From 7b9cd09ad85b5bd55f3d49473f783bd1336c61cf Mon Sep 17 00:00:00 2001
From: Isaac Whitfield <iw@whitfin.io>
Date: Sat, 14 Sep 2024 11:30:09 +0100
Subject: [PATCH] Migrate export to use streaming

---
 lib/cachex/actions/export.ex | 14 ++++++++++++--
 lib/cachex/actions/stream.ex |  8 +++++++-
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/lib/cachex/actions/export.ex b/lib/cachex/actions/export.ex
index fc587ac..a384c0d 100644
--- a/lib/cachex/actions/export.ex
+++ b/lib/cachex/actions/export.ex
@@ -5,6 +5,10 @@ defmodule Cachex.Actions.Export do
   # This command is extremely expensive as it turns the entire cache table into
   # a list, and so should be used sparingly. It's provided purely because it's
   # the backing implementation of the `dump/3` command.
+  alias Cachex.Actions.Stream, as: CachexStream
+  alias Cachex.Query
+
+  # add required imports
   import Cachex.Spec
 
   ##############
@@ -20,6 +24,12 @@ defmodule Cachex.Actions.Export do
   This action should only be used in the case of exports and/or debugging, due
   to the memory overhead involved, as well as the large concatenations.
   """
-  def execute(cache(name: name), _options),
-    do: {:ok, :ets.tab2list(name)}
+  def execute(cache() = cache, options) do
+    query = Query.create()
+    batch = Keyword.take(options, [:batch_size])
+
+    with {:ok, stream} <- CachexStream.execute(cache, query, batch) do
+      {:ok, Enum.to_list(stream)}
+    end
+  end
 end
diff --git a/lib/cachex/actions/stream.ex b/lib/cachex/actions/stream.ex
index 0252746..e01481f 100644
--- a/lib/cachex/actions/stream.ex
+++ b/lib/cachex/actions/stream.ex
@@ -61,7 +61,13 @@ defmodule Cachex.Actions.Stream do
 
         # we're starting!
         :"$start_of_table" ->
-          :ets.select(name, spec, batch)
+          case :ets.select(name, spec, batch) do
+            :"$end_of_table" ->
+              {:halt, nil}
+
+            continuation ->
+              continuation
+          end
 
         # we're continuing!
         continuation ->