Speedups geoprocessing with Fiona and LRU caching

fiona_cache.py

class CollectionLRU(fiona.Collection):
    """Wrapper for Fiona Collection that provides LRU read caching
    """
    def __init__(self, *args, **kwargs):
        fiona.Collection.__init__(self, *args, **kwargs)
        self.cache = LRU(200)
    def __getitem__(self, key):
        try:
            feature = self.cache[key]
        except KeyError:
            feature = fiona.Collection.__getitem__(self, key)
            self.cache[key] = feature
        return feature

def fiona_cache_open(path, mode='r', driver=None, schema=None, crs=None,
                     encoding=None, layer=None, vfs=None, enabled_drivers=None,
                     crs_wkt=None):
    """Open a new Fiona collection with LRU read caching
    """
    assert(mode == 'r')
    path, vsi, archive = fiona.parse_paths(path, vfs)
    collection = CollectionLRU(path, mode, driver=driver,
            encoding=encoding, layer=layer, vsi=vsi, archive=archive,
            enabled_drivers=enabled_drivers)
    return collection