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config:all_you_never_wanted_to_know_about_file_saving [2013/05/02 02:59] – add tags elextrconfig:all_you_never_wanted_to_know_about_file_saving [2025/02/22 21:46] (current) – Explicitly mention that use_atomic_file_saving loses links colombanw
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-====== Introduction ======+====== All you never wanted to know about file saving ====== 
 + 
 +===== Introduction =====
  
 Geany has a number of options and a plugin controlling the apparently simple operation of saving a buffer to a file.  This page gives a more detailed description of the options so that you can make an informed decision which to use, since no one combination is allways "right". Geany has a number of options and a plugin controlling the apparently simple operation of saving a buffer to a file.  This page gives a more detailed description of the options so that you can make an informed decision which to use, since no one combination is allways "right".
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 No matter what your options settings, if a file save fails you should try to save the buffer **to a different device** or clear the cause of the failure (disk full, network fault) and try again.  You will not lose anything until you close the buffer. No matter what your options settings, if a file save fails you should try to save the buffer **to a different device** or clear the cause of the failure (disk full, network fault) and try again.  You will not lose anything until you close the buffer.
  
-====== Various Options ======+===== Various Options =====
  
 The options controlling file saving are all in the "Various" preferences page. The options controlling file saving are all in the "Various" preferences page.
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   * gio_unsafe_save_backup   * gio_unsafe_save_backup
  
-===== use_atomic_file_saving =====+==== use_atomic_file_saving ====
  
 This is off by default. This is off by default.
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   * Uses Geany's own code so it can be modified.   * Uses Geany's own code so it can be modified.
  
-If use_atomic_file_saving is set, use_gio_file_saving is ignored and Geany will use an atomic file save method.  This means that the file is first written to a temporary file, then renamed to the existing file name.  On most file systems rename is atomic, that is it succeeds completely or nothing will change, especially on modern journalling systems.  This functionality is provided and maintained by the Glib library.+If use_atomic_file_saving is set, use_gio_unsafe_file_saving is ignored and Geany will use an atomic file save method.  This means that the file is first written to a temporary file, then renamed to the existing file name.  On most file systems rename is atomic, that is it succeeds completely or nothing will change, especially on modern journalling systems.  This functionality is provided and maintained by the Glib library.
  
 Advantages: Advantages:
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   * Because it writes the temporary file as a new file, it will get the permissions and other metadata (eg execute) of a new file, not those of the old file.   * Because it writes the temporary file as a new file, it will get the permissions and other metadata (eg execute) of a new file, not those of the old file.
 +  * Because of renaming over the old file rather than changing its content, if the old file was a symlink the link is lost and is replaced with a new file instead, leaving the link target untouched.
   * Does not work on all file systems since rename or rename over an existing file is not supported on all file systems.   * Does not work on all file systems since rename or rename over an existing file is not supported on all file systems.
   * Uses twice as much file space during the process.   * Uses twice as much file space during the process.
   * Uses library code so Geany can't modify its behaviour.   * Uses library code so Geany can't modify its behaviour.
  
-===== use_gio_unsafe_file_saving =====+==== use_gio_unsafe_file_saving ====
  
 This is on by the default, and is provided by the GIO library. This is on by the default, and is provided by the GIO library.
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 Disadvantages: Disadvantages:
  
-  * There is a long standing bug or design fault in the GIO library that deletes the temporary file from the non-atomic save if writing the data file fails.  **This means it is no more safe than the simple overwrite method since the previous data is not restored, or even left available for the user to restore.**+  * There is a [[https://bugzilla.gnome.org/show_bug.cgi?id=602412|long standing bug]] or design fault in the GIO library that deletes the temporary file from the non-atomic save if writing the data file fails.  **This means it is no more safe than the simple overwrite method since the previous data is not restored, or even left available for the user to restore.**
   * The non-atomic save copies data over the network three times (read and write to make the temporary file, write the output file) which can be slow on remote networks.   * The non-atomic save copies data over the network three times (read and write to make the temporary file, write the output file) which can be slow on remote networks.
   * Uses twice the disk space.   * Uses twice the disk space.
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   * Uses library code so Geany can't modify its behaviour.   * Uses library code so Geany can't modify its behaviour.
  
-===== gio_unsafe_save_backup =====+==== gio_unsafe_save_backup ====
  
 This is off by default. This is off by default.
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 Disadvantages: Disadvantages:
  
-  * Only works if use_gio_unsafe_file_saving is in operation, remember use_atomic_file_saving overrides it.+  * Only works if ''use_gio_unsafe_file_saving'' is in enabled and ''use_atomic_file_saving'' is disabled (''use_atomic_file_saving'' **overrides** ''use_gio_unsafe_file_saving'').
   * Uses twice the disk space.   * Uses twice the disk space.
   * Can be slow on remote filesystems as it may have to read and write data to create the backup if renaming fails.   * Can be slow on remote filesystems as it may have to read and write data to create the backup if renaming fails.
  
-====== Save Actions plugin ======+===== Save Actions plugin =====
  
 The Save Actions plugin is distributed with Geany and if it is enabled it provides two actions relevant to this discussion (plus others). The Save Actions plugin is distributed with Geany and if it is enabled it provides two actions relevant to this discussion (plus others).
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   * Backup Copy   * Backup Copy
  
-===== Autosave =====+==== Autosave ====
  
 Any situation that causes Geany to stop unexpectedly can cause unsaved files to be lost, that includes logout, shutdown, crash etc. Any situation that causes Geany to stop unexpectedly can cause unsaved files to be lost, that includes logout, shutdown, crash etc.
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   * Same limitations of the chosen save method, but now happens more often.   * Same limitations of the chosen save method, but now happens more often.
  
-===== Backup Copy =====+==== Backup Copy ====
  
 Makes a copy of the file every time after the buffer is saved successfully.  If the next save fails, this backup is available. Makes a copy of the file every time after the buffer is saved successfully.  If the next save fails, this backup is available.

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