Improved read label performance with blkid cached results

svn path=/trunk/; revision=963

ChangeLog

@@ -1,3 +1,11 @@
+2008-11-13  Curtis Gedak  <gedakc@gmail.com>
+
+	* include/FS_Info.h,
+	  src/FS_Info.cc,
+	  src/GParted_Core.cc,
+	  README: Improved read label performance with blkid cached results.
+	  - When possible use blkid cached results to determine volume label.
+
 2008-11-12  Curtis Gedak  <gedakc@gmail.com>
 
 	* README: Updated directories and dependencies.

README

@@ -121,4 +121,6 @@ Optional packages include:
             to read linux-swap, reiser4, hfs, and hfs+ file system
             volume labels.
           * If the blkid command is in the search path, it will be used
-            to read file system UUIDs.
+            to read file system UUIDs and labels. 
+            blkid is part of the e2fsprogs package.
+

include/FS_Info.h

@@ -28,6 +28,7 @@ class FS_Info
 public:
 	FS_Info() ;
 	~FS_Info() ;
+	Glib::ustring get_label( const Glib::ustring & path, bool & found ) ;
 	Glib::ustring get_uuid( const Glib::ustring & path ) ;
 private:
 	void load_fs_info_cache() ;

src/FS_Info.cc

@@ -41,6 +41,24 @@ void FS_Info::load_fs_info_cache()
 	}
 }
 
+Glib::ustring FS_Info::get_label( const Glib::ustring & path, bool & found )
+{
+	Glib::ustring label = "" ;
+	found = false ;
+
+	//Retrieve the line containing the device path
+	Glib::ustring regexp = "^" + path + ":([^\n]*)$" ;
+	Glib::ustring temp = Utils::regexp_label( fs_info_cache, regexp ) ;
+	
+	//Set indicator if LABEL found
+	if ( Utils::regexp_label( temp, "(LABEL=\")") != "" )
+		found = true ;
+
+	//Retrieve LABEL
+	label = Utils::regexp_label( temp, "LABEL=\"([^\"]*)\"" ) ;
+	return label ;
+}
+
 Glib::ustring FS_Info::get_uuid( const Glib::ustring & path )
 {
 	//Retrieve the line containing the device path

src/GParted_Core.cc

@@ -736,9 +736,13 @@ void GParted_Core::set_device_partitions( Device & device )
 		}
 
 		//Avoid reading additional file system information if there is no path
-		//FIXME:  Why is there an empty path for the first primary partition, and an empty path for each logical partition?
-		if ( partition_temp .get_path() != "" ) {
+		if ( partition_temp .get_path() != "" )
+		{
+			bool label_found = false ;
+			partition_temp .label = fs_info .get_label( partition_temp .get_path(), label_found ) ;
+			if ( ! label_found )
 				read_label( partition_temp ) ;
+
 			partition_temp .uuid = fs_info .get_uuid( partition_temp .get_path() ) ;
 		}