diff options
| -rw-r--r-- | guix/derivations.scm | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/guix/derivations.scm b/guix/derivations.scm index 6f73534c3c..60d57afa12 100644 --- a/guix/derivations.scm +++ b/guix/derivations.scm @@ -155,9 +155,8 @@ DRV and not already available in STORE, recursively." inputs) (map derivation-input-sub-derivations inputs)))))) -(define (read-derivation drv-port) - "Read the derivation from DRV-PORT and return the corresponding -<derivation> object." +(define (%read-derivation drv-port) + ;; Actually read derivation from DRV-PORT. (define comma (string->symbol ",")) @@ -222,6 +221,20 @@ DRV and not already available in STORE, recursively." (loop (read drv-port) (cons (ununquote exp) result)))))) +(define read-derivation + (let ((cache (make-weak-value-hash-table 200))) + (lambda (drv-port) + "Read the derivation from DRV-PORT and return the corresponding +<derivation> object." + ;; Memoize that operation because `%read-derivation' is quite expensive, + ;; and because the same argument is read more than 15 times on average + ;; during something like (package-derivation s gdb). + (let ((file (and=> (port-filename drv-port) basename))) + (or (and file (hash-ref cache file)) + (let ((drv (%read-derivation drv-port))) + (hash-set! cache file drv) + drv)))))) + (define (write-derivation drv port) "Write the ATerm-like serialization of DRV to PORT. See Section 2.4 of Eelco Dolstra's PhD dissertation for an overview of a previous version of |