refractor for HHD and depth backend

src/orisys/backend_availability.py

@@ -0,0 +1,152 @@
+"""
+Centralized backend availability checking for GPU acceleration libraries.
+
+This module provides a single source of truth for checking whether CuPy and OpenCL
+are available, avoiding duplicate import checks across the codebase.
+"""
+
+# CuPy availability and related objects
+_cupy_available = False
+_cupy_cp = None
+_cupy_cp_signal = None
+_cupy_streams_available = False
+_cupy_stream = None
+_cupy_torque_kernel = None
+_cupy_kernel_available = False
+
+# OpenCL availability and related objects
+_opencl_available = False
+_opencl_cl = None
+_opencl_cla = None
+_opencl_rfftn = None
+_opencl_irfftn = None
+
+# Try to import CuPy
+try:
+    import cupy as cp
+    import cupyx.scipy.signal as cp_signal
+    _cupy_cp = cp
+    _cupy_cp_signal = cp_signal
+    _cupy_available = True
+    
+    # Try to import CuPy streams for parallel execution
+    try:
+        from cupy.cuda import Stream
+        _cupy_stream = Stream
+        _cupy_streams_available = True
+    except ImportError:
+        _cupy_stream = None
+        _cupy_streams_available = False
+    
+    # Create fused elementwise kernel for torque computation
+    try:
+        _cupy_torque_kernel = cp.ElementwiseKernel(
+            'float32 r_x, float32 r_y, float32 grid_0, float32 grid_1, '
+            'float32 max_0, float32 max_1, float32 min_0, float32 min_1',
+            'float32 torque',
+            '''
+            float cross_p = (grid_0 - max_0) * r_y - (grid_1 - max_1) * r_x;
+            float cross_n = (grid_0 - min_0) * r_y - (grid_1 - min_1) * r_x;
+            torque = cross_p + cross_n;
+            ''',
+            'torque_kernel'
+        )
+        _cupy_kernel_available = True
+    except Exception:
+        _cupy_torque_kernel = None
+        _cupy_kernel_available = False
+        
+except ImportError:
+    pass
+
+# Try to import OpenCL
+try:
+    import pyopencl as cl
+    import pyopencl.array as cla
+    from pyvkfft.fft import rfftn as cl_rfftn
+    from pyvkfft.fft import irfftn as cl_irfftn
+    _opencl_cl = cl
+    _opencl_cla = cla
+    _opencl_rfftn = cl_rfftn
+    _opencl_irfftn = cl_irfftn
+    _opencl_available = True
+except ImportError:
+    pass
+
+
+def check_cupy_available():
+    """Check if CuPy is available."""
+    return _cupy_available
+
+
+def check_opencl_available():
+    """Check if OpenCL/pyvkfft is available."""
+    return _opencl_available
+
+
+def get_cupy():
+    """Get CuPy module if available, None otherwise."""
+    return _cupy_cp
+
+
+def get_cupy_signal():
+    """Get cupyx.scipy.signal module if available, None otherwise."""
+    return _cupy_cp_signal
+
+
+def get_cupy_stream():
+    """Get CuPy Stream class if available, None otherwise."""
+    return _cupy_stream
+
+
+def get_cupy_torque_kernel():
+    """Get CuPy torque kernel if available, None otherwise."""
+    return _cupy_torque_kernel
+
+
+def is_cupy_streams_available():
+    """Check if CuPy streams are available."""
+    return _cupy_streams_available
+
+
+def is_cupy_kernel_available():
+    """Check if CuPy torque kernel is available."""
+    return _cupy_kernel_available
+
+
+def get_opencl():
+    """Get pyopencl module if available, None otherwise."""
+    return _opencl_cl
+
+
+def get_opencl_array():
+    """Get pyopencl.array module if available, None otherwise."""
+    return _opencl_cla
+
+
+def get_opencl_rfftn():
+    """Get pyvkfft.fft.rfftn function if available, None otherwise."""
+    return _opencl_rfftn
+
+
+def get_opencl_irfftn():
+    """Get pyvkfft.fft.irfftn function if available, None otherwise."""
+    return _opencl_irfftn
+
+
+# For backward compatibility, export as module-level constants
+CUPY_AVAILABLE = _cupy_available
+OPENCL_AVAILABLE = _opencl_available
+STREAMS_AVAILABLE = _cupy_streams_available
+KERNEL_AVAILABLE = _cupy_kernel_available
+
+# Export commonly used objects
+cp = _cupy_cp
+cp_signal = _cupy_cp_signal
+Stream = _cupy_stream
+_torque_kernel = _cupy_torque_kernel
+cl = _opencl_cl
+cla = _opencl_cla
+cl_rfftn = _opencl_rfftn
+cl_irfftn = _opencl_irfftn
+