git: Increase modularity and expose 'update-cached-checkout'.

* guix/git.scm (repository->head-sha1, copy-to-store): Remove.
(switch-to-ref): Return the OID of OBJ.
(update-cached-checkout): New procedure, with code from
'latest-repository-commit'.
(latest-repository-commit): Use it.
This commit is contained in:
Ludovic Courtès 2018-04-02 23:11:07 +02:00
parent 576f245c2d
commit 9188198692
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@ -28,9 +28,11 @@
#:use-module (rnrs bytevectors)
#:use-module (ice-9 match)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-11)
#:use-module (srfi srfi-34)
#:use-module (srfi srfi-35)
#:export (%repository-cache-directory
update-cached-checkout
latest-repository-commit))
(define %repository-cache-directory
@ -68,11 +70,6 @@ make sure no empty directory is left behind."
(lambda _
(false-if-exception (rmdir directory)))))
(define (repository->head-sha1 repo)
"Return the sha1 of the HEAD commit in REPOSITORY as a string."
(let ((oid (reference-target (repository-head repo))))
(oid->string (commit-id (commit-lookup repo oid)))))
(define (url+commit->name url sha1)
"Return the string \"<REPO-NAME>-<SHA1:7>\" where REPO-NAME is the name of
the git repository, extracted from URL and SHA1:7 the seven first digits
@ -82,21 +79,9 @@ of SHA1 string."
(last (string-split url #\/)) ".git" "")
"-" (string-take sha1 7)))
(define* (copy-to-store store cache-directory #:key url repository)
"Copy CACHE-DIRECTORY recursively to STORE. URL and REPOSITORY are used to
create the store directory name."
(define (dot-git? file stat)
(and (string=? (basename file) ".git")
(eq? 'directory (stat:type stat))))
(let* ((commit (repository->head-sha1 repository))
(name (url+commit->name url commit)))
(values (add-to-store store name #t "sha256" cache-directory
#:select? (negate dot-git?))
commit)))
(define (switch-to-ref repository ref)
"Switch to REPOSITORY's branch, commit or tag specified by REF."
"Switch to REPOSITORY's branch, commit or tag specified by REF. Return the
OID (roughly the commit hash) corresponding to REF."
(define obj
(match ref
(('branch . branch)
@ -122,7 +107,38 @@ create the store directory name."
(string-append "refs/tags/" tag))))
(object-lookup repository oid)))))
(reset repository obj RESET_HARD))
(reset repository obj RESET_HARD)
(object-id obj))
(define* (update-cached-checkout url
#:key
(ref '(branch . "origin/master"))
(cache-directory
(%repository-cache-directory)))
"Update the cached checkout of URL to REF in CACHE-DIRECTORY. Return two
values: the cache directory name, and the SHA1 commit (a string) corresponding
to REF.
REF is pair whose key is [branch | commit | tag] and value the associated
data, respectively [<branch name> | <sha1> | <tag name>]."
(with-libgit2
(let* ((cache-dir (url-cache-directory url cache-directory))
(cache-exists? (openable-repository? cache-dir))
(repository (if cache-exists?
(repository-open cache-dir)
(clone* url cache-dir))))
;; Only fetch remote if it has not been cloned just before.
(when cache-exists?
(remote-fetch (remote-lookup repository "origin")))
(let ((oid (switch-to-ref repository ref)))
;; Reclaim file descriptors and memory mappings associated with
;; REPOSITORY as soon as possible.
(when (module-defined? (resolve-interface '(git repository))
'repository-close!)
(repository-close! repository))
(values cache-dir (oid->string oid))))))
(define* (latest-repository-commit store url
#:key
@ -137,23 +153,16 @@ data, respectively [<branch name> | <sha1> | <tag name>].
Git repositories are kept in the cache directory specified by
%repository-cache-directory parameter."
(with-libgit2
(let* ((cache-dir (url-cache-directory url cache-directory))
(cache-exists? (openable-repository? cache-dir))
(repository (if cache-exists?
(repository-open cache-dir)
(clone* url cache-dir))))
;; Only fetch remote if it has not been cloned just before.
(when cache-exists?
(remote-fetch (remote-lookup repository "origin")))
(switch-to-ref repository ref)
(define (dot-git? file stat)
(and (string=? (basename file) ".git")
(eq? 'directory (stat:type stat))))
;; Reclaim file descriptors and memory mappings associated with
;; REPOSITORY as soon as possible.
(when (module-defined? (resolve-interface '(git repository))
'repository-close!)
(repository-close! repository))
(copy-to-store store cache-dir
#:url url
#:repository repository))))
(let*-values (((checkout commit)
(update-cached-checkout url
#:ref ref
#:cache-directory cache-directory))
((name)
(url+commit->name url commit)))
(values (add-to-store store name #t "sha256" checkout
#:select? (negate dot-git?))
commit)))