From a612a6c4bfe309bf61f86f4f1026f19823165b00 Mon Sep 17 00:00:00 2001
From: Danijel Schorlemmer <ds@gfz-potsdam.de>
Date: Mon, 20 Jun 2022 15:56:58 +0200
Subject: [PATCH] Implement the export function with optional bounding box
parameter
---
exposurelib/database.py | 123 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 123 insertions(+)
diff --git a/exposurelib/database.py b/exposurelib/database.py
index 168e7974..2b2176b8 100644
--- a/exposurelib/database.py
+++ b/exposurelib/database.py
@@ -21,6 +21,8 @@ import sqlite3
import datetime
import csv
import glob
+import shutil
+import os.path
from exposurelib.utils import get_geom_of_quadkey
from shapely.geometry import box
from pygeotile.tile import Tile
@@ -394,6 +396,127 @@ class ExposureDatabase(SpatialiteDatabase):
self.connection.execute(sql_statement)
logger.debug("View %s deleted" % name)
+ def export(self, export_filepath, bounding_box=None, overwrite=False):
+ """
+ Exports the current database by copying it to the `export_filepath` location.
+ If a bounding box is given, all entities outside the bounding box including dependent
+ data values are removed and the database is compacted to save space.
+
+ Args:
+ export_filepath (str):
+ Filepath to export the database to.
+ bounding_box (dictionary, optional):
+ Dictionary containing the bounding-box coordinates as entries `lon_min`,
+ `lon_max`, `lat_min`, `lat_max`.
+ overwrite (boolean, optional):
+ Flag to allow for overwriting an existing file during export.
+ """
+
+ # Checks if writing is possible
+ if self.database_filepath == export_filepath:
+ raise FileExistsError("Cannot export database to iself. Exiting ...")
+ if os.path.exists(export_filepath) and not overwrite:
+ raise FileExistsError("File %s exists. Exiting ..." % export_filepath)
+ # Copy current database to new location
+ shutil.copyfile(self.database_filepath, export_filepath)
+ if bounding_box is None:
+ return
+
+ # Open the export database
+ try:
+ export_db = ExposureDatabase(export_filepath, self.spatialite_filepath)
+ export_db.connect(init_spatial_metadata=False)
+ except Exception:
+ raise ValueError(
+ "Exposure database %s cannot be created. Exiting ..." % export_filepath
+ )
+
+ # Remove the entities and related datasets outside the bounding box
+ logger.debug("Removing entities outside of bounding box")
+ sql_statement = "DELETE FROM Entity "
+ sql_statement += "WHERE NOT MBRContains(BuildMBR(%f, %f, %f, %f), geom)" % (
+ bounding_box["lon_min"],
+ bounding_box["lat_min"],
+ bounding_box["lon_max"],
+ bounding_box["lat_max"],
+ )
+ export_db.cursor.execute(sql_statement)
+
+ logger.debug("Removing tiles outside of bounding box")
+ sql_statement = """
+ DELETE FROM Tile
+ WHERE quadkey IN
+ (
+ SELECT Tile.quadkey FROM Tile
+ LEFT JOIN Entity ON Tile.quadkey = Entity.quadkey
+ WHERE Entity.id IS NULL
+ )
+ """
+ export_db.cursor.execute(sql_statement)
+
+ logger.debug("Removing buildings outside of bounding box")
+ sql_statement = """
+ DELETE FROM Building
+ WHERE osm_id IN
+ (
+ SELECT Building.osm_id FROM Building
+ LEFT JOIN Entity ON Building.osm_id = Entity.osm_id
+ WHERE Entity.id IS NULL
+ )
+ """
+ export_db.cursor.execute(sql_statement)
+
+ logger.debug("Removing assets outside of bounding box")
+ sql_statement = """
+ DELETE FROM Asset
+ WHERE entity_id IN
+ (
+ SELECT entity_id FROM Asset
+ LEFT JOIN Entity ON Asset.entity_id = Entity.id
+ WHERE Entity.id IS NULL
+ )
+ """
+ export_db.cursor.execute(sql_statement)
+
+ logger.debug("Removing unused taxonomy strings")
+ sql_statement = """
+ DELETE FROM Taxonomy
+ WHERE id IN
+ (
+ SELECT id FROM Taxonomy
+ LEFT JOIN Asset ON Asset.taxonomy_id = Taxonomy.id
+ WHERE Asset.taxonomy_id IS NULL
+ )
+ """
+ export_db.cursor.execute(sql_statement)
+
+ logger.debug("Removing unused damage assessments")
+ sql_statement = """
+ DELETE FROM DamageAssessment
+ WHERE entity_id IN
+ (
+ SELECT entity_id FROM DamageAssessment
+ LEFT JOIN Entity ON DamageAssessment.entity_id = Entity.id
+ WHERE Entity_id IS NULL
+ )
+ """
+ export_db.cursor.execute(sql_statement)
+ sql_statement = """
+ DELETE FROM Damage
+ WHERE assessment_id IN
+ (
+ SELECT assessment_id FROM Damage
+ LEFT JOIN DamageAssessment ON DamageAssessment.id = Damage.assessment_id
+ WHERE DamageAssessment.id IS NULL
+ )
+ """
+ export_db.cursor.execute(sql_statement)
+
+ export_db.connection.commit()
+ logger.debug("Reducing database size")
+ export_db.connection.execute("VACUUM")
+ export_db.close()
+
def insert_tile_entity(self, quadkey):
"""
Inserts a tile and its geometry to the `Entity` table. A database trigger checks if the
--
GitLab