elevation.cache
===============

.. py:module:: elevation.cache


Attributes
----------

.. autoapisummary::

   elevation.cache.CACHE_DIR
   elevation.cache.FOLDER_LOCKFILE_NAME
   elevation.cache.Tile


Functions
---------

.. autoapisummary::

   elevation.cache.build_vrt
   elevation.cache.ensure_setup
   elevation.cache.ensure_tiles
   elevation.cache.is_cached
   elevation.cache.lock_tiles
   elevation.cache.lock_vrt
   elevation.cache.resolve_cache_dir


Module Contents
---------------

.. py:function:: build_vrt(root, product)

   Build the ``<product>.vrt`` mosaic over the non empty cache tiles.


.. py:function:: ensure_setup(root)

   Create the product folder and its ``cache`` subfolder.

   The ``spool`` folder is created on demand by the cache write.


.. py:function:: ensure_tiles(root, tiles, prepare_tile, gdal_options = spatial.INT_TILE_GDAL_OPTIONS, empty_on_notfound = True, **kwargs)

   Fetch and cache *tiles*, skipping the tiles already in the cache.

   ``prepare_tile`` returns the GDAL source of the tile, that is read in place
   and written to the cache as a GeoTIFF.


.. py:function:: is_cached(root, tile_name)

   Return whether *tile_name* is cached, empty tiles included.


.. py:function:: lock_tiles(datasource_root, tile_names)

.. py:function:: lock_vrt(datasource_root, product)

.. py:function:: resolve_cache_dir(cache_dir)

   Return the DEM cache folder to use, as an absolute path.

   The ``cache_dir`` argument takes precedence over the ``EIO_CACHE_DIR`` environment
   variable, that takes precedence over the ``CACHE_DIR`` default.


.. py:data:: CACHE_DIR
   :type:  str

.. py:data:: FOLDER_LOCKFILE_NAME
   :value: '.folder_lock'


.. py:data:: Tile