Files
lancedb/java/core/lancedb-jni/src/traits.rs
LuQQiu db712b0f99 feat(java): add table names java api (#1279)
Add lancedb-jni and table names API

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Co-authored-by: Lei Xu <eddyxu@gmail.com>
2024-05-24 11:49:11 -07:00

123 lines
3.3 KiB
Rust

// Copyright 2024 Lance Developers.
//
// 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.
use jni::objects::{JMap, JObject, JString, JValue};
use jni::JNIEnv;
use crate::Result;
pub trait FromJObject<T> {
fn extract(&self) -> Result<T>;
}
/// Convert a Rust type into a Java Object.
pub trait IntoJava {
fn into_java<'a>(self, env: &mut JNIEnv<'a>) -> JObject<'a>;
}
impl FromJObject<i32> for JObject<'_> {
fn extract(&self) -> Result<i32> {
Ok(JValue::from(self).i()?)
}
}
impl FromJObject<i64> for JObject<'_> {
fn extract(&self) -> Result<i64> {
Ok(JValue::from(self).j()?)
}
}
impl FromJObject<f32> for JObject<'_> {
fn extract(&self) -> Result<f32> {
Ok(JValue::from(self).f()?)
}
}
impl FromJObject<f64> for JObject<'_> {
fn extract(&self) -> Result<f64> {
Ok(JValue::from(self).d()?)
}
}
pub trait FromJString {
fn extract(&self, env: &mut JNIEnv) -> Result<String>;
}
impl FromJString for JString<'_> {
fn extract(&self, env: &mut JNIEnv) -> Result<String> {
Ok(env.get_string(self)?.into())
}
}
pub trait JMapExt {
#[allow(dead_code)]
fn get_string(&self, env: &mut JNIEnv, key: &str) -> Result<Option<String>>;
#[allow(dead_code)]
fn get_i32(&self, env: &mut JNIEnv, key: &str) -> Result<Option<i32>>;
#[allow(dead_code)]
fn get_i64(&self, env: &mut JNIEnv, key: &str) -> Result<Option<i64>>;
#[allow(dead_code)]
fn get_f32(&self, env: &mut JNIEnv, key: &str) -> Result<Option<f32>>;
#[allow(dead_code)]
fn get_f64(&self, env: &mut JNIEnv, key: &str) -> Result<Option<f64>>;
}
fn get_map_value<T>(env: &mut JNIEnv, map: &JMap, key: &str) -> Result<Option<T>>
where
for<'a> JObject<'a>: FromJObject<T>,
{
let key_obj: JObject = env.new_string(key)?.into();
if let Some(value) = map.get(env, &key_obj)? {
if value.is_null() {
Ok(None)
} else {
Ok(Some(value.extract()?))
}
} else {
Ok(None)
}
}
impl JMapExt for JMap<'_, '_, '_> {
fn get_string(&self, env: &mut JNIEnv, key: &str) -> Result<Option<String>> {
let key_obj: JObject = env.new_string(key)?.into();
if let Some(value) = self.get(env, &key_obj)? {
let value_str: JString = value.into();
Ok(Some(value_str.extract(env)?))
} else {
Ok(None)
}
}
fn get_i32(&self, env: &mut JNIEnv, key: &str) -> Result<Option<i32>> {
get_map_value(env, self, key)
}
fn get_i64(&self, env: &mut JNIEnv, key: &str) -> Result<Option<i64>> {
get_map_value(env, self, key)
}
fn get_f32(&self, env: &mut JNIEnv, key: &str) -> Result<Option<f32>> {
get_map_value(env, self, key)
}
fn get_f64(&self, env: &mut JNIEnv, key: &str) -> Result<Option<f64>> {
get_map_value(env, self, key)
}
}