Refactor Blob support of external storage in preparation of job artifact blobs

4 files changed, 85 insertions, 50 deletions

diff --git a/app/models/blob.rb b/app/models/blob.rb
index 1cdb8811cff..a4fae22a0c4 100644
--- a/app/models/blob.rb
+++ b/app/models/blob.rb
@@ -28,7 +28,7 @@ class Blob < SimpleDelegator
     BlobViewer::Sketch,
 
     BlobViewer::Video,
-    
+
     BlobViewer::PDF,
 
     BlobViewer::BinarySTL,
@@ -75,19 +75,37 @@ class Blob < SimpleDelegator
   end
 
   def no_highlighting?
-    size && size > MAXIMUM_TEXT_HIGHLIGHT_SIZE
+    raw_size && raw_size > MAXIMUM_TEXT_HIGHLIGHT_SIZE
+  end
+
+  def empty?
+    raw_size == 0
   end
 
   def too_large?
     size && truncated?
   end
 
+  def external_storage_error?
+    if external_storage == :lfs
+      !project&.lfs_enabled?
+    else
+      false
+    end
+  end
+
+  def stored_externally?
+    return @stored_externally if defined?(@stored_externally)
+
+    @stored_externally = external_storage && !external_storage_error?
+  end
+
   # Returns the size of the file that this blob represents. If this blob is an
   # LFS pointer, this is the size of the file stored in LFS. Otherwise, this is
   # the size of the blob itself.
   def raw_size
-    if valid_lfs_pointer?
-      lfs_size
+    if stored_externally?
+      external_size
     else
       size
     end
@@ -98,9 +116,13 @@ class Blob < SimpleDelegator
   # text-based rich blob viewer matched on the file's extension. Otherwise, this
   # depends on the type of the blob itself.
   def raw_binary?
-    if valid_lfs_pointer?
+    if stored_externally?
       if rich_viewer
         rich_viewer.binary?
+      elsif Linguist::Language.find_by_filename(name).any?
+        false
+      elsif _mime_type
+        _mime_type.binary?
       else
         true
       end
@@ -118,15 +140,7 @@ class Blob < SimpleDelegator
   end
 
   def readable_text?
-    text? && !valid_lfs_pointer? && !too_large?
-  end
-
-  def valid_lfs_pointer?
-    lfs_pointer? && project&.lfs_enabled?
-  end
-
-  def invalid_lfs_pointer?
-    lfs_pointer? && !project&.lfs_enabled?
+    text? && !stored_externally? && !too_large?
   end
 
   def simple_viewer
@@ -165,10 +179,10 @@ class Blob < SimpleDelegator
   end
 
   def rich_viewer_class
-    return if invalid_lfs_pointer? || empty?
+    return if empty? || external_storage_error?
 
     classes =
-      if valid_lfs_pointer?
+      if stored_externally?
         BINARY_VIEWERS + TEXT_VIEWERS
       elsif binary?
         BINARY_VIEWERS
diff --git a/app/models/blob_viewer/base.rb b/app/models/blob_viewer/base.rb
index f944b00c9d3..a8b91d8d6bc 100644
--- a/app/models/blob_viewer/base.rb
+++ b/app/models/blob_viewer/base.rb
@@ -70,12 +70,13 @@ module BlobViewer
       return @render_error if defined?(@render_error)
 
       @render_error =
-        if server_side_but_stored_in_lfs?
-          # Files stored in LFS can only be rendered using a client-side viewer,
+        if server_side_but_stored_externally?
+          # Files that are not stored in the repository, like LFS files and
+          # build artifacts, can only be rendered using a client-side viewer,
           # since we do not want to read large amounts of data into memory on the
           # server side. Client-side viewers use JS and can fetch the file from
           # `blob_raw_url` using AJAX.
-          :server_side_but_stored_in_lfs
+          :server_side_but_stored_externally
         elsif override_max_size ? absolutely_too_large? : too_large?
           :too_large
         end
@@ -89,8 +90,8 @@ module BlobViewer
 
     private
 
-    def server_side_but_stored_in_lfs?
-      server_side? && blob.valid_lfs_pointer?
+    def server_side_but_stored_externally?
+      server_side? && blob.stored_externally?
     end
   end
 end
diff --git a/app/models/concerns/blob_like.rb b/app/models/concerns/blob_like.rb
new file mode 100644
index 00000000000..adb81561000
--- /dev/null
+++ b/app/models/concerns/blob_like.rb
@@ -0,0 +1,48 @@
+module BlobLike
+  extend ActiveSupport::Concern
+  include Linguist::BlobHelper
+
+  def id
+    raise NotImplementedError
+  end
+
+  def name
+    raise NotImplementedError
+  end
+
+  def path
+    raise NotImplementedError
+  end
+
+  def size
+    0
+  end
+
+  def data
+    nil
+  end
+
+  def mode
+    nil
+  end
+
+  def binary?
+    false
+  end
+
+  def load_all_data!(repository)
+    # No-op
+  end
+
+  def truncated?
+    false
+  end
+
+  def external_storage
+    nil
+  end
+
+  def external_size
+    nil
+  end
+end
diff --git a/app/models/snippet_blob.rb b/app/models/snippet_blob.rb
index d6cab74eb1a..fa5fa151607 100644
--- a/app/models/snippet_blob.rb
+++ b/app/models/snippet_blob.rb
@@ -1,5 +1,5 @@
 class SnippetBlob
-  include Linguist::BlobHelper
+  include BlobLike
 
   attr_reader :snippet
 
@@ -28,32 +28,4 @@ class SnippetBlob
 
     Banzai.render_field(snippet, :content)
   end
-
-  def mode
-    nil
-  end
-
-  def binary?
-    false
-  end
-
-  def load_all_data!(repository)
-    # No-op
-  end
-
-  def lfs_pointer?
-    false
-  end
-
-  def lfs_oid
-    nil
-  end
-
-  def lfs_size
-    nil
-  end
-
-  def truncated?
-    false
-  end
 end