From: Tomi Ollila <tomi.ollila@iki.fi>
Date: Wed, 13 Nov 2013 17:02:45 +0000 (+0200)
Subject: [PATCH v2 3/5] compact: preserve backup database until compacted database is in place
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=afab4bc6e9844afe4d2d44b83e5c4a46e31d2b54;p=notmuch-archives.git

[PATCH v2 3/5] compact: preserve backup database until compacted database is in place
---

diff --git a/bd/934a041d1ed492696104cccae9b9fc0368bc17 b/bd/934a041d1ed492696104cccae9b9fc0368bc17
new file mode 100644
index 000000000..c8a81ee87
--- /dev/null
+++ b/bd/934a041d1ed492696104cccae9b9fc0368bc17
@@ -0,0 +1,132 @@
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+From: Tomi Ollila <tomi.ollila@iki.fi>
+To: notmuch@notmuchmail.org
+Subject: [PATCH v2 3/5] compact: preserve backup database until compacted
+	database is in place
+Date: Wed, 13 Nov 2013 19:02:45 +0200
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+Cc: tomi.ollila@iki.fi
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+
+It is less error prone and window of failure opportunity is smaller
+if the old (backup) database is always renamed (instead of sometimes
+rmtree'd) before new (compacted) database is put into its place.
+Finally rmtree() old database in case old database backup is not kept.
+---
+ lib/database.cc | 42 +++++++++++++++++++++++++-----------------
+ 1 file changed, 25 insertions(+), 17 deletions(-)
+
+diff --git a/lib/database.cc b/lib/database.cc
+index 3530cb6..ee09c5e 100644
+--- a/lib/database.cc
++++ b/lib/database.cc
+@@ -873,6 +873,7 @@ notmuch_database_compact (const char *path,
+     notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
+     notmuch_database_t *notmuch = NULL;
+     struct stat statbuf;
++    notmuch_bool_t keep_backup;
+ 
+     local = talloc_new (NULL);
+     if (! local)
+@@ -898,17 +899,25 @@ notmuch_database_compact (const char *path,
+ 	goto DONE;
+     }
+ 
+-    if (backup_path != NULL) {
+-	if (stat (backup_path, &statbuf) != -1) {
+-	    fprintf (stderr, "Backup path already exists: %s\n", backup_path);
+-	    ret = NOTMUCH_STATUS_FILE_ERROR;
+-	    goto DONE;
+-	}
+-	if (errno != ENOENT) {
+-	    fprintf (stderr, "Unknown error while stat()ing backup path: %s\n",
+-		     strerror (errno));
++    if (backup_path == NULL) {
++	if (! (backup_path = talloc_asprintf (local, "%s.old", xapian_path))) {
++	    ret = NOTMUCH_STATUS_OUT_OF_MEMORY;
+ 	    goto DONE;
+ 	}
++	keep_backup = FALSE;
++    }
++    else
++	keep_backup = TRUE;
++
++    if (stat (backup_path, &statbuf) != -1) {
++	fprintf (stderr, "Backup path already exists: %s\n", backup_path);
++	ret = NOTMUCH_STATUS_FILE_ERROR;
++	goto DONE;
++    }
++    if (errno != ENOENT) {
++	fprintf (stderr, "Unknown error while stat()ing backup path: %s\n",
++		 strerror (errno));
++	goto DONE;
+     }
+ 
+     try {
+@@ -924,14 +933,10 @@ notmuch_database_compact (const char *path,
+ 	goto DONE;
+     }
+ 
+-    if (backup_path) {
+-	if (rename (xapian_path, backup_path)) {
+-	    fprintf (stderr, "Error moving old database out of the way\n");
+-	    ret = NOTMUCH_STATUS_FILE_ERROR;
+-	    goto DONE;
+-	}
+-    } else {
+-	rmtree (xapian_path);
++    if (rename (xapian_path, backup_path)) {
++	fprintf (stderr, "Error moving old database out of the way\n");
++	ret = NOTMUCH_STATUS_FILE_ERROR;
++	goto DONE;
+     }
+ 
+     if (rename (compact_xapian_path, xapian_path)) {
+@@ -940,6 +945,9 @@ notmuch_database_compact (const char *path,
+ 	goto DONE;
+     }
+ 
++    if (! keep_backup)
++	rmtree (backup_path);
++
+   DONE:
+     if (notmuch)
+ 	notmuch_database_destroy (notmuch);
+-- 
+1.8.3.1
+