store-copy: 'populate-store' can optionally deduplicate files.

Until now deduplication was performed as an additional pass after
copying files, which involve re-traversing all the files that had just
been copied.

* guix/store/deduplication.scm (copy-file/deduplicate): New procedure.
* tests/store-deduplication.scm ("copy-file/deduplicate"): New test.
* guix/build/store-copy.scm (populate-store): Add #:deduplicate?
parameter and honor it.
* tests/gexp.scm ("gexp->derivation, store copy"): Pass #:deduplicate? #f
to 'populate-store'.
* gnu/build/image.scm (initialize-root-partition): Pass #:deduplicate?
to 'populate-store'.  Pass #:deduplicate? #f to 'register-closure'.
* gnu/build/vm.scm (root-partition-initializer): Likewise.
* gnu/build/install.scm (populate-single-profile-directory): Pass
 #:deduplicate? #f to 'populate-store'.
* gnu/build/linux-initrd.scm (build-initrd): Likewise.
* guix/scripts/pack.scm (self-contained-tarball)[import-module?]: New
procedure.
[build]: Pass it as an argument to 'source-module-closure'.
* guix/scripts/pack.scm (squashfs-image)[build]: Wrap in
'with-extensions'.
* gnu/system/linux-initrd.scm (expression->initrd)[import-module?]: New
procedure.
[builder]: Pass it to 'source-module-closure'.
* gnu/system/install.scm (cow-store-service-type)[import-module?]: New
procedure.  Pass it to 'source-module-closure'.

1 files changed, 11 insertions, 2 deletions

diff --git a/guix/build/store-copy.scm b/guix/build/store-copy.scm
index 95dcb8e114..7f0672cd9d 100644
--- a/guix/build/store-copy.scm
+++ b/guix/build/store-copy.scm
@@ -20,6 +20,7 @@
   #:use-module ((guix build utils) #:hide (copy-recursively))
   #:use-module (guix sets)
   #:use-module (guix progress)
+  #:autoload   (guix store deduplication) (copy-file/deduplicate)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-9)
   #:use-module (srfi srfi-26)
@@ -242,10 +243,13 @@ permissions.  Write verbose output to the LOG port."
                         lstat)))
 
 (define* (populate-store reference-graphs target
-                         #:key (log-port (current-error-port)))
+                         #:key
+                         (deduplicate? #t)
+                         (log-port (current-error-port)))
   "Populate the store under directory TARGET with the items specified in
 REFERENCE-GRAPHS, a list of reference-graph files.  Items copied to TARGET
-maintain timestamps and permissions."
+maintain timestamps and permissions.  When DEDUPLICATE? is true, deduplicate
+regular files as they are copied to TARGET."
   (define store
     (string-append target (%store-directory)))
 
@@ -273,6 +277,11 @@ maintain timestamps and permissions."
                                       (string-append target thing)
                                       #:keep-mtime? #t
                                       #:keep-permissions? #t
+                                      #:copy-file
+                                      (if deduplicate?
+                                          (cut copy-file/deduplicate <> <>
+                                               #:store store)
+                                          copy-file)
                                       #:log (%make-void-port "w"))
                     (report))
                   things)))))