From 60b9004cdb106ce56589cbe587b6b5e7d6ad3cf9 Mon Sep 17 00:00:00 2001 From: "Shawn O. Pearce" Date: Wed, 7 Mar 2007 18:05:38 -0500 Subject: [PATCH] Use atomic updates to the fast-import mark file When we allow fast-import frontends to reload a mark file from a prior session we want to let them use the same file as they exported the marks to. This makes it very simple for the frontend to save state across incremental imports. But we don't want to lose the old marks table if anything goes wrong while writing our current marks table. So instead of truncating and overwriting the path specified to --export-marks we use the standard lockfile code to write the current marks out to a temporary file, then rename it over the old marks table. Signed-off-by: Shawn O. Pearce --- fast-import.c | 35 ++++++++++++++++++++++++++--------- 1 file changed, 26 insertions(+), 9 deletions(-) diff --git a/fast-import.c b/fast-import.c index 28f5e7c3b..a09221242 100644 --- a/fast-import.c +++ b/fast-import.c @@ -1375,16 +1375,33 @@ static void dump_marks_helper(FILE *f, static void dump_marks(void) { - if (mark_file) - { - FILE *f = fopen(mark_file, "w"); - if (f) { - dump_marks_helper(f, 0, marks); - fclose(f); - } else - failure |= error("Unable to write marks file %s: %s", - mark_file, strerror(errno)); + static struct lock_file mark_lock; + int mark_fd; + FILE *f; + + if (!mark_file) + return; + + mark_fd = hold_lock_file_for_update(&mark_lock, mark_file, 0); + if (mark_fd < 0) { + failure |= error("Unable to write marks file %s: %s", + mark_file, strerror(errno)); + return; } + + f = fdopen(mark_fd, "w"); + if (!f) { + rollback_lock_file(&mark_lock); + failure |= error("Unable to write marks file %s: %s", + mark_file, strerror(errno)); + return; + } + + dump_marks_helper(f, 0, marks); + fclose(f); + if (commit_lock_file(&mark_lock)) + failure |= error("Unable to write marks file %s: %s", + mark_file, strerror(errno)); } static void read_next_command(void) -- 2.26.2