Mac TimeMachine File Exclusions

third_party/sqlite/src/src/pager.c

Index: third_party/sqlite/src/src/pager.c
===================================================================
--- third_party/sqlite/src/src/pager.c	(revision 86831)
+++ third_party/sqlite/src/src/pager.c	(working copy)
@@ -429,6 +429,11 @@
 #define MAX_SECTOR_SIZE 0x10000
 
 /*
+** The string appended to the database file name giving the journal file name.
+*/
+static const char kPagerJournalSuffix[] = "-journal";
+
+/*
 ** An instance of the following structure is allocated for each active
 ** savepoint and statement transaction in the system. All such structures
 ** are stored in the Pager.aSavepoint[] array, which is allocated and
@@ -5130,7 +5135,20 @@
   }
 }
 
+#if defined(__APPLE__)
 /*
+** Create and return a CFURLRef given a cstring containing the path to a file.
+*/
+static CFURLRef create_cfurl_from_cstring(const char* file_path){
+  CFURLRef url_ref = CFURLCreateWithFileSystemPath(kCFAllocatorDefault,
+                         CFStringCreateWithFileSystemRepresentation(

[Mark Mentovai, 2011/05/26 21:23:40]

You still leak the CFString created with
CFStringCreateWithFileSystemRepresentation. You can CFRelease that CFString once
you give it to the CFURL. If the CFURL needs to hang on to it, it’ll retain it.

[mrossetti, 2011/05/27 17:11:36]

Done.

+                             kCFAllocatorDefault, file_path),
+                         kCFURLPOSIXPathStyle, FALSE);
+  return url_ref;
+}
+#endif
+
+/*
 ** This function is called at the start of every write transaction.
 ** There must already be a RESERVED or EXCLUSIVE lock on the database 
 ** file when this routine is called.
@@ -5191,6 +5209,28 @@
   #endif
       }
       assert( rc!=SQLITE_OK || isOpen(pPager->jfd) );
+#if defined(__APPLE__)
+      // Set the TimeMachine exclusion metadata for the journal if it has
+      // been set for the database.
+      if( rc == SQLITE_OK && pPager->zJournal ){

[Scott Hess - ex-Googler, 2011/05/26 21:30:54]

&& pPager->journalMode!=PAGER_JOURNALMODE_MEMORY .  Either that, or move it
after the #endif a few lines up.

[mrossetti, 2011/05/27 17:11:36]

Done. Moved up since there is no need to mark it excluded when in memory.

+        int database_path_size = strlen(pPager->zJournal)
+                                 - strlen(kPagerJournalSuffix) + 1;
+        char *database_path = sqlite3Malloc(database_path_size);
+        CFURLRef database_url = NULL;

[Mark Mentovai, 2011/05/26 21:23:40]

No need to initialize this to NULL or anything else.

[mrossetti, 2011/05/27 17:11:36]

Done.

+        strlcpy(database_path, pPager->zJournal, database_path_size);
+        database_url = create_cfurl_from_cstring(database_path);
+        sqlite3_free(database_path);

[Scott Hess - ex-Googler, 2011/05/26 21:30:54]

Instead of malloc'ing up a substring, use pPager->zFilename.

[mrossetti, 2011/05/27 17:11:36]

Done.

+        Boolean exclude_by_path;

[Mark Mentovai, 2011/05/26 21:23:40]

You need to declare this above, with the other declarations. For safety, since
you never assign to this but hope that CSBackupIsItemExcluded sets it through
the pointer, you should provide an initializer (FALSE).

[Scott Hess - ex-Googler, 2011/05/26 21:30:54]

C code, needs to be up by database_url, though my previous suggestion may moot
that.  Note that the docs say "Can be NULL" for excludeByPath.  Unless you pass
it to the below CSBackupSetItemExcluded(), you can probably just drop it.

[mrossetti, 2011/05/27 17:11:36]

Done.

[mrossetti, 2011/05/27 17:11:36]

I'm removing it. Previously we discussed not excluding the journal if the
database was excluded by-path but that doesn't make sense to me anymore. If the
database is excluded by path it's either because a) the full path for the
database has been excluded or b) a partial path referring to a containing
directory has been excluded. In case 'a' we still want to force the journal to
be excluded and in case 'b' the exclusion is potentially unnecessary (if the
exclusion applies to a containing directory) but harmless.

+        if( CSBackupIsItemExcluded(database_url, &exclude_by_path)
+         && !exclude_by_path){
+          CFURLRef journal_url = create_cfurl_from_cstring(pPager->zJournal);
+          // Ignore errors from the following exclusion call.
+          CSBackupSetItemExcluded(journal_url, TRUE, FALSE);
+          CFRelease(journal_url);
+        }
+        CFRelease(database_url);
+      }
+#endif
     }