// Copyright 2018 The Grin Developers
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//! Storage of core types using RocksDB.

#![deny(non_upper_case_globals)]
#![deny(non_camel_case_types)]
#![deny(non_snake_case)]
#![deny(unused_mut)]
#![warn(missing_docs)]

extern crate byteorder;
extern crate croaring;
extern crate env_logger;
extern crate libc;
extern crate lmdb_zero;
extern crate memmap;
extern crate serde;
#[macro_use]
extern crate log;
extern crate failure;
#[macro_use]
extern crate failure_derive;

#[macro_use]
extern crate grin_core as core;
extern crate grin_util as util;

pub mod leaf_set;
mod lmdb;
pub mod pmmr;
pub mod prune_list;
pub mod types;

const SEP: u8 = ':' as u8;

use byteorder::{BigEndian, WriteBytesExt};

pub use lmdb::*;

/// Build a db key from a prefix and a byte vector identifier.
pub fn to_key(prefix: u8, k: &mut Vec<u8>) -> Vec<u8> {
	let mut res = Vec::with_capacity(k.len() + 2);
	res.push(prefix);
	res.push(SEP);
	res.append(k);
	res
}

/// 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![];
	res.push(prefix);
	res.push(SEP);
	res.append(k);
	res.write_u64::<BigEndian>(val).unwrap();
	res
}
/// Build a db key from a prefix and a numeric identifier.
pub fn u64_to_key<'a>(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
}

/// 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,
	mut writer: F,
) -> Result<(), std::io::Error>
where
	F: FnMut(Box<std::io::Write>) -> Result<(), std::io::Error>,
{
	assert_ne!(*temp_suffix, *"");

	use std::fs::{remove_file, rename, File};
	use std::path::Path;

	// Write temporary file
	let temp_name = format!("{}{}", &path, temp_suffix);
	let temp_path = Path::new(&temp_name);
	if temp_path.exists() {
		remove_file(&temp_path)?;
	}

	let file = File::create(&temp_path)?;
	writer(Box::new(file))?;

	// Move temporary file into original
	let original = Path::new(&path);
	if original.exists() {
		remove_file(&original)?;
	}

	rename(&temp_path, &original)?;

	Ok(())
}