_ Git - dnsseed-rust/blob - src/datastore.rs

   1 use std::{cmp, mem};
   2 use std::collections::{HashSet, HashMap, hash_map};
   3 use std::sync::{Arc, RwLock};
   4 use std::net::SocketAddr;
   5 use std::time::{Duration, Instant};
   6 use std::io::{BufRead, BufReader};
   7
   8 use bitcoin::network::address::Address;
   9
  10 use rand::thread_rng;
  11 use rand::seq::{SliceRandom, IteratorRandom};
  12
  13 use tokio::prelude::*;
  14 use tokio::fs::File;
  15 use tokio::io::write_all;
  16
  17 use regex::Regex;
  18
  19 #[derive(Clone, Copy, Hash, PartialEq, Eq)]
  20 pub enum AddressState {
  21         Untested,
  22         LowBlockCount,
  23         HighBlockCount,
  24         LowVersion,
  25         BadVersion,
  26         NotFullNode,
  27         ProtocolViolation,
  28         Timeout,
  29         TimeoutDuringRequest,
  30         Good,
  31         WasGood,
  32 }
  33
  34 impl AddressState {
  35         pub fn from_num(num: u8) -> Option<AddressState> {
  36                 match num {
  37                         0x0 => Some(AddressState::Untested),
  38                         0x1 => Some(AddressState::LowBlockCount),
  39                         0x2 => Some(AddressState::HighBlockCount),
  40                         0x3 => Some(AddressState::LowVersion),
  41                         0x4 => Some(AddressState::BadVersion),
  42                         0x5 => Some(AddressState::NotFullNode),
  43                         0x6 => Some(AddressState::ProtocolViolation),
  44                         0x7 => Some(AddressState::Timeout),
  45                         0x8 => Some(AddressState::TimeoutDuringRequest),
  46                         0x9 => Some(AddressState::Good),
  47                         0xa => Some(AddressState::WasGood),
  48                         _   => None,
  49                 }
  50         }
  51
  52         pub fn to_num(&self) -> u8 {
  53                 match *self {
  54                         AddressState::Untested => 0,
  55                         AddressState::LowBlockCount => 1,
  56                         AddressState::HighBlockCount => 2,
  57                         AddressState::LowVersion => 3,
  58                         AddressState::BadVersion => 4,
  59                         AddressState::NotFullNode => 5,
  60                         AddressState::ProtocolViolation => 6,
  61                         AddressState::Timeout => 7,
  62                         AddressState::TimeoutDuringRequest => 8,
  63                         AddressState::Good => 9,
  64                         AddressState::WasGood => 10,
  65                 }
  66         }
  67
  68         pub fn to_str(&self) -> &'static str {
  69                 match *self {
  70                         AddressState::Untested => "Untested",
  71                         AddressState::LowBlockCount => "Low Block Count",
  72                         AddressState::HighBlockCount => "High Block Count",
  73                         AddressState::LowVersion => "Low Version",
  74                         AddressState::BadVersion => "Bad Version",
  75                         AddressState::NotFullNode => "Not Full Node",
  76                         AddressState::ProtocolViolation => "Protocol Violation",
  77                         AddressState::Timeout => "Timeout",
  78                         AddressState::TimeoutDuringRequest => "Timeout During Request",
  79                         AddressState::Good => "Good",
  80                         AddressState::WasGood => "Was Good",
  81                 }
  82         }
  83
  84         pub fn get_count() -> u8 {
  85                 11
  86         }
  87 }
  88
  89 #[derive(Hash, PartialEq, Eq)]
  90 pub enum U64Setting {
  91         ConnsPerSec,
  92         RunTimeout,
  93         WasGoodTimeout,
  94         RescanInterval(AddressState),
  95         MinProtocolVersion,
  96 }
  97
  98 #[derive(Hash, PartialEq, Eq)]
  99 pub enum RegexSetting {
 100         SubverRegex,
 101 }
 102
 103 struct Node {
 104         last_update: Instant,
 105         last_good: Instant, // Ignored unless state is Good or WasGood
 106         last_services: u64,
 107         state: AddressState,
 108 }
 109
 110 struct Nodes {
 111         good_node_services: HashMap<u8, HashSet<SocketAddr>>,
 112         nodes_to_state: HashMap<SocketAddr, Node>,
 113         state_next_scan: HashMap<AddressState, Vec<(Instant, SocketAddr)>>,
 114 }
 115 struct NodesMutRef<'a> {
 116         good_node_services: &'a mut HashMap<u8, HashSet<SocketAddr>>,
 117         nodes_to_state: &'a mut HashMap<SocketAddr, Node>,
 118         state_next_scan: &'a mut HashMap<AddressState, Vec<(Instant, SocketAddr)>>,
 119
 120 }
 121 impl Nodes {
 122         fn borrow_mut<'a>(&'a mut self) -> NodesMutRef<'a> {
 123                 NodesMutRef {
 124                         good_node_services: &mut self.good_node_services,
 125                         nodes_to_state: &mut self.nodes_to_state,
 126                         state_next_scan: &mut self.state_next_scan,
 127                 }
 128         }
 129 }
 130
 131 pub struct Store {
 132         u64_settings: RwLock<HashMap<U64Setting, u64>>,
 133         subver_regex: RwLock<Arc<Regex>>,
 134         nodes: RwLock<Nodes>,
 135         store: String,
 136 }
 137
 138 impl Store {
 139         pub fn new(store: String) -> impl Future<Item=Store, Error=()> {
 140                 let settings_future = File::open(store.clone() + "/settings").and_then(|f| {
 141                         let mut l = BufReader::new(f).lines();
 142                         macro_rules! try_read {
 143                                 ($lines: expr, $ty: ty) => { {
 144                                         match $lines.next() {
 145                                                 Some(line) => match line {
 146                                                         Ok(line) => match line.parse::<$ty>() {
 147                                                                 Ok(res) => res,
 148                                                                 Err(e) => return future::err(std::io::Error::new(std::io::ErrorKind::InvalidData, e)),
 149                                                         },
 150                                                         Err(e) => return future::err(e),
 151                                                 },
 152                                                 None => return future::err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "")),
 153                                         }
 154                                 } }
 155                         }
 156                         let mut u64s = HashMap::with_capacity(15);
 157                         u64s.insert(U64Setting::ConnsPerSec, try_read!(l, u64));
 158                         u64s.insert(U64Setting::RunTimeout, try_read!(l, u64));
 159                         u64s.insert(U64Setting::WasGoodTimeout, try_read!(l, u64));
 160                         u64s.insert(U64Setting::MinProtocolVersion, try_read!(l, u64));
 161                         u64s.insert(U64Setting::RescanInterval(AddressState::Untested), try_read!(l, u64));
 162                         u64s.insert(U64Setting::RescanInterval(AddressState::LowBlockCount), try_read!(l, u64));
 163                         u64s.insert(U64Setting::RescanInterval(AddressState::HighBlockCount), try_read!(l, u64));
 164                         u64s.insert(U64Setting::RescanInterval(AddressState::LowVersion), try_read!(l, u64));
 165                         u64s.insert(U64Setting::RescanInterval(AddressState::BadVersion), try_read!(l, u64));
 166                         u64s.insert(U64Setting::RescanInterval(AddressState::NotFullNode), try_read!(l, u64));
 167                         u64s.insert(U64Setting::RescanInterval(AddressState::ProtocolViolation), try_read!(l, u64));
 168                         u64s.insert(U64Setting::RescanInterval(AddressState::Timeout), try_read!(l, u64));
 169                         u64s.insert(U64Setting::RescanInterval(AddressState::TimeoutDuringRequest), try_read!(l, u64));
 170                         u64s.insert(U64Setting::RescanInterval(AddressState::Good), try_read!(l, u64));
 171                         u64s.insert(U64Setting::RescanInterval(AddressState::WasGood), try_read!(l, u64));
 172                         future::ok((u64s, try_read!(l, Regex)))
 173                 }).or_else(|_| -> future::FutureResult<(HashMap<U64Setting, u64>, Regex), ()> {
 174                         let mut u64s = HashMap::with_capacity(15);
 175                         u64s.insert(U64Setting::ConnsPerSec, 10);
 176                         u64s.insert(U64Setting::RunTimeout, 120);
 177                         u64s.insert(U64Setting::WasGoodTimeout, 21600);
 178                         u64s.insert(U64Setting::RescanInterval(AddressState::Untested), 0);
 179                         u64s.insert(U64Setting::RescanInterval(AddressState::LowBlockCount), 3600);
 180                         u64s.insert(U64Setting::RescanInterval(AddressState::HighBlockCount), 7200);
 181                         u64s.insert(U64Setting::RescanInterval(AddressState::LowVersion), 21600);
 182                         u64s.insert(U64Setting::RescanInterval(AddressState::BadVersion), 21600);
 183                         u64s.insert(U64Setting::RescanInterval(AddressState::NotFullNode), 86400);
 184                         u64s.insert(U64Setting::RescanInterval(AddressState::ProtocolViolation), 86400);
 185                         u64s.insert(U64Setting::RescanInterval(AddressState::Timeout), 86400);
 186                         u64s.insert(U64Setting::RescanInterval(AddressState::TimeoutDuringRequest), 21600);
 187                         u64s.insert(U64Setting::RescanInterval(AddressState::Good), 1800);
 188                         u64s.insert(U64Setting::RescanInterval(AddressState::WasGood), 1800);
 189                         u64s.insert(U64Setting::MinProtocolVersion, 10000); //XXX
 190                         future::ok((u64s, Regex::new(".*").unwrap()))
 191                 });
 192
 193                 macro_rules! nodes_uninitd {
 194                         () => { {
 195                                 let mut state_vecs = HashMap::with_capacity(11);
 196                                 state_vecs.insert(AddressState::Untested, Vec::new());
 197                                 state_vecs.insert(AddressState::LowBlockCount, Vec::new());
 198                                 state_vecs.insert(AddressState::HighBlockCount, Vec::new());
 199                                 state_vecs.insert(AddressState::LowVersion, Vec::new());
 200                                 state_vecs.insert(AddressState::BadVersion, Vec::new());
 201                                 state_vecs.insert(AddressState::NotFullNode, Vec::new());
 202                                 state_vecs.insert(AddressState::ProtocolViolation, Vec::new());
 203                                 state_vecs.insert(AddressState::Timeout, Vec::new());
 204                                 state_vecs.insert(AddressState::TimeoutDuringRequest, Vec::new());
 205                                 state_vecs.insert(AddressState::Good, Vec::new());
 206                                 state_vecs.insert(AddressState::WasGood, Vec::new());
 207                                 let mut good_node_services = HashMap::with_capacity(64);
 208                                 for i in 0..64 {
 209                                         good_node_services.insert(i, HashSet::new());
 210                                 }
 211                                 Nodes {
 212                                         good_node_services,
 213                                         nodes_to_state: HashMap::new(),
 214                                         state_next_scan: state_vecs,
 215                                 }
 216                         } }
 217                 }
 218
 219                 let nodes_future = File::open(store.clone() + "/nodes").and_then(|f| {
 220                         let mut res = nodes_uninitd!();
 221                         let l = BufReader::new(f).lines();
 222                         for line_res in l {
 223                                 let line = match line_res {
 224                                         Ok(l) => l,
 225                                         Err(_) => return future::ok(res),
 226                                 };
 227                                 let mut line_iter = line.split(',');
 228                                 macro_rules! try_read {
 229                                         ($lines: expr, $ty: ty) => { {
 230                                                 match $lines.next() {
 231                                                         Some(line) => match line.parse::<$ty>() {
 232                                                                 Ok(res) => res,
 233                                                                 Err(_) => return future::ok(res),
 234                                                         },
 235                                                         None => return future::ok(res),
 236                                                 }
 237                                         } }
 238                                 }
 239                                 let sockaddr = try_read!(line_iter, SocketAddr);
 240                                 let state = try_read!(line_iter, u8);
 241                                 let last_services = try_read!(line_iter, u64);
 242                                 let node = Node {
 243                                         state: match AddressState::from_num(state) {
 244                                                 Some(v) => v,
 245                                                 None => return future::ok(res),
 246                                         },
 247                                         last_services,
 248                                         last_update: Instant::now(),
 249                                         last_good: Instant::now(),
 250                                 };
 251                                 if node.state == AddressState::Good {
 252                                         for i in 0..64 {
 253                                                 if node.last_services & (1 << i) != 0 {
 254                                                         res.good_node_services.get_mut(&i).unwrap().insert(sockaddr);
 255                                                 }
 256                                         }
 257                                 }
 258                                 res.state_next_scan.get_mut(&node.state).unwrap().push((Instant::now(), sockaddr));
 259                                 res.nodes_to_state.insert(sockaddr, node);
 260                         }
 261                         future::ok(res)
 262                 }).or_else(|_| -> future::FutureResult<Nodes, ()> {
 263                         future::ok(nodes_uninitd!())
 264                 });
 265                 settings_future.join(nodes_future).and_then(move |((u64_settings, regex), nodes)| {
 266                         future::ok(Store {
 267                                 u64_settings: RwLock::new(u64_settings),
 268                                 subver_regex: RwLock::new(Arc::new(regex)),
 269                                 nodes: RwLock::new(nodes),
 270                                 store,
 271                         })
 272                 })
 273         }
 274
 275         pub fn get_u64(&self, setting: U64Setting) -> u64 {
 276                 *self.u64_settings.read().unwrap().get(&setting).unwrap()
 277         }
 278
 279         pub fn set_u64(&self, setting: U64Setting, value: u64) {
 280                 *self.u64_settings.write().unwrap().get_mut(&setting).unwrap() = value;
 281         }
 282
 283         pub fn get_node_count(&self, state: AddressState) -> usize {
 284                 self.nodes.read().unwrap().state_next_scan.get(&state).unwrap().len()
 285         }
 286
 287         pub fn get_regex(&self, _setting: RegexSetting) -> Arc<Regex> {
 288                 Arc::clone(&*self.subver_regex.read().unwrap())
 289         }
 290
 291         pub fn set_regex(&self, _setting: RegexSetting, value: Regex) {
 292                 *self.subver_regex.write().unwrap() = Arc::new(value);
 293         }
 294
 295         pub fn add_fresh_nodes(&self, addresses: &Vec<(u32, Address)>) {
 296                 let mut nodes = self.nodes.write().unwrap();
 297                 let cur_time = Instant::now();
 298                 for &(_, ref addr) in addresses {
 299                         if let Ok(socketaddr) = addr.socket_addr() {
 300                                 match nodes.nodes_to_state.entry(socketaddr.clone()) {
 301                                         hash_map::Entry::Vacant(e) => {
 302                                                 e.insert(Node {
 303                                                         state: AddressState::Untested,
 304                                                         last_services: 0,
 305                                                         last_update: cur_time,
 306                                                         last_good: Instant::now(),
 307                                                 });
 308                                                 nodes.state_next_scan.get_mut(&AddressState::Untested).unwrap().push((cur_time, socketaddr));
 309                                         },
 310                                         hash_map::Entry::Occupied(_) => {},
 311                                 }
 312                         } else {
 313                                 //TODO: Handle onions
 314                         }
 315                 }
 316         }
 317
 318         pub fn set_node_state(&self, addr: SocketAddr, state: AddressState, services: u64) -> AddressState {
 319                 let mut nodes_lock = self.nodes.write().unwrap();
 320                 let nodes = nodes_lock.borrow_mut();
 321                 let state_ref = nodes.nodes_to_state.get_mut(&addr).unwrap();
 322                 let ret = state_ref.state;
 323                 let now = Instant::now();
 324                 if (state_ref.state == AddressState::Good || state_ref.state == AddressState::WasGood)
 325                                 && state != AddressState::Good
 326                                 && state_ref.last_good >= now - Duration::from_secs(self.get_u64(U64Setting::WasGoodTimeout)) {
 327                         state_ref.state = AddressState::WasGood;
 328                         for i in 0..64 {
 329                                 if state_ref.last_services & (1 << i) != 0 {
 330                                         nodes.good_node_services.get_mut(&i).unwrap().remove(&addr);
 331                                 }
 332                         }
 333                         state_ref.last_services = 0;
 334                         nodes.state_next_scan.get_mut(&AddressState::WasGood).unwrap().push((now, addr));
 335                 } else {
 336                         state_ref.state = state;
 337                         if state == AddressState::Good {
 338                                 for i in 0..64 {
 339                                         if services & (1 << i) != 0 && state_ref.last_services & (1 << i) == 0 {
 340                                                 nodes.good_node_services.get_mut(&i).unwrap().insert(addr);
 341                                         } else if services & (1 << i) == 0 && state_ref.last_services & (1 << i) != 0 {
 342                                                 nodes.good_node_services.get_mut(&i).unwrap().remove(&addr);
 343                                         }
 344                                 }
 345                                 state_ref.last_services = services;
 346                                 state_ref.last_good = now;
 347                         }
 348                         nodes.state_next_scan.get_mut(&state).unwrap().push((now, addr));
 349                 }
 350                 state_ref.last_update = now;
 351                 ret
 352         }
 353
 354         pub fn save_data(&'static self) -> impl Future<Item=(), Error=()> {
 355                 let settings_file = self.store.clone() + "/settings";
 356                 let settings_future = File::create(settings_file.clone() + ".tmp").and_then(move |f| {
 357                         let settings_string = format!("{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}\n{}",
 358                                 self.get_u64(U64Setting::ConnsPerSec),
 359                                 self.get_u64(U64Setting::RunTimeout),
 360                                 self.get_u64(U64Setting::WasGoodTimeout),
 361                                 self.get_u64(U64Setting::MinProtocolVersion),
 362                                 self.get_u64(U64Setting::RescanInterval(AddressState::Untested)),
 363                                 self.get_u64(U64Setting::RescanInterval(AddressState::LowBlockCount)),
 364                                 self.get_u64(U64Setting::RescanInterval(AddressState::HighBlockCount)),
 365                                 self.get_u64(U64Setting::RescanInterval(AddressState::LowVersion)),
 366                                 self.get_u64(U64Setting::RescanInterval(AddressState::BadVersion)),
 367                                 self.get_u64(U64Setting::RescanInterval(AddressState::NotFullNode)),
 368                                 self.get_u64(U64Setting::RescanInterval(AddressState::ProtocolViolation)),
 369                                 self.get_u64(U64Setting::RescanInterval(AddressState::Timeout)),
 370                                 self.get_u64(U64Setting::RescanInterval(AddressState::TimeoutDuringRequest)),
 371                                 self.get_u64(U64Setting::RescanInterval(AddressState::Good)),
 372                                 self.get_u64(U64Setting::RescanInterval(AddressState::WasGood)),
 373                                 self.get_regex(RegexSetting::SubverRegex).as_str());
 374                         write_all(f, settings_string).and_then(|(mut f, _)| {
 375                                 f.poll_sync_all()
 376                         }).and_then(|_| {
 377                                 tokio::fs::rename(settings_file.clone() + ".tmp", settings_file)
 378                         })
 379                 });
 380
 381                 let nodes_file = self.store.clone() + "/nodes";
 382                 let nodes_future = File::create(nodes_file.clone() + ".tmp").and_then(move |f| {
 383                         let mut nodes_buff = String::new();
 384                         {
 385                                 let nodes = self.nodes.read().unwrap();
 386                                 nodes_buff.reserve(nodes.nodes_to_state.len() * 20);
 387                                 for (ref sockaddr, ref node) in nodes.nodes_to_state.iter() {
 388                                         nodes_buff += &sockaddr.to_string();
 389                                         nodes_buff += ",";
 390                                         nodes_buff += &node.state.to_num().to_string();
 391                                         nodes_buff += ",";
 392                                         nodes_buff += &node.last_services.to_string();
 393                                         nodes_buff += "\n";
 394                                 }
 395                         }
 396                         write_all(f, nodes_buff)
 397                 }).and_then(|(mut f, _)| {
 398                         f.poll_sync_all()
 399                 }).and_then(|_| {
 400                         tokio::fs::rename(nodes_file.clone() + ".tmp", nodes_file)
 401                 });
 402
 403                 let dns_file = self.store.clone() + "/nodes.dump";
 404                 let dns_future = File::create(dns_file.clone() + ".tmp").and_then(move |f| {
 405                         let mut dns_buff = String::new();
 406                         {
 407                                 let nodes = self.nodes.read().unwrap();
 408                                 let mut rng = thread_rng();
 409                                 for i in &[1u64, 4, 5, 8, 9, 12, 13, 1024, 1025, 1028, 1029, 1032, 1033, 1036, 1037] {
 410                                         let mut v6_set = Vec::new();
 411                                         let mut v4_set = Vec::new();
 412                                         if i.count_ones() == 1 {
 413                                                 for j in 0..64 {
 414                                                         if i & (1 << j) != 0 {
 415                                                                 let set_ref = nodes.good_node_services.get(&j).unwrap();
 416                                                                 v4_set = set_ref.iter().filter(|e| e.is_ipv4() && e.port() == 8333)
 417                                                                         .choose_multiple(&mut rng, 21).iter().map(|e| e.ip()).collect();
 418                                                                 v6_set = set_ref.iter().filter(|e| e.is_ipv6() && e.port() == 8333)
 419                                                                         .choose_multiple(&mut rng, 12).iter().map(|e| e.ip()).collect();
 420                                                                 break;
 421                                                         }
 422                                                 }
 423                                         } else if i.count_ones() == 2 {
 424                                                 let mut first_set = None;
 425                                                 let mut second_set = None;
 426                                                 for j in 0..64 {
 427                                                         if i & (1 << j) != 0 {
 428                                                                 if first_set == None {
 429                                                                         first_set = Some(nodes.good_node_services.get(&j).unwrap());
 430                                                                 } else {
 431                                                                         second_set = Some(nodes.good_node_services.get(&j).unwrap());
 432                                                                         break;
 433                                                                 }
 434                                                         }
 435                                                 }
 436                                                 v4_set = first_set.unwrap().intersection(second_set.unwrap())
 437                                                         .filter(|e| e.is_ipv4() && e.port() == 8333)
 438                                                         .choose_multiple(&mut rng, 21).iter().map(|e| e.ip()).collect();
 439                                                 v6_set = first_set.unwrap().intersection(second_set.unwrap())
 440                                                         .filter(|e| e.is_ipv6() && e.port() == 8333)
 441                                                         .choose_multiple(&mut rng, 12).iter().map(|e| e.ip()).collect();
 442                                         } else {
 443                                                 //TODO: Could optimize this one a bit
 444                                                 let mut intersection;
 445                                                 let mut intersection_set_ref = None;
 446                                                 for j in 0..64 {
 447                                                         if i & (1 << j) != 0 {
 448                                                                 if intersection_set_ref == None {
 449                                                                         intersection_set_ref = Some(nodes.good_node_services.get(&j).unwrap());
 450                                                                 } else {
 451                                                                         let new_intersection = intersection_set_ref.unwrap()
 452                                                                                 .intersection(nodes.good_node_services.get(&j).unwrap()).map(|e| (*e).clone()).collect();
 453                                                                         intersection = Some(new_intersection);
 454                                                                         intersection_set_ref = Some(intersection.as_ref().unwrap());
 455                                                                 }
 456                                                         }
 457                                                 }
 458                                                 v4_set = intersection_set_ref.unwrap().iter()
 459                                                         .filter(|e| e.is_ipv4() && e.port() == 8333)
 460                                                         .choose_multiple(&mut rng, 21).iter().map(|e| e.ip()).collect();
 461                                                 v6_set = intersection_set_ref.unwrap().iter()
 462                                                         .filter(|e| e.is_ipv6() && e.port() == 8333)
 463                                                         .choose_multiple(&mut rng, 12).iter().map(|e| e.ip()).collect();
 464                                         }
 465                                         for a in v4_set {
 466                                                 dns_buff += &format!("x{:x}.dnsseed\tIN\tA\t{}\n", i, a);
 467                                         }
 468                                         for a in v6_set {
 469                                                 dns_buff += &format!("x{:x}.dnsseed\tIN\tAAAA\t{}\n", i, a);
 470                                         }
 471                                 }
 472                         }
 473                         write_all(f, dns_buff)
 474                 }).and_then(|(mut f, _)| {
 475                         f.poll_sync_all()
 476                 }).and_then(|_| {
 477                         tokio::fs::rename(dns_file.clone() + ".tmp", dns_file)
 478                 });
 479
 480                 settings_future.join3(nodes_future, dns_future).then(|_| { future::ok(()) })
 481         }
 482
 483         pub fn get_next_scan_nodes(&self) -> Vec<SocketAddr> {
 484                 let results = 30 * self.get_u64(U64Setting::ConnsPerSec) as usize;
 485                 let per_bucket_results = results / (AddressState::get_count() as usize);
 486                 let mut res = Vec::with_capacity(results);
 487                 let cur_time = Instant::now();
 488
 489                 let mut nodes = self.nodes.write().unwrap();
 490                 for (state, state_nodes) in nodes.state_next_scan.iter_mut() {
 491                         let cmp_time = cur_time - Duration::from_secs(self.get_u64(U64Setting::RescanInterval(*state)));
 492                         let split_point = cmp::min(cmp::min(results - res.len(), per_bucket_results),
 493                                         state_nodes.binary_search_by(|a| a.0.cmp(&cmp_time)).unwrap_or_else(|idx| idx));
 494                         let mut new_nodes = state_nodes.split_off(split_point);
 495                         mem::swap(&mut new_nodes, state_nodes);
 496                         for (_, node) in new_nodes.drain(..) {
 497                                 res.push(node);
 498                         }
 499                 }
 500                 res.shuffle(&mut thread_rng());
 501                 res
 502         }
 503 }