blob file migrator speedup

.devcontainer/fish-shell-conf-d/utils.fish

@@ -0,0 +1,27 @@
+function blob-files-dir
+    if [ $RAILS_ENV = "production" ]
+        echo "/mnt/blob_files_production/v1"
+        return 0
+    else if [ $RAILS_ENV = "development" ]
+        echo "/mnt/blob_files_development/v1"
+        return 0
+    else
+        echo "unknown RAILS_ENV: $RAILS_ENV" >&2
+        return 1
+    end
+end
+
+function blob-file-path
+    set -l file_name $argv[1]
+    set -l prefix (blob-files-dir || return 1)
+    set -l p0 (string sub      -l 2 $file_name)
+    set -l p1 (string sub -s 3 -l 2 $file_name)
+    set -l p2 (string sub -s 5 -l 1 $file_name)
+    printf "%s/%s/%s/%s/%s" $prefix $p0 $p1 $p2 $file_name
+end
+
+function blob-files-stats
+    set -l files_dir (blob-files-dir || return 1)
+    printf "apparent size: %s\n" (du -sh --apparent-size $files_dir)
+    printf "actual size:   %s\n" (du -sh $files_dir)
+end