Don't dup fd when calculate sha1

Signed-off-by: GG Bond <whatever@tagkong.com>

app/src/main/rust/src/hash/sha1.rs

@@ -6,11 +6,13 @@ use jni::JNIEnv;
 use jni_fn::jni_fn;
 use jni_throwing;
 use sha1::{Digest, Sha1};
-use std::{fs::File, io::copy, os::fd::BorrowedFd};
+use std::mem::forget;
+use std::os::fd::FromRawFd;
+use std::{fs::File, io::copy};
 
-fn file_sha1(mut file: File, digest: &mut [u8; 40]) -> Result<&str> {
+fn file_sha1<'a>(file: &mut File, digest: &'a mut [u8; 40]) -> Result<&'a str> {
     let mut sha = Sha1::new();
-    copy(&mut file, &mut sha)?;
+    copy(file, &mut sha)?;
     Ok(encode_str(&sha.finalize(), digest)?)
 }
 
@@ -19,10 +21,11 @@ fn file_sha1(mut file: File, digest: &mut [u8; 40]) -> Result<&str> {
 #[jni_fn("com.hippo.ehviewer.jni.HashKt")]
 pub fn sha1(mut env: JNIEnv, _class: JClass, fd: jint) -> jstring {
     jni_throwing(&mut env, |env| {
-        let borrowed_fd = unsafe { BorrowedFd::borrow_raw(fd) };
-        let owned_fd = borrowed_fd.try_clone_to_owned()?;
         let mut hex_digest = [0u8; 40];
-        let hex = file_sha1(File::from(owned_fd), &mut hex_digest)?;
-        Ok(env.new_string(hex)?.into_raw())
+        let mut file = unsafe { File::from_raw_fd(fd) };
+        let hex = file_sha1(&mut file, &mut hex_digest);
+        // Avoid double close, we close it on Java side
+        forget(file);
+        Ok(env.new_string(hex?)?.into_raw())
     })
 }