From 0b5d43e1857e541af58575a7e1c2bbe729436b15 Mon Sep 17 00:00:00 2001 From: Alex Auvolat Date: Sat, 1 Sep 2018 15:04:53 +0200 Subject: Implement merge for Merkle search tree, not yet working over network --- lib/app/blockstore.ex | 6 ++++- lib/data/merklesearchtree.ex | 60 ++++++++++++++++++++++++++++++++++++++++---- lib/manager.ex | 2 +- test/mst_test.exs | 48 ++++++++++++++++++++++++++++++++++- 4 files changed, 108 insertions(+), 8 deletions(-) diff --git a/lib/app/blockstore.ex b/lib/app/blockstore.ex index 1523a44..4bef0b5 100644 --- a/lib/app/blockstore.ex +++ b/lib/app/blockstore.ex @@ -125,7 +125,11 @@ defmodule SApp.BlockStore do end def get(store, hash) do - GenServer.call(store.pid, {:get, hash, store.prefer_ask}) + try do + GenServer.call(store.pid, {:get, hash, store.prefer_ask}) + catch + :exit, {:timeout, _} -> nil + end end def copy(store, other_store, hash) do diff --git a/lib/data/merklesearchtree.ex b/lib/data/merklesearchtree.ex index b751a08..3676244 100644 --- a/lib/data/merklesearchtree.ex +++ b/lib/data/merklesearchtree.ex @@ -96,7 +96,7 @@ defmodule SData.MerkleSearchTree do if hash == nil do {nil, nil, store} else - %Page{ level: level, low: low, list: lst } = Store.get(store, hash) + %Page{ level: level, low: low, list: lst } = Store.get(store, hash) || Store.get(s.store, hash) store = Store.free(store, hash) [ { k0, _, _} | _ ] = lst case s.cmp.(key, k0) do @@ -189,7 +189,11 @@ defmodule SData.MerkleSearchTree do end @doc""" - Merge values from another MST in this MST + Merge values from another MST in this MST. + + The merge is not symmetrical in the sense that: + - new pages are added in the store of the first argument + - the callback is called for all items found in the second argument and not the first """ def merge(to, from, callback \\ fn _, _ -> nil end) do { store, root } = merge_aux(to, from, to.store, to.root, from.root, callback) @@ -198,6 +202,7 @@ defmodule SData.MerkleSearchTree do defp merge_aux(s1, s2, store, r1, r2, callback) do case {r1, r2} do + _ when r1 == r2 -> { store, r1 } {_, nil} -> { store, r1 } {nil, _} -> @@ -205,9 +210,54 @@ defmodule SData.MerkleSearchTree do rec_callback(store, r2, callback) { store, r2 } _ -> - IO.puts("not implemented: complex merge step") - #TODO - { store, r1 } + %Page{ level: level1, low: low1, list: lst1 } = Store.get(store, r1) + %Page{ level: level2, low: low2, list: lst2 } = Store.get(store, r2) || Store.get(s2.store, r2) + { level, low1, lst1, low2, lst2 } = cond do + level1 == level2 -> {level1, low1, lst1, low2, lst2} + level1 > level2 -> {level1, low1, lst1, r2, []} + level2 > level1 -> {level2, r1, [], low2, lst2} + end + { store, low, lst } = merge_aux_rec(s1, s2, store, low1, lst1, low2, lst2, callback) + page = %Page{ level: level, low: low, list: lst } + {hash, store} = Store.put(store, page) + {store, hash} + end + end + + defp merge_aux_rec(s1, s2, store, low1, lst1, low2, lst2, callback) do + case {lst1, lst2} do + { [], [] } -> + {store, hash} = merge_aux(s1, s2, store, low1, low2, callback) + {store, hash, []} + { [], [ {k, v, r} | rst2 ] } -> + {low1l, low1h, store} = split(s1, store, low1, k) + {store, newlow} = merge_aux(s1, s2, store, low1l, low2, callback) + {store, newr, newrst} = merge_aux_rec(s1, s2, store, low1h, [], r, rst2, callback) + {store, newlow, [ {k, v, newr} | newrst ]} + { [ {k, v, r} | rst1 ], [] } -> + {low2l, low2h, store} = split(s2, store, low2, k) + {store, newlow} = merge_aux(s1, s2, store, low1, low2l, callback) + {store, newr, newrst} = merge_aux_rec(s1, s2, store, r, rst1, low2h, [], callback) + {store, newlow, [ {k, v, newr} | newrst ]} + { [ {k1, v1, r1} | rst1 ], [ {k2, v2, r2} | rst2 ] } -> + case s1.cmp.(k1, k2) do + :before -> + {low2l, low2h, store} = split(s2, store, low2, k1) + {store, newlow} = merge_aux(s1, s2, store, low1, low2l, callback) + {store, newr, newrst} = merge_aux_rec(s1, s2, store, r1, rst1, low2h, lst2, callback) + {store, newlow, [ {k1, v1, newr} | newrst ]} + :after -> + {low1l, low1h, store} = split(s1, store, low1, k2) + {store, newlow} = merge_aux(s1, s2, store, low1l, low2, callback) + callback.(k2, v2) + {store, newr, newrst} = merge_aux_rec(s1, s2, store, low1h, lst1, r2, rst2, callback) + {store, newlow, [ {k2, v2, newr} | newrst ]} + :duplicate -> + {store, newlow} = merge_aux(s1, s2, store, low1, low2, callback) + newv = s1.merge.(v1, v2) ## TODO: callback here ?? + {store, newr, newrst} = merge_aux_rec(s1, s2, store, r1, rst1, r2, rst2, callback) + {store, newlow, [ {k1, newv, newr} | newrst ]} + end end end diff --git a/lib/manager.ex b/lib/manager.ex index f6910e4..7c6c849 100644 --- a/lib/manager.ex +++ b/lib/manager.ex @@ -94,7 +94,7 @@ defmodule Shard.Manager do end def handle_cast({:peer_up, pk, pid, ip, port}, state) do - for {pk2, _, _, _} <- :ets.match(:peer_db, {:_, :_, ip, port}) do + for [pk2] <- :ets.match(:peer_db, {:'$1', :_, ip, port}) do if pk2 != pk do # obsolete peer information :ets.delete(:peer_db, pk2) diff --git a/test/mst_test.exs b/test/mst_test.exs index 7fe340e..cf5a898 100644 --- a/test/mst_test.exs +++ b/test/mst_test.exs @@ -111,7 +111,7 @@ defmodule ShardTest.MST do MST.last(y, nil, 10) end - test "merkle search tree 5" do + test "merkle search tree 5: MST.last" do y = Enum.reduce(0..1000, %MST{}, fn i, acc -> MST.insert(acc, i) end) @@ -128,4 +128,50 @@ defmodule ShardTest.MST do assert MST.last(y, 500, 300) == stuff end + test "merkle search tree 6: MST.merge" do + y = Enum.reduce([1, 2, 42], %MST{}, fn i, acc -> MST.insert(acc, i) end) + z = Enum.reduce([2, 12], %MST{}, fn i, acc -> MST.insert(acc, i) end) + + IO.puts "y: " + MST.dump y + IO.puts "z: " + MST.dump z + + mg1 = MST.merge(y, z) + IO.puts "mg1: " + MST.dump mg1 + + mg2 = MST.merge(y, z) + IO.puts "mg2: " + MST.dump mg2 + assert mg1.root == mg2.root + end + + test "merkle search tree 7: MST.merge" do + items1 = (for i <- 1..1000, do: i*2+40) + items2 = (for i <- 1..1000, do: i*3) + + y = Enum.reduce(items1, %MST{}, fn i, acc -> MST.insert(acc, i) end) + z = Enum.reduce(items2, %MST{}, fn i, acc -> MST.insert(acc, i) end) + + IO.puts "(merge) y.root: #{y.root|>Base.encode16}" + IO.puts "(merge) z.root: #{z.root|>Base.encode16}" + + mg1 = MST.merge(y, z) + IO.puts "(merge) mg1.root: #{mg1.root|>Base.encode16}" + + mg2 = MST.merge(y, z) + IO.puts "(merge) mg2.root: #{mg2.root|>Base.encode16}" + + assert mg1.root == mg2.root + + items1t = (for i <- items1, do: {i, true}) + items2t = (for i <- items2, do: {i, true}) + assert MST.last(y, nil, 1000) == items1t + assert MST.last(z, nil, 1000) == items2t + + all_items = (items1t ++ items2t) |> Enum.sort |> Enum.uniq + assert MST.last(mg1, nil, 2000) == all_items + end + end -- cgit v1.2.3