Sort leftovers by last backup date THEN BY decreasing filesize.

[backups/.git] / main.cpp

diff --git a/main.cpp b/main.cpp
index 3a86a2bb2df27c03a56a987ff49419129ec683db..8540adfb56c480db0d6284b3811bafd051773ec2 100644 (file)
--- a/main.cpp
+++ b/main.cpp
@@ -64,25 +64,25 @@ void partition_sets( const SET &current, const SET &old,
                      SET &added, SET &common, SET &old_common, SET &deleted  ) {
   FileDataNameCmp cmp;
 
-  set_difference( current.begin(), current.end(),
-                  old.begin(),     old.end(),
-                  inserter( added, added.begin() ),
-                  cmp );
-
-  set_difference( old.begin(),     old.end(),
-                  current.begin(), current.end(),
-                  inserter( deleted, deleted.begin() ),
-                  cmp );
-
-  set_union(      current.begin(), current.end(),
-                  old.begin(),     old.end(),
-                  inserter( common, common.begin() ),
-                  cmp );
-
-  set_union(      old.begin(),    old.end(),
-                  common.begin(), common.end(),
-                  inserter( old_common, old_common.begin() ),
-                  cmp );
+  set_difference(   current.begin(), current.end(),
+                    old.begin(),     old.end(),
+                    inserter( added, added.begin() ),
+                    cmp );
+
+  set_difference(   old.begin(),     old.end(),
+                    current.begin(), current.end(),
+                    inserter( deleted, deleted.begin() ),
+                    cmp );
+
+  set_intersection( current.begin(), current.end(),
+                    old.begin(),     old.end(),
+                    inserter( common, common.begin() ),
+                    cmp );
+
+  set_intersection( old.begin(),    old.end(),
+                    common.begin(), common.end(),
+                    inserter( old_common, old_common.begin() ),
+                    cmp );
 }
 
 template<class INT>
@@ -177,12 +177,13 @@ int main() {
   unsigned long long modified_blocks, modified_bytes;
   sizes( modified_v.begin(), modified_v.end(), modified_blocks, modified_bytes );
 
-  // Now, sort the backups by filesize and build a list that'll fit on a DVD
+  // Now, sort the backups by filesize (decreasing) and build a list that'll fit
+  // on a DVD
   file_vector backups_s;
   copy( backups.begin(), backups.end(), back_inserter( backups_s ) );
 
   FileDataSizeCmp sizecmp;
-  sort( backups_s.begin(), backups_s.end(), sizecmp );
+  sort( backups_s.rbegin(), backups_s.rend(), sizecmp );
 
   file_set final;
   unsigned long long space = 0x100000000ULL;
@@ -191,13 +192,15 @@ int main() {
 
   // Copy files over until full or out of files
   bool complete
-    = copy_until_full( backups_s.rbegin(), backups_s.rend(), final_i, space );
+    = copy_until_full( backups_s.begin(), backups_s.end(), final_i, space );
 
   // Track the size filled up by essential backups
   unsigned long long essential_blocks, essential_bytes;
   sizes( final.begin(), final.end(), essential_blocks, essential_bytes );
 
-  // Now, sort the non-backed-up list by last_backup_date and back-fill
+  // Now, sort the non-backed-up list by last_backup_date, then by filesize
+  // (decreasing) and back-fill.  This should minimize the number of DVDs in the
+  // collection left with actual content.
   if( 0 != space ) {
     file_vector leftovers;
     FileDataNameCmp cmp;
@@ -207,7 +210,10 @@ int main() {
                     cmp );
 
     FileDataLastBackupCmp lastbackupcmp;
-    sort( leftovers.begin(), leftovers.end(), lastbackupcmp );
+    // Achieve 'last back date then by filesize' by first sorting by filesizing
+    // and then running stable sort by last backup date.
+    sort(        leftovers.rbegin(), leftovers.rend(), sizecmp );
+    stable_sort( leftovers.begin(),  leftovers.end(),  lastbackupcmp );
 
     copy_until_full( leftovers.begin(), leftovers.end(), final_i, space );
   }