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| author | Ludovic Courtès <ludo@gnu.org> | 2013-09-02 23:03:03 +0200 |
|---|---|---|
| committer | Ludovic Courtès <ludo@gnu.org> | 2013-09-02 23:04:25 +0200 |
| commit | 43dd92024ab54921fbf85285d04344cb2c6e77cc (patch) | |
| tree | 802ce4e8c2eab83358c0f1cd95373bd49ec76440 | |
| parent | 165fd9d5e628120a8355aec2d03f0b6f497d3db2 (diff) | |
| download | guix-43dd92024ab54921fbf85285d04344cb2c6e77cc.tar.gz | |
union: Don't traverse sub-directories only found in one element of the union.
This significantly reduces I/O when building profiles, especially with
lots of package-specific sub-directories (such as 'share/emacs/24.3',
'texmf', etc.)
* guix/build/union.scm (union-build)[file-tree](others-have-it?): New
procedure. Use it in the 'enter?' parameter of 'file-system-fold';
change 'skip' parameter accordingly.
* tests/union.scm ("union-build"): Ensure that 'include' is a symlink
and 'bin' is a directory.
| -rw-r--r-- | guix/build/union.scm | 29 | ||||
| -rw-r--r-- | tests/union.scm | 12 |
2 files changed, 36 insertions, 5 deletions
diff --git a/guix/build/union.scm b/guix/build/union.scm index 275746d83e..077b7fe530 100644 --- a/guix/build/union.scm +++ b/guix/build/union.scm @@ -105,7 +105,22 @@ single leaf." the DIRECTORIES." (define (file-tree dir) ;; Return the contents of DIR as a tree. - (match (file-system-fold (const #t) + + (define (others-have-it? subdir) + ;; Return #t if other elements of DIRECTORIES have SUBDIR. + (let ((subdir (substring subdir (string-length dir)))) + (any (lambda (other) + (and (not (string=? other dir)) + (file-exists? (string-append other "/" subdir)))) + directories))) + + (match (file-system-fold (lambda (subdir stat result) ; enter? + ;; No need to traverse DIR since there's + ;; nothing to union it with. Thus, we avoid + ;; creating a gazillon symlinks (think + ;; share/emacs/24.3, share/texmf, etc.) + (or (string=? subdir dir) + (others-have-it? subdir))) (lambda (file stat result) ; leaf (match result (((siblings ...) rest ...) @@ -117,7 +132,12 @@ the DIRECTORIES." (((leaves ...) (siblings ...) rest ...) `(((,(basename dir) ,@leaves) ,@siblings) ,@rest)))) - (const #f) ; skip + (lambda (dir stat result) ; skip + ;; DIR is not available elsewhere, so treat it + ;; as a leaf. + (match result + (((siblings ...) rest ...) + `((,dir ,@siblings) ,@rest)))) (lambda (file stat errno result) (format (current-error-port) "union-build: ~a: ~a~%" file (strerror errno))) @@ -158,8 +178,9 @@ the DIRECTORIES." (mkdir output) (let loop ((tree (delete-duplicate-leaves (cons "." - (tree-union (append-map (compose tree-leaves file-tree) - directories))) + (tree-union + (append-map (compose tree-leaves file-tree) + (delete-duplicates directories)))) leaf=? resolve-collision)) (dir '())) diff --git a/tests/union.scm b/tests/union.scm index 9816882101..6287cffc38 100644 --- a/tests/union.scm +++ b/tests/union.scm @@ -114,7 +114,17 @@ (file-exists? "bin/ld") (file-exists? "lib/libc.so") (directory-exists? "lib/gcc") - (file-exists? "include/unistd.h")))))) + (file-exists? "include/unistd.h") + + ;; The 'include' sub-directory is only found in + ;; glibc-bootstrap, so it should be unified in a + ;; straightforward way, without traversing it. + (eq? 'symlink (stat:type (lstat "include"))) + + ;; Conversely, several inputs have a 'bin' sub-directory, so + ;; unifying it requires traversing them all, and creating a + ;; new 'bin' sub-directory in the profile. + (eq? 'directory (stat:type (lstat "bin")))))))) (test-end) |