preload associations

apps/explorer/lib/explorer/chain.ex

@@ -1152,21 +1152,33 @@ defmodule Explorer.Chain do
     paging_options = Keyword.get(options, :paging_options) || @default_paging_options
     block_type = Keyword.get(options, :block_type, "Block")
 
-    if block_type == "Block" && !paging_options.key && BlocksCache.enough_elements?(paging_options.page_size) do
-      cached_blocks = BlocksCache.blocks()
+    if block_type == "Block" && !paging_options.key do
+      if BlocksCache.enough_elements?(paging_options.page_size) do
+        cached_blocks = BlocksCache.blocks()
 
-      Enum.slice(cached_blocks, 0, paging_options.page_size)
+        Enum.slice(cached_blocks, 0, paging_options.page_size)
+      else
+        elements = fetch_blocks(block_type, paging_options, necessity_by_association)
+
+        BlocksCache.rewrite_cache(elements)
+
+        elements
+      end
     else
-      Block
-      |> Block.block_type_filter(block_type)
-      |> page_blocks(paging_options)
-      |> limit(^paging_options.page_size)
-      |> order_by(desc: :number)
-      |> join_associations(necessity_by_association)
-      |> Repo.all()
+      fetch_blocks(block_type, paging_options, necessity_by_association)
     end
   end
 
+  defp fetch_blocks(block_type, paging_options, necessity_by_association) do
+    Block
+    |> Block.block_type_filter(block_type)
+    |> page_blocks(paging_options)
+    |> limit(^paging_options.page_size)
+    |> order_by(desc: :number)
+    |> join_associations(necessity_by_association)
+    |> Repo.all()
+  end
+
   @doc """
   Map `block_number`s to their `t:Explorer.Chain.Block.t/0` `hash` `t:Explorer.Chain.Hash.Full.t/0`.
 

apps/explorer/lib/explorer/chain/blocks_cache.ex

@@ -3,6 +3,8 @@ defmodule Explorer.Chain.BlocksCache do
   Caches the last imported blocks
   """
 
+  alias Explorer.Repo
+
   @block_numbers_key "block_numbers"
   @cache_name :blocks
   @number_of_elements 60
@@ -22,6 +24,24 @@ defmodule Explorer.Chain.BlocksCache do
     end
   end
 
+  def rewrite_cache(elements) do
+    numbers = block_numbers()
+
+    ConCache.delete(@cache_name, @block_numbers_key)
+
+    numbers
+    |> Enum.each(fn number ->
+      ConCache.delete(@cache_name, number)
+    end)
+
+    elements
+    |> Enum.reduce([], fn element, acc ->
+      put_block(element, acc)
+
+      [element.number | acc]
+    end)
+  end
+
   def enough_elements?(number) do
     ConCache.size(@cache_name) > number + 1
   end
@@ -54,7 +74,8 @@ defmodule Explorer.Chain.BlocksCache do
   end
 
   defp put_block(block, numbers) do
-    ConCache.put(@cache_name, block.number, block)
+    block_with_preloads = Repo.preload(block, [:transactions, [miner: :names], :rewards])
+    ConCache.put(@cache_name, block.number, block_with_preloads)
     ConCache.put(@cache_name, @block_numbers_key, [block.number | numbers])
   end
 end

apps/explorer/test/explorer/chain/blocks_cache_test.exs

@@ -2,6 +2,7 @@ defmodule Explorer.Chain.BlocksCacheTest do
   use Explorer.DataCase
 
   alias Explorer.Chain.BlocksCache
+  alias Explorer.Repo
 
   setup do
     Supervisor.terminate_child(Explorer.Supervisor, ConCache)
@@ -11,7 +12,7 @@ defmodule Explorer.Chain.BlocksCacheTest do
 
   describe "update/1" do
     test "adds a new value to cache" do
-      block = insert(:block)
+      block = insert(:block) |> Repo.preload([:transactions, [miner: :names], :rewards])
 
       BlocksCache.update(block)
 
@@ -37,4 +38,21 @@ defmodule Explorer.Chain.BlocksCacheTest do
       assert Enum.map(BlocksCache.blocks(), & &1.number) == new_blocks
     end
   end
+
+  describe "rewrite_cache/1" do
+    test "updates cache" do
+      block = insert(:block)
+
+      BlocksCache.update(block)
+
+      block1 = insert(:block) |> Repo.preload([:transactions, [miner: :names], :rewards])
+      block2 = insert(:block) |> Repo.preload([:transactions, [miner: :names], :rewards])
+
+      new_blocks = [block1, block2]
+
+      BlocksCache.rewrite_cache(new_blocks)
+
+      assert BlocksCache.blocks() == [block1, block2]
+    end
+  end
 end