83 lines
1.4 KiB
Go
83 lines
1.4 KiB
Go
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package main
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import (
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"crypto/rand"
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"sync"
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)
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/* Index=0 is reserved for unset indecies
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*
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*/
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type IndexTable struct {
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mutex sync.RWMutex
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keypairs map[uint32]*KeyPair
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handshakes map[uint32]*Handshake
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}
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func randUint32() (uint32, error) {
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var buff [4]byte
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_, err := rand.Read(buff[:])
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id := uint32(buff[0])
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id <<= 8
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id |= uint32(buff[1])
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id <<= 8
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id |= uint32(buff[2])
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id <<= 8
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id |= uint32(buff[3])
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return id, err
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}
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func (table *IndexTable) Init() {
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table.mutex.Lock()
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defer table.mutex.Unlock()
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table.keypairs = make(map[uint32]*KeyPair)
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table.handshakes = make(map[uint32]*Handshake)
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}
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func (table *IndexTable) NewIndex(handshake *Handshake) (uint32, error) {
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table.mutex.Lock()
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defer table.mutex.Unlock()
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for {
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// generate random index
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id, err := randUint32()
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if err != nil {
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return id, err
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}
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if id == 0 {
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continue
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}
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// check if index used
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_, ok := table.keypairs[id]
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if ok {
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continue
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}
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_, ok = table.handshakes[id]
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if ok {
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continue
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}
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// update the index
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delete(table.handshakes, handshake.localIndex)
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handshake.localIndex = id
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table.handshakes[id] = handshake
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return id, nil
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}
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}
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func (table *IndexTable) LookupKeyPair(id uint32) *KeyPair {
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table.mutex.RLock()
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defer table.mutex.RUnlock()
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return table.keypairs[id]
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}
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func (table *IndexTable) LookupHandshake(id uint32) *Handshake {
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table.mutex.RLock()
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defer table.mutex.RUnlock()
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return table.handshakes[id]
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}
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