dawn_wire: use memcpy on structures when possible
This patch sets 'is_wire_transparent' on the structures whose members
are all wire transparent and are not pointers, so that we can use
memcpy when serializing and deserializing these structures:
- GPUBlendComponent
- GPUColor
- GPUExtent3D
- GPULimits
- GPUOrigin3D
- GPUStencilFaceState
- GPUVertexAttribute
- GPUBlendState
In the next patch we will support memcpy on the qualified structures
whose members contain pointers (e.g. GPUVertexBufferLayout).
BUG=chromium:1266727
Change-Id: If46289f2d10cc7b17e6f5330cd2c2d4dc481f8b9
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/73000
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>
diff --git a/generator/dawn_json_generator.py b/generator/dawn_json_generator.py
index 60dfbe7..6a89240 100644
--- a/generator/dawn_json_generator.py
+++ b/generator/dawn_json_generator.py
@@ -242,6 +242,21 @@
# two nextInChain members.
assert not (self.extensible and self.chained)
+ def update_metadata(self):
+ Record.update_metadata(self)
+
+ if self.may_have_dawn_object:
+ self.is_wire_transparent = False
+ return
+
+ assert not (self.chained or self.extensible)
+
+ def get_is_wire_transparent(member):
+ return member.type.is_wire_transparent and member.annotation == 'value'
+
+ self.is_wire_transparent = all(
+ get_is_wire_transparent(m) for m in self.members)
+
@property
def output(self):
return self.chained == "out" or self.extensible == "out"
diff --git a/generator/templates/dawn_wire/WireCmd.cpp b/generator/templates/dawn_wire/WireCmd.cpp
index 0eb1bd1..7bc148f 100644
--- a/generator/templates/dawn_wire/WireCmd.cpp
+++ b/generator/templates/dawn_wire/WireCmd.cpp
@@ -63,9 +63,14 @@
{%- if member.type.category == "object" -%}
{%- set Optional = "Optional" if member.optional else "" -%}
WIRE_TRY(provider.Get{{Optional}}Id({{in}}, &{{out}}));
- {% elif member.type.category == "structure"%}
- {%- set Provider = ", provider" if member.type.may_have_dawn_object else "" -%}
- WIRE_TRY({{as_cType(member.type.name)}}Serialize({{in}}, &{{out}}, buffer{{Provider}}));
+ {%- elif member.type.category == "structure" -%}
+ {%- if member.type.is_wire_transparent -%}
+ static_assert(sizeof({{out}}) == sizeof({{in}}), "Serialize memcpy size must match.");
+ memcpy(&{{out}}, &{{in}}, {{member_transfer_sizeof(member)}});
+ {%- else -%}
+ {%- set Provider = ", provider" if member.type.may_have_dawn_object else "" -%}
+ WIRE_TRY({{as_cType(member.type.name)}}Serialize({{in}}, &{{out}}, buffer{{Provider}}));
+ {%- endif -%}
{%- else -%}
{{out}} = {{in}};
{%- endif -%}
@@ -77,11 +82,16 @@
{%- set Optional = "Optional" if member.optional else "" -%}
WIRE_TRY(resolver.Get{{Optional}}FromId({{in}}, &{{out}}));
{%- elif member.type.category == "structure" -%}
- WIRE_TRY({{as_cType(member.type.name)}}Deserialize(&{{out}}, &{{in}}, deserializeBuffer, allocator
- {%- if member.type.may_have_dawn_object -%}
- , resolver
- {%- endif -%}
- ));
+ {%- if member.type.is_wire_transparent -%}
+ static_assert(sizeof({{out}}) == sizeof({{in}}), "Deserialize memcpy size must match.");
+ memcpy(&{{out}}, const_cast<const {{member_transfer_type(member)}}*>(&{{in}}), {{member_transfer_sizeof(member)}});
+ {%- else -%}
+ WIRE_TRY({{as_cType(member.type.name)}}Deserialize(&{{out}}, &{{in}}, deserializeBuffer, allocator
+ {%- if member.type.may_have_dawn_object -%}
+ , resolver
+ {%- endif -%}
+ ));
+ {%- endif -%}
{%- else -%}
static_assert(sizeof({{out}}) >= sizeof({{in}}), "Deserialize assignment may not narrow.");
{{out}} = {{in}};
