Buffer mapping API (#377)

* I tried many ways, thought I found one, but did not.

* Remove test file again

* New buffer mapping API

* Allow read_mapped to return mapped data without making a copy

* also release memviews on buffer destroy

* Fix current tests

* more buffer tests, fix buffer read issue

* More tests and fixes

* Tests and fixes for copyless buffer reads

* codegen

* 3.7 compat

* Add changelog

* fix

CHANGELOG.md

@@ -25,6 +25,33 @@ Changed:
 * Update to wgpu-native 0.17.2.1. No changes are needed in downstream code.
 
 
+### [v0.11.0] - t.b.d.
+
+We have revised the buffer mapping API, making it more similar to the
+WebGPU spec, and providing more flexible and performant ways to set
+buffer data.
+
+Added:
+
+* The `GPUBuffer` has new methods `map()`, `map_async()`, `unmap()`. These have been
+  part of the WebGPU spec for a long time, but we had an alternative API, until now.
+* The `GPUBuffer` has new methods `read_mapped()` and `write_mapped()`. These are not
+  present in the WebGPU spec; they are the Pythonic alternative to `getMappedRange()`.
+
+Changed:
+
+* Can create a buffer that is initially mapped: `device.create_buffer(..., mapped_at_creation=True)` is enabled again.
+
+Removed:
+
+* The `GPUBuffer` methods `map_read()`and `map_write()` are deprecated, in favor of `map()`, `unmap()`, `read_mapped()` and `write_mapped()`.
+
+For the record, these are not changed:
+
+* The convenient `device.create_buffer_with_data()` (not part of the WebGPU spec) is also available.
+* The `GPUQueue.read_buffer()` and `GPUQueue.write_buffer()` methods are unchanged.
+
+
 ### [v0.10.0] - 09-10-2023
 
 In this release the API is aligned with the latest webgpu.idl, and

codegen/apipatcher.py

@@ -303,6 +303,8 @@ def get_method_def(self, classname, methodname):
         name_idl = self.name2idl(methodname)
         if methodname.endswith("_async") and name_idl not in functions:
             name_idl = self.name2idl(methodname.replace("_async", ""))
+        elif name_idl not in functions and name_idl + "Async" in functions:
+            name_idl += "Async"
         idl_line = functions[name_idl]
 
         # Construct preamble
@@ -369,6 +371,8 @@ def method_is_known(self, classname, methodname):
         name_idl = self.name2idl(methodname)
         if "_async" in methodname and name_idl not in functions:
             name_idl = self.name2idl(methodname.replace("_async", ""))
+        elif name_idl not in functions and name_idl + "Async" in functions:
+            name_idl += "Async"
         return name_idl if name_idl in functions else None
 
     def get_class_names(self):