From 15fe40a8e3372c1df6bbdce9ce56fee09209a5f7 Mon Sep 17 00:00:00 2001
From: "Craig M. Brandenburg" <c.m.brandenburg@gmail.com>
Date: Sun, 2 Jul 2017 18:02:59 -0700
Subject: [PATCH] Implement Debug for public types (#16)

---
 src/cursor.rs      | 26 +++++++++++++++++++++++++-
 src/environment.rs |  8 +++++++-
 src/transaction.rs | 20 +++++++++++++++++++-
 3 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/src/cursor.rs b/src/cursor.rs
index aa26746..b3f59a2 100644
--- a/src/cursor.rs
+++ b/src/cursor.rs
@@ -1,5 +1,5 @@
 use libc::{c_void, size_t, c_uint};
-use std::{ptr, slice};
+use std::{fmt, ptr, result, slice};
 use std::marker::PhantomData;
 
 use database::Database;
@@ -108,6 +108,12 @@ impl <'txn> Cursor<'txn> for RoCursor<'txn> {
     }
 }
 
+impl <'txn> fmt::Debug for RoCursor<'txn> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("RoCursor").finish()
+    }
+}
+
 impl <'txn> Drop for RoCursor<'txn> {
     fn drop(&mut self) {
         unsafe { ffi::mdb_cursor_close(self.cursor) }
@@ -141,6 +147,12 @@ impl <'txn> Cursor<'txn> for RwCursor<'txn> {
     }
 }
 
+impl <'txn> fmt::Debug for RwCursor<'txn> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("RwCursor").finish()
+    }
+}
+
 impl <'txn> Drop for RwCursor<'txn> {
     fn drop(&mut self) {
         unsafe { ffi::mdb_cursor_close(self.cursor) }
@@ -217,6 +229,12 @@ impl <'txn> Iter<'txn> {
     }
 }
 
+impl <'txn> fmt::Debug for Iter<'txn> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("Iter").finish()
+    }
+}
+
 impl <'txn> Iterator for Iter<'txn> {
 
     type Item = (&'txn [u8], &'txn [u8]);
@@ -257,6 +275,12 @@ impl <'txn> IterDup<'txn> {
     }
 }
 
+impl <'txn> fmt::Debug for IterDup<'txn> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("IterDup").finish()
+    }
+}
+
 impl <'txn> Iterator for IterDup<'txn> {
 
     type Item = Iter<'txn>;
diff --git a/src/environment.rs b/src/environment.rs
index 80251d1..c800bd5 100644
--- a/src/environment.rs
+++ b/src/environment.rs
@@ -1,11 +1,11 @@
 use libc::{c_uint, size_t};
+use std::{fmt, ptr, result};
 use std::ffi::CString;
 #[cfg(unix)]
 use std::os::unix::ffi::OsStrExt;
 #[cfg(windows)]
 use std::ffi::OsStr;
 use std::path::Path;
-use std::ptr;
 use std::sync::Mutex;
 
 use ffi;
@@ -156,6 +156,12 @@ impl Environment {
 unsafe impl Send for Environment {}
 unsafe impl Sync for Environment {}
 
+impl fmt::Debug for Environment {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("Environment").finish()
+    }
+}
+
 impl Drop for Environment {
     fn drop(&mut self) {
         unsafe { ffi::mdb_env_close(self.env) }
diff --git a/src/transaction.rs b/src/transaction.rs
index ab481a4..b5278d8 100644
--- a/src/transaction.rs
+++ b/src/transaction.rs
@@ -1,5 +1,5 @@
 use libc::{c_uint, c_void, size_t};
-use std::{mem, ptr, slice};
+use std::{fmt, mem, ptr, result, slice};
 use std::marker::PhantomData ;
 
 use ffi;
@@ -110,6 +110,12 @@ pub struct RoTransaction<'env> {
     _marker: PhantomData<&'env ()>,
 }
 
+impl <'env> fmt::Debug for RoTransaction<'env> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("RoTransaction").finish()
+    }
+}
+
 impl <'env> Drop for RoTransaction<'env> {
     fn drop(&mut self) {
         unsafe { ffi::mdb_txn_abort(self.txn) }
@@ -166,6 +172,12 @@ pub struct InactiveTransaction<'env> {
     _marker: PhantomData<&'env ()>,
 }
 
+impl <'env> fmt::Debug for InactiveTransaction<'env> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("InactiveTransaction").finish()
+    }
+}
+
 impl <'env> Drop for InactiveTransaction<'env> {
     fn drop(&mut self) {
         unsafe { ffi::mdb_txn_abort(self.txn) }
@@ -195,6 +207,12 @@ pub struct RwTransaction<'env> {
     _marker: PhantomData<&'env ()>,
 }
 
+impl <'env> fmt::Debug for RwTransaction<'env> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> result::Result<(), fmt::Error> {
+        f.debug_struct("RwTransaction").finish()
+    }
+}
+
 impl <'env> Drop for RwTransaction<'env> {
     fn drop(&mut self) {
         unsafe { ffi::mdb_txn_abort(self.txn) }