Merge pull request #2866 from karalabe/downloader-future-ancestors

eth/downloader: fewer headers and futures too in ancestor lookup
This commit is contained in:
Péter Szilágyi 2016-08-16 10:01:52 +03:00 committed by GitHub
commit 89a3fbc0fb

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@ -572,11 +572,17 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
if head > height { if head > height {
head = height head = height
} }
from := int64(head) - int64(MaxHeaderFetch) + 1 from := int64(head) - int64(MaxHeaderFetch)
if from < 0 { if from < 0 {
from = 0 from = 0
} }
go p.getAbsHeaders(uint64(from), MaxHeaderFetch, 0, false) // Span out with 15 block gaps into the future to catch bad head reports
limit := 2 * MaxHeaderFetch / 16
count := 1 + int((int64(ceil)-from)/16)
if count > limit {
count = limit
}
go p.getAbsHeaders(uint64(from), count, 15, false)
// Wait for the remote response to the head fetch // Wait for the remote response to the head fetch
number, hash := uint64(0), common.Hash{} number, hash := uint64(0), common.Hash{}
@ -601,12 +607,8 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
} }
// Make sure the peer's reply conforms to the request // Make sure the peer's reply conforms to the request
for i := 0; i < len(headers); i++ { for i := 0; i < len(headers); i++ {
if number := headers[i].Number.Int64(); number != from+int64(i) { if number := headers[i].Number.Int64(); number != from+int64(i)*16 {
glog.V(logger.Warn).Infof("%v: head header set (item %d) broke chain ordering: requested %d, got %d", p, i, from+int64(i), number) glog.V(logger.Warn).Infof("%v: head header set (item %d) broke chain ordering: requested %d, got %d", p, i, from+int64(i)*16, number)
return 0, errInvalidChain
}
if i > 0 && headers[i-1].Hash() != headers[i].ParentHash {
glog.V(logger.Warn).Infof("%v: head header set (item %d) broke chain ancestry: expected [%x], got [%x]", p, i, headers[i-1].Hash().Bytes()[:4], headers[i].ParentHash[:4])
return 0, errInvalidChain return 0, errInvalidChain
} }
} }
@ -614,12 +616,18 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
finished = true finished = true
for i := len(headers) - 1; i >= 0; i-- { for i := len(headers) - 1; i >= 0; i-- {
// Skip any headers that underflow/overflow our requested set // Skip any headers that underflow/overflow our requested set
if headers[i].Number.Int64() < from || headers[i].Number.Uint64() > head { if headers[i].Number.Int64() < from || headers[i].Number.Uint64() > ceil {
continue continue
} }
// Otherwise check if we already know the header or not // Otherwise check if we already know the header or not
if (d.mode == FullSync && d.hasBlockAndState(headers[i].Hash())) || (d.mode != FullSync && d.hasHeader(headers[i].Hash())) { if (d.mode == FullSync && d.hasBlockAndState(headers[i].Hash())) || (d.mode != FullSync && d.hasHeader(headers[i].Hash())) {
number, hash = headers[i].Number.Uint64(), headers[i].Hash() number, hash = headers[i].Number.Uint64(), headers[i].Hash()
// If every header is known, even future ones, the peer straight out lied about its head
if number > height && i == limit-1 {
glog.V(logger.Warn).Infof("%v: lied about chain head: reported %d, found above %d", p, height, number)
return 0, errStallingPeer
}
break break
} }
} }