diff --git a/.gitignore b/.gitignore
index c2a6954d3..728c195b5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,10 +5,11 @@ node*
 !node_clients
 !node_clients.rs
 target
-Cargo.lock
+*/Cargo.lock
 *.iml
 grin.log
 wallet.seed
 test_output
 wallet_data
 wallet/db
+.idea/
diff --git a/chain/src/store.rs b/chain/src/store.rs
index a3ed032df..1b0265316 100644
--- a/chain/src/store.rs
+++ b/chain/src/store.rs
@@ -270,7 +270,7 @@ impl<'a> Batch<'a> {
 	fn save_block_input_bitmap(&self, bh: &Hash, bm: &Bitmap) -> Result<(), Error> {
 		self.db.put(
 			&to_key(BLOCK_INPUT_BITMAP_PREFIX, &mut bh.to_vec())[..],
-			bm.serialize(),
+			&bm.serialize(),
 		)
 	}
 
diff --git a/core/src/consensus.rs b/core/src/consensus.rs
index 00f471a9c..70d5d8c3b 100644
--- a/core/src/consensus.rs
+++ b/core/src/consensus.rs
@@ -309,19 +309,13 @@ where
 
 /// Count, in units of 1/100 (a percent), the number of "secondary" (AR) blocks in the provided window of blocks.
 pub fn ar_count(_height: u64, diff_data: &[HeaderInfo]) -> u64 {
-	100 * diff_data
-		.iter()
-		.filter(|n| n.is_secondary)
-		.count() as u64
+	100 * diff_data.iter().filter(|n| n.is_secondary).count() as u64
 }
 
 /// Factor by which the secondary proof of work difficulty will be adjusted
 pub fn secondary_pow_scaling(height: u64, diff_data: &[HeaderInfo]) -> u32 {
 	// Get the scaling factor sum of the last DIFFICULTY_ADJUST_WINDOW elements
-	let scale_sum: u64 = diff_data
-		.iter()
-		.map(|dd| dd.secondary_scaling as u64)
-		.sum();
+	let scale_sum: u64 = diff_data.iter().map(|dd| dd.secondary_scaling as u64).sum();
 
 	// compute ideal 2nd_pow_fraction in pct and across window
 	let target_pct = secondary_pow_ratio(height);
diff --git a/core/src/core/block.rs b/core/src/core/block.rs
index 8b017a4f8..72f62ba6c 100644
--- a/core/src/core/block.rs
+++ b/core/src/core/block.rs
@@ -27,10 +27,7 @@ use crate::core::committed::{self, Committed};
 use crate::core::compact_block::{CompactBlock, CompactBlockBody};
 use crate::core::hash::{Hash, Hashed, ZERO_HASH};
 use crate::core::verifier_cache::VerifierCache;
-use crate::core::{
-	transaction, Commitment, Input, Output, Transaction,
-	TransactionBody, TxKernel,
-};
+use crate::core::{transaction, Commitment, Input, Output, Transaction, TransactionBody, TxKernel};
 use crate::global;
 use crate::keychain::{self, BlindingFactor};
 use crate::pow::{Difficulty, Proof, ProofOfWork};
diff --git a/core/src/core/pmmr/backend.rs b/core/src/core/pmmr/backend.rs
index f77917ac8..4f6789d93 100644
--- a/core/src/core/pmmr/backend.rs
+++ b/core/src/core/pmmr/backend.rs
@@ -17,6 +17,7 @@ use croaring::Bitmap;
 use crate::core::hash::Hash;
 use crate::core::BlockHeader;
 use crate::ser::PMMRable;
+use std::path::Path;
 
 /// Storage backend for the MMR, just needs to be indexed by order of insertion.
 /// The PMMR itself does not need the Backend to be accurate on the existence
@@ -59,7 +60,7 @@ pub trait Backend<T: PMMRable> {
 	/// Returns the data file path.. this is a bit of a hack now that doesn't
 	/// sit well with the design, but TxKernels have to be summed and the
 	/// fastest way to to be able to allow direct access to the file
-	fn get_data_file_path(&self) -> &str;
+	fn get_data_file_path(&self) -> &Path;
 
 	/// Also a bit of a hack...
 	/// Saves a snapshot of the rewound utxo file with the block hash as
diff --git a/core/src/core/pmmr/pmmr.rs b/core/src/core/pmmr/pmmr.rs
index 1c48376a8..6df1a46f6 100644
--- a/core/src/core/pmmr/pmmr.rs
+++ b/core/src/core/pmmr/pmmr.rs
@@ -22,6 +22,7 @@ use crate::core::merkle_proof::MerkleProof;
 use crate::core::pmmr::{Backend, ReadonlyPMMR};
 use crate::core::BlockHeader;
 use crate::ser::{PMMRIndexHashable, PMMRable};
+use std::path::Path;
 
 /// 64 bits all ones: 0b11111111...1
 const ALL_ONES: u64 = u64::MAX;
@@ -323,7 +324,7 @@ where
 	}
 
 	/// Return the path of the data file (needed to sum kernels efficiently)
-	pub fn data_file_path(&self) -> &str {
+	pub fn data_file_path(&self) -> &Path {
 		self.backend.get_data_file_path()
 	}
 
diff --git a/core/src/libtx/reward.rs b/core/src/libtx/reward.rs
index a85c12507..ab161f951 100644
--- a/core/src/libtx/reward.rs
+++ b/core/src/libtx/reward.rs
@@ -23,11 +23,7 @@ use crate::libtx::{aggsig, proof};
 use crate::util::static_secp_instance;
 
 /// output a reward output
-pub fn output<K>(
-	keychain: &K,
-	key_id: &Identifier,
-	fees: u64,
-) -> Result<(Output, TxKernel), Error>
+pub fn output<K>(keychain: &K, key_id: &Identifier, fees: u64) -> Result<(Output, TxKernel), Error>
 where
 	K: Keychain,
 {
diff --git a/core/tests/consensus.rs b/core/tests/consensus.rs
index 44407bc39..924477181 100644
--- a/core/tests/consensus.rs
+++ b/core/tests/consensus.rs
@@ -342,7 +342,6 @@ fn adjustment_scenarios() {
 	println!("*********************************************************");
 	print_chain_sim(chain_sim);
 	println!("*********************************************************");
-
 }
 
 /// Checks different next_target adjustments and difficulty boundaries
diff --git a/core/tests/vec_backend.rs b/core/tests/vec_backend.rs
index 83ebb8665..675d5b05e 100644
--- a/core/tests/vec_backend.rs
+++ b/core/tests/vec_backend.rs
@@ -20,6 +20,7 @@ use self::core::ser::{FixedLength, PMMRable, Readable, Reader, Writeable, Writer
 use croaring;
 use croaring::Bitmap;
 use grin_core as core;
+use std::path::Path;
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub struct TestElem(pub [u32; 4]);
@@ -117,8 +118,8 @@ impl<T: PMMRable> Backend<T> for VecBackend<T> {
 		Ok(())
 	}
 
-	fn get_data_file_path(&self) -> &str {
-		""
+	fn get_data_file_path(&self) -> &Path {
+		Path::new("")
 	}
 
 	fn dump_stats(&self) {}
diff --git a/store/src/leaf_set.rs b/store/src/leaf_set.rs
index f40ab0dd3..c1f718a03 100644
--- a/store/src/leaf_set.rs
+++ b/store/src/leaf_set.rs
@@ -15,7 +15,7 @@
 //! Compact (roaring) bitmap representing the set of leaf positions
 //! that exist and are not currently pruned in the MMR.
 
-use std::path::Path;
+use std::path::{Path, PathBuf};
 
 use croaring::Bitmap;
 
@@ -31,7 +31,7 @@ use std::io::{self, BufWriter, Write};
 /// Compact (roaring) bitmap representing the set of positions of
 /// leaves that are currently unpruned in the MMR.
 pub struct LeafSet {
-	path: String,
+	path: PathBuf,
 	bitmap: Bitmap,
 	bitmap_bak: Bitmap,
 }
@@ -39,35 +39,42 @@ pub struct LeafSet {
 impl LeafSet {
 	/// Open the remove log file.
 	/// The content of the file will be read in memory for fast checking.
-	pub fn open(path: &str) -> io::Result<LeafSet> {
-		let file_path = Path::new(&path);
+	pub fn open<P: AsRef<Path>>(path: P) -> io::Result<LeafSet> {
+		let file_path = path.as_ref();
 		let bitmap = if file_path.exists() {
-			read_bitmap(file_path)?
+			read_bitmap(&file_path)?
 		} else {
 			Bitmap::create()
 		};
 
 		Ok(LeafSet {
-			path: path.to_string(),
+			path: file_path.to_path_buf(),
 			bitmap_bak: bitmap.clone(),
 			bitmap,
 		})
 	}
 
 	/// Copies a snapshot of the utxo file into the primary utxo file.
-	pub fn copy_snapshot(path: &str, cp_path: &str) -> io::Result<()> {
-		let cp_file_path = Path::new(&cp_path);
+	pub fn copy_snapshot<P: AsRef<Path>>(path: P, cp_path: P) -> io::Result<()> {
+		let cp_file_path = cp_path.as_ref();
 
 		if !cp_file_path.exists() {
-			debug!("leaf_set: rewound leaf file not found: {}", cp_path);
+			debug!(
+				"leaf_set: rewound leaf file not found: {}",
+				cp_file_path.display()
+			);
 			return Ok(());
 		}
 
-		let bitmap = read_bitmap(cp_file_path)?;
-		debug!("leaf_set: copying rewound file {} to {}", cp_path, path);
+		let bitmap = read_bitmap(&cp_file_path)?;
+		debug!(
+			"leaf_set: copying rewound file {} to {}",
+			cp_file_path.display(),
+			path.as_ref().display()
+		);
 
 		let mut leaf_set = LeafSet {
-			path: path.to_string(),
+			path: path.as_ref().to_path_buf(),
 			bitmap_bak: bitmap.clone(),
 			bitmap,
 		};
@@ -148,7 +155,7 @@ impl LeafSet {
 		let mut cp_bitmap = self.bitmap.clone();
 		cp_bitmap.run_optimize();
 
-		let cp_path = format!("{}.{}", self.path, header.hash());
+		let cp_path = self.path.join(header.hash().to_string());
 		let mut file = BufWriter::new(File::create(cp_path)?);
 		file.write_all(&cp_bitmap.serialize())?;
 		file.flush()?;
diff --git a/store/src/lib.rs b/store/src/lib.rs
index 24ca75736..7c76efbcf 100644
--- a/store/src/lib.rs
+++ b/store/src/lib.rs
@@ -56,7 +56,7 @@ pub fn to_key(prefix: u8, k: &mut Vec<u8>) -> Vec<u8> {
 
 /// Build a db key from a prefix and a byte vector identifier and numeric identifier
 pub fn to_key_u64(prefix: u8, k: &mut Vec<u8>, val: u64) -> Vec<u8> {
-	let mut res = vec![];
+	let mut res = Vec::with_capacity(k.len() + 10);
 	res.push(prefix);
 	res.push(SEP);
 	res.append(k);
@@ -65,31 +65,36 @@ pub fn to_key_u64(prefix: u8, k: &mut Vec<u8>, val: u64) -> Vec<u8> {
 }
 /// Build a db key from a prefix and a numeric identifier.
 pub fn u64_to_key(prefix: u8, val: u64) -> Vec<u8> {
-	let mut u64_vec = vec![];
-	u64_vec.write_u64::<BigEndian>(val).unwrap();
-	u64_vec.insert(0, SEP);
-	u64_vec.insert(0, prefix);
-	u64_vec
+	let mut res = Vec::with_capacity(10);
+	res.push(prefix);
+	res.push(SEP);
+	res.write_u64::<BigEndian>(val).unwrap();
+	res
 }
 
+use std::ffi::OsStr;
+use std::fs::{remove_file, rename, File};
+use std::path::Path;
 /// Creates temporary file with name created by adding `temp_suffix` to `path`.
 /// Applies writer function to it and renames temporary file into original specified by `path`.
-pub fn save_via_temp_file<F>(
-	path: &str,
-	temp_suffix: &str,
+pub fn save_via_temp_file<F, P, E>(
+	path: P,
+	temp_suffix: E,
 	mut writer: F,
 ) -> Result<(), std::io::Error>
 where
 	F: FnMut(Box<dyn std::io::Write>) -> Result<(), std::io::Error>,
+	P: AsRef<Path>,
+	E: AsRef<OsStr>,
 {
-	assert_ne!(*temp_suffix, *"");
-
-	use std::fs::{remove_file, rename, File};
-	use std::path::Path;
+	let temp_suffix = temp_suffix.as_ref();
+	assert!(!temp_suffix.is_empty());
 
+	let original = path.as_ref();
+	let mut _original = original.as_os_str().to_os_string();
+	_original.push(temp_suffix);
 	// Write temporary file
-	let temp_name = format!("{}{}", &path, temp_suffix);
-	let temp_path = Path::new(&temp_name);
+	let temp_path = Path::new(&_original);
 	if temp_path.exists() {
 		remove_file(&temp_path)?;
 	}
@@ -98,7 +103,6 @@ where
 	writer(Box::new(file))?;
 
 	// Move temporary file into original
-	let original = Path::new(&path);
 	if original.exists() {
 		remove_file(&original)?;
 	}
@@ -110,10 +114,8 @@ where
 
 use croaring::Bitmap;
 use std::io::{self, Read};
-use std::path::Path;
 /// Read Bitmap from a file
 pub fn read_bitmap<P: AsRef<Path>>(file_path: P) -> io::Result<Bitmap> {
-	use std::fs::File;
 	let mut bitmap_file = File::open(file_path)?;
 	let f_md = bitmap_file.metadata()?;
 	let mut buffer = Vec::with_capacity(f_md.len() as usize);
diff --git a/store/src/lmdb.rs b/store/src/lmdb.rs
index 212a3edfb..9b326daee 100644
--- a/store/src/lmdb.rs
+++ b/store/src/lmdb.rs
@@ -67,15 +67,17 @@ pub fn new_env(path: String) -> lmdb::Environment {
 pub fn new_named_env(path: String, name: String) -> lmdb::Environment {
 	let full_path = [path, name].join("/");
 	fs::create_dir_all(&full_path).unwrap();
-	unsafe {
-		let mut env_builder = lmdb::EnvBuilder::new().unwrap();
-		env_builder.set_maxdbs(8).unwrap();
-		// half a TB should give us plenty room, will be an issue on 32 bits
-		// (which we don't support anyway)
-		env_builder.set_mapsize(549755813888).unwrap_or_else(|e| {
+
+	let mut env_builder = lmdb::EnvBuilder::new().unwrap();
+	env_builder.set_maxdbs(8).unwrap();
+	// half a TB should give us plenty room, will be an issue on 32 bits
+	// (which we don't support anyway)
+	env_builder
+		.set_mapsize(549_755_813_888)
+		.unwrap_or_else(|e| {
 			panic!("Unable to allocate LMDB space: {:?}", e);
 		});
-
+	unsafe {
 		env_builder
 			.open(&full_path, lmdb::open::Flags::empty(), 0o600)
 			.unwrap()
@@ -178,10 +180,10 @@ pub struct Batch<'a> {
 
 impl<'a> Batch<'a> {
 	/// Writes a single key/value pair to the db
-	pub fn put(&self, key: &[u8], value: Vec<u8>) -> Result<(), Error> {
+	pub fn put(&self, key: &[u8], value: &[u8]) -> Result<(), Error> {
 		self.tx
 			.access()
-			.put(&self.store.db, key, &value, lmdb::put::Flags::empty())?;
+			.put(&self.store.db, key, value, lmdb::put::Flags::empty())?;
 		Ok(())
 	}
 
@@ -190,7 +192,7 @@ impl<'a> Batch<'a> {
 	pub fn put_ser<W: ser::Writeable>(&self, key: &[u8], value: &W) -> Result<(), Error> {
 		let ser_value = ser::ser_vec(value);
 		match ser_value {
-			Ok(data) => self.put(key, data),
+			Ok(data) => self.put(key, &data),
 			Err(err) => Err(Error::SerErr(format!("{}", err))),
 		}
 	}
diff --git a/store/src/pmmr.rs b/store/src/pmmr.rs
index c21681a58..5f770088b 100644
--- a/store/src/pmmr.rs
+++ b/store/src/pmmr.rs
@@ -23,6 +23,7 @@ use crate::leaf_set::LeafSet;
 use crate::prune_list::PruneList;
 use crate::types::{prune_noop, DataFile};
 use croaring::Bitmap;
+use std::path::{Path, PathBuf};
 
 const PMMR_HASH_FILE: &str = "pmmr_hash.bin";
 const PMMR_DATA_FILE: &str = "pmmr_data.bin";
@@ -50,7 +51,7 @@ pub const PMMR_FILES: [&str; 4] = [
 /// * A prune_list tracks the positions of pruned (and compacted) roots in the
 /// MMR.
 pub struct PMMRBackend<T: PMMRable> {
-	data_dir: String,
+	data_dir: PathBuf,
 	prunable: bool,
 	hash_file: DataFile<Hash>,
 	data_file: DataFile<T::E>,
@@ -147,7 +148,7 @@ impl<T: PMMRable> Backend<T> for PMMRBackend<T> {
 	}
 
 	/// Return data file path
-	fn get_data_file_path(&self) -> &str {
+	fn get_data_file_path(&self) -> &Path {
 		self.data_file.path()
 	}
 
@@ -173,28 +174,32 @@ impl<T: PMMRable> Backend<T> for PMMRBackend<T> {
 impl<T: PMMRable> PMMRBackend<T> {
 	/// Instantiates a new PMMR backend.
 	/// Use the provided dir to store its files.
-	pub fn new(
-		data_dir: String,
+	pub fn new<P: AsRef<Path>>(
+		data_dir: P,
 		prunable: bool,
 		header: Option<&BlockHeader>,
 	) -> io::Result<PMMRBackend<T>> {
-		let hash_file = DataFile::open(&format!("{}/{}", data_dir, PMMR_HASH_FILE))?;
-		let data_file = DataFile::open(&format!("{}/{}", data_dir, PMMR_DATA_FILE))?;
+		let data_dir = data_dir.as_ref();
+		let hash_file = DataFile::open(&data_dir.join(PMMR_HASH_FILE))?;
+		let data_file = DataFile::open(&data_dir.join(PMMR_DATA_FILE))?;
 
-		let leaf_set_path = format!("{}/{}", data_dir, PMMR_LEAF_FILE);
+		let leaf_set_path = data_dir.join(PMMR_LEAF_FILE);
 
 		// If we received a rewound "snapshot" leaf_set file move it into
 		// place so we use it.
 		if let Some(header) = header {
-			let leaf_snapshot_path = format!("{}/{}.{}", data_dir, PMMR_LEAF_FILE, header.hash());
+			let _leaf_snapshot_path = (data_dir.join(PMMR_LEAF_FILE).to_string_lossy()
+				+ header.hash().to_string().as_ref())
+			.into_owned();
+			let leaf_snapshot_path = PathBuf::from(_leaf_snapshot_path);
 			LeafSet::copy_snapshot(&leaf_set_path, &leaf_snapshot_path)?;
 		}
 
 		let leaf_set = LeafSet::open(&leaf_set_path)?;
-		let prune_list = PruneList::open(&format!("{}/{}", data_dir, PMMR_PRUN_FILE))?;
+		let prune_list = PruneList::open(&data_dir.join(PMMR_PRUN_FILE))?;
 
 		Ok(PMMRBackend {
-			data_dir,
+			data_dir: data_dir.to_path_buf(),
 			prunable,
 			hash_file,
 			data_file,
@@ -278,9 +283,10 @@ impl<T: PMMRable> PMMRBackend<T> {
 		assert!(self.prunable, "Trying to compact a non-prunable PMMR");
 
 		// Paths for tmp hash and data files.
-		let tmp_prune_file_hash = format!("{}/{}.hashprune", self.data_dir, PMMR_HASH_FILE);
-		let tmp_prune_file_data = format!("{}/{}.dataprune", self.data_dir, PMMR_DATA_FILE);
-
+		let tmp_prune_file_hash =
+			format!("{}.hashprune", self.data_dir.join(PMMR_HASH_FILE).display());
+		let tmp_prune_file_data =
+			format!("{}.dataprune", self.data_dir.join(PMMR_DATA_FILE).display());
 		// Calculate the sets of leaf positions and node positions to remove based
 		// on the cutoff_pos provided.
 		let (leaves_removed, pos_to_rm) = self.pos_to_rm(cutoff_pos, rewind_rm_pos);
@@ -293,7 +299,7 @@ impl<T: PMMRable> PMMRBackend<T> {
 			});
 
 			self.hash_file
-				.save_prune(tmp_prune_file_hash.clone(), &off_to_rm, &prune_noop)?;
+				.save_prune(&tmp_prune_file_hash, &off_to_rm, &prune_noop)?;
 		}
 
 		// 2. Save compact copy of the data file, skipping removed leaves.
@@ -311,7 +317,7 @@ impl<T: PMMRable> PMMRBackend<T> {
 			});
 
 			self.data_file
-				.save_prune(tmp_prune_file_data.clone(), &off_to_rm, prune_cb)?;
+				.save_prune(&tmp_prune_file_data, &off_to_rm, prune_cb)?;
 		}
 
 		// 3. Update the prune list and write to disk.
@@ -325,16 +331,16 @@ impl<T: PMMRable> PMMRBackend<T> {
 		// 4. Rename the compact copy of hash file and reopen it.
 		fs::rename(
 			tmp_prune_file_hash.clone(),
-			format!("{}/{}", self.data_dir, PMMR_HASH_FILE),
+			self.data_dir.join(PMMR_HASH_FILE),
 		)?;
-		self.hash_file = DataFile::open(&format!("{}/{}", self.data_dir, PMMR_HASH_FILE))?;
+		self.hash_file = DataFile::open(self.data_dir.join(PMMR_HASH_FILE))?;
 
 		// 5. Rename the compact copy of the data file and reopen it.
 		fs::rename(
 			tmp_prune_file_data.clone(),
-			format!("{}/{}", self.data_dir, PMMR_DATA_FILE),
+			self.data_dir.join(PMMR_DATA_FILE),
 		)?;
-		self.data_file = DataFile::open(&format!("{}/{}", self.data_dir, PMMR_DATA_FILE))?;
+		self.data_file = DataFile::open(self.data_dir.join(PMMR_DATA_FILE))?;
 
 		// 6. Write the leaf_set to disk.
 		// Optimize the bitmap storage in the process.
diff --git a/store/src/prune_list.rs b/store/src/prune_list.rs
index adda822e3..7417a706e 100644
--- a/store/src/prune_list.rs
+++ b/store/src/prune_list.rs
@@ -22,7 +22,7 @@
 //! files.
 
 use std::io::{self, BufWriter, Write};
-use std::path::Path;
+use std::path::{Path, PathBuf};
 
 use croaring::Bitmap;
 
@@ -41,7 +41,7 @@ use crate::{read_bitmap, save_via_temp_file};
 /// backend storage anymore. The PruneList accounts for that mismatch and does
 /// the position translation.
 pub struct PruneList {
-	path: Option<String>,
+	path: Option<PathBuf>,
 	/// Bitmap representing pruned root node positions.
 	bitmap: Bitmap,
 	/// Bitmap representing all pruned node positions (everything under the pruned roots).
@@ -63,8 +63,8 @@ impl PruneList {
 	}
 
 	/// Open an existing prune_list or create a new one.
-	pub fn open(path: &str) -> io::Result<PruneList> {
-		let file_path = Path::new(&path);
+	pub fn open<P: AsRef<Path>>(path: P) -> io::Result<PruneList> {
+		let file_path = PathBuf::from(path.as_ref());
 		let bitmap = if file_path.exists() {
 			read_bitmap(&file_path)?
 		} else {
@@ -72,7 +72,7 @@ impl PruneList {
 		};
 
 		let mut prune_list = PruneList {
-			path: Some(path.to_string()),
+			path: Some(file_path),
 			bitmap,
 			pruned_cache: Bitmap::create(),
 			shift_cache: vec![],
@@ -111,7 +111,7 @@ impl PruneList {
 
 		// Write the updated bitmap file to disk.
 		if let Some(ref path) = self.path {
-			save_via_temp_file(&path, ".tmp", |w| {
+			save_via_temp_file(path, ".tmp", |w| {
 				let mut w = BufWriter::new(w);
 				w.write_all(&self.bitmap.serialize())?;
 				w.flush()
@@ -264,7 +264,7 @@ impl PruneList {
 			return;
 		}
 		self.pruned_cache = Bitmap::create_with_capacity(self.bitmap.maximum());
-		for pos in 1..(self.bitmap.maximum() + 1) {
+		for pos in 1..=self.bitmap.maximum() {
 			let path = path(pos as u64, self.bitmap.maximum() as u64);
 			let pruned = path.into_iter().any(|x| self.bitmap.contains(x as u32));
 			if pruned {
@@ -279,3 +279,9 @@ impl PruneList {
 		self.bitmap.contains(pos as u32)
 	}
 }
+
+impl Default for PruneList {
+	fn default() -> Self {
+		Self::new()
+	}
+}
diff --git a/store/src/types.rs b/store/src/types.rs
index e06ba14e9..d53f81b1c 100644
--- a/store/src/types.rs
+++ b/store/src/types.rs
@@ -18,6 +18,7 @@ use crate::core::ser::{self, FixedLength, Readable, Writeable};
 use std::fs::{self, File, OpenOptions};
 use std::io::{self, BufWriter, ErrorKind, Read, Write};
 use std::marker;
+use std::path::{Path, PathBuf};
 
 /// A no-op function for doing nothing with some pruned data.
 pub fn prune_noop(_pruned_data: &[u8]) {}
@@ -33,7 +34,7 @@ where
 	T: FixedLength + Readable + Writeable,
 {
 	/// Open (or create) a file at the provided path on disk.
-	pub fn open(path: &str) -> io::Result<DataFile<T>> {
+	pub fn open<P: AsRef<Path>>(path: P) -> io::Result<DataFile<T>> {
 		let file = AppendOnlyFile::open(path)?;
 		Ok(DataFile {
 			file,
@@ -96,12 +97,12 @@ where
 	}
 
 	/// Path of the underlying file
-	pub fn path(&self) -> &str {
+	pub fn path(&self) -> &Path {
 		self.file.path()
 	}
 
 	/// Write the file out to disk, pruning removed elements.
-	pub fn save_prune<F>(&self, target: String, prune_offs: &[u64], prune_cb: F) -> io::Result<()>
+	pub fn save_prune<F>(&self, target: &str, prune_offs: &[u64], prune_cb: F) -> io::Result<()>
 	where
 		F: Fn(&[u8]),
 	{
@@ -123,7 +124,7 @@ where
 /// former simply happens by rewriting it, ignoring some of the data. The
 /// latter by truncating the underlying file and re-creating the mmap.
 pub struct AppendOnlyFile {
-	path: String,
+	path: PathBuf,
 	file: File,
 	mmap: Option<memmap::Mmap>,
 	buffer_start: usize,
@@ -133,7 +134,7 @@ pub struct AppendOnlyFile {
 
 impl AppendOnlyFile {
 	/// Open a file (existing or not) as append-only, backed by a mmap.
-	pub fn open(path: &str) -> io::Result<AppendOnlyFile> {
+	pub fn open<P: AsRef<Path>>(path: P) -> io::Result<AppendOnlyFile> {
 		let file = OpenOptions::new()
 			.read(true)
 			.append(true)
@@ -141,7 +142,7 @@ impl AppendOnlyFile {
 			.open(&path)?;
 		let mut aof = AppendOnlyFile {
 			file,
-			path: path.to_string(),
+			path: path.as_ref().to_path_buf(),
 			mmap: None,
 			buffer_start: 0,
 			buffer: vec![],
@@ -258,15 +259,16 @@ impl AppendOnlyFile {
 
 	/// Saves a copy of the current file content, skipping data at the provided
 	/// prune indices. The prune Vec must be ordered.
-	pub fn save_prune<T>(
+	pub fn save_prune<T, P>(
 		&self,
-		target: String,
+		target: P,
 		prune_offs: &[u64],
 		prune_len: u64,
 		prune_cb: T,
 	) -> io::Result<()>
 	where
 		T: Fn(&[u8]),
+		P: AsRef<Path>,
 	{
 		if prune_offs.is_empty() {
 			fs::copy(&self.path, &target)?;
@@ -322,7 +324,7 @@ impl AppendOnlyFile {
 	}
 
 	/// Path of the underlying file
-	pub fn path(&self) -> &str {
+	pub fn path(&self) -> &Path {
 		&self.path
 	}
 }
diff --git a/store/tests/pmmr.rs b/store/tests/pmmr.rs
index 258a46826..0f63a332e 100644
--- a/store/tests/pmmr.rs
+++ b/store/tests/pmmr.rs
@@ -17,7 +17,6 @@ use grin_core as core;
 use grin_store as store;
 
 use std::fs;
-use std::io::prelude::*;
 
 use chrono::prelude::Utc;
 use croaring::Bitmap;
@@ -822,9 +821,9 @@ fn create_numbered_files(
 			prefix,
 			start_index + rewind_file_num
 		));
-		let mut file = fs::File::create(path.clone()).unwrap();
+		let file = fs::File::create(path.clone()).unwrap();
 		let metadata = file.metadata().unwrap();
-		filetime::set_file_times(path, time_to_set_ft, time_to_set_ft);
+		filetime::set_file_times(path, time_to_set_ft, time_to_set_ft).unwrap();
 	}
 }
 
diff --git a/wallet/src/test_framework/testclient.rs b/wallet/src/test_framework/testclient.rs
index 2af6d8b6e..c64aefbbc 100644
--- a/wallet/src/test_framework/testclient.rs
+++ b/wallet/src/test_framework/testclient.rs
@@ -111,7 +111,8 @@ where
 			verifier_cache,
 			false,
 			Arc::new(Mutex::new(StopState::new())),
-		).unwrap();
+		)
+		.unwrap();
 		let (tx, rx) = channel();
 		let retval = WalletProxy {
 			chain_dir: chain_dir.to_owned(),