
+    maven { url "https://aws.oss.sonatype.org/content/repositories/snapshots" }
+}
+
+ext {
+    projectSubstitutions = [:]
+    licenseFile = rootProject.file('LICENSE.txt')
+    noticeFile = rootProject.file('NOTICE')
+}
+
+jacoco {
+    toolVersion = '0.8.7'
+    reportsDirectory = file("$buildDir/JacocoReport")
+}
+
+jacocoTestReport {
+    reports {
+        xml.required = false
+        csv.required = false
+        html.destination file("${buildDir}/jacoco/")
+    }
+}
+check.dependsOn jacocoTestReport
+
+def slf4j_version_of_cronutils = "1.7.36"
+dependencies {
+    compileOnly "org.opensearch:opensearch:${opensearch_version}"
+
+    testImplementation "org.opensearch.test:framework:${opensearch_version}"
+    testImplementation "org.apache.logging.log4j:log4j-core:${versions.log4j}"
+}
+
+configurations.all {
+    if (it.state != Configuration.State.UNRESOLVED) return
+    resolutionStrategy {
+        force "org.slf4j:slf4j-api:${slf4j_version_of_cronutils}"
+    }
+}
+
+shadowJar {
+    archiveClassifier = null
+}
+
+test {
+    doFirst {
+        test.classpath -= project.files(project.tasks.named('shadowJar'))
+        test.classpath -= project.configurations.getByName(ShadowBasePlugin.CONFIGURATION_NAME)
+        test.classpath += project.extensions.getByType(SourceSetContainer).getByName(SourceSet.MAIN_SOURCE_SET_NAME).runtimeClasspath
+    }
+    systemProperty 'tests.security.manager', 'false'
+}
+
+task integTest(type: RestIntegTestTask) {
+    description 'Run integ test with opensearch test framework'
+    group 'verification'
+    systemProperty 'tests.security.manager', 'false'
+    dependsOn test
+}
+check.dependsOn integTest
+
+task sourcesJar(type: Jar) {
+    archiveClassifier.set 'sources'
+    from sourceSets.main.allJava
+}
+
+task javadocJar(type: Jar) {
+    archiveClassifier.set 'javadoc'
+    from javadoc.destinationDir
+    dependsOn javadoc
+}
+
+publishing {
+    repositories {
+        maven {
+            name = 'staging'
+            url = "${rootProject.buildDir}/local-staging-repo"
+        }
+        maven {
+            name = "Snapshots" //  optional target repository name
+            url = "https://aws.oss.sonatype.org/content/repositories/snapshots"
+            credentials {
+                username "$System.env.SONATYPE_USERNAME"
+                password "$System.env.SONATYPE_PASSWORD"
+            }
+        }
+    }
+    publications {
+        shadow(MavenPublication) { publication ->
+            project.shadow.component(publication)
+            artifact sourcesJar
+            artifact javadocJar
+
+            pom {
+                name = "OpenSearch ML Commons SPI"
+                packaging = "jar"
+                url = "https://github.com/opensearch-project/ml-commons"
+                description = "OpenSearch ML spi"
+                scm {
+                    connection = "scm:[email protected]:opensearch-project/ml-commons.git"
+                    developerConnection = "scm:[email protected]:opensearch-project/ml-commons.git"
+                    url = "[email protected]:opensearch-project/ml-commons.git"
+                }
+                licenses {
+                    license {
+                        name = "The Apache License, Version 2.0"
+                        url = "http://www.apache.org/licenses/LICENSE-2.0.txt"
+                    }
+                }
+                developers {
+                    developer {
+                        name = "OpenSearch"
+                        url = "https://github.com/opensearch-project/ml-commons"
+                    }
+                }
+            }
+        }
+    }
+}

spi/src/main/java/org/opensearch/ml/common/spi/memory/Memory.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.ml.common.spi.memory;
+
+import org.opensearch.core.action.ActionListener;
+
+import java.util.Map;
+
+/**
+ * A general memory interface.
+ * @param <T>
+ */
+public interface Memory<T extends Message> {
+
+    /**
+     * Get memory type.
+     * @return
+     */
+    String getType();
+
+    /**
+     * Save message to id.
+     * @param id memory id
+     * @param message message to be saved
+     */
+    default void save(String id, T message) {}
+
+    default <S> void save(String id, T message, ActionListener<S> listener){}
+
+    /**
+     * Get messages of memory id.
+     * @param id memory id
+     * @return
+     */
+    default T[] getMessages(String id){return null;}
+    default void getMessages(String id, ActionListener<T> listener){}
+
+    /**
+     * Clear all memory.
+     */
+    void clear();
+
+    /**
+     * Remove memory of specific id.
+     * @param id memory id
+     */
+    void remove(String id);
+
+    interface Factory<T extends Memory> {
+        /**
+         * Create an instance of this Memory.
+         *
+         * @param params Parameters for the memory
+         * @param listener Action listern for the memory creation action
+         */
+        void create(Map<String, Object> params, ActionListener<T> listener);
+    }
+}

spi/src/main/java/org/opensearch/ml/common/spi/memory/Message.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.ml.common.spi.memory;
+
+/**
+ * General message interface.
+ */
+public interface Message {
+
+    /**
+     * Get message type.
+     * @return
+     */
+    String getType();
+
+    /**
+     * Get message content.
+     * @return
+     */
+    String getContent();
+}