Added match algorithms and tests

.gitignore

@@ -2,3 +2,4 @@
 *.swo
 venv
 docs/build/
+sniffpy.egg-info

sniffpy/constants.py

@@ -1,10 +1,11 @@
 # This document contains all of the tables specified in https://mimesniff.spec.whatwg.org/
 # Each table is implemented as an Array and a comment before each
 # table indicates title of the table and meaning of each column.
+from mimetype import MIMEtype
 
 # Bytes that the specification defines as whitespace
 WHITESPACE = b'\x09\x0a\x0c\x0d\x20'
-
+UNDEFINED = MIMEType('undefined', 'undefined')
 
 # Apache Bug Flag Table
 # Bytes as Bytes | Bytes as String

sniffpy/match.py

@@ -1,7 +1,39 @@
-from .mimetype import MIMEType
+""" This module implements matching algorithms as described in
+https://mimesniff.spec.whatwg.org/#matching-a-mime-type-pattern"""
+
+from sniffpy.mimetype import MIMEType
 
 def match_image_type_pattern(resource: bytes) -> MIMEType:
     raise NotImplementedError
 
 def match_video_audio_type_pattern(resource: bytes) -> MIMEType:
     raise NotImplementedError
+
+def match_pattern(resource: bytes, pattern: bytes, mask: bytes, ignored: bytes):
+    """
+    Implementation of algorithm in:x
+    https://mimesniff.spec.whatwg.org/#matching-a-mime-type-pattern
+    True if pattern matches the resource. False otherwise.
+    """
+    resource = bytearray(resource)
+    pattern = bytearray(pattern)
+    mask = bytearray(mask)
+
+    if len(pattern) != len(mask):
+        return False
+    if len(resource) < len(pattern):
+        return False
+
+    start = 0
+    for byte in resource:
+        if byte in ignored:
+            start += 1
+        else:
+            break
+
+    iteration_tuples = zip(resource[start:], pattern, mask)
+    for resource_byte, pattern_byte, mask_byte in iteration_tuples:
+        masked_byte = resource_byte & mask_byte
+        if masked_byte != pattern_byte:
+            return False
+    return True

sniffpy/ref.py

@@ -1,3 +1,5 @@
+from typing import List
+
 def check_condition(code_point: str, condition: List[str]) -> bool:
     for char in condition:
         if code_point == char: