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|
use crate::sys::jsize;
use log::error;
use std::ptr::NonNull;
use crate::objects::release_mode::ReleaseMode;
use crate::sys::{jboolean, jbyte, jchar, jdouble, jfloat, jint, jlong, jshort};
use crate::{errors::*, objects::JObject, sys, JNIEnv};
/// Trait to define type array access/release
pub trait TypeArray {
/// getter
fn get(env: &JNIEnv, obj: JObject, is_copy: &mut jboolean) -> Result<*mut Self>;
/// releaser
fn release(env: &JNIEnv, obj: JObject, ptr: NonNull<Self>, mode: i32) -> Result<()>;
}
// TypeArray builder
macro_rules! type_array {
( $jni_type:ty, $jni_get:tt, $jni_release:tt ) => {
/// $jni_type array access/release impl
impl TypeArray for $jni_type {
/// Get Java $jni_type array
fn get(env: &JNIEnv, obj: JObject, is_copy: &mut jboolean) -> Result<*mut Self> {
let internal = env.get_native_interface();
// Even though this method may throw OoME, use `jni_unchecked`
// instead of `jni_non_null_call` to remove (a slight) overhead
// of exception checking. An error will still be detected as a `null`
// result inside AutoArray ctor. Also, modern Hotspot in case of lack
// of memory will return null and won't throw an exception:
// https://sourcegraph.com/github.com/openjdk/jdk/-/blob/src/hotspot/share/memory/allocation.hpp#L488-489
let res = jni_unchecked!(internal, $jni_get, *obj, is_copy);
Ok(res)
}
/// Release Java $jni_type array
fn release(env: &JNIEnv, obj: JObject, ptr: NonNull<Self>, mode: i32) -> Result<()> {
let internal = env.get_native_interface();
jni_unchecked!(internal, $jni_release, *obj, ptr.as_ptr(), mode as i32);
Ok(())
}
}
};
}
type_array!(jint, GetIntArrayElements, ReleaseIntArrayElements);
type_array!(jlong, GetLongArrayElements, ReleaseLongArrayElements);
type_array!(jbyte, GetByteArrayElements, ReleaseByteArrayElements);
type_array!(
jboolean,
GetBooleanArrayElements,
ReleaseBooleanArrayElements
);
type_array!(jchar, GetCharArrayElements, ReleaseCharArrayElements);
type_array!(jshort, GetShortArrayElements, ReleaseShortArrayElements);
type_array!(jfloat, GetFloatArrayElements, ReleaseFloatArrayElements);
type_array!(jdouble, GetDoubleArrayElements, ReleaseDoubleArrayElements);
/// Auto-release wrapper for pointer-based generic arrays.
///
/// This wrapper is used to wrap pointers returned by Get<Type>ArrayElements.
/// While wrapped, the object can be accessed via the `From` impl.
///
/// AutoArray provides automatic array release through a call to appropriate
/// Release<Type>ArrayElements when it goes out of scope.
pub struct AutoArray<'a, T: TypeArray> {
obj: JObject<'a>,
ptr: NonNull<T>,
mode: ReleaseMode,
is_copy: bool,
env: JNIEnv<'a>,
}
impl<'a, T: TypeArray> AutoArray<'a, T> {
pub(crate) fn new(env: &JNIEnv<'a>, obj: JObject<'a>, mode: ReleaseMode) -> Result<Self> {
let mut is_copy: jboolean = 0xff;
Ok(AutoArray {
obj,
ptr: {
let ptr = T::get(env, obj, &mut is_copy)?;
NonNull::new(ptr).ok_or(Error::NullPtr("Non-null ptr expected"))?
},
mode,
is_copy: is_copy == sys::JNI_TRUE,
env: *env,
})
}
/// Get a reference to the wrapped pointer
pub fn as_ptr(&self) -> *mut T {
self.ptr.as_ptr()
}
/// Commits the changes to the array, if it is a copy
pub fn commit(&self) -> Result<()> {
self.release_array_elements(sys::JNI_COMMIT)
}
fn release_array_elements(&self, mode: i32) -> Result<()> {
T::release(&self.env, self.obj, self.ptr, mode)
}
/// Don't commit the changes to the array on release (if it is a copy).
/// This has no effect if the array is not a copy.
/// This method is useful to change the release mode of an array originally created
/// with `ReleaseMode::CopyBack`.
pub fn discard(&mut self) {
self.mode = ReleaseMode::NoCopyBack;
}
/// Indicates if the array is a copy or not
pub fn is_copy(&self) -> bool {
self.is_copy
}
/// Returns the array size
pub fn size(&self) -> Result<jsize> {
self.env.get_array_length(*self.obj)
}
}
impl<'a, T: TypeArray> Drop for AutoArray<'a, T> {
fn drop(&mut self) {
let res = self.release_array_elements(self.mode as i32);
match res {
Ok(()) => {}
Err(e) => error!("error releasing array: {:#?}", e),
}
}
}
impl<'a, T: TypeArray> From<&'a AutoArray<'a, T>> for *mut T {
fn from(other: &'a AutoArray<T>) -> *mut T {
other.as_ptr()
}
}
|
