[bug#46100] [PATCH 0/4] Memoize inferior package access.

[bug#46100] [PATCH 0/4] Memoize inferior package access.

[Ricardo Wurmus]

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Hi Guix,

this patch set improves performance of inferior lookups by caching previous
results.  The change in inferior-package->manifest-entry has the biggest
impact in my test case, where I'm building a profile consisting of a few R
packages.  Without this patch it takes more than 14 seconds.  With cached
results it takes less than a second.

Included is a patch that Ludo provided on #guix-hpc for which I wrote a
commit message.

The test case is attached.

Ludovic Courtès (1):
  inferior: Memoize package input field access.

Ricardo Wurmus (3):
  guix: Fix typo.
  inferior: Memoize inferior-package->manifest-entry.
  inferior: Memoize inferior package search path access.

 guix/inferior.scm | 155 ++++++++++++++++++++++++----------------------
 1 file changed, 81 insertions(+), 74 deletions(-)


base-commit: 90a6ce0b1852608185e3ba7fe09e585b43eac3be
-- 
2.29.2


-- 
Ricardo


[-- Attachment #2: inferior-slow.scm --]
[-- Type: text/plain, Size: 1371 bytes --]

(import (guix packages)
        (guix inferior)
        (guix store)
        (guix monads)(guix gexp)
        (guix profiles)
        (guix derivations)
        (ice-9 match)
        (srfi srfi-19))

(pk 'current-guix)
(define current-guix
  ;; /home/rekado/.config/guix/current
  (let* ((default-guix "/gnu/store/ig6alp71w39bmfy51f1w32z0k2rbh6ra-profile")
         (current-guix-inferior #false))
    (lambda ()
      (or current-guix-inferior
          (begin
            (set! current-guix-inferior (open-inferior
                                         (canonicalize-path default-guix)))
            current-guix-inferior)))))

(define (lookup-package specification)
  (match (lookup-inferior-packages (current-guix) specification)
    ((first . rest) first)
    (x (error "oops" x))))

(define specs
  (list "bash-minimal"
        "r-minimal"
        "r-ggplot2"
        "r-ggrepel"
        "r-deseq2"
        "r-dt"
        "r-pheatmap"
        "r-corrplot"
        "r-reshape2"
        "r-plotly"
        "r-scales"
        "r-crosstalk"
        "r-gprofiler"
        "r-rtracklayer"
        "r-summarizedexperiment"))

(pk 'packages)
(define packages
  (map lookup-package specs))

(pk 'packages->manifest)
(let ((start (current-time)))
  (let ((manifest (packages->manifest packages)))
    (pk 'packages->manifest-done (time-difference (current-time) start))))

[bug#46101] [PATCH 1/4] guix: Fix typo.

[Ricardo Wurmus]

* guix/inferior.scm (inferior-available-packages): Remove extra word in
docstring.
---
 guix/inferior.scm | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/guix/inferior.scm b/guix/inferior.scm
index 2fe91beaab..da6983d9a6 100644
--- a/guix/inferior.scm
+++ b/guix/inferior.scm
@@ -311,8 +311,7 @@ Raise '&inferior-exception' when an exception is read from PORT."
   "Return the list of name/version pairs corresponding to the set of packages
 available in INFERIOR.
 
-This is faster and requires less resource-intensive than calling
-'inferior-packages'."
+This is faster and less resource-intensive than calling 'inferior-packages'."
   (if (inferior-eval '(defined? 'fold-available-packages)
                      inferior)
       (inferior-eval '(fold-available-packages
-- 
2.29.2

[bug#46102] [PATCH 2/4] inferior: Memoize inferior-package->manifest-entry.

[Ricardo Wurmus]

* guix/inferior.scm (inferior-package->manifest-entry): Memoize.
---
 guix/inferior.scm | 55 ++++++++++++++++++++++++++---------------------
 1 file changed, 30 insertions(+), 25 deletions(-)

diff --git a/guix/inferior.scm b/guix/inferior.scm
index da6983d9a6..7bfce5d810 100644
--- a/guix/inferior.scm
+++ b/guix/inferior.scm
@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2021 Ricardo Wurmus <rekado@elephly.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -639,31 +640,35 @@ failing when GUIX is too old and lacks the 'guix repl' command."
 ;;; Manifest entries.
 ;;;
 
-(define* (inferior-package->manifest-entry package
-                                           #:optional (output "out")
-                                           #:key (parent (delay #f))
-                                           (properties '()))
-  "Return a manifest entry for the OUTPUT of package PACKAGE."
-  ;; For each dependency, keep a promise pointing to its "parent" entry.
-  (letrec* ((deps  (map (match-lambda
-                          ((label package)
-                           (inferior-package->manifest-entry package
-                                                             #:parent (delay entry)))
-                          ((label package output)
-                           (inferior-package->manifest-entry package output
-                                                             #:parent (delay entry))))
-                        (inferior-package-propagated-inputs package)))
-            (entry (manifest-entry
-                     (name (inferior-package-name package))
-                     (version (inferior-package-version package))
-                     (output output)
-                     (item package)
-                     (dependencies (delete-duplicates deps))
-                     (search-paths
-                      (inferior-package-transitive-native-search-paths package))
-                     (parent parent)
-                     (properties properties))))
-    entry))
+(define inferior-package->manifest-entry
+  (let ((results vlist-null))
+    (lambda* (package #:optional (output "out")
+                      #:key (parent (delay #f))
+                      (properties '()))
+      "Return a manifest entry for the OUTPUT of package PACKAGE."
+      (or (and=> (vhash-assoc package results) cdr)
+          ;; For each dependency, keep a promise pointing to its "parent" entry.
+          (letrec* ((deps  (map (match-lambda
+                                  ((label package)
+                                   (inferior-package->manifest-entry package
+                                                                     #:parent (delay entry)))
+                                  ((label package output)
+                                   (inferior-package->manifest-entry package output
+                                                                     #:parent (delay entry))))
+                                (inferior-package-propagated-inputs package)))
+                    (entry (manifest-entry
+                             (name (inferior-package-name package))
+                             (version (inferior-package-version package))
+                             (output output)
+                             (item package)
+                             (dependencies (delete-duplicates deps))
+                             (search-paths
+                              (inferior-package-transitive-native-search-paths package))
+                             (parent parent)
+                             (properties properties))))
+            (begin
+              (set! results (vhash-cons package entry results))
+              entry))))))
 
 \f
 ;;;
-- 
2.29.2

[bug#46101] [PATCH 3/4] inferior: Memoize inferior package search path access.

[Ricardo Wurmus]

* guix/inferior.scm (%inferior-package-search-paths): Return memoized
procedure accepting a package.
(inferior-package-native-search-paths, inferior-package-search-paths,
inferior-package-transitive-native-search-paths): Adapt.
---
 guix/inferior.scm | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/guix/inferior.scm b/guix/inferior.scm
index 7bfce5d810..0c85a9ea08 100644
--- a/guix/inferior.scm
+++ b/guix/inferior.scm
@@ -45,6 +45,7 @@
   #:use-module (guix store)
   #:use-module (guix derivations)
   #:use-module (guix base32)
+  #:use-module ((guix memoization) #:select (mlambdaq))
   #:use-module (gcrypt hash)
   #:autoload   (guix cache) (maybe-remove-expired-cache-entries
                              file-expiration-time)
@@ -430,27 +431,28 @@ inferior package."
 (define inferior-package-transitive-propagated-inputs
   (cut inferior-package-input-field <> 'package-transitive-propagated-inputs))
 
-(define (%inferior-package-search-paths package field)
+(define (%inferior-package-search-paths field)
   "Return the list of search path specifications of PACKAGE, an inferior
 package."
-  (define paths
-    (inferior-package-field package
-                            `(compose (lambda (paths)
-                                        (map (@ (guix search-paths)
-                                                search-path-specification->sexp)
-                                             paths))
-                                      ,field)))
+  (mlambdaq (package)
+    (define paths
+      (inferior-package-field package
+                              `(compose (lambda (paths)
+                                          (map (@ (guix search-paths)
+                                                  search-path-specification->sexp)
+                                               paths))
+                                        ,field)))
 
-  (map sexp->search-path-specification paths))
+    (map sexp->search-path-specification paths)))
 
 (define inferior-package-native-search-paths
-  (cut %inferior-package-search-paths <> 'package-native-search-paths))
+  (%inferior-package-search-paths 'package-native-search-paths))
 
 (define inferior-package-search-paths
-  (cut %inferior-package-search-paths <> 'package-search-paths))
+  (%inferior-package-search-paths 'package-search-paths))
 
 (define inferior-package-transitive-native-search-paths
-  (cut %inferior-package-search-paths <> 'package-transitive-native-search-paths))
+  (%inferior-package-search-paths 'package-transitive-native-search-paths))
 
 (define (inferior-package-provenance package)
   "Return a \"provenance sexp\" for PACKAGE, an inferior package.  The result
-- 
2.29.2

[bug#46100] [PATCH 4/4] inferior: Memoize package input field access.

[Ricardo Wurmus]

From: Ludovic Courtès <ludo@gnu.org>

* guix/inferior.scm (inferior-package-input-field): Return memoized procedure
accepting a package.
(inferior-package-inputs, inferior-package-native-inputs,
inferior-package-propagated-inputs,
inferior-package-transitive-propagated-inputs): Adapt.
---
 guix/inferior.scm | 71 ++++++++++++++++++++++++-----------------------
 1 file changed, 36 insertions(+), 35 deletions(-)

diff --git a/guix/inferior.scm b/guix/inferior.scm
index 0c85a9ea08..b5e8939a1d 100644
--- a/guix/inferior.scm
+++ b/guix/inferior.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2018, 2019, 2020 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2018, 2019, 2020, 2021 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2021 Ricardo Wurmus <rekado@elephly.net>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -386,50 +386,51 @@ record."
                                              loc)))
                                      package-location))))
 
-(define (inferior-package-input-field package field)
+(define (inferior-package-input-field field)
   "Return the input field FIELD (e.g., 'native-inputs') of PACKAGE, an
 inferior package."
-  (define field*
-    `(compose (lambda (inputs)
-                (map (match-lambda
-                       ;; XXX: Origins are not handled.
-                       ((label (? package? package) rest ...)
-                        (let ((id (object-address package)))
-                          (hashv-set! %package-table id package)
-                          `(,label (package ,id
-                                            ,(package-name package)
-                                            ,(package-version package))
-                                   ,@rest)))
-                       (x
-                        x))
-                     inputs))
-              ,field))
-
-  (define inputs
-    (inferior-package-field package field*))
-
-  (define inferior
-    (inferior-package-inferior package))
-
-  (map (match-lambda
-         ((label ('package id name version) . rest)
-          ;; XXX: eq?-ness of inferior packages is not preserved here.
-          `(,label ,(inferior-package inferior name version id)
-                   ,@rest))
-         (x x))
-       inputs))
+  (mlambdaq (package)
+    (define field*
+      `(compose (lambda (inputs)
+                  (map (match-lambda
+                         ;; XXX: Origins are not handled.
+                         ((label (? package? package) rest ...)
+                          (let ((id (object-address package)))
+                            (hashv-set! %package-table id package)
+                            `(,label (package ,id
+                                              ,(package-name package)
+                                              ,(package-version package))
+                                     ,@rest)))
+                         (x
+                          x))
+                       inputs))
+                ,field))
+
+    (define inputs
+      (inferior-package-field package field*))
+
+    (define inferior
+      (inferior-package-inferior package))
+
+    (map (match-lambda
+           ((label ('package id name version) . rest)
+            ;; XXX: eq?-ness of inferior packages is not preserved here.
+            `(,label ,(inferior-package inferior name version id)
+                     ,@rest))
+           (x x))
+         inputs)))
 
 (define inferior-package-inputs
-  (cut inferior-package-input-field <> 'package-inputs))
+  (inferior-package-input-field 'package-inputs))
 
 (define inferior-package-native-inputs
-  (cut inferior-package-input-field <> 'package-native-inputs))
+  (inferior-package-input-field 'package-native-inputs))
 
 (define inferior-package-propagated-inputs
-  (cut inferior-package-input-field <> 'package-propagated-inputs))
+  (inferior-package-input-field 'package-propagated-inputs))
 
 (define inferior-package-transitive-propagated-inputs
-  (cut inferior-package-input-field <> 'package-transitive-propagated-inputs))
+  (inferior-package-input-field 'package-transitive-propagated-inputs))
 
 (define (%inferior-package-search-paths field)
   "Return the list of search path specifications of PACKAGE, an inferior
-- 
2.29.2

[bug#46100] [PATCH 0/4] Memoize inferior package access.

[Ludovic Courtès]

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Hi!

Thanks for digging into this!

Ricardo Wurmus <rekado@elephly.net> skribis:

> +(define inferior-package->manifest-entry
> +  (let ((results vlist-null))
> +    (lambda* (package #:optional (output "out")
> +                      #:key (parent (delay #f))
> +                      (properties '()))
> +      "Return a manifest entry for the OUTPUT of package PACKAGE."
> +      (or (and=> (vhash-assoc package results) cdr)

There’s a catch here: OUTPUT should be taken into account.

Also it’s better to use eq?-ness but… I realized
‘inferior-package-inputs’ & co. do not preserve eq?-ness.

So I came up with the attached patch, which addresses these two issues.

For me the ‘packages->manifest’ phase goes from 13s to 2.5s (19s to 4.6s
for the whole script), which is still a lot, but that was without the
other patches.

Thoughts?

Ludo’.


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diff --git a/guix/inferior.scm b/guix/inferior.scm
index 2fe91beaab..91bbb5aa70 100644
--- a/guix/inferior.scm
+++ b/guix/inferior.scm
@@ -109,13 +109,14 @@
 
 ;; Inferior Guix process.
 (define-record-type <inferior>
-  (inferior pid socket close version packages table)
+  (inferior pid socket close version packages id-table table)
   inferior?
   (pid      inferior-pid)
   (socket   inferior-socket)
   (close    inferior-close-socket)               ;procedure
   (version  inferior-version)                    ;REPL protocol version
   (packages inferior-package-promise)            ;promise of inferior packages
+  (id-table inferior-package-id-table)           ;promise of vhash
   (table    inferior-package-table))             ;promise of vhash
 
 (define* (inferior-pipe directory command error-port)
@@ -160,6 +161,7 @@ inferior."
     (('repl-version 0 rest ...)
      (letrec ((result (inferior 'pipe pipe close (cons 0 rest)
                                 (delay (%inferior-packages result))
+                                (delay (%inferior-package-id-table result))
                                 (delay (%inferior-package-table result)))))
 
        ;; For protocol (0 1) and later, send the protocol version we support.
@@ -295,6 +297,18 @@ Raise '&inferior-exception' when an exception is read from PORT."
             (inferior-package inferior name version id)))
          result)))
 
+(define (%inferior-package-id-table inferior)
+  (fold (lambda (package table)
+          (vhash-consv (inferior-package-id package) package
+                       table))
+        vlist-null
+        (inferior-packages inferior)))
+
+(define (lookup-inferior-package-by-id inferior id)
+  (match (vhash-assv id (force (inferior-package-id-table inferior)))
+    (#f #f)
+    ((_ . package) package)))
+
 (define (inferior-packages inferior)
   "Return the list of packages known to INFERIOR."
   (force (inferior-package-promise inferior)))
@@ -412,8 +426,10 @@ inferior package."
 
   (map (match-lambda
          ((label ('package id name version) . rest)
-          ;; XXX: eq?-ness of inferior packages is not preserved here.
-          `(,label ,(inferior-package inferior name version id)
+          ;; XXX: eq?-ness of inferior packages is preserved, unless the
+          ;; package is not public.
+          `(,label ,(or (lookup-inferior-package-by-id inferior id)
+                        (inferior-package inferior name version id))
                    ,@rest))
          (x x))
        inputs))
@@ -642,29 +658,50 @@ failing when GUIX is too old and lacks the 'guix repl' command."
 
 (define* (inferior-package->manifest-entry package
                                            #:optional (output "out")
-                                           #:key (parent (delay #f))
-                                           (properties '()))
+                                           #:key (properties '()))
   "Return a manifest entry for the OUTPUT of package PACKAGE."
   ;; For each dependency, keep a promise pointing to its "parent" entry.
-  (letrec* ((deps  (map (match-lambda
-                          ((label package)
-                           (inferior-package->manifest-entry package
-                                                             #:parent (delay entry)))
-                          ((label package output)
-                           (inferior-package->manifest-entry package output
-                                                             #:parent (delay entry))))
-                        (inferior-package-propagated-inputs package)))
-            (entry (manifest-entry
-                     (name (inferior-package-name package))
-                     (version (inferior-package-version package))
-                     (output output)
-                     (item package)
-                     (dependencies (delete-duplicates deps))
-                     (search-paths
-                      (inferior-package-transitive-native-search-paths package))
-                     (parent parent)
-                     (properties properties))))
-    entry))
+  (define cache
+    (make-hash-table))
+
+  (define-syntax-rule (memoized package output exp)
+    (let ((compute (lambda () exp)))
+      (match (hashq-ref cache package)
+        (#f
+         (let ((result (compute)))
+           (hashq-set! cache package `((,output . ,result)))
+           result))
+        (alist
+         (match (assoc-ref alist output)
+           (#f
+            (let ((result (compute)))
+              (hashq-set! cache package
+                          `((, output . ,result) ,@alist))
+              result))
+           (result
+            result))))))
+
+  (let loop ((package package)
+             (output  output)
+             (parent  (delay #f)))
+    (memoized package output
+      (letrec* ((deps  (map (match-lambda
+                              ((label package)
+                               (loop package "out" (delay entry)))
+                              ((label package output)
+                               (loop package output (delay entry))))
+                            (inferior-package-propagated-inputs package)))
+                (entry (manifest-entry
+                         (name (inferior-package-name package))
+                         (version (inferior-package-version package))
+                         (output output)
+                         (item package)
+                         (dependencies (delete-duplicates deps))
+                         (search-paths
+                          (inferior-package-transitive-native-search-paths package))
+                         (parent parent)
+                         (properties properties))))
+        entry))))
 
 \f
 ;;;
@@ -750,3 +787,7 @@ This is a convenience procedure that people may use in manifests passed to
                                #:cache-directory cache-directory
                                #:ttl ttl)))
   (open-inferior cached))
+
+;;; Local Variables:
+;;; eval: (put 'memoized 'scheme-indent-function 1)
+;;; End:
diff --git a/tests/inferior.scm b/tests/inferior.scm
index 7c3d730d0c..ddfae8236d 100644
--- a/tests/inferior.scm
+++ b/tests/inferior.scm
@@ -195,6 +195,25 @@
     (close-inferior inferior)
     result))
 
+(test-assert "inferior-package-inputs & pointer identity"
+  (let* ((inferior (open-inferior %top-builddir
+                                  #:command "scripts/guix"))
+         (lookup       (lambda (name)
+                         (first (lookup-inferior-packages inferior name))))
+         (guile-gcrypt (lookup "guile-gcrypt"))
+         (libgcrypt    (lookup "libgcrypt"))
+         (pkg-config   (lookup "pkg-config")))
+    (define (input name)
+      (match (assoc name (inferior-package-inputs guile-gcrypt))
+        ((label package . _) package)))
+
+    (and (eq? libgcrypt
+              (car (assoc-ref (inferior-package-inputs guile-gcrypt)
+                              "libgcrypt")))
+         (eq? pkg-config
+              (car (assoc-ref (inferior-package-native-inputs guile-gcrypt)
+                              "pkg-config"))))))
+
 (test-equal "inferior-package-search-paths"
   (package-native-search-paths guile-3.0)
   (let* ((inferior (open-inferior %top-builddir

[bug#46100] [PATCH 0/4] Memoize inferior package access.

[Ludovic Courtès]

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Ludovic Courtès <ludo@gnu.org> skribis:

> There’s a catch here: OUTPUT should be taken into account.
>
> Also it’s better to use eq?-ness but… I realized
> ‘inferior-package-inputs’ & co. do not preserve eq?-ness.

I think I went overboard here: given that <inferior-package> is a simple
flat record type, using ‘equal?’/‘hash-ref’ is reasonable and that way
we avoid the troubles of building an ID-to-package table.  All in all
it’s slightly more efficient.

WDYT?

Ludo’.


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diff --git a/guix/inferior.scm b/guix/inferior.scm
index 2fe91beaab..d813b3b918 100644
--- a/guix/inferior.scm
+++ b/guix/inferior.scm
@@ -642,29 +642,41 @@ failing when GUIX is too old and lacks the 'guix repl' command."
 
 (define* (inferior-package->manifest-entry package
                                            #:optional (output "out")
-                                           #:key (parent (delay #f))
-                                           (properties '()))
+                                           #:key (properties '()))
   "Return a manifest entry for the OUTPUT of package PACKAGE."
   ;; For each dependency, keep a promise pointing to its "parent" entry.
-  (letrec* ((deps  (map (match-lambda
-                          ((label package)
-                           (inferior-package->manifest-entry package
-                                                             #:parent (delay entry)))
-                          ((label package output)
-                           (inferior-package->manifest-entry package output
-                                                             #:parent (delay entry))))
-                        (inferior-package-propagated-inputs package)))
-            (entry (manifest-entry
-                     (name (inferior-package-name package))
-                     (version (inferior-package-version package))
-                     (output output)
-                     (item package)
-                     (dependencies (delete-duplicates deps))
-                     (search-paths
-                      (inferior-package-transitive-native-search-paths package))
-                     (parent parent)
-                     (properties properties))))
-    entry))
+  (define cache
+    (make-hash-table))
+
+  (define-syntax-rule (memoized package output exp)
+    (let ((compute (lambda () exp))
+          (key     (cons package output)))
+      (or (hash-ref cache key)
+          (let ((result (compute)))
+            (hash-set! cache key result)
+            result))))
+
+  (let loop ((package package)
+             (output  output)
+             (parent  (delay #f)))
+    (memoized package output
+      (letrec* ((deps  (map (match-lambda
+                              ((label package)
+                               (loop package "out" (delay entry)))
+                              ((label package output)
+                               (loop package output (delay entry))))
+                            (inferior-package-propagated-inputs package)))
+                (entry (manifest-entry
+                         (name (inferior-package-name package))
+                         (version (inferior-package-version package))
+                         (output output)
+                         (item package)
+                         (dependencies (delete-duplicates deps))
+                         (search-paths
+                          (inferior-package-transitive-native-search-paths package))
+                         (parent parent)
+                         (properties properties))))
+        entry))))
 
 \f
 ;;;
@@ -750,3 +762,7 @@ This is a convenience procedure that people may use in manifests passed to
                                #:cache-directory cache-directory
                                #:ttl ttl)))
   (open-inferior cached))
+
+;;; Local Variables:
+;;; eval: (put 'memoized 'scheme-indent-function 1)
+;;; End:

[bug#46100] [PATCH 0/4] Memoize inferior package access.

[Ricardo Wurmus]

Ludovic Courtès <ludo@gnu.org> writes:

> Ludovic Courtès <ludo@gnu.org> skribis:
>
>> There’s a catch here: OUTPUT should be taken into account.
>>
>> Also it’s better to use eq?-ness but… I realized
>> ‘inferior-package-inputs’ & co. do not preserve eq?-ness.
>
> I think I went overboard here: given that <inferior-package> is a simple
> flat record type, using ‘equal?’/‘hash-ref’ is reasonable and that way
> we avoid the troubles of building an ID-to-package table.  All in all
> it’s slightly more efficient.

This looks good to me.

It is very similar to my first version (which I didn’t send to the
list), which also built a key consisting of the arguments to
inferior-package->manifest-entry — I wasn’t sure which of them was
important so I used them all instead of just consing package and
output.

I also like the use of define-syntax-rule to make it all look neater.


-- 
Ricardo

[bug#46100] [PATCH 0/4] Memoize inferior package access.

[Ludovic Courtès]

Ricardo Wurmus <rekado@elephly.net> skribis:

> Ludovic Courtès <ludo@gnu.org> writes:
>
>> Ludovic Courtès <ludo@gnu.org> skribis:
>>
>>> There’s a catch here: OUTPUT should be taken into account.
>>>
>>> Also it’s better to use eq?-ness but… I realized
>>> ‘inferior-package-inputs’ & co. do not preserve eq?-ness.
>>
>> I think I went overboard here: given that <inferior-package> is a simple
>> flat record type, using ‘equal?’/‘hash-ref’ is reasonable and that way
>> we avoid the troubles of building an ID-to-package table.  All in all
>> it’s slightly more efficient.
>
> This looks good to me.
>
> It is very similar to my first version (which I didn’t send to the
> list), which also built a key consisting of the arguments to
> inferior-package->manifest-entry — I wasn’t sure which of them was
> important so I used them all instead of just consing package and
> output.
>
> I also like the use of define-syntax-rule to make it all look neater.

I pushed it as 0f20b3fa2050ba6e442e340a204516b9375cd231.

I wonder if the other patches improve the situation.  If you run the
same test case with:

  GUIX_PROFILING=memoization

what hit rates does it show for these spots?

Thanks,
Ludo’.

[bug#46100] [PATCH 0/4] Memoize inferior package access.

[Ricardo Wurmus]

Ludovic Courtès <ludo@gnu.org> writes:

> I pushed it as 0f20b3fa2050ba6e442e340a204516b9375cd231.

Thanks!

> I wonder if the other patches improve the situation.  If you run the
> same test case with:
>
>   GUIX_PROFILING=memoization
>
> what hit rates does it show for these spots?

Memoization: 15 tables, 2 non-empty
  guix/inferior.scm:438:2: 	403 entries, 403 lookups, 0% hits
  guix/inferior.scm:392:2: 	403 entries, 403 lookups, 0% hits

So, I guess we can drop those two patches.

-- 
Ricardo

bug#46100: [PATCH 0/4] Memoize inferior package access.

[Ludovic Courtès]

Ricardo Wurmus <rekado@elephly.net> skribis:

> Ludovic Courtès <ludo@gnu.org> writes:
>
>> I pushed it as 0f20b3fa2050ba6e442e340a204516b9375cd231.
>
> Thanks!
>
>> I wonder if the other patches improve the situation.  If you run the
>> same test case with:
>>
>>   GUIX_PROFILING=memoization
>>
>> what hit rates does it show for these spots?
>
> Memoization: 15 tables, 2 non-empty
>   guix/inferior.scm:438:2: 	403 entries, 403 lookups, 0% hits
>   guix/inferior.scm:392:2: 	403 entries, 403 lookups, 0% hits
>
> So, I guess we can drop those two patches.

Looks like it.  :-)

Closing!

Thanks,
Ludo’.