| Message ID | 20220401224104.145961-6-victortoso@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | qapi: add generator for Golang interface | expand |
On Sat, Apr 02, 2022 at 12:41:01AM +0200, Victor Toso wrote: > This patch handles QAPI event types and generates data structures in > Go that handles it. > > At the moment of this writing, it generates 51 structures (49 events) > > In Golang, each event is handled as a Go structure and there is no big > difference, in the Go generated code, between what is a QAPI event > type and what is a QAPI struct. > > Each QAPI event has the suffix 'Event' in its Golang data structure > and contains the fields, mandatory and optional, that can be > sent or received. > > In addition, there are two structures added to handle QAPI > specification for event types: 'Event' and 'EventBase'. > > 'EventBase' contains @Name and @Timestamp fields and then 'Event' > extends 'EventBase' with an @Arg field of type 'Any'. Again, I don't think we should need to use an Any type here. Rather than type EventBase struct { Name string `json:"event"` Timestamp struct { Seconds int64 `json:"seconds"` Microseconds int64 `json:"microseconds"` } `json:"timestamp"` } type Event struct { EventBase Arg Any `json:"data,omitempty"` } type ShutdownEvent struct { Guest bool `json:"guest"` Reason ShutdownCause `json:"reason"` } I think we should just embed EventBase directly in each specific event eg type Event struct { Name string `json:"event"` Timestamp struct { Seconds int64 `json:"seconds"` Microseconds int64 `json:"microseconds"` } `json:"timestamp"` } type ShutdownEvent struct { Event Event Guest bool `json:"guest"` Reason ShutdownCause `json:"reason"` } Or perhaps better still, use an interface type Event interface { GetName() string GetTimestamp() string } type Timestamp struct { Seconds int64 `json:"seconds"` Microseconds int64 `json:"microseconds"` } type ShutdownEvent struct { Timestamp Timestamp `json:"timestamp"` Guest bool `json:"guest"` Reason ShutdownCause `json:"reason"` } func (ev *ShutdownEvent) GetName() string { return "SHUTDOWN" } That way you can define public APIs taking 'Event' as a type, and impls of the events can be passed directly in/out. Similar comment for the Command type. > > The 'Event' type implements the Unmarshaler to decode the QMP JSON > Object into the correct Golang (event) struct. The goal here is to > facilitate receiving Events. > > A TODO for this type is to implement Marshaler for 'Event'. It'll > containt runtime checks to validate before transforming the struct > into a JSON Object. > > Example: > ```go > qmpMsg := `{ > "event" : "MIGRATION", > "timestamp":{ > "seconds": 1432121972, > "microseconds": 744001 > }, > "data":{ > "status": "completed" > } > }` > > e := Event{} > _ = json.Unmarshal([]byte(qmpMsg), &e) > // e.Name == "MIGRATION" > // e.Arg.(MigrationEvent).Status == MigrationStatusCompleted > ``` > > Signed-off-by: Victor Toso <victortoso@redhat.com> > --- > scripts/qapi/golang.py | 92 ++++++++++++++++++++++++++++++++++++++---- > 1 file changed, 84 insertions(+), 8 deletions(-) > > diff --git a/scripts/qapi/golang.py b/scripts/qapi/golang.py > index 0a1bf430ba..3bb66d07c7 100644 > --- a/scripts/qapi/golang.py > +++ b/scripts/qapi/golang.py > @@ -31,9 +31,10 @@ class QAPISchemaGenGolangVisitor(QAPISchemaVisitor): > > def __init__(self, prefix: str): > super().__init__() > - self.target = {name: "" for name in ["alternate", "enum", "helper", "struct", "union"]} > + self.target = {name: "" for name in ["alternate", "enum", "event", "helper", "struct", "union"]} > self.objects_seen = {} > self.schema = None > + self.events = {} > self._docmap = {} > self.golang_package_name = "qapi" > > @@ -57,6 +58,24 @@ def visit_begin(self, schema): > def visit_end(self): > self.schema = None > > + # EventBase and Event are not specified in the QAPI schema, > + # so we need to generate it ourselves. > + self.target["event"] += ''' > +type EventBase struct { > + Name string `json:"event"` > + Timestamp struct { > + Seconds int64 `json:"seconds"` > + Microseconds int64 `json:"microseconds"` > + } `json:"timestamp"` > +} > + > +type Event struct { > + EventBase > + Arg Any `json:"data,omitempty"` > +} > +''' > + self.target["event"] += generate_marshal_methods('Event', self.events) > + > self.target["helper"] += ''' > // Creates a decoder that errors on unknown Fields > // Returns true if successfully decoded @from string @into type > @@ -279,7 +298,28 @@ def visit_command(self, > pass > > def visit_event(self, name, info, ifcond, features, arg_type, boxed): > - pass > + assert name == info.defn_name > + type_name = qapi_to_go_type_name(name, info.defn_meta) > + self.events[name] = type_name > + > + doc = self._docmap.get(name, None) > + self_contained = True if not arg_type or not arg_type.name.startswith("q_obj") else False > + content = "" > + if self_contained: > + doc_struct, _ = qapi_to_golang_struct_docs(doc) > + content = generate_struct_type(type_name, "", doc_struct) > + else: > + assert isinstance(arg_type, QAPISchemaObjectType) > + content = qapi_to_golang_struct(name, > + doc, > + arg_type.info, > + arg_type.ifcond, > + arg_type.features, > + arg_type.base, > + arg_type.members, > + arg_type.variants) > + > + self.target["event"] += content > > def write(self, output_dir: str) -> None: > for module_name, content in self.target.items(): > @@ -351,15 +391,41 @@ def generate_marshal_methods_enum(members: List[QAPISchemaEnumMember]) -> str: > }} > ''' > > -# Marshal methods for Union types > +# Marshal methods for Event and Union types > def generate_marshal_methods(type: str, > type_dict: Dict[str, str], > discriminator: str = "", > base: str = "") -> str: > - assert base != "" > - discriminator = "base." + discriminator > - > - switch_case_format = ''' > + type_is_union = False > + json_field = "" > + struct_field = "" > + if type == "Event": > + base = type + "Base" > + discriminator = "base.Name" > + struct_field = "Arg" > + json_field = "data" > + else: > + assert base != "" > + discriminator = "base." + discriminator > + type_is_union = True > + > + switch_case_format = "" > + if not type_is_union: > + switch_case_format = ''' > + case "{name}": > + tmp := struct {{ > + Value {isptr}{case_type} `json:"{json_field},omitempty"` > + }}{{}} > + if err := json.Unmarshal(data, &tmp); err != nil {{ > + return err > + }} > + if tmp.Value == nil {{ > + s.{struct_field} = nil > + }} else {{ > + s.{struct_field} = {isptr}tmp.Value > + }}''' > + else: > + switch_case_format = ''' > case {name}: > value := {case_type}{{}} > if err := json.Unmarshal(data, &value); err != nil {{ > @@ -374,12 +440,17 @@ def generate_marshal_methods(type: str, > case_type = type_dict[name] > isptr = "*" if case_type[0] not in "*[" else "" > switch_cases += switch_case_format.format(name = name, > + struct_field = struct_field, > + json_field = json_field, > + isptr = isptr, > case_type = case_type) > if case_type not in added: > if_supported_types += f'''typestr != "{case_type}" &&\n\t\t''' > added[case_type] = True > > - marshalfn = f''' > + marshalfn = "" > + if type_is_union: > + marshalfn = f''' > func (s {type}) MarshalJSON() ([]byte, error) {{ > base, err := json.Marshal(s.{base}) > if err != nil {{ > @@ -564,4 +635,9 @@ def qapi_to_go_type_name(name: str, meta: str) -> str: > words = [word for word in name.replace("_", "-").split("-")] > name = words[0].title() if words[0].islower() or words[0].isupper() else words[0] > name += ''.join(word.title() for word in words[1:]) > + > + if meta == "event": > + name = name[:-3] if name.endswith("Arg") else name > + name += meta.title() > + > return name > -- > 2.35.1 > > With regards, Daniel
Hi, On Tue, May 10, 2022 at 11:42:10AM +0100, Daniel P. Berrangé wrote: > On Sat, Apr 02, 2022 at 12:41:01AM +0200, Victor Toso wrote: > > This patch handles QAPI event types and generates data structures in > > Go that handles it. > > > > At the moment of this writing, it generates 51 structures (49 events) > > > > In Golang, each event is handled as a Go structure and there is no big > > difference, in the Go generated code, between what is a QAPI event > > type and what is a QAPI struct. > > > > Each QAPI event has the suffix 'Event' in its Golang data structure > > and contains the fields, mandatory and optional, that can be > > sent or received. > > > > In addition, there are two structures added to handle QAPI > > specification for event types: 'Event' and 'EventBase'. > > > > 'EventBase' contains @Name and @Timestamp fields and then 'Event' > > extends 'EventBase' with an @Arg field of type 'Any'. > > Again, I don't think we should need to use an Any type here. > > Rather than > > type EventBase struct { > Name string `json:"event"` > Timestamp struct { > Seconds int64 `json:"seconds"` > Microseconds int64 `json:"microseconds"` > } `json:"timestamp"` > } > > type Event struct { > EventBase > Arg Any `json:"data,omitempty"` > } > > type ShutdownEvent struct { > Guest bool `json:"guest"` > Reason ShutdownCause `json:"reason"` > } > > > I think we should just embed EventBase directly in each specific > event eg > > > type Event struct { > Name string `json:"event"` > Timestamp struct { > Seconds int64 `json:"seconds"` > Microseconds int64 `json:"microseconds"` > } `json:"timestamp"` > } > > type ShutdownEvent struct { > Event Event > Guest bool `json:"guest"` > Reason ShutdownCause `json:"reason"` > } > > > Or perhaps better still, use an interface > > type Event interface { > GetName() string > GetTimestamp() string > } > > type Timestamp struct { > Seconds int64 `json:"seconds"` > Microseconds int64 `json:"microseconds"` > } > > type ShutdownEvent struct { > Timestamp Timestamp `json:"timestamp"` > Guest bool `json:"guest"` > Reason ShutdownCause `json:"reason"` > } > > func (ev *ShutdownEvent) GetName() string { > return "SHUTDOWN" > } > > That way you can define public APIs taking 'Event' as a type, > and impls of the events can be passed directly in/out. > > Similar comment for the Command type. Yeah, if we are removing Any for Unions and Alternates, we can sure do the same for Events and Commands. > > The 'Event' type implements the Unmarshaler to decode the QMP JSON > > Object into the correct Golang (event) struct. The goal here is to > > facilitate receiving Events. > > > > A TODO for this type is to implement Marshaler for 'Event'. It'll > > containt runtime checks to validate before transforming the struct > > into a JSON Object. > > > > Example: > > ```go > > qmpMsg := `{ > > "event" : "MIGRATION", > > "timestamp":{ > > "seconds": 1432121972, > > "microseconds": 744001 > > }, > > "data":{ > > "status": "completed" > > } > > }` > > > > e := Event{} > > _ = json.Unmarshal([]byte(qmpMsg), &e) > > // e.Name == "MIGRATION" > > // e.Arg.(MigrationEvent).Status == MigrationStatusCompleted > > ``` > > > > Signed-off-by: Victor Toso <victortoso@redhat.com> > > --- > > scripts/qapi/golang.py | 92 ++++++++++++++++++++++++++++++++++++++---- > > 1 file changed, 84 insertions(+), 8 deletions(-) > > > > diff --git a/scripts/qapi/golang.py b/scripts/qapi/golang.py > > index 0a1bf430ba..3bb66d07c7 100644 > > --- a/scripts/qapi/golang.py > > +++ b/scripts/qapi/golang.py > > @@ -31,9 +31,10 @@ class QAPISchemaGenGolangVisitor(QAPISchemaVisitor): > > > > def __init__(self, prefix: str): > > super().__init__() > > - self.target = {name: "" for name in ["alternate", "enum", "helper", "struct", "union"]} > > + self.target = {name: "" for name in ["alternate", "enum", "event", "helper", "struct", "union"]} > > self.objects_seen = {} > > self.schema = None > > + self.events = {} > > self._docmap = {} > > self.golang_package_name = "qapi" > > > > @@ -57,6 +58,24 @@ def visit_begin(self, schema): > > def visit_end(self): > > self.schema = None > > > > + # EventBase and Event are not specified in the QAPI schema, > > + # so we need to generate it ourselves. > > + self.target["event"] += ''' > > +type EventBase struct { > > + Name string `json:"event"` > > + Timestamp struct { > > + Seconds int64 `json:"seconds"` > > + Microseconds int64 `json:"microseconds"` > > + } `json:"timestamp"` > > +} > > + > > +type Event struct { > > + EventBase > > + Arg Any `json:"data,omitempty"` > > +} > > +''' > > + self.target["event"] += generate_marshal_methods('Event', self.events) > > + > > self.target["helper"] += ''' > > // Creates a decoder that errors on unknown Fields > > // Returns true if successfully decoded @from string @into type > > @@ -279,7 +298,28 @@ def visit_command(self, > > pass > > > > def visit_event(self, name, info, ifcond, features, arg_type, boxed): > > - pass > > + assert name == info.defn_name > > + type_name = qapi_to_go_type_name(name, info.defn_meta) > > + self.events[name] = type_name > > + > > + doc = self._docmap.get(name, None) > > + self_contained = True if not arg_type or not arg_type.name.startswith("q_obj") else False > > + content = "" > > + if self_contained: > > + doc_struct, _ = qapi_to_golang_struct_docs(doc) > > + content = generate_struct_type(type_name, "", doc_struct) > > + else: > > + assert isinstance(arg_type, QAPISchemaObjectType) > > + content = qapi_to_golang_struct(name, > > + doc, > > + arg_type.info, > > + arg_type.ifcond, > > + arg_type.features, > > + arg_type.base, > > + arg_type.members, > > + arg_type.variants) > > + > > + self.target["event"] += content > > > > def write(self, output_dir: str) -> None: > > for module_name, content in self.target.items(): > > @@ -351,15 +391,41 @@ def generate_marshal_methods_enum(members: List[QAPISchemaEnumMember]) -> str: > > }} > > ''' > > > > -# Marshal methods for Union types > > +# Marshal methods for Event and Union types > > def generate_marshal_methods(type: str, > > type_dict: Dict[str, str], > > discriminator: str = "", > > base: str = "") -> str: > > - assert base != "" > > - discriminator = "base." + discriminator > > - > > - switch_case_format = ''' > > + type_is_union = False > > + json_field = "" > > + struct_field = "" > > + if type == "Event": > > + base = type + "Base" > > + discriminator = "base.Name" > > + struct_field = "Arg" > > + json_field = "data" > > + else: > > + assert base != "" > > + discriminator = "base." + discriminator > > + type_is_union = True > > + > > + switch_case_format = "" > > + if not type_is_union: > > + switch_case_format = ''' > > + case "{name}": > > + tmp := struct {{ > > + Value {isptr}{case_type} `json:"{json_field},omitempty"` > > + }}{{}} > > + if err := json.Unmarshal(data, &tmp); err != nil {{ > > + return err > > + }} > > + if tmp.Value == nil {{ > > + s.{struct_field} = nil > > + }} else {{ > > + s.{struct_field} = {isptr}tmp.Value > > + }}''' > > + else: > > + switch_case_format = ''' > > case {name}: > > value := {case_type}{{}} > > if err := json.Unmarshal(data, &value); err != nil {{ > > @@ -374,12 +440,17 @@ def generate_marshal_methods(type: str, > > case_type = type_dict[name] > > isptr = "*" if case_type[0] not in "*[" else "" > > switch_cases += switch_case_format.format(name = name, > > + struct_field = struct_field, > > + json_field = json_field, > > + isptr = isptr, > > case_type = case_type) > > if case_type not in added: > > if_supported_types += f'''typestr != "{case_type}" &&\n\t\t''' > > added[case_type] = True > > > > - marshalfn = f''' > > + marshalfn = "" > > + if type_is_union: > > + marshalfn = f''' > > func (s {type}) MarshalJSON() ([]byte, error) {{ > > base, err := json.Marshal(s.{base}) > > if err != nil {{ > > @@ -564,4 +635,9 @@ def qapi_to_go_type_name(name: str, meta: str) -> str: > > words = [word for word in name.replace("_", "-").split("-")] > > name = words[0].title() if words[0].islower() or words[0].isupper() else words[0] > > name += ''.join(word.title() for word in words[1:]) > > + > > + if meta == "event": > > + name = name[:-3] if name.endswith("Arg") else name > > + name += meta.title() > > + > > return name > > -- > > 2.35.1 > > > > > > With regards, > Daniel > -- > |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| Cheers, Victor
diff --git a/scripts/qapi/golang.py b/scripts/qapi/golang.py index 0a1bf430ba..3bb66d07c7 100644 --- a/scripts/qapi/golang.py +++ b/scripts/qapi/golang.py @@ -31,9 +31,10 @@ class QAPISchemaGenGolangVisitor(QAPISchemaVisitor): def __init__(self, prefix: str): super().__init__() - self.target = {name: "" for name in ["alternate", "enum", "helper", "struct", "union"]} + self.target = {name: "" for name in ["alternate", "enum", "event", "helper", "struct", "union"]} self.objects_seen = {} self.schema = None + self.events = {} self._docmap = {} self.golang_package_name = "qapi" @@ -57,6 +58,24 @@ def visit_begin(self, schema): def visit_end(self): self.schema = None + # EventBase and Event are not specified in the QAPI schema, + # so we need to generate it ourselves. + self.target["event"] += ''' +type EventBase struct { + Name string `json:"event"` + Timestamp struct { + Seconds int64 `json:"seconds"` + Microseconds int64 `json:"microseconds"` + } `json:"timestamp"` +} + +type Event struct { + EventBase + Arg Any `json:"data,omitempty"` +} +''' + self.target["event"] += generate_marshal_methods('Event', self.events) + self.target["helper"] += ''' // Creates a decoder that errors on unknown Fields // Returns true if successfully decoded @from string @into type @@ -279,7 +298,28 @@ def visit_command(self, pass def visit_event(self, name, info, ifcond, features, arg_type, boxed): - pass + assert name == info.defn_name + type_name = qapi_to_go_type_name(name, info.defn_meta) + self.events[name] = type_name + + doc = self._docmap.get(name, None) + self_contained = True if not arg_type or not arg_type.name.startswith("q_obj") else False + content = "" + if self_contained: + doc_struct, _ = qapi_to_golang_struct_docs(doc) + content = generate_struct_type(type_name, "", doc_struct) + else: + assert isinstance(arg_type, QAPISchemaObjectType) + content = qapi_to_golang_struct(name, + doc, + arg_type.info, + arg_type.ifcond, + arg_type.features, + arg_type.base, + arg_type.members, + arg_type.variants) + + self.target["event"] += content def write(self, output_dir: str) -> None: for module_name, content in self.target.items(): @@ -351,15 +391,41 @@ def generate_marshal_methods_enum(members: List[QAPISchemaEnumMember]) -> str: }} ''' -# Marshal methods for Union types +# Marshal methods for Event and Union types def generate_marshal_methods(type: str, type_dict: Dict[str, str], discriminator: str = "", base: str = "") -> str: - assert base != "" - discriminator = "base." + discriminator - - switch_case_format = ''' + type_is_union = False + json_field = "" + struct_field = "" + if type == "Event": + base = type + "Base" + discriminator = "base.Name" + struct_field = "Arg" + json_field = "data" + else: + assert base != "" + discriminator = "base." + discriminator + type_is_union = True + + switch_case_format = "" + if not type_is_union: + switch_case_format = ''' + case "{name}": + tmp := struct {{ + Value {isptr}{case_type} `json:"{json_field},omitempty"` + }}{{}} + if err := json.Unmarshal(data, &tmp); err != nil {{ + return err + }} + if tmp.Value == nil {{ + s.{struct_field} = nil + }} else {{ + s.{struct_field} = {isptr}tmp.Value + }}''' + else: + switch_case_format = ''' case {name}: value := {case_type}{{}} if err := json.Unmarshal(data, &value); err != nil {{ @@ -374,12 +440,17 @@ def generate_marshal_methods(type: str, case_type = type_dict[name] isptr = "*" if case_type[0] not in "*[" else "" switch_cases += switch_case_format.format(name = name, + struct_field = struct_field, + json_field = json_field, + isptr = isptr, case_type = case_type) if case_type not in added: if_supported_types += f'''typestr != "{case_type}" &&\n\t\t''' added[case_type] = True - marshalfn = f''' + marshalfn = "" + if type_is_union: + marshalfn = f''' func (s {type}) MarshalJSON() ([]byte, error) {{ base, err := json.Marshal(s.{base}) if err != nil {{ @@ -564,4 +635,9 @@ def qapi_to_go_type_name(name: str, meta: str) -> str: words = [word for word in name.replace("_", "-").split("-")] name = words[0].title() if words[0].islower() or words[0].isupper() else words[0] name += ''.join(word.title() for word in words[1:]) + + if meta == "event": + name = name[:-3] if name.endswith("Arg") else name + name += meta.title() + return name
This patch handles QAPI event types and generates data structures in Go that handles it. At the moment of this writing, it generates 51 structures (49 events) In Golang, each event is handled as a Go structure and there is no big difference, in the Go generated code, between what is a QAPI event type and what is a QAPI struct. Each QAPI event has the suffix 'Event' in its Golang data structure and contains the fields, mandatory and optional, that can be sent or received. In addition, there are two structures added to handle QAPI specification for event types: 'Event' and 'EventBase'. 'EventBase' contains @Name and @Timestamp fields and then 'Event' extends 'EventBase' with an @Arg field of type 'Any'. The 'Event' type implements the Unmarshaler to decode the QMP JSON Object into the correct Golang (event) struct. The goal here is to facilitate receiving Events. A TODO for this type is to implement Marshaler for 'Event'. It'll containt runtime checks to validate before transforming the struct into a JSON Object. Example: ```go qmpMsg := `{ "event" : "MIGRATION", "timestamp":{ "seconds": 1432121972, "microseconds": 744001 }, "data":{ "status": "completed" } }` e := Event{} _ = json.Unmarshal([]byte(qmpMsg), &e) // e.Name == "MIGRATION" // e.Arg.(MigrationEvent).Status == MigrationStatusCompleted ``` Signed-off-by: Victor Toso <victortoso@redhat.com> --- scripts/qapi/golang.py | 92 ++++++++++++++++++++++++++++++++++++++---- 1 file changed, 84 insertions(+), 8 deletions(-)