Exemple #1
0
// ClaimForPeers claims the entire ring for the array of peers passed
// in.  Only works for empty rings.
func (r *Ring) ClaimForPeers(peers []router.PeerName) {
	common.Assert(r.Empty())
	defer r.assertInvariants()
	defer r.updateExportedVariables()

	totalSize := r.distance(r.Start, r.End)
	share := totalSize/address.Offset(len(peers)) + 1
	remainder := totalSize % address.Offset(len(peers))
	pos := r.Start

	for i, peer := range peers {
		if address.Offset(i) == remainder {
			share--
			if share == 0 {
				break
			}
		}

		if e, found := r.Entries.get(pos); found {
			e.update(peer, share)
		} else {
			r.Entries.insert(entry{Token: pos, Peer: peer, Free: share})
		}

		pos += address.Address(share)
	}

	common.Assert(pos == r.End)
}
Exemple #2
0
func TestFuzzRing(t *testing.T) {
	var (
		numPeers   = 25
		iterations = 1000
	)

	peers := make([]router.PeerName, numPeers)
	for i := 0; i < numPeers; i++ {
		peer, _ := router.PeerNameFromString(fmt.Sprintf("%02d:00:00:00:02:00", i))
		peers[i] = peer
	}

	// Make a valid, random ring
	makeGoodRandomRing := func() *Ring {
		addressSpace := end - start
		numTokens := rand.Intn(int(addressSpace))

		tokenMap := make(map[address.Address]bool)
		for i := 0; i < numTokens; i++ {
			tokenMap[address.Address(rand.Intn(int(addressSpace)))] = true
		}
		var tokens []address.Address
		for token := range tokenMap {
			tokens = append(tokens, token)
		}
		sort.Sort(addressSlice(tokens))

		peer := peers[rand.Intn(len(peers))]
		ring := New(start, end, peer)
		for _, token := range tokens {
			peer = peers[rand.Intn(len(peers))]
			ring.Entries = append(ring.Entries, &entry{Token: start + token, Peer: peer})
		}

		ring.assertInvariants()
		return ring
	}

	for i := 0; i < iterations; i++ {
		// make 2 random rings
		ring1 := makeGoodRandomRing()
		ring2 := makeGoodRandomRing()

		// Merge them - this might fail, we don't care
		// We just want to make sure it doesn't panic
		ring1.Merge(*ring2)

		// Check whats left still passes assertions
		ring1.assertInvariants()
		ring2.assertInvariants()
	}

	// Make an invalid, random ring
	makeBadRandomRing := func() *Ring {
		addressSpace := end - start
		numTokens := rand.Intn(int(addressSpace))
		tokens := make([]address.Address, numTokens)
		for i := 0; i < numTokens; i++ {
			tokens[i] = address.Address(rand.Intn(int(addressSpace)))
		}

		peer := peers[rand.Intn(len(peers))]
		ring := New(start, end, peer)
		for _, token := range tokens {
			peer = peers[rand.Intn(len(peers))]
			ring.Entries = append(ring.Entries, &entry{Token: start + token, Peer: peer})
		}

		return ring
	}

	for i := 0; i < iterations; i++ {
		// make 2 random rings
		ring1 := makeGoodRandomRing()
		ring2 := makeBadRandomRing()

		// Merge them - this might fail, we don't care
		// We just want to make sure it doesn't panic
		ring1.Merge(*ring2)

		// Check whats left still passes assertions
		ring1.assertInvariants()
	}
}