use std::cmp;
use std::ops::Range;
use std::collections::{HashMap, BTreeMap};
use log::trace;
use libp2p::PeerId;
use sp_runtime::traits::{Block as BlockT, NumberFor, One};
use crate::protocol::message;
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct BlockData<B: BlockT> {
pub block: message::BlockData<B>,
pub origin: Option<PeerId>,
}
#[derive(Debug)]
enum BlockRangeState<B: BlockT> {
Downloading {
len: NumberFor<B>,
downloading: u32,
},
Complete(Vec<BlockData<B>>),
}
impl<B: BlockT> BlockRangeState<B> {
pub fn len(&self) -> NumberFor<B> {
match *self {
BlockRangeState::Downloading { len, .. } => len,
BlockRangeState::Complete(ref blocks) => (blocks.len() as u32).into(),
}
}
}
#[derive(Default)]
pub struct BlockCollection<B: BlockT> {
blocks: BTreeMap<NumberFor<B>, BlockRangeState<B>>,
peer_requests: HashMap<PeerId, NumberFor<B>>,
}
impl<B: BlockT> BlockCollection<B> {
pub fn new() -> Self {
BlockCollection {
blocks: BTreeMap::new(),
peer_requests: HashMap::new(),
}
}
pub fn clear(&mut self) {
self.blocks.clear();
self.peer_requests.clear();
}
pub fn insert(&mut self, start: NumberFor<B>, blocks: Vec<message::BlockData<B>>, who: PeerId) {
if blocks.is_empty() {
return;
}
match self.blocks.get(&start) {
Some(&BlockRangeState::Downloading { .. }) => {
trace!(target: "sync", "Inserting block data still marked as being downloaded: {}", start);
},
Some(&BlockRangeState::Complete(ref existing)) if existing.len() >= blocks.len() => {
trace!(target: "sync", "Ignored block data already downloaded: {}", start);
return;
},
_ => (),
}
self.blocks.insert(start, BlockRangeState::Complete(blocks.into_iter()
.map(|b| BlockData { origin: Some(who.clone()), block: b }).collect()));
}
pub fn needed_blocks(
&mut self,
who: PeerId,
count: usize,
peer_best: NumberFor<B>,
common: NumberFor<B>,
max_parallel: u32,
max_ahead: u32,
) -> Option<Range<NumberFor<B>>> {
if peer_best <= common {
return None;
}
let first_different = common + <NumberFor<B>>::one();
let count = (count as u32).into();
let (mut range, downloading) = {
let mut downloading_iter = self.blocks.iter().peekable();
let mut prev: Option<(&NumberFor<B>, &BlockRangeState<B>)> = None;
loop {
let next = downloading_iter.next();
break match (prev, next) {
(Some((start, &BlockRangeState::Downloading { ref len, downloading })), _)
if downloading < max_parallel =>
(*start .. *start + *len, downloading),
(Some((start, r)), Some((next_start, _))) if *start + r.len() < *next_start =>
(*start + r.len() .. cmp::min(*next_start, *start + r.len() + count), 0),
(Some((start, r)), None) =>
(*start + r.len() .. *start + r.len() + count, 0),
(None, None) =>
(first_different .. first_different + count, 0),
(None, Some((start, _))) if *start > first_different =>
(first_different .. cmp::min(first_different + count, *start), 0),
_ => {
prev = next;
continue
},
}
}
};
if range.start > peer_best {
trace!(target: "sync", "Out of range for peer {} ({} vs {})", who, range.start, peer_best);
return None;
}
range.end = cmp::min(peer_best + One::one(), range.end);
if self.blocks.iter().next().map_or(false, |(n, _)| range.start > *n + max_ahead.into()) {
trace!(target: "sync", "Too far ahead for peer {} ({})", who, range.start);
return None;
}
self.peer_requests.insert(who, range.start);
self.blocks.insert(range.start, BlockRangeState::Downloading {
len: range.end - range.start,
downloading: downloading + 1
});
if range.end <= range.start {
panic!("Empty range {:?}, count={}, peer_best={}, common={}, blocks={:?}",
range, count, peer_best, common, self.blocks);
}
Some(range)
}
pub fn drain(&mut self, from: NumberFor<B>) -> Vec<BlockData<B>> {
let mut drained = Vec::new();
let mut ranges = Vec::new();
let mut prev = from;
for (start, range_data) in &mut self.blocks {
match range_data {
BlockRangeState::Complete(blocks) if *start <= prev => {
prev = *start + (blocks.len() as u32).into();
drained.append(blocks);
ranges.push(*start);
},
_ => break,
}
}
for r in ranges {
self.blocks.remove(&r);
}
trace!(target: "sync", "Drained {} blocks", drained.len());
drained
}
pub fn clear_peer_download(&mut self, who: &PeerId) {
if let Some(start) = self.peer_requests.remove(who) {
let remove = match self.blocks.get_mut(&start) {
Some(&mut BlockRangeState::Downloading { ref mut downloading, .. }) if *downloading > 1 => {
*downloading -= 1;
false
},
Some(&mut BlockRangeState::Downloading { .. }) => {
true
},
_ => {
false
}
};
if remove {
self.blocks.remove(&start);
}
}
}
}
#[cfg(test)]
mod test {
use super::{BlockCollection, BlockData, BlockRangeState};
use crate::{protocol::message, PeerId};
use sp_runtime::testing::{Block as RawBlock, ExtrinsicWrapper};
use sp_core::H256;
type Block = RawBlock<ExtrinsicWrapper<u64>>;
fn is_empty(bc: &BlockCollection<Block>) -> bool {
bc.blocks.is_empty() &&
bc.peer_requests.is_empty()
}
fn generate_blocks(n: usize) -> Vec<message::BlockData<Block>> {
(0 .. n).map(|_| message::generic::BlockData {
hash: H256::random(),
header: None,
body: None,
message_queue: None,
receipt: None,
justification: None,
}).collect()
}
#[test]
fn create_clear() {
let mut bc = BlockCollection::new();
assert!(is_empty(&bc));
bc.insert(1, generate_blocks(100), PeerId::random());
assert!(!is_empty(&bc));
bc.clear();
assert!(is_empty(&bc));
}
#[test]
fn insert_blocks() {
let mut bc = BlockCollection::new();
assert!(is_empty(&bc));
let peer0 = PeerId::random();
let peer1 = PeerId::random();
let peer2 = PeerId::random();
let blocks = generate_blocks(150);
assert_eq!(bc.needed_blocks(peer0.clone(), 40, 150, 0, 1, 200), Some(1 .. 41));
assert_eq!(bc.needed_blocks(peer1.clone(), 40, 150, 0, 1, 200), Some(41 .. 81));
assert_eq!(bc.needed_blocks(peer2.clone(), 40, 150, 0, 1, 200), Some(81 .. 121));
bc.clear_peer_download(&peer1);
bc.insert(41, blocks[41..81].to_vec(), peer1.clone());
assert_eq!(bc.drain(1), vec![]);
assert_eq!(bc.needed_blocks(peer1.clone(), 40, 150, 0, 1, 200), Some(121 .. 151));
bc.clear_peer_download(&peer0);
bc.insert(1, blocks[1..11].to_vec(), peer0.clone());
assert_eq!(bc.needed_blocks(peer0.clone(), 40, 150, 0, 1, 200), Some(11 .. 41));
assert_eq!(bc.drain(1), blocks[1..11].iter()
.map(|b| BlockData { block: b.clone(), origin: Some(peer0.clone()) }).collect::<Vec<_>>());
bc.clear_peer_download(&peer0);
bc.insert(11, blocks[11..41].to_vec(), peer0.clone());
let drained = bc.drain(12);
assert_eq!(drained[..30], blocks[11..41].iter()
.map(|b| BlockData { block: b.clone(), origin: Some(peer0.clone()) }).collect::<Vec<_>>()[..]);
assert_eq!(drained[30..], blocks[41..81].iter()
.map(|b| BlockData { block: b.clone(), origin: Some(peer1.clone()) }).collect::<Vec<_>>()[..]);
bc.clear_peer_download(&peer2);
assert_eq!(bc.needed_blocks(peer2.clone(), 40, 150, 80, 1, 200), Some(81 .. 121));
bc.clear_peer_download(&peer2);
bc.insert(81, blocks[81..121].to_vec(), peer2.clone());
bc.clear_peer_download(&peer1);
bc.insert(121, blocks[121..150].to_vec(), peer1.clone());
assert_eq!(bc.drain(80), vec![]);
let drained = bc.drain(81);
assert_eq!(drained[..40], blocks[81..121].iter()
.map(|b| BlockData { block: b.clone(), origin: Some(peer2.clone()) }).collect::<Vec<_>>()[..]);
assert_eq!(drained[40..], blocks[121..150].iter()
.map(|b| BlockData { block: b.clone(), origin: Some(peer1.clone()) }).collect::<Vec<_>>()[..]);
}
#[test]
fn large_gap() {
let mut bc: BlockCollection<Block> = BlockCollection::new();
bc.blocks.insert(100, BlockRangeState::Downloading {
len: 128,
downloading: 1,
});
let blocks = generate_blocks(10).into_iter().map(|b| BlockData { block: b, origin: None }).collect();
bc.blocks.insert(114305, BlockRangeState::Complete(blocks));
let peer0 = PeerId::random();
assert_eq!(bc.needed_blocks(peer0.clone(), 128, 10000, 000, 1, 200), Some(1 .. 100));
assert_eq!(bc.needed_blocks(peer0.clone(), 128, 10000, 600, 1, 200), None);
assert_eq!(bc.needed_blocks(peer0.clone(), 128, 10000, 600, 1, 200000), Some(100 + 128 .. 100 + 128 + 128));
}
}