grin/store/src/lib.rs
hashmap 8a22fb516a
Reduce number of allocations in to_key calls (#3311)
We have to make an extra allocation per db get request because key generation function to_key takes Vec. Taking byte slice (AsRef<[u8]> to be precise) also simplifes the code a bit.
2020-04-30 17:47:44 +02:00

124 lines
3.3 KiB
Rust

// Copyright 2020 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)]
#[macro_use]
extern crate log;
use failure;
#[macro_use]
extern crate failure_derive;
#[macro_use]
extern crate grin_core as core;
extern crate grin_util as util;
//use grin_core as core;
pub mod leaf_set;
pub mod lmdb;
pub mod pmmr;
pub mod prune_list;
pub mod types;
const SEP: u8 = b':';
use byteorder::{BigEndian, WriteBytesExt};
pub use crate::lmdb::*;
/// Build a db key from a prefix and a byte vector identifier.
pub fn to_key<K: AsRef<[u8]>>(prefix: u8, k: K) -> Vec<u8> {
let k = k.as_ref();
let mut res = Vec::with_capacity(k.len() + 2);
res.push(prefix);
res.push(SEP);
res.extend_from_slice(k);
res
}
/// Build a db key from a prefix and a byte vector identifier and numeric identifier
pub fn to_key_u64<K: AsRef<[u8]>>(prefix: u8, k: K, val: u64) -> Vec<u8> {
let k = k.as_ref();
let mut res = Vec::with_capacity(k.len() + 10);
res.push(prefix);
res.push(SEP);
res.extend_from_slice(k);
res.write_u64::<BigEndian>(val).unwrap();
res
}
/// Build a db key from a prefix and a numeric identifier.
pub fn u64_to_key(prefix: u8, val: u64) -> Vec<u8> {
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, 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>,
{
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_path = Path::new(&_original);
if temp_path.exists() {
remove_file(&temp_path)?;
}
let file = File::create(&temp_path)?;
writer(Box::new(file))?;
// Move temporary file into original
if original.exists() {
remove_file(&original)?;
}
rename(&temp_path, &original)?;
Ok(())
}
use croaring::Bitmap;
use std::io::{self, Read};
/// Read Bitmap from a file
pub fn read_bitmap<P: AsRef<Path>>(file_path: P) -> io::Result<Bitmap> {
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);
bitmap_file.read_to_end(&mut buffer)?;
Ok(Bitmap::deserialize(&buffer))
}