Make av/opaque pure

Author: WyattBlue

av/opaque.py

@@ -0,0 +1,63 @@
+# type:ignore
+import cython
+import cython.cimports.libav as lib
+from cython import NULL, sizeof
+from cython.cimports.libc.stdint import uint8_t, uintptr_t
+from cython.cimports.libc.string import memcpy
+
+u8ptr = cython.typedef(cython.pointer[uint8_t])
+
+
+@cython.cfunc
+@cython.exceptval(check=False)
+@cython.nogil
+def noop_free(opaque: cython.p_void, data: u8ptr) -> cython.void:
+    pass
+
+
+@cython.cfunc
+@cython.exceptval(check=False)
+@cython.nogil
+def key_free(opaque: cython.p_void, data: u8ptr) -> cython.void:
+    name: cython.p_char = cython.cast(cython.p_char, data)
+    with cython.gil:
+        opaque_container.pop(name)
+
+
+@cython.cclass
+class OpaqueContainer:
+    def __cinit__(self):
+        self._objects = {}
+
+    @cython.cfunc
+    def add(self, v: object) -> cython.pointer[lib.AVBufferRef]:
+        # Use object's memory address as key
+        key: uintptr_t = cython.cast(cython.longlong, id(v))
+        self._objects[key] = v
+
+        data: u8ptr = cython.cast(u8ptr, lib.av_malloc(sizeof(uintptr_t)))
+        if data == NULL:
+            raise MemoryError("Failed to allocate memory for key")
+
+        memcpy(data, cython.address(key), sizeof(uintptr_t))
+
+        # Create the buffer with our free callback
+        buffer_ref: cython.pointer[lib.AVBufferRef] = lib.av_buffer_create(
+            data, sizeof(uintptr_t), key_free, NULL, 0
+        )
+
+        if buffer_ref == NULL:
+            raise MemoryError("Failed to create AVBufferRef")
+
+        return buffer_ref
+
+    def get(self, name) -> object:
+        key: uintptr_t = cython.cast(cython.pointer[uintptr_t], name)[0]
+        return self._objects.get(key)
+
+    def pop(self, name) -> object:
+        key: uintptr_t = cython.cast(cython.pointer[uintptr_t], name)[0]
+        return self._objects.pop(key, None)
+
+
+opaque_container: OpaqueContainer = OpaqueContainer()