From ffda43c082b79f7698152287b8236b6c0c9918ec Mon Sep 17 00:00:00 2001
From: Justus Winter <justus@sequoia-pgp.org>
Date: Tue, 8 Dec 2020 18:12:44 +0100
Subject: buffered-reader: Don't explicitly storing the mapping.

  - This makes file_unix::File Send and Sync.
---
 buffered-reader/src/file_unix.rs | 20 +++++++++-----------
 buffered-reader/src/memory.rs    |  5 +++++
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/buffered-reader/src/file_unix.rs b/buffered-reader/src/file_unix.rs
index 0b645f3c..8adca1e6 100644
--- a/buffered-reader/src/file_unix.rs
+++ b/buffered-reader/src/file_unix.rs
@@ -4,7 +4,7 @@
 //! performance of the statistics example by ~10% over the
 //! Generic.
 
-use libc::{c_void, size_t, mmap, munmap, PROT_READ, MAP_PRIVATE};
+use libc::{mmap, munmap, PROT_READ, MAP_PRIVATE};
 use std::fmt;
 use std::fs;
 use std::io;
@@ -46,8 +46,6 @@ impl<'a, C: fmt::Debug> fmt::Debug for File<'a, C> {
 enum Imp<'a, C: fmt::Debug> {
     Generic(Generic<fs::File, C>),
     MMAP {
-        addr: *mut c_void,
-        length: size_t,
         reader: Memory<'a, C>,
     }
 }
@@ -56,10 +54,12 @@ impl<'a, C: fmt::Debug> Drop for Imp<'a, C> {
     fn drop(&mut self) {
         match self {
             Imp::Generic(_) => (),
-            Imp::MMAP { addr, length, .. } =>
+            Imp::MMAP { reader, } => {
+                let buf = reader.source_buffer();
                 unsafe {
-                    munmap(*addr, *length);
-                },
+                    munmap(buf.as_ptr() as *mut _, buf.len());
+                }
+            },
         }
     }
 }
@@ -82,10 +82,10 @@ impl<'a, C: fmt::Debug> fmt::Debug for Imp<'a, C> {
                 f.debug_tuple("Generic")
                 .field(&g)
                 .finish(),
-            Imp::MMAP { ref addr, ref length, ref reader } =>
+            Imp::MMAP { reader, } =>
                 f.debug_struct("MMAP")
-                .field("addr", addr)
-                .field("length", length)
+                .field("addr", &reader.source_buffer().as_ptr())
+                .field("length", &reader.source_buffer().len())
                 .field("reader", reader)
                 .finish(),
         }
@@ -150,8 +150,6 @@ impl<'a, C: fmt::Debug> File<'a, C> {
 
         Ok(File(
             Imp::MMAP {
-                addr,
-                length,
                 reader: Memory::with_cookie(slice, cookie),
             },
             path.into(),
diff --git a/buffered-reader/src/memory.rs b/buffered-reader/src/memory.rs
index b09a3478..de2f61bb 100644
--- a/buffered-reader/src/memory.rs
+++ b/buffered-reader/src/memory.rs
@@ -55,6 +55,11 @@ impl<'a, C: fmt::Debug> Memory<'a, C> {
     pub fn total_out(&self) -> usize {
         return self.cursor;
     }
+
+    #[allow(dead_code)]
+    pub(crate) fn source_buffer(&self) -> &[u8] {
+        self.buffer
+    }
 }
 
 impl<'a, C: fmt::Debug> io::Read for Memory<'a, C> {
-- 
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