libbinder_rs: Switch dump() argument type to Write trait

Generalize the first argument of Interface::dump() to take
any type implementing the Write trait instead of a std::fs::File.

Bug: 242243245
Test: atest aidl_integration_test
Merged-In: Iabd7ce5e424011488f16be219f5e7276c4ed19ba
Change-Id: Iabd7ce5e424011488f16be219f5e7276c4ed19ba

3 files changed, 11 insertions, 10 deletions

diff --git a/libs/binder/rust/src/binder.rs b/libs/binder/rust/src/binder.rs
index 78f8877c1d..6d122c5388 100644
--- a/libs/binder/rust/src/binder.rs
+++ b/libs/binder/rust/src/binder.rs
@@ -27,7 +27,7 @@ use std::cmp::Ordering;
 use std::convert::TryFrom;
 use std::ffi::{c_void, CStr, CString};
 use std::fmt;
-use std::fs::File;
+use std::io::Write;
 use std::marker::PhantomData;
 use std::ops::Deref;
 use std::os::raw::c_char;
@@ -62,7 +62,7 @@ pub trait Interface: Send + Sync + DowncastSync {
     ///
     /// This handler is a no-op by default and should be implemented for each
     /// Binder service struct that wishes to respond to dump transactions.
-    fn dump(&self, _file: &File, _args: &[&CStr]) -> Result<()> {
+    fn dump(&self, _writer: &mut dyn Write, _args: &[&CStr]) -> Result<()> {
         Ok(())
     }
 }
@@ -165,7 +165,7 @@ pub trait Remotable: Send + Sync + 'static {
 
     /// Handle a request to invoke the dump transaction on this
     /// object.
-    fn on_dump(&self, file: &File, args: &[&CStr]) -> Result<()>;
+    fn on_dump(&self, file: &mut dyn Write, args: &[&CStr]) -> Result<()>;
 
     /// Retrieve the class of this remote object.
     ///
@@ -934,8 +934,8 @@ macro_rules! declare_binder_interface {
                 }
             }
 
-            fn on_dump(&self, file: &std::fs::File, args: &[&std::ffi::CStr]) -> std::result::Result<(), $crate::StatusCode> {
-                self.0.dump(file, args)
+            fn on_dump(&self, writer: &mut dyn std::io::Write, args: &[&std::ffi::CStr]) -> std::result::Result<(), $crate::StatusCode> {
+                self.0.dump(writer, args)
             }
 
             fn get_class() -> $crate::binder_impl::InterfaceClass {
diff --git a/libs/binder/rust/src/native.rs b/libs/binder/rust/src/native.rs
index b248f5eb28..b250012801 100644
--- a/libs/binder/rust/src/native.rs
+++ b/libs/binder/rust/src/native.rs
@@ -25,6 +25,7 @@ use crate::sys;
 use std::convert::TryFrom;
 use std::ffi::{c_void, CStr, CString};
 use std::fs::File;
+use std::io::Write;
 use std::mem::ManuallyDrop;
 use std::ops::Deref;
 use std::os::raw::c_char;
@@ -341,7 +342,7 @@ impl<T: Remotable> InterfaceClassMethods for Binder<T> {
         }
         // Safety: Our caller promised that fd is a file descriptor. We don't
         // own this file descriptor, so we need to be careful not to drop it.
-        let file = unsafe { ManuallyDrop::new(File::from_raw_fd(fd)) };
+        let mut file = unsafe { ManuallyDrop::new(File::from_raw_fd(fd)) };
 
         if args.is_null() && num_args != 0 {
             return StatusCode::UNEXPECTED_NULL as status_t;
@@ -366,7 +367,7 @@ impl<T: Remotable> InterfaceClassMethods for Binder<T> {
         // Safety: Our caller promised that the binder has a `T` pointer in its
         // user data.
         let binder: &T = unsafe { &*(object as *const T) };
-        let res = binder.on_dump(&file, &args);
+        let res = binder.on_dump(&mut *file, &args);
 
         match res {
             Ok(()) => 0,
@@ -569,7 +570,7 @@ impl Remotable for () {
         Ok(())
     }
 
-    fn on_dump(&self, _file: &File, _args: &[&CStr]) -> Result<()> {
+    fn on_dump(&self, _writer: &mut dyn Write, _args: &[&CStr]) -> Result<()> {
         Ok(())
     }
 
diff --git a/libs/binder/rust/tests/integration.rs b/libs/binder/rust/tests/integration.rs
index c049b807df..c87fa89756 100644
--- a/libs/binder/rust/tests/integration.rs
+++ b/libs/binder/rust/tests/integration.rs
@@ -26,7 +26,7 @@ use binder::binder_impl::{
 
 use std::convert::{TryFrom, TryInto};
 use std::ffi::CStr;
-use std::fs::File;
+use std::io::Write;
 use std::sync::Mutex;
 
 /// Name of service runner.
@@ -118,7 +118,7 @@ impl TryFrom<u32> for TestTransactionCode {
 }
 
 impl Interface for TestService {
-    fn dump(&self, _file: &File, args: &[&CStr]) -> Result<(), StatusCode> {
+    fn dump(&self, _writer: &mut dyn Write, args: &[&CStr]) -> Result<(), StatusCode> {
         let mut dump_args = self.dump_args.lock().unwrap();
         dump_args.extend(args.iter().map(|s| s.to_str().unwrap().to_owned()));
         Ok(())