Directory Restructure (#1163)

* Move tests -> testing

* Directory restructure

* Update Cargo.toml during restructure

* Update Makefile during restructure

* Fix arbitrary path

common/eth2_wallet_manager/src/filesystem.rs

@@ -0,0 +1,97 @@
+//! Provides some CRUD functions for wallets on the filesystem.
+
+use eth2_wallet::Error as WalletError;
+use eth2_wallet::{Uuid, Wallet};
+use std::fs::{copy as copy_file, remove_file, OpenOptions};
+use std::io;
+use std::path::{Path, PathBuf};
+
+#[derive(Debug)]
+pub enum Error {
+    WalletAlreadyExists(PathBuf),
+    WalletDoesNotExist(PathBuf),
+    WalletBackupAlreadyExists(PathBuf),
+    UnableToCreateBackup(io::Error),
+    UnableToRemoveBackup(io::Error),
+    UnableToRemoveWallet(io::Error),
+    UnableToCreateWallet(io::Error),
+    UnableToReadWallet(io::Error),
+    JsonWriteError(WalletError),
+    JsonReadError(WalletError),
+}
+
+/// Read a wallet with the given `uuid` from the `wallet_dir`.
+pub fn read<P: AsRef<Path>>(wallet_dir: P, uuid: &Uuid) -> Result<Wallet, Error> {
+    let json_path = wallet_json_path(wallet_dir, uuid);
+
+    if !json_path.exists() {
+        Err(Error::WalletDoesNotExist(json_path))
+    } else {
+        OpenOptions::new()
+            .read(true)
+            .create(false)
+            .open(json_path)
+            .map_err(Error::UnableToReadWallet)
+            .and_then(|f| Wallet::from_json_reader(f).map_err(Error::JsonReadError))
+    }
+}
+
+/// Update the JSON file in the `wallet_dir` with the given `wallet`.
+///
+/// Performs a three-step copy:
+///
+/// 1. Copy the current JSON file to a backup file.
+/// 2. Over-write the existing JSON file.
+/// 3. Delete the backup file.
+pub fn update<P: AsRef<Path>>(wallet_dir: P, wallet: &Wallet) -> Result<(), Error> {
+    let wallet_dir = wallet_dir.as_ref();
+
+    let json_path = wallet_json_path(wallet_dir, wallet.uuid());
+    let json_backup_path = wallet_json_backup_path(wallet_dir, wallet.uuid());
+
+    // Require that a wallet already exists.
+    if !json_path.exists() {
+        return Err(Error::WalletDoesNotExist(json_path));
+    // Require that there is no existing backup.
+    } else if json_backup_path.exists() {
+        return Err(Error::WalletBackupAlreadyExists(json_backup_path));
+    }
+
+    // Copy the existing wallet to the backup location.
+    copy_file(&json_path, &json_backup_path).map_err(Error::UnableToCreateBackup)?;
+
+    // Remove the existing wallet
+    remove_file(json_path).map_err(Error::UnableToRemoveWallet)?;
+
+    // Create the new wallet.
+    create(wallet_dir, wallet)?;
+
+    // Remove the backup file.
+    remove_file(json_backup_path).map_err(Error::UnableToRemoveBackup)?;
+
+    Ok(())
+}
+
+/// Writes the `wallet` into the `wallet_dir`, returning an error if it already exists.
+pub fn create<P: AsRef<Path>>(wallet_dir: P, wallet: &Wallet) -> Result<(), Error> {
+    let json_path = wallet_json_path(wallet_dir, wallet.uuid());
+
+    if json_path.exists() {
+        Err(Error::WalletAlreadyExists(json_path))
+    } else {
+        OpenOptions::new()
+            .write(true)
+            .create_new(true)
+            .open(json_path)
+            .map_err(Error::UnableToCreateWallet)
+            .and_then(|f| wallet.to_json_writer(f).map_err(Error::JsonWriteError))
+    }
+}
+
+fn wallet_json_backup_path<P: AsRef<Path>>(wallet_dir: P, uuid: &Uuid) -> PathBuf {
+    wallet_dir.as_ref().join(format!("{}.backup", uuid))
+}
+
+fn wallet_json_path<P: AsRef<Path>>(wallet_dir: P, uuid: &Uuid) -> PathBuf {
+    wallet_dir.as_ref().join(format!("{}", uuid))
+}