Add JNI bindings along with a package

Add JNI bindings for use via Java (intended for an offline translation
android application). The cache which is meant to speed up translations
(especially while typing), which was not working previously is
configured to work now.

MacOS CI requires some fixing since SentencePiece 0.2.0 (via brew)
breaks some assumptions here. Using internal sentencepiece for
time-being as a stopgap solution.

Pull-Request: #49

.gitignore

@@ -51,3 +51,7 @@ __pycache__
 slimt.egg-info
 env
 dist
+
+# Java compiled stuff
+*.class
+

CMakeLists.txt

@@ -18,6 +18,7 @@ option(WITH_RUY "Use ruy" OFF)
 option(WITH_GEMMOLOGY "Use gemmology" ON)
 option(WITH_BLAS "Use BLAS. Otherwise moves to ruy" ON)
 
+option(SLIMT_USE_INTERNAL_PCRE2 "Use external PCRE2, not system" OFF)
 option(USE_BUILTIN_SENTENCEPIECE "Use SentencePiece supplied as 3rd-party" ON)
 
 option(USE_AVX512 "Use AVX512" OFF)
@@ -221,3 +222,7 @@ if(BUILD_PYTHON)
 
   add_subdirectory(bindings/python)
 endif(BUILD_PYTHON)
+
+if(BUILD_JNI)
+  add_subdirectory(bindings/java)
+endif(BUILD_JNI)

bindings/java/.gitignore

@@ -0,0 +1,2 @@
+*.class
+generated-include/

bindings/java/CMakeLists.txt

@@ -0,0 +1,4 @@
+find_package(JNI REQUIRED)
+
+add_library(slimt_jni SHARED slimt.cpp)
+target_link_libraries(slimt_jni PRIVATE slimt-static JNI::JNI)

bindings/java/io/github/jerinphilip/slimt/Driver.java

@@ -0,0 +1,40 @@
+package io.github.jerinphilip.slimt;
+
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+
+class Driver {
+  public static void main(String[] args) {
+    int encoderLayers = 6;
+    int decoderLayers = 2;
+    int feedForwardDepth = 2;
+    int numHeads = 8;
+    ModelConfig config =
+        new ModelConfig(encoderLayers, decoderLayers, feedForwardDepth, numHeads, "paragraph");
+    // Package archive = new Package();
+    String root = args[0];
+
+    int cacheSize = 1024;
+    Service service = new Service(cacheSize);
+
+    Package archive =
+        new Package(
+            Paths.get(root, args[1]).toString(),
+            Paths.get(root, args[2]).toString(),
+            Paths.get(root, args[3]).toString(),
+            "");
+
+    Model model = new Model(config, archive);
+    System.out.println("Construction success");
+    boolean html = false;
+    List<String> sources = new ArrayList<>();
+    sources.add("Hello World. Help me out here, will you?");
+    sources.add("Goodbye World. Fine, don't help me.");
+    String[] targets = service.translate(model, sources, html);
+    for (int i = 0; i < sources.size(); i++) {
+      System.out.println("> " + sources.get(i));
+      System.out.println("< " + targets[i]);
+    }
+  }
+}

bindings/java/io/github/jerinphilip/slimt/Model.java

@@ -0,0 +1,22 @@
+package io.github.jerinphilip.slimt;
+
+public class Model {
+  static {
+    System.loadLibrary("slimt_jni");
+  }
+
+  public long modelPtr;
+
+  public Model(ModelConfig config, Package archive) {
+    modelPtr = ncreate(config, archive);
+  }
+
+  public void destroy() {
+    ndestroy(modelPtr);
+  }
+
+  // Native methods
+  private native long ncreate(ModelConfig config, Package archive);
+
+  private native void ndestroy(long modelPtr);
+}

bindings/java/io/github/jerinphilip/slimt/ModelConfig.java

@@ -0,0 +1,23 @@
+package io.github.jerinphilip.slimt;
+
+public class ModelConfig {
+  public long encoder_layers;
+  public long decoder_layers;
+  public long feed_forward_depth;
+  public long num_heads;
+  public String split_mode;
+
+  // Constructor
+  public ModelConfig(
+      long encoder_layers,
+      long decoder_layers,
+      long feed_forward_depth,
+      long num_heads,
+      String split_mode) {
+    this.encoder_layers = encoder_layers;
+    this.decoder_layers = decoder_layers;
+    this.feed_forward_depth = feed_forward_depth;
+    this.num_heads = num_heads;
+    this.split_mode = split_mode;
+  }
+}

bindings/java/io/github/jerinphilip/slimt/Package.java

@@ -0,0 +1,16 @@
+package io.github.jerinphilip.slimt;
+
+public class Package {
+  public String model;
+  public String vocabulary;
+  public String shortlist;
+  public String ssplit;
+
+  // Constructors, methods, etc. can be added as needed
+  public Package(String model, String vocabulary, String shortlist, String ssplit) {
+    this.model = model;
+    this.vocabulary = vocabulary;
+    this.shortlist = shortlist;
+    this.ssplit = ssplit;
+  }
+}

bindings/java/io/github/jerinphilip/slimt/Service.java

@@ -0,0 +1,30 @@
+package io.github.jerinphilip.slimt;
+
+import java.util.List;
+
+public class Service {
+  static {
+    System.loadLibrary("slimt_jni");
+  }
+
+  private long servicePtr;
+
+  public Service(long cacheSize) {
+    servicePtr = ncreate(cacheSize);
+  }
+
+  public void destroy() {
+    ndestroy(servicePtr);
+  }
+
+  public String[] translate(Model model, List<String> texts, boolean html) {
+    return ntranslate(servicePtr, model.modelPtr, texts.toArray(new String[0]), html);
+  }
+
+  // Native methods
+  private native long ncreate(long cacheSize);
+
+  private native void ndestroy(long servicePtr);
+
+  private native String[] ntranslate(long servicePtr, long modelPtr, String[] texts, boolean html);
+}

bindings/java/slimt.cpp

@@ -0,0 +1,165 @@
+#include "slimt/slimt.hh"
+
+#include <jni.h>
+
+#include <iostream>
+#include <string>
+#include <vector>
+
+using namespace slimt;  // NOLINT
+
+// using Service = Async;
+using Service = Blocking;
+
+extern "C" {
+
+// NOLINTBEGIN
+// Model
+#define SLIMT_JNI_EXPORT(cls, method) \
+  JNICALL Java_io_github_jerinphilip_slimt_##cls##_##method
+
+JNIEXPORT jlong SLIMT_JNI_EXPORT(Model, ncreate)(JNIEnv *env, jobject obj,
+                                                 jobject jconfig,
+                                                 jobject jpackage) {
+  // Extract Config object fields
+  jclass cls = env->GetObjectClass(jconfig);
+  jfieldID encoder_layers_field = env->GetFieldID(cls, "encoder_layers", "J");
+  jfieldID decoder_layers_field = env->GetFieldID(cls, "decoder_layers", "J");
+  jfieldID ffn_depth_field = env->GetFieldID(cls, "feed_forward_depth", "J");
+  jfieldID num_heads_field = env->GetFieldID(cls, "num_heads", "J");
+  jfieldID split_mode_field =
+      env->GetFieldID(cls, "split_mode", "Ljava/lang/String;");
+
+  jlong j_encoder_layers = env->GetLongField(jconfig, encoder_layers_field);
+  jlong j_decoder_layers = env->GetLongField(jconfig, decoder_layers_field);
+  jlong j_ffn_depth = env->GetLongField(jconfig, ffn_depth_field);
+  jlong j_num_heads = env->GetLongField(jconfig, num_heads_field);
+  jstring j_split_mode =
+      (jstring)env->GetObjectField(jconfig, split_mode_field);
+  const char *split_mode_cstr = env->GetStringUTFChars(j_split_mode, NULL);
+
+  // Create Config object
+  slimt::Model::Config config;
+  config.encoder_layers = static_cast<size_t>(j_encoder_layers);
+  config.decoder_layers = static_cast<size_t>(j_decoder_layers);
+  config.feed_forward_depth = static_cast<size_t>(j_ffn_depth);
+  config.num_heads = static_cast<size_t>(j_num_heads);
+  config.split_mode = std::string(split_mode_cstr);
+
+  // Extract Package object fields
+  // Assuming Package object contains necessary fields for Model creation
+
+  jclass package_cls = env->GetObjectClass(jpackage);
+  jfieldID model_field =
+      env->GetFieldID(package_cls, "model", "Ljava/lang/String;");
+  jfieldID vocabulary_field =
+      env->GetFieldID(package_cls, "vocabulary", "Ljava/lang/String;");
+  jfieldID shortlist_field =
+      env->GetFieldID(package_cls, "shortlist", "Ljava/lang/String;");
+  jfieldID ssplit_field =
+      env->GetFieldID(package_cls, "ssplit", "Ljava/lang/String;");
+
+  jstring j_model = (jstring)env->GetObjectField(jpackage, model_field);
+  jstring j_vocabulary =
+      (jstring)env->GetObjectField(jpackage, vocabulary_field);
+  jstring j_shortlist = (jstring)env->GetObjectField(jpackage, shortlist_field);
+  jstring j_ssplit = (jstring)env->GetObjectField(jpackage, ssplit_field);
+
+  const char *model_cstr = env->GetStringUTFChars(j_model, nullptr);
+  const char *vocabulary_cstr = env->GetStringUTFChars(j_vocabulary, nullptr);
+  const char *shortlist_cstr = env->GetStringUTFChars(j_shortlist, nullptr);
+  const char *ssplit_cstr = env->GetStringUTFChars(j_ssplit, nullptr);
+
+  // Create Package object
+  slimt::Package<std::string> package;
+  package.model = std::string(model_cstr);
+  package.vocabulary = std::string(vocabulary_cstr);
+  package.shortlist = std::string(shortlist_cstr);
+  package.ssplit = std::string(ssplit_cstr);
+
+  // Release Java string references
+  env->ReleaseStringUTFChars(j_model, model_cstr);
+  env->ReleaseStringUTFChars(j_vocabulary, vocabulary_cstr);
+  env->ReleaseStringUTFChars(j_shortlist, shortlist_cstr);
+  env->ReleaseStringUTFChars(j_ssplit, ssplit_cstr);
+
+  // Create Model object
+  slimt::Model *model = new slimt::Model(config, package);
+
+  // Clean up
+  env->ReleaseStringUTFChars(j_split_mode, split_mode_cstr);
+
+  return reinterpret_cast<jlong>(model);
+}
+
+JNIEXPORT void SLIMT_JNI_EXPORT(Model, ndestroy)(JNIEnv *env, jobject obj,
+                                                 jlong model_addr) {
+  delete reinterpret_cast<Model *>(model_addr);
+}
+
+// Service
+JNIEXPORT jlong SLIMT_JNI_EXPORT(Service, ncreate)(JNIEnv *env, jobject obj,
+                                                   jlong cache_size) {
+  Config config;
+  config.cache_size = cache_size;
+  return reinterpret_cast<jlong>(new Service(config));
+}
+
+JNIEXPORT void SLIMT_JNI_EXPORT(Service, ndestroy)(JNIEnv *env, jobject obj,
+                                                   jlong service_addr) {
+  delete reinterpret_cast<Service *>(service_addr);
+}
+
+JNIEXPORT jobjectArray SLIMT_JNI_EXPORT(Service, ntranslate)(
+    JNIEnv *env, jobject obj, jlong service_addr, jobject jmodel,
+    jobjectArray texts, jboolean html) {
+  Service *service = reinterpret_cast<Service *>(service_addr);
+  std::vector<std::string> sources;
+  std::vector<std::string> targets;
+
+  jsize length = env->GetArrayLength(texts);
+
+  for (int i = 0; i < length; ++i) {
+    std::string text = "";  // Convert jstring to std::string
+    jobject jtext = env->GetObjectArrayElement(texts, i);
+    if (jtext != nullptr) {
+      const char *cstr =
+          env->GetStringUTFChars(static_cast<jstring>(jtext), nullptr);
+      if (cstr != nullptr) {
+        text = std::string(cstr);
+        sources.push_back(text);
+        env->ReleaseStringUTFChars(static_cast<jstring>(jtext), cstr);
+      }
+      env->DeleteLocalRef(jtext);
+    }
+  }
+
+  // Translate text using the service
+  Model *model_raw_ptr = reinterpret_cast<Model *>(jmodel);
+  auto pseudo_deleter = [](Model *model_raw_ptr) {};
+  Ptr<Model> model(model_raw_ptr, pseudo_deleter);
+  Options options{
+      .html = static_cast<bool>(html)  //
+  };
+
+  Responses responses = service->translate(model, std::move(sources), options);
+  for (Response &response : responses) {
+    targets.push_back(response.target.text);
+  }
+
+  // Convert vector of strings to jobjectArray
+  jobjectArray jtargets = env->NewObjectArray(
+      targets.size(), env->FindClass("java/lang/String"), nullptr);
+  for (size_t i = 0; i < targets.size(); ++i) {
+    env->SetObjectArrayElement(jtargets, i,
+                               env->NewStringUTF(targets[i].c_str()));
+  }
+
+  return jtargets;
+}
+
+// NOLINTEND
+
+#undef SLIMT_JNI_EXPORT
+
+}  // extern "C"

cmake/FindPCRE2.cmake

@@ -1,4 +1,4 @@
-# Depending on the value of SLIMT_USE_INTERNAL_PRCRE2 this cmake file either
+# Depending on the value of SLIMT_USE_INTERNAL_PCRE2 this cmake file either
 # tries to find the Perl Compatible Regular Expresison library (pcre2) on the
 # system (when OFF), or downloads and compiles them locally (when ON).
 
@@ -9,7 +9,7 @@
 if(SLIMT_USE_INTERNAL_PCRE2)
   include(ExternalProject)
 
-  set(PCRE2_VERSION "10.39")
+  set(PCRE2_VERSION "10.43")
   set(PCRE2_FILENAME "pcre2-${PCRE2_VERSION}")
   set(PCRE2_TARBALL "${PCRE2_FILENAME}.tar.gz")
   set(PCRE2_SOURCE_DIR "${CMAKE_BINARY_DIR}/${PCRE2_FILENAME}")
@@ -23,7 +23,7 @@ if(SLIMT_USE_INTERNAL_PCRE2)
     set(PCRE2_URL "")
   else()
     set(PCRE2_URL
-        "https://github.com/PhilipHazel/pcre2/releases/download/${PCRE2_FILENAME}/${PCRE2_TARBALL}"
+        "https://github.com/PCRE2Project/pcre2/releases/download/${PCRE2_FILENAME}/${PCRE2_TARBALL}"
     )
     message("Downloading pcre2 source code from ${PCRE2_URL}")
   endif()

scripts/ci/android/01-setup.sh

@@ -3,3 +3,7 @@
 sudo apt-get -y install ccache cmake
 wget -c --quiet https://dl.google.com/android/repository/android-ndk-r23b-linux.zip
 unzip -qq android-ndk-r23b-linux.zip
+
+# Install Java
+sudo apt install default-jdk
+sudo apt install default-jdk-headless

scripts/ci/android/02-build.sh

@@ -3,7 +3,7 @@
 set -eo pipefail
 
 function cmake-configure {
-  NDK=android-ndk-r23b
+  NDK=${NDK:-android-ndk-r23b}
   ABI="arm64-v8a"
   MINSDK_VERSION=28
   ANDROID_PLATFORM=android-28
@@ -18,6 +18,7 @@ function cmake-configure {
     -DUSE_BUILTIN_SENTENCEPIECE=ON
     -DWITH_BLAS=OFF
     -DSLIMT_USE_INTERNAL_PCRE2=ON
+    -DBUILD_JNI=ON
   )
 
   OTHER_ANDROID_ARGS=(