Improve space check logic

- Modified `enough_free_space` to check both target and current directories
- Estimates the storage size with du
- Fixed showing the estimated size if there's enough space

Author: mrrfv

functions/backup_func.sh

@@ -52,14 +52,20 @@ function backup_func() {
   done
 
   # Ensure that there's enough space in the directory according to what is backed up
-  local space=$(enough_free_space "$archive_path")
-  if [[ -n "$space" && "$space" -ne 0 ]]; then
-    local bkp_size_mb=$(echo "scale=2; $space/1024" | bc)
-    echo -e "\033[31mThere isn't enough space in the selected directory for the backup. Estimated backup size: $bkp_size_mb MB\033[0m"
+  cecho "Estimating backup size, please wait..."
+
+  local estimated_size
+  enough_free_space "$archive_path" estimated_size
+  local fs_status=$?
+  local bkp_size_mb=$(echo "scale=2; $estimated_size/1024" | bc)
+
+  if [ $fs_status -ne 0 ]; then
+    echo -e "\033[31mThere isn't enough space for the backup. Estimated backup size: ${bkp_size_mb} MB\033[0m"
+    echo -e "\033[31mFree up space on both the target and backup script locations (to handle temporary files). Double the space is needed if backing up to the drive the backup script is located on.\033[0m"
     cecho "Exiting..."
     exit 1
   else
-    cecho "Enough space in the current directory. Estimated backup size: $bkp_size_mb MB"
+    cecho "Enough space in the current directory. Estimated backup size: ${bkp_size_mb} MB"
   fi
 
   # The companion app is needed only for contact backups.
@@ -210,4 +216,4 @@ backup_contacts: $backup_contacts
   cecho "Backed up successfully."
   cecho "Note: SMS messages and call logs cannot be restored by Open Android Backup at the moment. They are included in the backup archive for your own purposes."
   cecho "You can find them by opening the backup archive using 7-Zip."
-}
+}

functions/helper.sh

@@ -18,7 +18,7 @@ function estimate_backup_size() {
     local contacts_count=$(adb shell content query --uri content://contacts/people | wc -l)
     local sms_count=$(adb shell content query --uri content://sms/ | wc -l)
     local call_log_count=$(adb shell content query --uri content://call_log/calls | wc -l)
-    
+
     # Here we estimate that a contact is 4 KB, an SMS is 1 KB and a call log is 0,5 KB
     local contacts_size=$(echo "$contacts_count * 4" | bc)
     local sms_size=$(echo "$sms_count * 1" | bc)
@@ -27,7 +27,8 @@ function estimate_backup_size() {
   fi
 
   if [ "$backup_storage" = "yes" ]; then
-    local storage_size=$(adb shell df -k /storage/emulated/0 | tail -n 1 | awk '{print $3}')
+    # Use du to get the actual used space in KB
+    local storage_size=$(adb shell du -sk /storage/emulated/0 | awk '{print $1}')
     backup_size=$(echo "$backup_size + $storage_size" | bc)
   fi
 
@@ -41,17 +42,38 @@ function estimate_backup_size() {
 }
 
 # Checks if the user has enough free space to backup the device in the current directory
-# Usage: enough_free_space <directory>
-# Returns 0 (enough space) or 1 (not enough space) and echoes the estimated size of the backup
+# Usage: enough_free_space <directory> <estimated_size_var>
+# Returns 0 (enough space) or 1 (not enough space)
+# Stores the estimated size in the variable named by the second parameter
 function enough_free_space() {
   local directory="$1"
+  local -n estimated_size_ref="$2" # Use nameref for indirect assignment
+
   local backup_size=$(estimate_backup_size)
-  # Get the free space in the directory in kilobytes
-  local free_space=$(df -k "$directory" | tail -n 1 | awk '{print $4}')
-  if [ "$free_space" -lt "$backup_size" ]; then
-    echo "$backup_size"
+  estimated_size_ref=$backup_size
+  local required_size=$backup_size
+
+  # The script first gathers all data to ./backup-tmp, compresses it into an archive and finally deletes the temporary directory.
+  # Therefore, we need to bear both cases in mind.
+
+  # Get device IDs to check if directories are on the same drive
+  local current_dir_device=$(stat -c %m .)
+  local target_dir_device=$(stat -c %m "$directory")
+
+  # Double required space if that's the case
+  if [ "$current_dir_device" = "$target_dir_device" ]; then
+    required_size=$((backup_size * 2))
+  fi
+
+  # Check free space in both the target directory and current working directory
+  local target_free_space=$(df -k "$directory" | tail -n 1 | awk '{print $4}')
+  local current_free_space=$(df -k . | tail -n 1 | awk '{print $4}')
+
+  # Check if either directory has insufficient space
+  if [ "$target_free_space" -lt "$required_size" ] || [ "$current_free_space" -lt "$required_size" ]; then
     return 1
   fi
+
   return 0
 }