diff options
Diffstat (limited to 'guix/store.scm')
| -rw-r--r-- | guix/store.scm | 39 |
1 files changed, 23 insertions, 16 deletions
diff --git a/guix/store.scm b/guix/store.scm index 220901f6ce..a3240eb2e0 100644 --- a/guix/store.scm +++ b/guix/store.scm @@ -1362,8 +1362,12 @@ object, only for build requests on EXPECTED-STORE." (unresolved things continue) (continue #t)))) +(define default-cutoff + ;; Default cutoff parameter for 'map/accumulate-builds'. + (make-parameter 32)) + (define* (map/accumulate-builds store proc lst - #:key (cutoff 30)) + #:key (cutoff (default-cutoff))) "Apply PROC over each element of LST, accumulating 'build-things' calls and coalescing them into a single call. @@ -1377,21 +1381,24 @@ CUTOFF is the threshold above which we stop accumulating unresolved nodes." (build-accumulator store)) (define-values (result rest) - (let loop ((lst lst) - (result '()) - (unresolved 0)) - (match lst - ((head . tail) - (match (with-build-handler accumulator - (proc head)) - ((? unresolved? obj) - (if (>= unresolved cutoff) - (values (reverse (cons obj result)) tail) - (loop tail (cons obj result) (+ 1 unresolved)))) - (obj - (loop tail (cons obj result) unresolved)))) - (() - (values (reverse result) lst))))) + ;; Have the default cutoff decay as we go deeper in the call stack to + ;; avoid pessimal behavior. + (parameterize ((default-cutoff (quotient cutoff 2))) + (let loop ((lst lst) + (result '()) + (unresolved 0)) + (match lst + ((head . tail) + (match (with-build-handler accumulator + (proc head)) + ((? unresolved? obj) + (if (>= unresolved cutoff) + (values (reverse (cons obj result)) tail) + (loop tail (cons obj result) (+ 1 unresolved)))) + (obj + (loop tail (cons obj result) unresolved)))) + (() + (values (reverse result) lst)))))) (match (append-map (lambda (obj) (if (unresolved? obj) |