Commit d6481709 authored by Nika Layzell's avatar Nika Layzell
Browse files

Bug 1822863 - Use `Span<...>` in IPDL send signatures, r=ipc-reviewers,mccr8 

This should make it possible to send data without copying in some
situations.

This requires adding the `rightconst` attribute to the C++ `Type` type
in order to allow specifying `Span<PFoo* const>`, which isn't possible
to specify with a left const. The type is getting very gross with all of
these flags and it's probably worth switching it to be a recursive
type at this point.

Differential Revision: https://phabricator.services.mozilla.com/D173570
parent 2b45e5a7

dom/ipc/ContentChild.cpp

+2 −2
Original line number Diff line number Diff line
@@ -3144,7 +3144,7 @@ mozilla::ipc::IPCResult ContentChild::RecvUpdateWindow( 


PContentPermissionRequestChild*

ContentChild::AllocPContentPermissionRequestChild(

    const nsTArray<PermissionRequest>& aRequests, nsIPrincipal* aPrincipal,

    Span<const PermissionRequest> aRequests, nsIPrincipal* aPrincipal,

    nsIPrincipal* aTopLevelPrincipal, const bool& aIsHandlingUserInput,

    const bool& aMaybeUnsafePermissionDelegate, const TabId& aTabId) {

  MOZ_CRASH("unused");
@@ -3422,7 +3422,7 @@ bool ContentChild::DeallocPURLClassifierChild(PURLClassifierChild* aActor) { 
}



PURLClassifierLocalChild* ContentChild::AllocPURLClassifierLocalChild(

    nsIURI* aUri, const nsTArray<IPCURLClassifierFeature>& aFeatures) {

    nsIURI* aUri, Span<const IPCURLClassifierFeature> aFeatures) {

  return new URLClassifierLocalChild();

}

dom/ipc/ContentChild.h

+2 −2
Original line number Diff line number Diff line
@@ -481,7 +481,7 @@ class ContentChild final : public PContentChild, 
#endif



  PContentPermissionRequestChild* AllocPContentPermissionRequestChild(

      const nsTArray<PermissionRequest>& aRequests, nsIPrincipal* aPrincipal,

      Span<const PermissionRequest> aRequests, nsIPrincipal* aPrincipal,

      nsIPrincipal* aTopLevelPrincipal, const bool& aIsHandlingUserInput,

      const bool& aMaybeUnsafePermissionDelegate, const TabId& aTabId);

  bool DeallocPContentPermissionRequestChild(
@@ -565,7 +565,7 @@ class ContentChild final : public PContentChild, 


  // PURLClassifierLocalChild

  PURLClassifierLocalChild* AllocPURLClassifierLocalChild(

      nsIURI* aUri, const nsTArray<IPCURLClassifierFeature>& aFeatures);

      nsIURI* aUri, Span<const IPCURLClassifierFeature> aFeatures);

  bool DeallocPURLClassifierLocalChild(PURLClassifierLocalChild* aActor);



  PLoginReputationChild* AllocPLoginReputationChild(nsIURI* aUri);

ipc/chromium/src/chrome/common/ipc_message_utils.h

+9 −0
Original line number Diff line number Diff line
@@ -1015,6 +1015,15 @@ struct ParamTraitsIPC<mozilla::UniqueMachSendRight> { 
template <class P>

struct ParamTraitsMozilla : ParamTraitsIPC<P> {};



// Sending-only specialization for mozilla::Span<T const>. Uses an identical

// serialization format as `const nsTArray<T>&`.

template <class T>

struct ParamTraitsMozilla<mozilla::Span<const T>> {

  static void Write(MessageWriter* writer, mozilla::Span<const T> p) {

    WriteSequenceParam<const T>(writer, p.Elements(), p.Length());

  }

};



template <>

struct ParamTraitsMozilla<nsresult> {

  typedef nsresult param_type;

ipc/ipdl/ipdl/cxx/ast.py

+6 −0
Original line number Diff line number Diff line
@@ -366,6 +366,7 @@ class Type(Node): 
        ptrconstptr=False,

        ref=False,

        rvalref=False,

        rightconst=False,

        hasimplicitcopyctor=True,

        T=None,

        inner=None,
@@ -384,6 +385,8 @@ class Type(Node): 
          rvalref        => T&&



        Any type, naked or pointer, can be const (const T) or ref (T&)."""

        # XXX(nika): This type is complex enough at this point, perhaps we

        # should get "fancy with recursive types" to simplify it.

        assert isinstance(name, str)

        assert isinstance(const, bool)

        assert isinstance(ptr, bool)
@@ -391,6 +394,7 @@ class Type(Node): 
        assert isinstance(ptrconstptr, bool)

        assert isinstance(ref, bool)

        assert isinstance(rvalref, bool)

        assert isinstance(rightconst, bool)

        assert not isinstance(T, str)



        Node.__init__(self)
@@ -401,6 +405,7 @@ class Type(Node): 
        self.ptrconstptr = ptrconstptr

        self.ref = ref

        self.rvalref = rvalref

        self.rightconst = rightconst

        self.hasimplicitcopyctor = hasimplicitcopyctor

        self.T = T

        self.inner = inner
@@ -416,6 +421,7 @@ class Type(Node): 
            ptrconstptr=self.ptrconstptr,

            ref=self.ref,

            rvalref=self.rvalref,

            rightconst=self.rightconst,

            T=copy.deepcopy(self.T, memo),

            inner=copy.deepcopy(self.inner, memo),

        )

ipc/ipdl/ipdl/cxx/cgen.py

+2 −0
Original line number Diff line number Diff line
@@ -76,6 +76,8 @@ class CxxCodeGen(CodePrinter, Visitor): 
            ts += "&"

        elif t.rvalref:

            ts += "&&"

        elif t.rightconst:

            ts += " const"



        self.write(ts)