Improve decompress method

Author: rhpvorderman

benchmark.py

@@ -5,7 +5,7 @@
 from pathlib import Path
 from typing import Dict
 
-from isal import isal_zlib
+from isal import igzip, isal_zlib  # noqa: F401 used in timeit strings
 
 DATA_DIR = Path(__file__).parent / "tests" / "data"
 COMPRESSED_FILE = DATA_DIR / "test.fastq.gz"

src/isal/igzip.py

@@ -166,8 +166,7 @@ def decompress(data):
     """Decompress a gzip compressed string in one shot.
     Return the decompressed string.
     """
-    with IGzipFile(fileobj=io.BytesIO(data), mode="rb") as f:
-        return f.read()
+    return isal_zlib.decompress(data, wbits=16 + isal_zlib.MAX_WBITS)
 
 
 def main():