speedups

* add more static typing to cython to speedup

* release gil

* add multithread example

Author: synodriver

src/qoi/qoi.pxd

@@ -1,4 +1,4 @@
-cdef extern from "phoboslab_qoi/qoi.h":
+cdef extern from "phoboslab_qoi/qoi.h" nogil:
     ctypedef struct qoi_desc:
         unsigned int width
         unsigned int height

src/qoi/qoi.pyx

@@ -8,6 +8,7 @@ from pathlib import Path
 
 np.import_array()
 
+ctypedef np.uint8_t DTYPE_t
 
 class QOIColorSpace(enum.Enum):
     SRGB = qoi.QOI_SRGB
@@ -16,9 +17,9 @@ class QOIColorSpace(enum.Enum):
 cdef class PixelWrapper:
     cdef void* pixels
 
-    cdef np.ndarray as_ndarray(self, int height, int width, int channels, char * pixels):
+    cdef np.ndarray[DTYPE_t, ndim=3] as_ndarray(self, int height, int width, int channels, char * pixels):
         cdef np.npy_intp shape[3]
-        cdef np.ndarray ndarray
+        cdef np.ndarray[DTYPE_t, ndim=3] ndarray
         self.pixels = pixels
         shape[:] = (height, width, channels)
         ndarray = np.PyArray_SimpleNewFromData(3, shape, np.NPY_UINT8, self.pixels)
@@ -52,12 +53,14 @@ cpdef int write(filename, unsigned char[:,:,::1] rgb, colorspace: QOIColorSpace
         # Makes a contiguous copy of the numpy array so we can process bytes directly:
         # rgb = np.ascontiguousarray(rgb)
 
-    cdef int bytes_written = qoi.qoi_write(_filename, &rgb[0][0][0], &desc)
+    cdef int bytes_written
+    with nogil:
+        bytes_written = qoi.qoi_write(_filename, &rgb[0][0][0], &desc)
     if bytes_written == 0:
         raise RuntimeError("Failed to write!")
     return bytes_written
 
-cpdef np.ndarray read(filename, int channels = 0, unsigned char[::1] colorspace = bytearray(1)):
+cpdef np.ndarray[DTYPE_t, ndim=3] read(filename, int channels = 0, unsigned char[::1] colorspace = bytearray(1)):
     # TODO: how to return desc.colorspace? A: How about return a tuple of ndarray and a wrapper around struct qoi_desc? or we can add another param like char[:] to simulate pointer
     cdef bytes filename_bytes
     cdef char* _filename
@@ -71,8 +74,8 @@ cpdef np.ndarray read(filename, int channels = 0, unsigned char[::1] colorspace
     filename_bytes = str(filename).encode('utf8')
     _filename = filename_bytes
 
-
-    pixels = <char *>qoi.qoi_read(_filename, &desc, channels)
+    with nogil:
+        pixels = <char *>qoi.qoi_read(_filename, &desc, channels)
     if pixels is NULL:
         raise RuntimeError("Failed to read!")
     try:
@@ -97,7 +100,8 @@ cpdef bytes encode(unsigned char[:,:,::1] rgb, colorspace: QOIColorSpace = QOICo
 
     # if not rgb.flags['C_CONTIGUOUS']:
     #     rgb = np.ascontiguousarray(rgb) # makes a contiguous copy of the numpy array so we can read memory directly
-    encoded = <char *>qoi.qoi_encode(&rgb[0][0][0], &desc, &size)
+    with nogil:
+        encoded = <char *>qoi.qoi_encode(&rgb[0][0][0], &desc, &size)
     if encoded is NULL or size <= 0:
         raise RuntimeError("Failed to encode!")
     try:
@@ -106,12 +110,13 @@ cpdef bytes encode(unsigned char[:,:,::1] rgb, colorspace: QOIColorSpace = QOICo
     finally:
         PyMem_Free(encoded)
 
-cpdef np.ndarray decode(const unsigned char[::1] data, int channels = 0, unsigned char[::1] colorspace = bytearray(1)):
+cpdef np.ndarray[DTYPE_t, ndim=3] decode(const unsigned char[::1] data, int channels = 0, unsigned char[::1] colorspace = bytearray(1)):
     # TODO: what to do about desc.colorspace? A: How about return a tuple of ndarray and a wrapper around struct qoi_desc? or we can add another param like char[:] to simulate pointer
     cdef qoi.qoi_desc desc
     cdef int ret
     cdef char * pixels
-    pixels = <char *>qoi.qoi_decode(&data[0], <int>data.shape[0], &desc, channels)
+    with nogil:
+        pixels = <char *>qoi.qoi_decode(&data[0], <int>data.shape[0], &desc, channels)
     if pixels is NULL:
         raise RuntimeError("Failed to decode!")
     try:

tests/test_multithread.py

@@ -0,0 +1,24 @@
+from concurrent.futures import ThreadPoolExecutor, wait
+
+import numpy as np
+
+import qoi
+
+RGB = np.random.randint(low=0, high=255, size=(224, 244, 3)).astype(np.uint8)
+RGBA = np.random.randint(low=0, high=255, size=(224, 244, 4)).astype(np.uint8)
+
+
+def worker():
+    bites = bytearray(qoi.encode(RGB))
+    img_decoded = qoi.decode(bites)
+    # print("done")
+
+
+def main():
+    with ThreadPoolExecutor(8) as pool:
+        futures = [pool.submit(worker) for _ in range(10000)]
+        wait(futures)
+    print("Did you see that in top? Congratulations you have bypass the gil")
+
+if __name__ == "__main__":
+    main()