Add a hexdump function for debugging

src/components/util/debug.rs

@@ -0,0 +1,31 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use std::io;
+use std::vec::raw::buf_as_slice;
+use std::cast::transmute;
+use std::sys::size_of;
+
+fn hexdump_slice(buf: &[u8]) {
+    let stderr = io::stderr();
+    stderr.write_str("    ");
+    for (i, &v) in buf.iter().enumerate() {
+        stderr.write_str(fmt!("%02X ", v as uint));
+        match i % 16 {
+            15 => stderr.write_str("\n    "),
+             7 => stderr.write_str("   "),
+             _ => ()
+        }
+        stderr.flush();
+    }
+    stderr.write_char('\n');
+}
+
+pub fn hexdump<T>(obj: &T) {
+    unsafe {
+        let buf: *u8 = transmute(obj);
+        debug!("dumping at %p", buf);
+        buf_as_slice(buf, size_of::<T>(), hexdump_slice);
+    }
+}

src/components/util/util.rc

@@ -16,4 +16,4 @@ pub mod time;
 pub mod tree;
 pub mod url;
 pub mod vec;
-
+pub mod debug;