1 files changed, 100 insertions, 0 deletions
diff --git a/tensorflow_lite_support/cc/utils/jni_utils.cc b/tensorflow_lite_support/cc/utils/jni_utils.cc
new file mode 100644
index 00000000..25cf3266
--- /dev/null
+++ b/tensorflow_lite_support/cc/utils/jni_utils.cc
@@ -0,0 +1,100 @@
+/* Copyright 2020 The TensorFlow Authors. All Rights Reserved.
+
+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
+
+    http://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.
+==============================================================================*/
+
+#include "tensorflow_lite_support/cc/utils/jni_utils.h"
+
+#include <string.h>
+
+namespace tflite {
+namespace support {
+namespace utils {
+
+std::string JStringToString(JNIEnv* env, jstring jstr) {
+  if (jstr == nullptr) {
+    return std::string();
+  }
+  const char* cstring = env->GetStringUTFChars(jstr, nullptr);
+  std::string result(cstring);
+  env->ReleaseStringUTFChars(jstr, cstring);
+  return result;
+}
+
+std::vector<std::string> StringListToVector(JNIEnv* env, jobject list_object) {
+  jobject j_iterator = env->CallObjectMethod(
+      list_object, env->GetMethodID(env->GetObjectClass(list_object),
+                                    "iterator", "()Ljava/util/Iterator;"));
+  std::vector<std::string> result;
+  jmethodID has_next =
+      env->GetMethodID(env->GetObjectClass(j_iterator), "hasNext", "()Z");
+  jmethodID get_next = env->GetMethodID(env->GetObjectClass(j_iterator), "next",
+                                        "()Ljava/lang/Object;");
+  while (env->CallBooleanMethod(j_iterator, has_next)) {
+    jstring jstr =
+        static_cast<jstring>(env->CallObjectMethod(j_iterator, get_next));
+    const char* raw_str = env->GetStringUTFChars(jstr, JNI_FALSE);
+    result.emplace_back(std::string(raw_str));
+    env->ReleaseStringUTFChars(jstr, raw_str);
+  }
+  return result;
+}
+
+absl::string_view GetMappedFileBuffer(JNIEnv* env, const jobject& file_buffer) {
+  return absl::string_view(
+      static_cast<char*>(env->GetDirectBufferAddress(file_buffer)),
+      static_cast<size_t>(env->GetDirectBufferCapacity(file_buffer)));
+}
+
+jbyteArray CreateByteArray(JNIEnv* env, const jbyte* data, int num_bytes) {
+  jbyteArray ret = env->NewByteArray(num_bytes);
+  env->SetByteArrayRegion(ret, 0, num_bytes, data);
+
+  return ret;
+}
+
+void ThrowException(JNIEnv* env, const char* clazz, const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  const size_t max_msg_len = 512;
+  auto* message = static_cast<char*>(malloc(max_msg_len));
+  if (message && (vsnprintf(message, max_msg_len, fmt, args) >= 0)) {
+    ThrowExceptionWithMessage(env, clazz, message);
+  } else {
+    ThrowExceptionWithMessage(env, clazz, "");
+  }
+  if (message) {
+    free(message);
+  }
+  va_end(args);
+}
+
+void ThrowExceptionWithMessage(JNIEnv* env, const char* clazz,
+                               const char* message) {
+  jclass e_class = env->FindClass(clazz);
+  if (strcmp(clazz, kAssertionError) == 0) {
+    // AssertionError cannot use ThrowNew in Java 7
+    jmethodID constructor =
+        env->GetMethodID(e_class, "<init>", "(Ljava/lang/Object;)V");
+    jstring jstr_message = env->NewStringUTF(message);
+    jobject e_object = env->NewObject(e_class, constructor,
+                                      static_cast<jobject>(jstr_message));
+    env->Throw(static_cast<jthrowable>(e_object));
+    return;
+  }
+  env->ThrowNew(e_class, message);
+}
+
+}  // namespace utils
+}  // namespace support
+}  // namespace tflite