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| author | Ludovic Courtès <ludo@gnu.org> | 2020-12-10 11:21:14 +0100 |
|---|---|---|
| committer | Ludovic Courtès <ludo@gnu.org> | 2020-12-15 17:32:09 +0100 |
| commit | 2718c29c3fb9f9de2ec897248ad49ae11ca39b7a (patch) | |
| tree | 6698852d62943afa23f01f8fbeec8033db9c7ef7 /guix/serialization.scm | |
| parent | ed7d02f7c198970ce3fe94bcee47592963326446 (diff) | |
| download | guix-2718c29c3fb9f9de2ec897248ad49ae11ca39b7a.tar guix-2718c29c3fb9f9de2ec897248ad49ae11ca39b7a.tar.gz | |
nar: Deduplicate files right as they are restored.
This avoids having to traverse and re-read the files that we have just
restored, thereby reducing I/O.
* guix/serialization.scm (dump-file): New procedure.
(restore-file): Add #:dump-file parameter and honor it.
* guix/store/deduplication.scm (tee, dump-file/deduplicate): New
procedures.
* guix/nar.scm (restore-one-item): Pass #:dump-file to 'restore-file'.
(finalize-store-file): Pass #:deduplicate? #f to 'register-items'.
* tests/nar.scm <top level>: Call 'setenv' to set "NIX_STORE".
Diffstat (limited to 'guix/serialization.scm')
| -rw-r--r-- | guix/serialization.scm | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/guix/serialization.scm b/guix/serialization.scm index 677ca60b66..9e2dce8bb0 100644 --- a/guix/serialization.scm +++ b/guix/serialization.scm @@ -457,9 +457,22 @@ depends on TYPE." (&message (message "unsupported nar entry type")) (&nar-read-error (port port) (file file) (token x))))))))) -(define (restore-file port file) +(define (dump-file file input size type) + "Dump SIZE bytes from INPUT to FILE." + (call-with-output-file file + (lambda (output) + (dump input output size)))) + +(define* (restore-file port file + #:key (dump-file dump-file)) "Read a file (possibly a directory structure) in Nar format from PORT. -Restore it as FILE with canonical permissions and timestamps." +Restore it as FILE with canonical permissions and timestamps. To write a +regular or executable file, call: + + (DUMP-FILE FILE INPUT SIZE TYPE) + +The default is to dump SIZE bytes from INPUT to FILE, but callers can provide +a custom procedure, for instance to deduplicate FILE on the fly." (fold-archive (lambda (file type content result) (match type ('directory @@ -473,12 +486,10 @@ Restore it as FILE with canonical permissions and timestamps." ((or 'regular 'executable) (match content ((input . size) - (call-with-output-file file - (lambda (output) - (dump input output size) - (chmod output (if (eq? type 'executable) - #o555 - #o444)))) + (dump-file file input size type) + (chmod file (if (eq? type 'executable) + #o555 + #o444)) (utime file 1 1 0 0)))))) #t port |