diff options
Diffstat (limited to 'guix/memoization.scm')
| -rw-r--r-- | guix/memoization.scm | 93 |
1 files changed, 69 insertions, 24 deletions
diff --git a/guix/memoization.scm b/guix/memoization.scm index 69343f592b..0201fe4cb3 100644 --- a/guix/memoization.scm +++ b/guix/memoization.scm @@ -20,10 +20,48 @@ #:use-module (guix profiling) #:use-module (ice-9 match) #:autoload (srfi srfi-1) (count) + #:use-module (srfi srfi-9) #:export (memoize mlambda mlambdaq)) +;; Data type representation a memoization cache when profiling is on. +(define-record-type <cache> + (make-cache table lookups hits) + cache? + (table cache-table) + (lookups cache-lookups set-cache-lookups!) + (hits cache-hits set-cache-hits!)) + +(define-syntax-rule (define-lookup-procedure proc get) + "Define a lookup procedure PROC. When profiling is turned off, PROC is set +to GET; when profiling is on, PROC is a wrapper around GET that keeps tracks +of lookups and cache hits." + (define proc + (if (profiled? "memoization") + (lambda (cache key default) + (let ((result (get (cache-table cache) key default))) + (set-cache-lookups! cache (+ 1 (cache-lookups cache))) + (unless (eq? result default) + (set-cache-hits! cache (+ 1 (cache-hits cache)))) + result)) + get))) + +(define-syntax-rule (define-update-procedure proc put!) + "Define an update procedure PROC. When profiling is turned off, PROC is +equal to PUT!; when profiling is on, PROC is a wrapper around PUT and unboxes +the underlying hash table." + (define proc + (if (profiled? "memoization") + (lambda (cache key value) + (put! (cache-table cache) key value)) + put!))) + +(define-lookup-procedure cache-ref hash-ref) +(define-lookup-procedure cacheq-ref hashq-ref) +(define-update-procedure cache-set! hash-set!) +(define-update-procedure cacheq-set! hashq-set!) + (define-syntax-rule (call/mv thunk) (call-with-values thunk list)) (define-syntax-rule (return/mv lst) @@ -56,22 +94,24 @@ already-cached result." (define-cache-procedure name hash-ref hash-set! call/mv return/mv)))) -(define-cache-procedure cached/mv hash-ref hash-set!) -(define-cache-procedure cachedq/mv hashq-ref hashq-set!) -(define-cache-procedure cached hash-ref hash-set! call/1 return/1) -(define-cache-procedure cachedq hashq-ref hashq-set! call/1 return/1) +(define-cache-procedure cached/mv cache-ref cache-set!) +(define-cache-procedure cachedq/mv cacheq-ref cacheq-set!) +(define-cache-procedure cached cache-ref cache-set! call/1 return/1) +(define-cache-procedure cachedq cacheq-ref cacheq-set! call/1 return/1) (define %memoization-tables ;; Map procedures to the underlying hash table. (make-weak-key-hash-table)) (define %make-hash-table* + ;; When profiling is off, this is equivalent to 'make-hash-table'. When + ;; profiling is on, return a hash table wrapped in a <cache> object. (if (profiled? "memoization") (lambda (proc location) - (let ((table (make-hash-table))) + (let ((cache (make-cache (make-hash-table) 0 0))) (hashq-set! %memoization-tables proc - (cons table location)) - table)) + (cons cache location)) + cache)) (lambda (proc location) (make-hash-table)))) @@ -80,35 +120,40 @@ already-cached result." (define* (show-memoization-tables #:optional (port (current-error-port))) "Display to PORT statistics about the memoization tables." - (define (table<? p1 p2) + (define (cache<? p1 p2) (match p1 - ((table1 . _) + ((cache1 . _) (match p2 - ((table2 . _) - (< (hash-count (const #t) table1) - (hash-count (const #t) table2))))))) + ((cache2 . _) + (< (hash-count (const #t) (cache-table cache1)) + (hash-count (const #t) (cache-table cache2)))))))) - (define tables + (define caches (hash-map->list (lambda (key value) value) %memoization-tables)) - (match (sort tables (negate table<?)) - (((tables . locations) ...) + (match (sort caches (negate cache<?)) + (((caches . locations) ...) (format port "Memoization: ~a tables, ~a non-empty~%" - (length tables) - (count (lambda (table) - (> (hash-count (const #t) table) 0)) - tables)) - (for-each (lambda (table location) - (let ((size (hash-count (const #t) table))) + (length caches) + (count (lambda (cache) + (> (hash-count (const #t) (cache-table cache)) 0)) + caches)) + (for-each (lambda (cache location) + (let ((size (hash-count (const #t) (cache-table cache)))) (unless (zero? size) - (format port " ~a:~a:~a: \t~a entries~%" + (format port " ~a:~a:~a: \t~a entries, ~a lookups, ~a% hits~%" (assq-ref location 'filename) (and=> (assq-ref location 'line) 1+) (assq-ref location 'column) - size)))) - tables locations)))) + size + (cache-lookups cache) + (inexact->exact + (round + (* 100. (/ (cache-hits cache) + (cache-lookups cache) 1.)))))))) + caches locations)))) (register-profiling-hook! "memoization" show-memoization-tables) |