Abstract over MutexGuards.

database/src/fs.rs

@@ -1,4 +1,4 @@
-use parking_lot::{Mutex, MutexGuard};
+use parking_lot::Mutex;
 use std::convert::{TryInto, TryFrom};
 use std::fs::{create_dir_all, read_link, remove_file, rename, File};
 use std::io::{Read, Write};
@@ -14,6 +14,7 @@ use pathdiff::diff_paths;
 
 use {Database, Delete, Verify, Query};
 use types::{Email, Fingerprint, KeyID};
+use sync::MutexGuard;
 use Result;
 
 pub struct Filesystem {
@@ -381,7 +382,7 @@ fn symlink(symlink_content: &Path, symlink_name: &Path) -> Result<()> {
 
 impl Database for Filesystem {
     fn lock(&self) -> MutexGuard<()> {
-        self.update_lock.lock()
+        self.update_lock.lock().into()
     }
 
     fn new_verify_token(&self, payload: Verify) -> Result<String> {

database/src/lib.rs

@@ -15,7 +15,6 @@ use failure::Fallible as Result;
 extern crate idna;
 #[macro_use] extern crate log;
 extern crate parking_lot;
-use parking_lot::MutexGuard;
 extern crate pathdiff;
 extern crate rand;
 extern crate serde;
@@ -41,6 +40,9 @@ use serde::{Serialize, Deserialize, Deserializer, Serializer};
 pub mod types;
 use types::{Email, Fingerprint, KeyID};
 
+pub mod sync;
+use sync::MutexGuard;
+
 mod fs;
 pub use self::fs::Filesystem;
 mod memory;

database/src/memory.rs

@@ -1,8 +1,9 @@
-use parking_lot::{Mutex, MutexGuard};
+use parking_lot::Mutex;
 use std::collections::HashMap;
 
 use {Database, Delete, Verify, Query};
 use types::{Email, Fingerprint, KeyID};
+use sync::MutexGuard;
 use Result;
 
 #[derive(Debug)]
@@ -34,7 +35,7 @@ impl Default for Memory {
 
 impl Database for Memory {
     fn lock(&self) -> MutexGuard<()> {
-        self.update_lock.lock()
+        self.update_lock.lock().into()
     }
 
     fn new_verify_token(&self, payload: Verify) -> Result<String> {

database/src/poly.rs

@@ -3,7 +3,7 @@ use std::path::PathBuf;
 use {Database, Delete, Filesystem, Memory, Verify, Query};
 use Result;
 use types::{Email, Fingerprint, KeyID};
-use parking_lot::MutexGuard;
+use sync::MutexGuard;
 
 pub enum Polymorphic {
     Memory(Memory),

database/src/sync.rs

@@ -0,0 +1,11 @@
+use parking_lot;
+
+pub enum MutexGuard<'a, T> {
+    ParkingLot(parking_lot::MutexGuard<'a, T>),
+}
+
+impl<'a, T> From<parking_lot::MutexGuard<'a, T>> for MutexGuard<'a, T> {
+    fn from(g: parking_lot::MutexGuard<'a, T>) -> Self {
+        MutexGuard::ParkingLot(g)
+    }
+}