fix

Signed-off-by: pushkarm029 <pushkarmishra029@gmail.com>

fs-storage/src/base_storage.rs

@@ -58,6 +58,9 @@ pub trait BaseStorage<K, V>: AsRef<BTreeMap<K, V>> {
     /// from pre-configured location in the filesystem.
     fn read_fs(&mut self) -> Result<&BTreeMap<K, V>>;
 
+    /// Get a value from the internal key-value mapping.
+    fn get(&self, id: &K) -> Result<&V>;
+
     /// Write the internal key-value mapping
     /// to pre-configured location in the filesystem.
     fn write_fs(&mut self) -> Result<()>;

fs-storage/src/btreemap_iter.rs

@@ -0,0 +1,30 @@
+use crate::base_storage::BaseStorage;
+use std::cell::RefCell;
+use std::collections::btree_map::Iter;
+use std::rc::Rc;
+
+pub struct BTreeMapIterator<'a, K, V> {
+    iter: Rc<RefCell<Iter<'a, K, V>>>,
+}
+
+impl<'a, K, V> BTreeMapIterator<'a, K, V>
+where
+    K: Ord + Clone,
+    V: Clone,
+{
+    pub fn new<S: BaseStorage<K, V>>(storage: &'a S) -> Self {
+        BTreeMapIterator {
+            iter: Rc::new(RefCell::new(storage.as_ref().iter())),
+        }
+    }
+
+    pub fn has_next(&mut self) -> bool {
+        let borrow = self.iter.borrow();
+        borrow.clone().peekable().peek().is_some()
+    }
+
+    pub fn native_next(&mut self) -> Option<(K, V)> {
+        let mut borrow = self.iter.borrow_mut();
+        borrow.next().map(|(k, v)| (k.clone(), v.clone()))
+    }
+}

fs-storage/src/file_storage.rs

@@ -242,6 +242,13 @@ where
         Ok(&self.data.entries)
     }
 
+    /// Get a value from the internal mapping
+    fn get(&self, id: &K) -> Result<&V> {
+        self.data.entries.get(id).ok_or_else(|| {
+            ArklibError::Storage(self.label.clone(), "Key not found".to_owned())
+        })
+    }
+
     /// Write the data to file
     ///
     /// Update the modified timestamp in file metadata to avoid OS timing issues

fs-storage/src/jni/btreemap_iter.rs

@@ -0,0 +1,75 @@
+use crate::btreemap_iter::BTreeMapIterator;
+use crate::file_storage::FileStorage;
+// This is the interface to the JVM that we'll call the majority of our
+// methods on.
+use jni::JNIEnv;
+
+// These objects are what you should use as arguments to your native
+// function. They carry extra lifetime information to prevent them escaping
+// this context and getting used after being GC'd.
+use jni::objects::{JClass, JValue};
+
+// This is just a pointer. We'll be returning it from our function. We
+// can't return one of the objects with lifetime information because the
+// lifetime checker won't let us.
+use jni::sys::{jboolean, jlong, jobject};
+
+impl BTreeMapIterator<'_, String, String> {
+    pub fn from_jlong(value: jlong) -> &'static mut Self {
+        unsafe { &mut *(value as *mut BTreeMapIterator<String, String>) }
+    }
+}
+
+#[no_mangle]
+pub extern "system" fn Java_dev_arkbuilders_core_BTreeMapIterator_create(
+    _env: JNIEnv<'_>,
+    _class: JClass,
+    file_storage_ptr: jlong,
+) -> jlong {
+    let file_storage = FileStorage::from_jlong(file_storage_ptr);
+    let iter = BTreeMapIterator::new(file_storage);
+    Box::into_raw(Box::new(iter)) as jlong
+}
+
+#[no_mangle]
+pub extern "system" fn Java_dev_arkbuilders_core_BTreeMapIterator_hasNext(
+    _env: JNIEnv<'_>,
+    _class: JClass,
+    btreemap_ptr: jlong,
+) -> jboolean {
+    let iter = BTreeMapIterator::from_jlong(btreemap_ptr);
+    iter.has_next() as jboolean
+}
+
+#[no_mangle]
+pub extern "system" fn Java_dev_arkbuilders_core_BTreeMapIterator_next(
+    mut env: JNIEnv<'_>,
+    _class: JClass,
+    btreemap_ptr: jlong,
+) -> jobject {
+    let iter = BTreeMapIterator::from_jlong(btreemap_ptr);
+    let (key, value) = iter.native_next().unwrap();
+    let key = env.new_string(key).unwrap();
+    let value = env.new_string(value).unwrap();
+    let pair = env
+        .new_object(
+            "java/util/AbstractMap$SimpleImmutableEntry",
+            "(Ljava/lang/Object;Ljava/lang/Object;)V",
+            &[JValue::Object(&key), JValue::Object(&value)],
+        )
+        .unwrap();
+    pair.as_raw()
+}
+
+#[no_mangle]
+pub extern "system" fn Java_dev_arkbuilders_core_BTreeMapIterator_drop(
+    _env: JNIEnv<'_>,
+    _class: JClass,
+    btreemap_ptr: jlong,
+) {
+    unsafe {
+        let _ = Box::from_raw(
+            btreemap_ptr as *mut BTreeMapIterator<String, String>,
+        );
+    }
+}

fs-storage/src/jni/file_storage.rs

@@ -14,15 +14,15 @@ use jni::objects::{JClass, JObject, JString, JValue};
 // This is just a pointer. We'll be returning it from our function. We
 // can't return one of the objects with lifetime information because the
 // lifetime checker won't let us.
-use jni::sys::{jlong, jobject};
+use jni::sys::{jlong, jobject, jstring};
 use jnix::{IntoJava, JnixEnv};
 
 use crate::base_storage::BaseStorage;
 
 use crate::file_storage::FileStorage;
 
 impl FileStorage<String, String> {
-    fn from_jlong<'a>(value: jlong) -> &'a mut Self {
+    pub fn from_jlong<'a>(value: jlong) -> &'a mut Self {
         unsafe { &mut *(value as *mut FileStorage<String, String>) }
     }
 }
@@ -172,6 +172,31 @@ pub extern "system" fn Java_dev_arkbuilders_core_FileStorage_readFS(
     linked_hash_map.as_raw()
 }
 
+#[no_mangle]
+pub extern "system" fn Java_dev_arkbuilders_core_FileStorage_get<'local>(
+    mut env: JNIEnv<'local>,
+    _class: JClass<'local>,
+    id: JString<'local>,
+    file_storage_ptr: jlong,
+) -> jstring {
+    let id: String = env
+        .get_string(&id)
+        .expect("Failed to get string from JNI")
+        .into();
+    let file_storage = FileStorage::from_jlong(file_storage_ptr);
+
+    match file_storage.get(&id) {
+        Ok(value) => env
+            .new_string(value)
+            .expect("Failed to create new JString")
+            .into_raw(),
+        Err(err) => {
+            env.throw_new("java/lang/RuntimeException", &err.to_string())
+                .unwrap();
+            env.new_string("").expect("").into_raw()
+        }
+    }
+}
 #[no_mangle]
 pub extern "system" fn Java_dev_arkbuilders_core_FileStorage_writeFS(
     mut env: JNIEnv<'_>,

fs-storage/src/jni/mod.rs

@@ -1 +1,2 @@
+pub mod btreemap_iter;
 pub mod file_storage;

fs-storage/src/lib.rs

@@ -1,9 +1,9 @@
 pub mod base_storage;
+pub mod btreemap_iter;
 pub mod file_storage;
 #[cfg(feature = "jni-bindings")]
 pub mod jni;
 pub mod monoid;
-pub mod wrapper_btreemap;
 
 mod utils;
 pub const ARK_FOLDER: &str = ".ark";

java/.gitignore

@@ -3,3 +3,4 @@
 
 # Ignore Gradle build output directory
 build
+*.log