Merge pull request #1 from erikronstrom/master

Encoding and decoding blobs now follows the spec with regards to size

osc.lisp

@@ -96,6 +96,7 @@
    f => #(102) => float
    s => #(115) => string 
    b => #(98)  => blob
+   h => #(104) => int64
   and considers non int/float/string data to be a blob." 
 
   (let ((lump (make-array 0 :adjustable t 
@@ -106,7 +107,7 @@
       (write-to-vector #\,)
       (dolist (x data) 
         (typecase x
-          (integer (write-to-vector #\i))
+          (integer (if (>= x 4294967296) (write-to-vector #\h) (write-to-vector #\i)))
           (float (write-to-vector #\f))
           (simple-string (write-to-vector #\s))
 	  (t (write-to-vector #\b)))))
@@ -120,7 +121,7 @@
                  `(setf lump (cat lump (,f x)))))
       (dolist (x data) 
         (typecase x
-          (integer (enc encode-int32)) 
+          (integer (if (>= x 4294967296) (enc encode-int64) (enc encode-int32)))
           (float (enc encode-float32))
           (simple-string (enc encode-string))
 	  (t (enc encode-blob))))
@@ -174,7 +175,8 @@
    i => #(105) => int32
    f => #(102) => float
    s => #(115) => string
-   b => #(98)  => blob"
+   b => #(98)  => blob
+   h => #(104) => int64"
 
   (let ((div (position 0 data)))
     (let ((tags (subseq data 1 div)) 
@@ -187,6 +189,10 @@
                  (push (decode-int32 (subseq acc 0 4)) 
                        result)
                  (setf acc (subseq acc 4)))
+                ((eq x (char-code #\h))
+                 (push (decode-uint64 (subseq acc 0 8))
+                       result)
+                 (setf acc (subseq acc 8)))
                 ((eq x (char-code #\f))
                  (push (decode-float32 (subseq acc 0 4)) 
                        result)
@@ -199,11 +205,12 @@
                    (setf acc (subseq acc pointer))))
                 ((eq x (char-code #\b)) 
                  (let* ((size (decode-int32 (subseq acc 0 4)))
-                        (end (padded-length (+ 4 size))))
+                        (bl (+ 4 size))
+                        (end (+ bl (mod (- 4 bl) 4)))) ; NOTE: cannot use (padded-length bl), as it is not the same algorithm. Blobs of 4, 8, 12 etc bytes should not be padded!
                    (push (decode-blob (subseq acc 0 end)) 
                          result)
                    (setf acc (subseq acc end))))
-		(t (error "unrecognised typetag"))))
+                (t (error "unrecognised typetag ~a" x))))
            tags)
       (nreverse result))))
 
@@ -316,6 +323,50 @@
       (set-byte 3))
     buf))
 
+(defun encode-int64 (i)
+  "convert an integer into a sequence of 8 bytes in network byte order."
+  (declare (type integer i))
+  (let ((buf (make-sequence
+	      '(vector (unsigned-byte 8)) 8)))
+    (macrolet ((set-byte (n)
+		 `(setf (elt buf ,n)
+			(logand #xff (ash i ,(* 8 (- n 7)))))))
+      (set-byte 0)
+      (set-byte 1)
+      (set-byte 2)
+      (set-byte 3)
+      (set-byte 4)
+      (set-byte 5)
+      (set-byte 6)
+      (set-byte 7))
+    buf))
+
+(defun decode-uint64 (s)
+  "8 byte -> 64 bit unsigned int"
+  (let ((i (+ (ash (elt s 0) 56)
+	      (ash (elt s 1) 48)
+	      (ash (elt s 2) 40)
+	      (ash (elt s 3) 32)
+	      (ash (elt s 4) 24)
+	      (ash (elt s 5) 16)
+	      (ash (elt s 6) 8)
+	      (elt s 7))))
+    i))
+
+(defun decode-int64 (s)
+  "8 byte -> 64 bit int -> two's compliment (in network byte order)"
+  (let ((i (+ (ash (elt s 0) 56)
+	      (ash (elt s 1) 48)
+	      (ash (elt s 2) 40)
+	      (ash (elt s 3) 32)
+	      (ash (elt s 4) 24)
+	      (ash (elt s 5) 16)
+	      (ash (elt s 6) 8)
+	      (elt s 7))))
+    (if (>= i #x7fffffffffffffff)
+        (- 0 (- #x10000000000000000 i))
+	i)))
+
 ;; osc-strings are unsigned bytes, padded to a 4 byte boundary 
 
 (defun decode-string (data)
@@ -340,7 +391,7 @@
   "encodes a blob from a given vector"
   (let ((bl (length blob)))
     (cat (encode-int32 bl) blob
-	 (pad (padding-length bl)))))      
+	 (pad (mod (- 4 bl) 4))))) ; NOTE: cannot use (padding-length bl), as it is not the same algorithm. Blobs of 4, 8, 12 etc bytes should not be padded!
 
 ;; utility functions for osc-string/padding slonking