Rust bindings: Add Event structs, Clarify Handle lifetime

Without clarifying handle's lifetime, it is unable
to see how long the callbacks which the handle
owns will live. Then, Rust compiler will infer
that the callbacks have 'static lifetime. It is
not convenient for users.

rust/src/base.rs

@@ -17,6 +17,9 @@
  */
 
 use crate::error;
+use crate::event;
+use crate::guestfs;
+use std::collections;
 
 #[allow(non_camel_case_types)]
 #[repr(C)]
@@ -34,31 +37,37 @@ extern "C" {
 const GUESTFS_CREATE_NO_ENVIRONMENT: i64 = 1;
 const GUESTFS_CREATE_NO_CLOSE_ON_EXIT: i64 = 2;
 
-pub struct Handle {
+pub struct Handle<'a> {
     pub(crate) g: *mut guestfs_h,
+    pub(crate) callbacks: collections::HashMap<
+        event::EventHandle,
+        Box<Box<dyn Fn(guestfs::Event, event::EventHandle, &[u8], &[u64]) + 'a>>,
+    >,
 }
 
-impl Handle {
-    pub fn create() -> Result<Handle, error::Error> {
+impl<'a> Handle<'a> {
+    pub fn create() -> Result<Handle<'a>, error::Error> {
         let g = unsafe { guestfs_create() };
         if g.is_null() {
             Err(error::Error::Create)
         } else {
-            Ok(Handle { g })
+            let callbacks = collections::HashMap::new();
+            Ok(Handle { g, callbacks })
         }
     }
 
-    pub fn create_flags(flags: CreateFlags) -> Result<Handle, error::Error> {
+    pub fn create_flags(flags: CreateFlags) -> Result<Handle<'a>, error::Error> {
         let g = unsafe { guestfs_create_flags(flags.to_libc_int()) };
         if g.is_null() {
             Err(error::Error::Create)
         } else {
-            Ok(Handle { g })
+            let callbacks = collections::HashMap::new();
+            Ok(Handle { g, callbacks })
         }
     }
 }
 
-impl Drop for Handle {
+impl<'a> Drop for Handle<'a> {
     fn drop(&mut self) {
         unsafe { guestfs_close(self.g) }
     }

rust/src/error.rs

@@ -56,7 +56,7 @@ impl convert::From<str::Utf8Error> for Error {
     }
 }
 
-impl base::Handle {
+impl<'a> base::Handle<'a> {
     pub(crate) fn get_error_from_handle(&self, operation: &'static str) -> Error {
         let c_msg = unsafe { guestfs_last_error(self.g) };
         let message = unsafe { utils::char_ptr_to_string(c_msg).unwrap() };

rust/src/event.rs

@@ -0,0 +1,4 @@
+#[derive(Hash, PartialEq, Eq)]
+pub struct EventHandle {
+    eh: i32,
+}

rust/src/lib.rs

@@ -18,9 +18,11 @@
 
 mod base;
 mod error;
+mod event;
 mod guestfs;
 mod utils;
 
 pub use crate::base::*;
 pub use crate::error::*;
+pub use crate::event::*;
 pub use crate::guestfs::*;

rust/tests/040_create_multiple.rs

@@ -18,7 +18,7 @@
 
 extern crate guestfs;
 
-fn create() -> guestfs::Handle {
+fn create<'a>() -> guestfs::Handle<'a> {
     match guestfs::Handle::create() {
         Ok(g) => g,
         Err(e) => panic!("fail: {:?}", e),