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authorWim <wim@42.be>2018-03-04 23:46:13 +0100
committerWim <wim@42.be>2018-03-04 23:46:13 +0100
commit25a72113b122f984c904b24c4af23a1cba1eff45 (patch)
treef0fb7067d7c958d60ac964afa5b8d5fb79ebc339 /vendor/github.com/pkg/sftp/packet-manager.go
parent79c4ad5015bd2be47b32141c6d53f0d128bf865b (diff)
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Add vendor files for spf13/viper
Diffstat (limited to 'vendor/github.com/pkg/sftp/packet-manager.go')
-rw-r--r--vendor/github.com/pkg/sftp/packet-manager.go173
1 files changed, 173 insertions, 0 deletions
diff --git a/vendor/github.com/pkg/sftp/packet-manager.go b/vendor/github.com/pkg/sftp/packet-manager.go
new file mode 100644
index 00000000..bf822e67
--- /dev/null
+++ b/vendor/github.com/pkg/sftp/packet-manager.go
@@ -0,0 +1,173 @@
+package sftp
+
+import (
+ "encoding"
+ "sort"
+ "sync"
+)
+
+// The goal of the packetManager is to keep the outgoing packets in the same
+// order as the incoming. This is due to some sftp clients requiring this
+// behavior (eg. winscp).
+
+type packetSender interface {
+ sendPacket(encoding.BinaryMarshaler) error
+}
+
+type packetManager struct {
+ requests chan requestPacket
+ responses chan responsePacket
+ fini chan struct{}
+ incoming requestPacketIDs
+ outgoing responsePackets
+ sender packetSender // connection object
+ working *sync.WaitGroup
+}
+
+func newPktMgr(sender packetSender) *packetManager {
+ s := &packetManager{
+ requests: make(chan requestPacket, SftpServerWorkerCount),
+ responses: make(chan responsePacket, SftpServerWorkerCount),
+ fini: make(chan struct{}),
+ incoming: make([]uint32, 0, SftpServerWorkerCount),
+ outgoing: make([]responsePacket, 0, SftpServerWorkerCount),
+ sender: sender,
+ working: &sync.WaitGroup{},
+ }
+ go s.controller()
+ return s
+}
+
+type responsePackets []responsePacket
+
+func (r responsePackets) Sort() {
+ sort.Slice(r, func(i, j int) bool {
+ return r[i].id() < r[j].id()
+ })
+}
+
+type requestPacketIDs []uint32
+
+func (r requestPacketIDs) Sort() {
+ sort.Slice(r, func(i, j int) bool {
+ return r[i] < r[j]
+ })
+}
+
+// register incoming packets to be handled
+// send id of 0 for packets without id
+func (s *packetManager) incomingPacket(pkt requestPacket) {
+ s.working.Add(1)
+ s.requests <- pkt // buffer == SftpServerWorkerCount
+}
+
+// register outgoing packets as being ready
+func (s *packetManager) readyPacket(pkt responsePacket) {
+ s.responses <- pkt
+ s.working.Done()
+}
+
+// shut down packetManager controller
+func (s *packetManager) close() {
+ // pause until current packets are processed
+ s.working.Wait()
+ close(s.fini)
+}
+
+// Passed a worker function, returns a channel for incoming packets.
+// The goal is to process packets in the order they are received as is
+// requires by section 7 of the RFC, while maximizing throughput of file
+// transfers.
+func (s *packetManager) workerChan(runWorker func(requestChan)) requestChan {
+
+ rwChan := make(chan requestPacket, SftpServerWorkerCount)
+ for i := 0; i < SftpServerWorkerCount; i++ {
+ runWorker(rwChan)
+ }
+
+ cmdChan := make(chan requestPacket)
+ runWorker(cmdChan)
+
+ pktChan := make(chan requestPacket, SftpServerWorkerCount)
+ go func() {
+ // start with cmdChan
+ curChan := cmdChan
+ for pkt := range pktChan {
+ // on file open packet, switch to rwChan
+ switch pkt.(type) {
+ case *sshFxpOpenPacket:
+ curChan = rwChan
+ // on file close packet, switch back to cmdChan
+ // after waiting for any reads/writes to finish
+ case *sshFxpClosePacket:
+ // wait for rwChan to finish
+ s.working.Wait()
+ // stop using rwChan
+ curChan = cmdChan
+ }
+ s.incomingPacket(pkt)
+ curChan <- pkt
+ }
+ close(rwChan)
+ close(cmdChan)
+ s.close()
+ }()
+
+ return pktChan
+}
+
+// process packets
+func (s *packetManager) controller() {
+ for {
+ select {
+ case pkt := <-s.requests:
+ debug("incoming id: %v", pkt.id())
+ s.incoming = append(s.incoming, pkt.id())
+ if len(s.incoming) > 1 {
+ s.incoming.Sort()
+ }
+ case pkt := <-s.responses:
+ debug("outgoing pkt: %v", pkt.id())
+ s.outgoing = append(s.outgoing, pkt)
+ if len(s.outgoing) > 1 {
+ s.outgoing.Sort()
+ }
+ case <-s.fini:
+ return
+ }
+ s.maybeSendPackets()
+ }
+}
+
+// send as many packets as are ready
+func (s *packetManager) maybeSendPackets() {
+ for {
+ if len(s.outgoing) == 0 || len(s.incoming) == 0 {
+ debug("break! -- outgoing: %v; incoming: %v",
+ len(s.outgoing), len(s.incoming))
+ break
+ }
+ out := s.outgoing[0]
+ in := s.incoming[0]
+ // debug("incoming: %v", s.incoming)
+ // debug("outgoing: %v", outfilter(s.outgoing))
+ if in == out.id() {
+ s.sender.sendPacket(out)
+ // pop off heads
+ copy(s.incoming, s.incoming[1:]) // shift left
+ s.incoming = s.incoming[:len(s.incoming)-1] // remove last
+ copy(s.outgoing, s.outgoing[1:]) // shift left
+ s.outgoing = s.outgoing[:len(s.outgoing)-1] // remove last
+ } else {
+ break
+ }
+ }
+}
+
+//func outfilter(o []responsePacket) []uint32 {
+// res := make([]uint32, 0, len(o))
+// for _, v := range o {
+// res = append(res, v.id())
+// }
+// return res
+//}