Non-path Time Machine Exclusions

Enable setting of file exclusion for non-admin/non-root users. We no longer support setting exclusion-by-path.
Enhanced error reporting in SetFileBackupExclusion.
Change exclusion calls for History and Thumbnail databases.
Made MacUtilTest.TestExcludeFileFromBackups more robust.

BUG=74053
TEST=Updated base_unittests's MacUtilTest.TestExcludeFileFromBackups.
Review URL: http://codereview.chromium.org/7069021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86778 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 43 insertions, 57 deletions

diff --git a/base/mac/mac_util.h b/base/mac/mac_util.h
index 1bd936d..808716c 100644
--- a/base/mac/mac_util.h
+++ b/base/mac/mac_util.h
@@ -77,8 +77,8 @@ bool ShouldWindowsMiniaturizeOnDoubleClick();
 // Activates the process with the given PID.
 void ActivateProcess(pid_t pid);
 
-// Set the Time Machine exclusion property for the given file.
-bool SetFileBackupExclusion(const FilePath& file_path, bool exclude);
+// Excludes the file given by |file_path| from being backed up by Time Machine.
+bool SetFileBackupExclusion(const FilePath& file_path);
 
 // Sets the process name as displayed in Activity Monitor to process_name.
 void SetProcessName(CFStringRef process_name);
diff --git a/base/mac/mac_util.mm b/base/mac/mac_util.mm
index dc34a8e..16b3341 100644
--- a/base/mac/mac_util.mm
+++ b/base/mac/mac_util.mm
@@ -8,6 +8,7 @@
 
 #include "base/file_path.h"
 #include "base/logging.h"
+#include "base/mac/foundation_util.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/memory/scoped_nsobject.h"
 #include "base/sys_string_conversions.h"
@@ -238,47 +239,29 @@ void ActivateProcess(pid_t pid) {
   }
 }
 
-bool SetFileBackupExclusion(const FilePath& file_path, bool exclude) {
+bool SetFileBackupExclusion(const FilePath& file_path) {
   NSString* filePath =
       [NSString stringWithUTF8String:file_path.value().c_str()];
-
-  // If being asked to exclude something in a tmp directory, just lie and say it
-  // was done.  TimeMachine will already ignore tmp directories.  This keeps the
-  // temporary profiles used by unittests from being added to the exclude list.
-  // Otherwise, as /Library/Preferences/com.apple.TimeMachine.plist grows the
-  // bots slow down due to reading/writing all the temporary profiles used over
-  // time.
-
-  NSString* tmpDir = NSTemporaryDirectory();
-  // Make sure the temp dir is terminated with a slash
-  if (tmpDir && ![tmpDir hasSuffix:@"/"])
-    tmpDir = [tmpDir stringByAppendingString:@"/"];
-  // '/var' is a link to '/private/var', make sure to check both forms.
-  NSString* privateTmpDir = nil;
-  if ([tmpDir hasPrefix:@"/var/"])
-    privateTmpDir = [@"/private" stringByAppendingString:tmpDir];
-
-  if ((tmpDir && [filePath hasPrefix:tmpDir]) ||
-      (privateTmpDir && [filePath hasPrefix:privateTmpDir]) ||
-      [filePath hasPrefix:@"/tmp/"] ||
-      [filePath hasPrefix:@"/var/tmp/"] ||
-      [filePath hasPrefix:@"/private/tmp/"] ||
-      [filePath hasPrefix:@"/private/var/tmp/"]) {
-    return true;
-  }
-
   NSURL* url = [NSURL fileURLWithPath:filePath];
-  // Note that we always set CSBackupSetItemExcluded's excludeByPath param
-  // to true.  This prevents a problem with toggling the setting: if the file
-  // is excluded with excludeByPath set to true then excludeByPath must
-  // also be true when un-excluding the file, otherwise the un-excluding
-  // will be ignored.
-  bool success =
-      CSBackupSetItemExcluded((CFURLRef)url, exclude, true) == noErr;
-  if (!success)
+  // Do a pre-emptive unexclude by-path since by-path exclusions may have been
+  // performed on this file in the past.
+  CSBackupSetItemExcluded(base::mac::NSToCFCast(url), FALSE, TRUE);
+  // When excludeByPath is true the application must be running with root
+  // privileges (admin for 10.6 and earlier) but the URL does not have to
+  // already exist. When excludeByPath is false the URL must already exist but
+  // can be used in non-root (or admin as above) mode. We use false so that
+  // non-root (or admin) users don't get their TimeMachine drive filled up with
+  // unnecessary backups.
+  OSStatus os_err =
+      CSBackupSetItemExcluded(base::mac::NSToCFCast(url), TRUE, FALSE);
+  if (os_err != noErr) {
     LOG(WARNING) << "Failed to set backup exclusion for file '"
-                 << file_path.value().c_str() << "'.  Continuing.";
-  return success;
+                 << file_path.value().c_str() << "' with error "
+                 << os_err << " (" << GetMacOSStatusErrorString(os_err)
+                 << ": " << GetMacOSStatusCommentString(os_err)
+                 << ").  Continuing.";
+  }
+  return os_err == noErr;
 }
 
 void SetProcessName(CFStringRef process_name) {
diff --git a/base/mac/mac_util_unittest.mm b/base/mac/mac_util_unittest.mm
index b4f9268..92a6001 100644
--- a/base/mac/mac_util_unittest.mm
+++ b/base/mac/mac_util_unittest.mm
@@ -8,8 +8,10 @@
 
 #include "base/file_path.h"
 #include "base/file_util.h"
+#include "base/mac/foundation_util.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/memory/scoped_nsobject.h"
+#include "base/scoped_temp_dir.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 
@@ -95,26 +97,27 @@ TEST_F(MacUtilTest, TestGetAppBundlePath) {
 }
 
 TEST_F(MacUtilTest, TestExcludeFileFromBackups) {
-  NSString* homeDirectory = NSHomeDirectory();
-  NSString* dummyFilePath =
-      [homeDirectory stringByAppendingPathComponent:@"DummyFile"];
-  const char* dummy_file_path = [dummyFilePath fileSystemRepresentation];
-  ASSERT_TRUE(dummy_file_path);
-  FilePath file_path(dummy_file_path);
-  // It is not actually necessary to have a physical file in order to
-  // set its exclusion property.
-  NSURL* fileURL = [NSURL URLWithString:dummyFilePath];
-  // Reset the exclusion in case it was set previously.
-  SetFileBackupExclusion(file_path, false);
-  Boolean excludeByPath;
+  // The file must already exist in order to set its exclusion property.
+  ScopedTempDir temp_dir_;
+  ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+  FilePath dummy_file_path = temp_dir_.path().Append("DummyFile");
+  const char dummy_data[] = "All your base are belong to us!";
+  // Dump something real into the file.
+  ASSERT_EQ(static_cast<int>(arraysize(dummy_data)),
+      file_util::WriteFile(dummy_file_path, dummy_data, arraysize(dummy_data)));
+  NSString* fileURLString =
+      [NSString stringWithUTF8String:dummy_file_path.value().c_str()];
+  NSURL* fileURL = [NSURL URLWithString:fileURLString];
   // Initial state should be non-excluded.
-  EXPECT_FALSE(CSBackupIsItemExcluded((CFURLRef)fileURL, &excludeByPath));
+  EXPECT_FALSE(CSBackupIsItemExcluded(base::mac::NSToCFCast(fileURL), NULL));
   // Exclude the file.
-  EXPECT_TRUE(SetFileBackupExclusion(file_path, true));
-  EXPECT_TRUE(CSBackupIsItemExcluded((CFURLRef)fileURL, &excludeByPath));
-  // Un-exclude the file.
-  EXPECT_TRUE(SetFileBackupExclusion(file_path, false));
-  EXPECT_FALSE(CSBackupIsItemExcluded((CFURLRef)fileURL, &excludeByPath));
+  EXPECT_TRUE(SetFileBackupExclusion(dummy_file_path));
+  // SetFileBackupExclusion never excludes by path.
+  Boolean excluded_by_path = FALSE;
+  Boolean excluded =
+      CSBackupIsItemExcluded(base::mac::NSToCFCast(fileURL), &excluded_by_path);
+  EXPECT_TRUE(excluded);
+  EXPECT_FALSE(excluded_by_path);
 }
 
 TEST_F(MacUtilTest, TestGetValueFromDictionary) {