Store image hashes in the db - part 1

lib/music_library/records/importer.ex

@@ -129,6 +129,23 @@ defmodule MusicLibrary.Records.Importer do
     end)
   end
 
+  def generate_all_cover_hashes do
+    Rec
+    |> Repo.all()
+    |> Enum.each(fn r ->
+      if r.image_data != nil do
+        generate_cover_image_hash(r)
+        IO.puts("Generated cover image hash for #{r.title}")
+      end
+    end)
+  end
+
+  def generate_cover_image_hash(record) do
+    record
+    |> Rec.generate_image_data_hash()
+    |> Repo.update!()
+  end
+
   defp blob_get(url) do
     req =
       Finch.build(:get, url, [

lib/music_library/records/record.ex

@@ -12,6 +12,7 @@ defmodule MusicLibrary.Records.Record do
     field :title, :string
     field :image_url, :string
     field :image_data, :binary
+    field :image_data_hash, :string
     field :year, :integer
     field :musicbrainz_id, Ecto.UUID
     field :genres, {:array, :string}
@@ -40,6 +41,7 @@ defmodule MusicLibrary.Records.Record do
       :image_data
     ])
     |> cast_embed(:artists, with: &artist_changeset/2)
+    |> generate_image_data_hash()
     |> validate_required([:type, :title, :musicbrainz_id, :year, :genres])
   end
 
@@ -57,7 +59,28 @@ defmodule MusicLibrary.Records.Record do
   end
 
   def add_image_data(record, image_data) do
-    change(record, image_data: image_data)
+    record
+    |> change(image_data: image_data)
+    |> generate_image_data_hash()
+  end
+
+  def generate_image_data_hash(record = %__MODULE__{image_data: image_data}) do
+    hash = :crypto.hash(:sha256, image_data) |> Base.encode16()
+
+    record
+    |> change()
+    |> put_change(:image_data_hash, hash)
+  end
+
+  def generate_image_data_hash(changeset) do
+    case get_change(changeset, :image_data) do
+      nil ->
+        changeset
+
+      image_data ->
+        hash = :crypto.hash(:sha256, image_data) |> Base.encode16()
+        put_change(changeset, :image_data_hash, hash)
+    end
   end
 
   def formats, do: @formats

lib/music_library_web/live/record_live/index.html.heex

@@ -25,7 +25,11 @@
 >
   <:col :let={{_id, record}} label="Image">
     <span class="relative inline-block drop-shadow-xl">
-      <img class="max-w-16 rounded-lg" src={~p"/images/#{record.id}"} alt={record.title} />
+      <img
+        class="max-w-16 rounded-lg"
+        alt={record.title}
+        src={~p"/images/#{record.id}?vsn=#{record.image_data_hash || ""}"}
+      />
       <span class="absolute right-1 bottom-0 block text-white drop-shadow-md">
         <%= Records.Record.format_short_label(record.format) %>
       </span>

lib/music_library_web/live/record_live/show.html.heex

@@ -13,7 +13,11 @@
 
 <div class="md:columns-2">
   <span class="relative block md:inline-block drop-shadow">
-    <img class="w-full" src={~p"/images/#{@record.id}"} alt={@record.title} />
+    <img
+      class="w-full"
+      src={~p"/images/#{@record.id}?vsn=#{@record.image_data_hash}"}
+      alt={@record.title}
+    />
     <span class="absolute right-2 bottom-1 block text-white drop-shadow-md">
       <%= Records.Record.format_short_label(@record.format) %>
     </span>

priv/repo/migrations/20240930145536_add_image_data_hash_to_records.exs

@@ -0,0 +1,9 @@
+defmodule MusicLibrary.Repo.Migrations.AddImageDataHashToRecords do
+  use Ecto.Migration
+
+  def change do
+    alter table(:records) do
+      add :image_data_hash, :string
+    end
+  end
+end