From ab8f1e889d5c4c57cb12397d4bd3ad22defd132c Mon Sep 17 00:00:00 2001
From: Brandon Liu <bdon@bdon.org>
Date: Thu, 18 Feb 2021 10:59:39 +0800
Subject: [PATCH] detect and decompress gzipped tile data

---
 python/pmtiles/writer.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/python/pmtiles/writer.py b/python/pmtiles/writer.py
index 1c2ca6c..8ac70a7 100644
--- a/python/pmtiles/writer.py
+++ b/python/pmtiles/writer.py
@@ -1,3 +1,4 @@
+import gzip
 import itertools
 import json
 from contextlib import contextmanager
@@ -20,6 +21,10 @@ class Writer:
         self.leaves = []
 
     def write_tile(self,z,x,y,data):
+        # if the tile is GZIP-encoded, it won't work with range queries
+        # until transfer-encoding: gzip is well supported.
+        if data[0:2] == b'\x1f\x8b':
+            data = gzip.decompress(data)
         hsh = hash(data)
         if hsh in self.hash_to_offset:
             self.tiles.append((z,x,y,self.hash_to_offset[hsh],len(data)))