derivations: <derivation-input> now aggregates a <derivation>.

Consequently, the whole graph of <derivation> object is readily
available without having to go through 'read-derivation-from-file',
which could have cache misses if the requested <derivation> object had
been GC'd in the meantime.  This is an important property for the
performance of things like 'derivation-build-plan' that traverse the
derivation graph.

* guix/derivations.scm (<derivation-input>): Replace 'path' field by
'derivation'.
(derivation-input-path): Adjust accordingly.
(derivation-input-key): New procedure.
(derivation-input-output-paths): Adjust accordingly.
(coalesce-duplicate-inputs): Likewise.
(derivation-prerequisites): Use 'derivation-input-key' to compute keys
for INPUT-SET.
(derivation-build-plan): Likewise.
(read-derivation): Add optional 'read-derivation-from-file' parameter.
[make-input-drvs]: Call it.
(write-derivation)[write-input]: Adjust to new <derivation-input>.
(derivation/masked-inputs): Likewise, and remove redundant
'coalesce-duplicate-inputs' call.
(derivation)[input->derivation-input]: Change to consider only the
derivation case.  Update call to 'make-derivation-input'.
[input->source]: New procedure.
Separate sources from inputs.
(map-derivation): Adjust to new <derivation-input>.
* tests/derivations.scm ("parse & export"): Pass a second argument to
'read-derivation'.
("build-expression->derivation and derivation-prerequisites")
("derivation-prerequisites and valid-derivation-input?"): Adjust to new
<derivation-input>.

1 files changed, 6 insertions, 4 deletions

diff --git a/tests/derivations.scm b/tests/derivations.scm
index 35fb20bab0..54fa588969 100644
--- a/tests/derivations.scm
+++ b/tests/derivations.scm
@@ -87,9 +87,11 @@
 (test-assert "parse & export"
   (let* ((f  (search-path %load-path "tests/test.drv"))
          (b1 (call-with-input-file f get-bytevector-all))
-         (d1 (read-derivation (open-bytevector-input-port b1)))
+         (d1 (read-derivation (open-bytevector-input-port b1)
+                              identity))
          (b2 (call-with-bytevector-output-port (cut write-derivation d1 <>)))
-         (d2 (read-derivation (open-bytevector-input-port b2))))
+         (d2 (read-derivation (open-bytevector-input-port b2)
+                              identity)))
     (and (equal? b1 b2)
          (equal? d1 d2))))
 
@@ -724,7 +726,7 @@
 (test-assert "build-expression->derivation and derivation-prerequisites"
   (let ((drv (build-expression->derivation %store "fail" #f)))
     (any (match-lambda
-          (($ <derivation-input> path)
+          (($ <derivation-input> (= derivation-file-name path))
            (string=? path (derivation-file-name (%guile-for-build)))))
          (derivation-prerequisites drv))))
 
@@ -741,7 +743,7 @@
     (match (derivation-prerequisites c
                                      (cut valid-derivation-input? %store
                                           <>))
-      ((($ <derivation-input> file ("out")))
+      ((($ <derivation-input> (= derivation-file-name file) ("out")))
        (string=? file (derivation-file-name b)))
       (x
        (pk 'fail x #f)))))