Import wpt@758b3b4cfa805067f36121333ba031e583d3a62c

third_party/WebKit/LayoutTests/external/wpt/referrer-policy/generic/subresource/image.py

+import os, sys, array, json, math, StringIO
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+import subresource
+
+class Image:
+    """This class partially implements the interface of the PIL.Image.Image.
+       One day in the future WPT might support the PIL module or another imaging
+       library, so this hacky BMP implementation will no longer be required.
+    """
+    def __init__(self, width, height):
+        self.width = width
+        self.height = height
+        self.img = bytearray([0 for i in range(3 * width * height)])
+
+    @staticmethod
+    def new(mode, size, color=0):
+        return Image(size[0], size[1])
+
+    def _int_to_bytes(self, number):
+        packed_bytes = [0, 0, 0, 0]
+        for i in range(4):
+            packed_bytes[i] = number & 0xFF
+            number >>= 8
+
+        return packed_bytes
+
+    def putdata(self, color_data):
+        for y in range(self.height):
+            for x in range(self.width):
+                i = x + y * self.width
+                if i > len(color_data) - 1:
+                    return
+
+                self.img[i * 3: i * 3 + 3] = color_data[i][::-1]
+
+    def save(self, f, type):
+        assert type == "BMP"
+        # 54 bytes of preambule + image color data.
+        filesize = 54 + 3 * self.width * self.height;
+        # 14 bytes of header.
+        bmpfileheader = bytearray(['B', 'M'] + self._int_to_bytes(filesize) +
+                                  [0, 0, 0, 0, 54, 0, 0, 0])
+        # 40 bytes of info.
+        bmpinfoheader = bytearray([40, 0, 0, 0] +
+                                  self._int_to_bytes(self.width) +
+                                  self._int_to_bytes(self.height) +
+                                  [1, 0, 24] + (25 * [0]))
+
+        padlength = (4 - (self.width * 3) % 4) % 4
+        bmppad = bytearray([0, 0, 0]);
+        padding = bmppad[0 : padlength]
+
+        f.write(bmpfileheader)
+        f.write(bmpinfoheader)
+
+        for i in range(self.height):
+            offset = self.width * (self.height - i - 1) * 3
+            f.write(self.img[offset : offset + 3 * self.width])
+            f.write(padding)
+
+def encode_string_as_bmp_image(string_data):
+    data_bytes = array.array("B", string_data)
+    num_bytes = len(data_bytes)
+
+    # Convert data bytes to color data (RGB).
+    color_data = []
+    num_components = 3
+    rgb = [0] * num_components
+    i = 0
+    for byte in data_bytes:
+        component_index = i % num_components
+        rgb[component_index] = byte
+        if component_index == (num_components - 1) or i == (num_bytes - 1):
+            color_data.append(tuple(rgb))
+            rgb = [0] * num_components
+        i += 1
+
+    # Render image.
+    num_pixels = len(color_data)
+    sqrt = int(math.ceil(math.sqrt(num_pixels)))
+    img = Image.new("RGB", (sqrt, sqrt), "black")
+    img.putdata(color_data)
+
+    # Flush image to string.
+    f = StringIO.StringIO()
+    img.save(f, "BMP")
+    f.seek(0)
+
+    return f.read()
+
+def generate_payload(server_data):
+    data = ('{"headers": %(headers)s}') % server_data
+    return encode_string_as_bmp_image(data)
+
+def main(request, response):
+    subresource.respond(request,
+                        response,
+                        payload_generator = generate_payload,
+                        content_type = "image/bmp",
+                        access_control_allow_origin = "*")