// positionsLocked returns the positions in the blockfile of all packets matched by
// the passed-in query. b.mu must be locked.
func (b *BlockFile) positionsLocked(ctx context.Context, q query.Query) (base.Positions, error) {
if b.i == nil || b.f == nil {
// If we're closed, just return nothing.
return nil, nil
}
return q.LookupIn(ctx, b.i)
}
// Lookup returns all packets in the blockfile matched by the passed-in query.
func (b *BlockFile) Lookup(ctx context.Context, q query.Query, out *base.PacketChan) {
b.mu.RLock()
defer b.mu.RUnlock()
var ci gopacket.CaptureInfo
v(2, "Blockfile %q looking up query %q", q.String(), b.name)
start := time.Now()
positions, err := b.positionsLocked(ctx, q)
if err != nil {
out.Close(fmt.Errorf("index lookup failure: %v", err))
return
}
if positions.IsAllPositions() {
v(2, "Blockfile %q reading all packets", b.name)
iter := &allPacketsIter{BlockFile: b}
all_packets_loop:
for iter.Next() {
select {
case <-ctx.Done():
v(2, "Blockfile %q canceling packet read", b.name)
break all_packets_loop
case <-b.done:
v(2, "Blockfile %q closing, breaking out of query", b.name)
break all_packets_loop
case out.C <- iter.Packet():
}
}
if iter.Err() != nil {
out.Close(fmt.Errorf("error reading all packets from %q: %v", b.name, iter.Err()))
return
}
} else {
v(2, "Blockfile %q reading %v packets", b.name, len(positions))
query_packets_loop:
for _, pos := range positions {
buffer, err := b.readPacket(pos, &ci)
if err != nil {
v(2, "Blockfile %q error reading packet: %v", b.name, err)
out.Close(fmt.Errorf("error reading packets from %q @ %v: %v", b.name, pos, err))
return
}
select {
case <-ctx.Done():
v(2, "Blockfile %q canceling packet read", b.name)
break query_packets_loop
case <-b.done:
v(2, "Blockfile %q closing, breaking out of query", b.name)
break query_packets_loop
case out.C <- &base.Packet{Data: buffer, CaptureInfo: ci}:
}
}
}
v(2, "Blockfile %q finished reading all packets in %v", b.name, time.Since(start))
out.Close(ctx.Err())
}