Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Avoid needless allocation in read-bytevector! #950

Merged
merged 4 commits into from
Mar 18, 2024
Merged

Avoid needless allocation in read-bytevector! #950

Changes from 2 commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
d0e6dc7
Avoid needless allocation in read-bytevector!
wasamasa Mar 17, 2024
1b1e8b3
Correct read-bytevector logic for small reads
wasamasa Mar 18, 2024
c837c71
Correct let to let*
wasamasa Mar 18, 2024
0fd351e
Fix read-bytevector logic
wasamasa Mar 18, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
37 changes: 16 additions & 21 deletions lib/scheme/extras.scm
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -135,36 +135,31 @@
(if (zero? n)
#u8()
(let ((in (if (pair? o) (car o) (current-input-port)))
Copy link
Owner

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

let*

(res (make-bytevector n)))
(let lp ((i 0))
(if (>= i n)
res
(let ((x (read-u8 in)))
(cond ((eof-object? x)
(if (zero? i) x (subbytes res 0 i)))
(else
(bytevector-u8-set! res i x)
(lp (+ i 1))))))))))
(vec (make-bytevector n))
(res (read-bytevector! vec in)))
(cond ((eof-object? res) res)
((< res n) (subbytes vec 0 i))
Copy link
Owner

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
((< res n) (subbytes vec 0 i))
((< res n) (subbytes vec 0 res))

(else res)))))
Copy link
Owner

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
(else res)))))
(else vec)))))


(define (read-bytevector! vec . o)
(let* ((in (if (pair? o) (car o) (current-input-port)))
(o (if (pair? o) (cdr o) o))
(start (if (pair? o) (car o) 0))
(end (if (and (pair? o) (pair? (cdr o)))
(cadr o)
(bytevector-length vec))))
(bytevector-length vec)))
(n (- end start)))
(if (>= start end)
0
(let ((res (read-bytevector (- end start) in)))
(cond
((eof-object? res)
res)
(else
(let ((len (bytevector-length res)))
(do ((i 0 (+ i 1)))
((>= i len) len)
(bytevector-u8-set! vec (+ i start) (bytevector-u8-ref res i))
))))))))
(let lp ((i 0))
(if (>= i n)
i
(let ((x (read-u8 in)))
(cond ((eof-object? x)
(if (zero? i) x i))
(else
(bytevector-u8-set! vec (+ i start) x)
(lp (+ i 1))))))))))

(define (write-bytevector vec . o)
(let* ((out (if (pair? o) (car o) (current-output-port)))
Expand Down
Loading