README, cargo update, add python wrapper library

.cargo/config

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+[build]
+target = "wasm32-unknown-unknown"

.gitignore

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 # Project specific ignores
 target
-out.jpg
+__pycache__
+*.pyc

Makefile

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+all: wasm-thumbnail-py/src/wasm_thumbnail/data/wasm_thumbnail.wasm
+
+wasm-thumbnail-py/src/wasm_thumbnail/data/wasm_thumbnail.wasm: wasm-thumbnail/src/lib.rs
+	cd wasm-thumbnail && cargo build --release
+	cp wasm-thumbnail/target/wasm32-unknown-unknown/release/wasm_thumbnail.wasm wasm-thumbnail-py/src/wasm_thumbnail/data/

README.md

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+# wasm-thumbnail
+
+A tiny library for creating padded image thumbnails intended for use inside
+webassembly sandboxes.
+
+Supports resizing gif, jpeg, png and webp images.

wasm-thumbnail-py/pyproject.toml

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+[build-system]
+requires = [
+    "setuptools>=42",
+    "wheel"
+]

wasm-thumbnail-py/setup.cfg

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+[metadata]
+name = wasm-thumbnail
+version = 0.0.1
+author = ev Quirk
+author_email = ev@7pr.xyz
+description = WASM based thumbnail library
+long_description = file: README.md
+long_description_content_type = text/markdown
+url = https://github.com/brave-intl/wasm-thumbnail
+project_urls =
+    Bug Tracker = https://github.com/brave-intl/wasm-thumbnail/issues
+classifiers =
+    Programming Language :: Python :: 3
+    License :: OSI Approved :: MPL License
+    Operating System :: OS Independent
+
+[options]
+package_dir =
+    = src
+packages = find:
+python_requires = >=3.6
+include_package_data = True
+
+[options.package_data]
+wasm_thumbnail = data/*.wasm
+
+[options.packages.find]
+where = src

wasm-thumbnail-py/src/wasm_thumbnail/__init__.py

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+#!/usr/bin/env python
+from .thumbnail import *

wasm-thumbnail-py/src/wasm_thumbnail/thumbnail.py

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+#!/usr/bin/env python
+
+import importlib
+from importlib import resources
+import struct
+
+from wasmer import engine, Store, Module, Instance, ImportObject, Function, FunctionType, Type
+from wasmer_compiler_cranelift import Compiler
+
+def decode_padded_image(data):
+    """Extract a payload from its padding by reading its length header."""
+    data_length_without_header = len(data) - 4
+    if data_length_without_header < 0:
+        raise ValueError('Data must be at least 4 bytes long', len(data))
+
+    payload_length = struct.unpack('!L', data[0:4])[0]
+
+    if data_length_without_header < payload_length:
+        raise ValueError('Payload is shorter than the expected length',
+                         data_length_without_header, payload_length)
+
+    return data[4:4 + payload_length]
+
+def resize_and_pad_image(image_bytes, width, height, size):
+    """Resize an image and pad to fit size, output is prefixed by image length without padding.
+    Throws an error if the resized image does not fit in size or is not a supported format"""
+    instance = Instance(module, import_object)
+
+    image_length = len(image_bytes)
+    input_pointer = instance.exports.allocate(image_length)
+    memory = instance.exports.memory.uint8_view(input_pointer)
+    memory[0:image_length] = image_bytes
+
+    output_pointer = instance.exports.resize_and_pad(input_pointer, image_length, width, height, size)
+    instance.exports.deallocate(input_pointer, image_length)
+
+    memory = instance.exports.memory.uint8_view(output_pointer)
+    out_bytes = bytes(memory[:size])
+    instance.exports.deallocate(output_pointer, size)
+
+    return out_bytes
+
+def register_panic(msg_ptr: int, msg_len: int, file_ptr: int, file_len: int, line: int, column: int):
+    """Panic handler to be called from WASM for debugging purposes"""
+    msg = bytes(instance.exports.memory.uint8_view(msg_ptr)[:msg_len]).decode("utf-8")
+    file = bytes(instance.exports.memory.uint8_view(file_ptr)[:file_len]).decode("utf-8")
+    print("wasm panicked at '{}', {}:{}:{}".format(msg, file, line, column))
+
+wasm = resources.open_binary('wasm_thumbnail.data', "wasm_thumbnail.wasm")
+store = Store(engine.JIT(Compiler))
+module = Module(store, wasm.read())
+import_object = ImportObject()
+import_object.register(
+    "env",
+    {
+        "register_panic": Function(store, register_panic)
+    }
+)

wasm-thumbnail-py/tests/test.py

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+#!/usr/bin/env python
+
+import os
+import time
+
+from wasm_thumbnail import *
+
+
+IMAGE = os.path.join(os.path.dirname(os.path.abspath(__file__)), "brave.png")
+
+with open(IMAGE, 'rb') as image:
+    image_bytes = image.read()
+
+    tic = time.perf_counter()
+
+    out_bytes = resize_and_pad_image(image_bytes, 100, 100, 240000)
+    with open('out.jpg', 'wb+') as out_image:
+        out_image.write(out_bytes)
+
+    toc = time.perf_counter()
+    print(f"Resized brave.png with WASM in {toc - tic:0.4f} seconds")