Implement buffer reuse encoding.

This implements a buffer reuse mechanism in eris-encode. This is also a
backwards incompatible change, as the provided OUTPUT-FUNCTION now has an
additional argument and has to return an octet-vector buffer of equal size. This
is not yet implemented optimally, but should amount to a reduce of memory usage
and GC required, especially for larger files.

4 files changed, 12 insertions, 4 deletions

diff --git a/tests/backend-tests.lisp b/tests/backend-tests.lisp
index 625740f..dc411d5 100644
--- a/tests/backend-tests.lisp
+++ b/tests/backend-tests.lisp
@@ -21,7 +21,7 @@
   `(let ((backend (make-instance 'hash-backend))
          (array ,array))
      (is (equalp (alexandria:read-stream-content-into-byte-vector
-                  (fetch-read-capability
+                  (fetch-data
                    (store-data array backend :block-size ,block-size :secret ,secret) backend))
                  array))))
 
@@ -49,7 +49,7 @@
           (let* ((backend (make-instance 'file-backend :directory tmpdir))
                  (array ,array))
             (is (equalp (alexandria:read-stream-content-into-byte-vector
-                         (fetch-read-capability
+                         (fetch-data
                           (store-data array backend :secret ,secret) backend))
                         array)))
        (uiop:delete-directory-tree tmpdir :validate t))))
diff --git a/tests/decode-tests.lisp b/tests/decode-tests.lisp
index 27ff4e3..5053d11 100644
--- a/tests/decode-tests.lisp
+++ b/tests/decode-tests.lisp
@@ -22,7 +22,8 @@
 (defvar *stream* nil)
 
 (defun hashtable-encode (block ref)
-  (setf (gethash ref *table*) block))
+  (setf (gethash ref *table*) (copy-seq block))
+  block)
 
 (defun hashtable-decode (ref)
   (copy-seq (gethash ref *table*)))
diff --git a/tests/encode-tests.lisp b/tests/encode-tests.lisp
index 36cc435..abbeb0d 100644
--- a/tests/encode-tests.lisp
+++ b/tests/encode-tests.lisp
@@ -36,6 +36,12 @@
   (check-urn (base32-to-bytes-unpadded "JBSWY3DPEB3W64TMMQQQ") 1024
              "urn:eris:BIAD77QDJMFAKZYH2DXBUZYAP3MXZ3DJZVFYQ5DFWC6T65WSFCU5S2IT4YZGJ7AC4SYQMP2DM2ANS2ZTCP3DJJIRV733CRAAHOSWIYZM3M"))
 
+(test empty-stream
+  (check-urn (serapeum:make-octet-vector 0) 1024
+             "urn:eris:BIADFUKDPYKJNLGCVSIIDI3FVKND7MO5AGOCXBK2C4ITT5MAL4LSCZF62B4PDOFQCLLNL7AXXSJFGINUYXVGVTDCQ2V7S7W5S234WFXCJ4")
+  (check-urn (serapeum:make-octet-vector 0) eris:32kib
+             "urn:eris:B4AC3MKL2BYR3E2WPMY2QRA6QZBLY4VNWJEBTSK5KWD66BRIT2EXVQVWY6TWVKJCZLC66RE3T2PKWDU3TBAKZZZIZRBTMP6BSOPE4CRXII"))
+
 ;; simple gray stream class for this particular construction.
 (defclass null-stream (fundamental-binary-input-stream)
   ((counter :initform 0 :accessor counter)
diff --git a/tests/rfc.lisp b/tests/rfc.lisp
index 15b993e..dafa086 100644
--- a/tests/rfc.lisp
+++ b/tests/rfc.lisp
@@ -24,7 +24,8 @@
 
 (defun test-output (block ref)
   (assert (equalp block
-                  (base32-to-bytes-unpadded (getf *alist* (intern (bytes-to-base32-unpadded ref) :keyword))))))
+                  (base32-to-bytes-unpadded (getf *alist* (intern (bytes-to-base32-unpadded ref) :keyword)))))
+  block)
 
 (defmacro positive-test (urn content block-alist secret block-size)
   `(let ((*alist* ,block-alist)