[PATCH v3 3/5] compact: preserve backup database until compacted database is in place

diff --git a/fa/4121bba3a5f5829b95f72332dbf83a8e578605 b/fa/4121bba3a5f5829b95f72332dbf83a8e578605
new file mode 100644 (file)
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--- /dev/null
+++ b/fa/4121bba3a5f5829b95f72332dbf83a8e578605
@@ -0,0 +1,171 @@
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+From: Tomi Ollila <tomi.ollila@iki.fi>\r
+To: notmuch@notmuchmail.org\r
+Subject: [PATCH v3 3/5] compact: preserve backup database until compacted\r
+       database is in place\r
+Date: Fri, 15 Nov 2013 00:03:25 +0200\r
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+Cc: tomi.ollila@iki.fi\r
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+\r
+It is less error prone and window of failure opportunity is smaller\r
+if the old (backup) database is always renamed (instead of sometimes\r
+rmtree'd) before new (compacted) database is put into its place.\r
+Finally rmtree() old database in case old database backup is not kept.\r
+---\r
+\r
+The patches 3-5 in this series are updated based on Jani's comments.\r
+\r
+I've kept the fprintf(stderr,...)'s due to reasons explained in\r
+\r
+id:m28uwquccd.fsf@guru.guru-group.fi\r
+\r
+Diff v2-v3 for first (3/5) patch. Second (4/5) has just // -> /* .. */ change.\r
+\r
+|--- a/lib/database.cc\r
+|+++ b/lib/database.cc\r
+|@@ -906,17 +906,19 @@ notmuch_database_compact (const char *path,\r
+|        }\r
+|        keep_backup = FALSE;\r
+|     }\r
+|-    else\r
+|+    else {\r
+|        keep_backup = TRUE;\r
+|+    }\r
+|\r
+|     if (stat (backup_path, &statbuf) != -1) {\r
+|-       fprintf (stderr, "Backup path already exists: %s\n", backup_path);\r
+|+       fprintf (stderr, "Path already exists: %s\n", backup_path);\r
+|        ret = NOTMUCH_STATUS_FILE_ERROR;\r
+|        goto DONE;\r
+|     }\r
+|     if (errno != ENOENT) {\r
+|-       fprintf (stderr, "Unknown error while stat()ing backup path: %s\n",\r
+|+       fprintf (stderr, "Unknown error while stat()ing path: %s\n",\r
+|                 strerror (errno));\r
+|+       ret = NOTMUCH_STATUS_FILE_ERROR;\r
+|        goto DONE;\r
+|     }\r
+\r
+\r
+\r
+\r
+ lib/database.cc | 44 +++++++++++++++++++++++++++-----------------\r
+ 1 file changed, 27 insertions(+), 17 deletions(-)\r
+\r
+diff --git a/lib/database.cc b/lib/database.cc\r
+index 3530cb6..d79cc30 100644\r
+--- a/lib/database.cc\r
++++ b/lib/database.cc\r
+@@ -873,6 +873,7 @@ notmuch_database_compact (const char *path,\r
+     notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;\r
+     notmuch_database_t *notmuch = NULL;\r
+     struct stat statbuf;\r
++    notmuch_bool_t keep_backup;\r
+ \r
+     local = talloc_new (NULL);\r
+     if (! local)\r
+@@ -898,17 +899,27 @@ notmuch_database_compact (const char *path,\r
+       goto DONE;\r
+     }\r
+ \r
+-    if (backup_path != NULL) {\r
+-      if (stat (backup_path, &statbuf) != -1) {\r
+-          fprintf (stderr, "Backup path already exists: %s\n", backup_path);\r
+-          ret = NOTMUCH_STATUS_FILE_ERROR;\r
+-          goto DONE;\r
+-      }\r
+-      if (errno != ENOENT) {\r
+-          fprintf (stderr, "Unknown error while stat()ing backup path: %s\n",\r
+-                   strerror (errno));\r
++    if (backup_path == NULL) {\r
++      if (! (backup_path = talloc_asprintf (local, "%s.old", xapian_path))) {\r
++          ret = NOTMUCH_STATUS_OUT_OF_MEMORY;\r
+           goto DONE;\r
+       }\r
++      keep_backup = FALSE;\r
++    }\r
++    else {\r
++      keep_backup = TRUE;\r
++    }\r
++\r
++    if (stat (backup_path, &statbuf) != -1) {\r
++      fprintf (stderr, "Path already exists: %s\n", backup_path);\r
++      ret = NOTMUCH_STATUS_FILE_ERROR;\r
++      goto DONE;\r
++    }\r
++    if (errno != ENOENT) {\r
++      fprintf (stderr, "Unknown error while stat()ing path: %s\n",\r
++               strerror (errno));\r
++      ret = NOTMUCH_STATUS_FILE_ERROR;\r
++      goto DONE;\r
+     }\r
+ \r
+     try {\r
+@@ -924,14 +935,10 @@ notmuch_database_compact (const char *path,\r
+       goto DONE;\r
+     }\r
+ \r
+-    if (backup_path) {\r
+-      if (rename (xapian_path, backup_path)) {\r
+-          fprintf (stderr, "Error moving old database out of the way\n");\r
+-          ret = NOTMUCH_STATUS_FILE_ERROR;\r
+-          goto DONE;\r
+-      }\r
+-    } else {\r
+-      rmtree (xapian_path);\r
++    if (rename (xapian_path, backup_path)) {\r
++      fprintf (stderr, "Error moving old database out of the way\n");\r
++      ret = NOTMUCH_STATUS_FILE_ERROR;\r
++      goto DONE;\r
+     }\r
+ \r
+     if (rename (compact_xapian_path, xapian_path)) {\r
+@@ -940,6 +947,9 @@ notmuch_database_compact (const char *path,\r
+       goto DONE;\r
+     }\r
+ \r
++    if (! keep_backup)\r
++      rmtree (backup_path);\r
++\r
+   DONE:\r
+     if (notmuch)\r
+       notmuch_database_destroy (notmuch);\r
+-- \r
+1.8.0\r
+\r