From 1e18e71b9de892b255516cdd9fbfdfa4304f7c57 Mon Sep 17 00:00:00 2001
From: Darko Poljak <darko.poljak@gmail.com>
Date: Thu, 17 Oct 2019 07:42:31 +0200
Subject: [PATCH] Use oldest backup as destination dir without deletion

---
 ccollect | 35 ++++++++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff --git a/ccollect b/ccollect
index c744e27..cf7abe9 100755
--- a/ccollect
+++ b/ccollect
@@ -715,6 +715,12 @@ while [ "${source_no}" -lt "${no_sources}" ]; do
         fi
     fi
 
+    #
+    # Include current time in name, not the time when we began to remove above
+    #
+    export destination_name="${INTERVAL}.$(${CDATE}).$$-${source_no}"
+    export destination_dir="${ddir}/${destination_name}"
+
     #
     # Check: maximum number of backups is reached?
     #
@@ -723,13 +729,26 @@ while [ "${source_no}" -lt "${no_sources}" ]; do
     _techo "Existing backups: ${count} Total keeping backups: ${c_interval}"
 
     if [ "${count}" -ge "${c_interval}" ]; then
-        remove="$((${count} - ${c_interval} + 1))"
-        _techo "Removing ${remove} backup(s)..."
+        # Use oldest directory as new backup destination directory.
+        # It need not to be deleted, rsync will sync its content.
+        oldest_bak=$(ls -${TSORT}1r | grep "^${INTERVAL}\\." | head -n 1 || \
+            _exit_err "Listing oldest backup failed")
+        _techo "Using ${oldest_bak} for destination dir"
+        mv "${oldest_bak}" "${destination_dir}" ||
+            _exit_err "Moving oldest backup ${oldest_bak} to ${destination_dir} failed."
+        # Touch dest dir so it is not sorted wrong in listings below.
+        touch "${destination_dir}"
 
-        ls -${TSORT}1r | grep "^${INTERVAL}\\." | head -n "${remove}" > "${TMP}" || \
-                _exit_err "Listing old backups failed"
+        # We have something to remove only if count > interval.
+        if [ "${count}" -gt "${c_interval}" ]; then
+            remove="$((${count} - ${c_interval}))"
+            _techo "Removing ${remove} backup(s)..."
 
-        delete_from_file "${TMP}" &
+            ls -${TSORT}1r | grep "^${INTERVAL}\\." | head -n "${remove}" > "${TMP}" || \
+                    _exit_err "Listing old backups failed"
+
+            delete_from_file "${TMP}" &
+        fi
     fi
 
     #
@@ -746,12 +765,6 @@ while [ "${source_no}" -lt "${no_sources}" ]; do
         _techo "Hard linking from ${last_dir}"
     fi
 
-    #
-    # Include current time in name, not the time when we began to remove above
-    #
-    export destination_name="${INTERVAL}.$(${CDATE}).$$-${source_no}"
-    export destination_dir="${ddir}/${destination_name}"
-
     #
     # Mark backup running and go back to original directory
     #