refac

pitfall/pitfall/reference.rkt

@@ -2,17 +2,6 @@
 (require "object.rkt" "zlib.rkt")
 (provide PDFReference)
 
-(define-subclass object% (Chunks)
-  (super-new)
-  (define chunks null)
-  (define/public (append-chunk chunk)
-    (set! chunks (append chunks (list chunk))))
-  )
-
-(define-subclass Chunks (CompressedChunks)
-  (super-new))
-
-
 (define-subclass object% (PDFReference document id [data (mhash)])
   (super-new)
   (field [gen 0]
@@ -37,40 +26,38 @@
   (define chunk (if (isBuffer? chunk-in)
                     chunk-in
                     (newBuffer (string-append chunk-in "\n"))))
-  (hash-ref! (· this data) 'Length 0)
   (push-end-field! chunks this chunk)
-  (hash-update! (· this data) 'Length (curry + (buffer-length chunk)))
+  (hash-update! (· this data) 'Length (curry + (buffer-length chunk)) 0)
   (callback))
 
 
-(define/contract (end this [chunk #f])
-  (() ((or/c any/c #f)) . ->*m . void?)
+(define/contract (end this)
+  (->m void?)
 
-  (when (and (· this compress) (positive? (length (· this chunks))))
-    (define deflated-chunk (deflate (apply bytes-append (· this chunks))))
-    (set-field! chunks this (list deflated-chunk))
-    (hash-set*! (· this data)
-                'Filter "FlateDecode"
-                'Length (buffer-length deflated-chunk)))
-  
-  (define this-doc (· this document)) 
+  (define chunks-to-write
+    (let ([current-chunks (· this chunks)])
+      (if (and (· this compress) (pair? current-chunks))
+          (let ([deflated-chunk (deflate (apply bytes-append current-chunks))])
+            (hash-set*! (· this data)
+                        'Filter "FlateDecode"
+                        'Length (buffer-length deflated-chunk))
+            (list deflated-chunk))
+          current-chunks)))
 
+  (define this-doc (· this document)) 
   (set-field! offset this (· this-doc _offset))
-
-  (send* this-doc
-    [_write (format "~a ~a obj" (· this id) (· this gen))]
-    [_write (convert (· this data))])
-
-  (let ([this-chunks (· this chunks)])
-    (when (positive? (length this-chunks))
-      (send this-doc _write "stream")
-      (for ([chunk (in-list this-chunks)])
-           (send this-doc _write chunk))
-      (send this-doc _write "\nendstream")))
-
-  (send* this-doc
-    [_write "endobj"]
-    [_refEnd this]))
+  
+  (with-method ([doc_write (this-doc _write)])
+    (doc_write (format "~a ~a obj" (· this id) (· this gen)))
+    (doc_write (convert (· this data)))
+    (when (pair? chunks-to-write)
+      (doc_write "stream")
+      (for ([chunk (in-list chunks-to-write)])
+           (doc_write chunk))
+      (doc_write "\nendstream"))
+    (doc_write "endobj"))
+  
+  (send this-doc _refEnd this))
 
 
 (define/contract (toString this)