michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
michael@0: /* vim: set ts=8 sts=4 et sw=4 tw=99: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /* Manage the shared info about interfaces for use by wrappedNatives. */
michael@0: 
michael@0: #include "xpcprivate.h"
michael@0: #include "jswrapper.h"
michael@0: #include "nsCxPusher.h"
michael@0: 
michael@0: #include "mozilla/MemoryReporting.h"
michael@0: #include "mozilla/XPTInterfaceInfoManager.h"
michael@0: 
michael@0: using namespace JS;
michael@0: using namespace mozilla;
michael@0: 
michael@0: /***************************************************************************/
michael@0: 
michael@0: // XPCNativeMember
michael@0: 
michael@0: // static
michael@0: bool
michael@0: XPCNativeMember::GetCallInfo(JSObject* funobj,
michael@0:                              XPCNativeInterface** pInterface,
michael@0:                              XPCNativeMember**    pMember)
michael@0: {
michael@0:     funobj = js::UncheckedUnwrap(funobj);
michael@0:     jsval ifaceVal = js::GetFunctionNativeReserved(funobj, 0);
michael@0:     jsval memberVal = js::GetFunctionNativeReserved(funobj, 1);
michael@0: 
michael@0:     *pInterface = (XPCNativeInterface*) JSVAL_TO_PRIVATE(ifaceVal);
michael@0:     *pMember = (XPCNativeMember*) JSVAL_TO_PRIVATE(memberVal);
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: bool
michael@0: XPCNativeMember::NewFunctionObject(XPCCallContext& ccx,
michael@0:                                    XPCNativeInterface* iface, HandleObject parent,
michael@0:                                    jsval* pval)
michael@0: {
michael@0:     MOZ_ASSERT(!IsConstant(), "Only call this if you're sure this is not a constant!");
michael@0: 
michael@0:     return Resolve(ccx, iface, parent, pval);
michael@0: }
michael@0: 
michael@0: bool
michael@0: XPCNativeMember::Resolve(XPCCallContext& ccx, XPCNativeInterface* iface,
michael@0:                          HandleObject parent, jsval *vp)
michael@0: {
michael@0:     if (IsConstant()) {
michael@0:         const nsXPTConstant* constant;
michael@0:         if (NS_FAILED(iface->GetInterfaceInfo()->GetConstant(mIndex, &constant)))
michael@0:             return false;
michael@0: 
michael@0:         const nsXPTCMiniVariant& mv = *constant->GetValue();
michael@0: 
michael@0:         // XXX Big Hack!
michael@0:         nsXPTCVariant v;
michael@0:         v.flags = 0;
michael@0:         v.type = constant->GetType();
michael@0:         memcpy(&v.val, &mv.val, sizeof(mv.val));
michael@0: 
michael@0:         RootedValue resultVal(ccx);
michael@0: 
michael@0:         if (!XPCConvert::NativeData2JS(&resultVal, &v.val, v.type, nullptr, nullptr))
michael@0:             return false;
michael@0: 
michael@0:         *vp = resultVal;
michael@0: 
michael@0:         return true;
michael@0:     }
michael@0:     // else...
michael@0: 
michael@0:     // This is a method or attribute - we'll be needing a function object
michael@0: 
michael@0:     int argc;
michael@0:     JSNative callback;
michael@0: 
michael@0:     if (IsMethod()) {
michael@0:         const nsXPTMethodInfo* info;
michael@0:         if (NS_FAILED(iface->GetInterfaceInfo()->GetMethodInfo(mIndex, &info)))
michael@0:             return false;
michael@0: 
michael@0:         // Note: ASSUMES that retval is last arg.
michael@0:         argc = (int) info->GetParamCount();
michael@0:         if (argc && info->GetParam((uint8_t)(argc-1)).IsRetval())
michael@0:             argc-- ;
michael@0: 
michael@0:         callback = XPC_WN_CallMethod;
michael@0:     } else {
michael@0:         argc = 0;
michael@0:         callback = XPC_WN_GetterSetter;
michael@0:     }
michael@0: 
michael@0:     JSFunction *fun = js::NewFunctionByIdWithReserved(ccx, callback, argc, 0, parent, GetName());
michael@0:     if (!fun)
michael@0:         return false;
michael@0: 
michael@0:     JSObject* funobj = JS_GetFunctionObject(fun);
michael@0:     if (!funobj)
michael@0:         return false;
michael@0: 
michael@0:     js::SetFunctionNativeReserved(funobj, 0, PRIVATE_TO_JSVAL(iface));
michael@0:     js::SetFunctionNativeReserved(funobj, 1, PRIVATE_TO_JSVAL(this));
michael@0: 
michael@0:     *vp = OBJECT_TO_JSVAL(funobj);
michael@0: 
michael@0:     return true;
michael@0: }
michael@0: 
michael@0: /***************************************************************************/
michael@0: // XPCNativeInterface
michael@0: 
michael@0: // static
michael@0: XPCNativeInterface*
michael@0: XPCNativeInterface::GetNewOrUsed(const nsIID* iid)
michael@0: {
michael@0:     AutoJSContext cx;
michael@0:     AutoMarkingNativeInterfacePtr iface(cx);
michael@0:     XPCJSRuntime* rt = XPCJSRuntime::Get();
michael@0: 
michael@0:     IID2NativeInterfaceMap* map = rt->GetIID2NativeInterfaceMap();
michael@0:     if (!map)
michael@0:         return nullptr;
michael@0: 
michael@0:     iface = map->Find(*iid);
michael@0: 
michael@0:     if (iface)
michael@0:         return iface;
michael@0: 
michael@0:     nsCOMPtr<nsIInterfaceInfo> info;
michael@0:     XPTInterfaceInfoManager::GetSingleton()->GetInfoForIID(iid, getter_AddRefs(info));
michael@0:     if (!info)
michael@0:         return nullptr;
michael@0: 
michael@0:     iface = NewInstance(info);
michael@0:     if (!iface)
michael@0:         return nullptr;
michael@0: 
michael@0:     XPCNativeInterface* iface2 = map->Add(iface);
michael@0:     if (!iface2) {
michael@0:         NS_ERROR("failed to add our interface!");
michael@0:         DestroyInstance(iface);
michael@0:         iface = nullptr;
michael@0:     } else if (iface2 != iface) {
michael@0:         DestroyInstance(iface);
michael@0:         iface = iface2;
michael@0:     }
michael@0: 
michael@0:     return iface;
michael@0: }
michael@0: 
michael@0: // static
michael@0: XPCNativeInterface*
michael@0: XPCNativeInterface::GetNewOrUsed(nsIInterfaceInfo* info)
michael@0: {
michael@0:     AutoJSContext cx;
michael@0:     AutoMarkingNativeInterfacePtr iface(cx);
michael@0: 
michael@0:     const nsIID* iid;
michael@0:     if (NS_FAILED(info->GetIIDShared(&iid)) || !iid)
michael@0:         return nullptr;
michael@0: 
michael@0:     XPCJSRuntime* rt = XPCJSRuntime::Get();
michael@0: 
michael@0:     IID2NativeInterfaceMap* map = rt->GetIID2NativeInterfaceMap();
michael@0:     if (!map)
michael@0:         return nullptr;
michael@0: 
michael@0:     iface = map->Find(*iid);
michael@0: 
michael@0:     if (iface)
michael@0:         return iface;
michael@0: 
michael@0:     iface = NewInstance(info);
michael@0:     if (!iface)
michael@0:         return nullptr;
michael@0: 
michael@0:     XPCNativeInterface* iface2 = map->Add(iface);
michael@0:     if (!iface2) {
michael@0:         NS_ERROR("failed to add our interface!");
michael@0:         DestroyInstance(iface);
michael@0:         iface = nullptr;
michael@0:     } else if (iface2 != iface) {
michael@0:         DestroyInstance(iface);
michael@0:         iface = iface2;
michael@0:     }
michael@0: 
michael@0:     return iface;
michael@0: }
michael@0: 
michael@0: // static
michael@0: XPCNativeInterface*
michael@0: XPCNativeInterface::GetNewOrUsed(const char* name)
michael@0: {
michael@0:     nsCOMPtr<nsIInterfaceInfo> info;
michael@0:     XPTInterfaceInfoManager::GetSingleton()->GetInfoForName(name, getter_AddRefs(info));
michael@0:     return info ? GetNewOrUsed(info) : nullptr;
michael@0: }
michael@0: 
michael@0: // static
michael@0: XPCNativeInterface*
michael@0: XPCNativeInterface::GetISupports()
michael@0: {
michael@0:     // XXX We should optimize this to cache this common XPCNativeInterface.
michael@0:     return GetNewOrUsed(&NS_GET_IID(nsISupports));
michael@0: }
michael@0: 
michael@0: // static
michael@0: XPCNativeInterface*
michael@0: XPCNativeInterface::NewInstance(nsIInterfaceInfo* aInfo)
michael@0: {
michael@0:     AutoJSContext cx;
michael@0:     static const uint16_t MAX_LOCAL_MEMBER_COUNT = 16;
michael@0:     XPCNativeMember local_members[MAX_LOCAL_MEMBER_COUNT];
michael@0:     XPCNativeInterface* obj = nullptr;
michael@0:     XPCNativeMember* members = nullptr;
michael@0: 
michael@0:     int i;
michael@0:     bool failed = false;
michael@0:     uint16_t constCount;
michael@0:     uint16_t methodCount;
michael@0:     uint16_t totalCount;
michael@0:     uint16_t realTotalCount = 0;
michael@0:     XPCNativeMember* cur;
michael@0:     RootedString str(cx);
michael@0:     RootedId interfaceName(cx);
michael@0: 
michael@0:     // XXX Investigate lazy init? This is a problem given the
michael@0:     // 'placement new' scheme - we need to at least know how big to make
michael@0:     // the object. We might do a scan of methods to determine needed size,
michael@0:     // then make our object, but avoid init'ing *any* members until asked?
michael@0:     // Find out how often we create these objects w/o really looking at
michael@0:     // (or using) the members.
michael@0: 
michael@0:     bool canScript;
michael@0:     if (NS_FAILED(aInfo->IsScriptable(&canScript)) || !canScript)
michael@0:         return nullptr;
michael@0: 
michael@0:     if (NS_FAILED(aInfo->GetMethodCount(&methodCount)) ||
michael@0:         NS_FAILED(aInfo->GetConstantCount(&constCount)))
michael@0:         return nullptr;
michael@0: 
michael@0:     // If the interface does not have nsISupports in its inheritance chain
michael@0:     // then we know we can't reflect its methods. However, some interfaces that
michael@0:     // are used just to reflect constants are declared this way. We need to
michael@0:     // go ahead and build the thing. But, we'll ignore whatever methods it may
michael@0:     // have.
michael@0:     if (!nsXPConnect::IsISupportsDescendant(aInfo))
michael@0:         methodCount = 0;
michael@0: 
michael@0:     totalCount = methodCount + constCount;
michael@0: 
michael@0:     if (totalCount > MAX_LOCAL_MEMBER_COUNT) {
michael@0:         members = new XPCNativeMember[totalCount];
michael@0:         if (!members)
michael@0:             return nullptr;
michael@0:     } else {
michael@0:         members = local_members;
michael@0:     }
michael@0: 
michael@0:     // NOTE: since getters and setters share a member, we might not use all
michael@0:     // of the member objects.
michael@0: 
michael@0:     for (i = 0; i < methodCount; i++) {
michael@0:         const nsXPTMethodInfo* info;
michael@0:         if (NS_FAILED(aInfo->GetMethodInfo(i, &info))) {
michael@0:             failed = true;
michael@0:             break;
michael@0:         }
michael@0: 
michael@0:         // don't reflect Addref or Release
michael@0:         if (i == 1 || i == 2)
michael@0:             continue;
michael@0: 
michael@0:         if (!XPCConvert::IsMethodReflectable(*info))
michael@0:             continue;
michael@0: 
michael@0:         str = JS_InternString(cx, info->GetName());
michael@0:         if (!str) {
michael@0:             NS_ERROR("bad method name");
michael@0:             failed = true;
michael@0:             break;
michael@0:         }
michael@0:         jsid name = INTERNED_STRING_TO_JSID(cx, str);
michael@0: 
michael@0:         if (info->IsSetter()) {
michael@0:             MOZ_ASSERT(realTotalCount,"bad setter");
michael@0:             // Note: ASSUMES Getter/Setter pairs are next to each other
michael@0:             // This is a rule of the typelib spec.
michael@0:             cur = &members[realTotalCount-1];
michael@0:             MOZ_ASSERT(cur->GetName() == name,"bad setter");
michael@0:             MOZ_ASSERT(cur->IsReadOnlyAttribute(),"bad setter");
michael@0:             MOZ_ASSERT(cur->GetIndex() == i-1,"bad setter");
michael@0:             cur->SetWritableAttribute();
michael@0:         } else {
michael@0:             // XXX need better way to find dups
michael@0:             // MOZ_ASSERT(!LookupMemberByID(name),"duplicate method name");
michael@0:             cur = &members[realTotalCount++];
michael@0:             cur->SetName(name);
michael@0:             if (info->IsGetter())
michael@0:                 cur->SetReadOnlyAttribute(i);
michael@0:             else
michael@0:                 cur->SetMethod(i);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     if (!failed) {
michael@0:         for (i = 0; i < constCount; i++) {
michael@0:             const nsXPTConstant* constant;
michael@0:             if (NS_FAILED(aInfo->GetConstant(i, &constant))) {
michael@0:                 failed = true;
michael@0:                 break;
michael@0:             }
michael@0: 
michael@0:             str = JS_InternString(cx, constant->GetName());
michael@0:             if (!str) {
michael@0:                 NS_ERROR("bad constant name");
michael@0:                 failed = true;
michael@0:                 break;
michael@0:             }
michael@0:             jsid name = INTERNED_STRING_TO_JSID(cx, str);
michael@0: 
michael@0:             // XXX need better way to find dups
michael@0:             //MOZ_ASSERT(!LookupMemberByID(name),"duplicate method/constant name");
michael@0: 
michael@0:             cur = &members[realTotalCount++];
michael@0:             cur->SetName(name);
michael@0:             cur->SetConstant(i);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     if (!failed) {
michael@0:         const char* bytes;
michael@0:         if (NS_FAILED(aInfo->GetNameShared(&bytes)) || !bytes ||
michael@0:             nullptr == (str = JS_InternString(cx, bytes))) {
michael@0:             failed = true;
michael@0:         }
michael@0:         interfaceName = INTERNED_STRING_TO_JSID(cx, str);
michael@0:     }
michael@0: 
michael@0:     if (!failed) {
michael@0:         // Use placement new to create an object with the right amount of space
michael@0:         // to hold the members array
michael@0:         int size = sizeof(XPCNativeInterface);
michael@0:         if (realTotalCount > 1)
michael@0:             size += (realTotalCount - 1) * sizeof(XPCNativeMember);
michael@0:         void* place = new char[size];
michael@0:         if (place)
michael@0:             obj = new(place) XPCNativeInterface(aInfo, interfaceName);
michael@0: 
michael@0:         if (obj) {
michael@0:             obj->mMemberCount = realTotalCount;
michael@0:             // copy valid members
michael@0:             if (realTotalCount)
michael@0:                 memcpy(obj->mMembers, members,
michael@0:                        realTotalCount * sizeof(XPCNativeMember));
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     if (members && members != local_members)
michael@0:         delete [] members;
michael@0: 
michael@0:     return obj;
michael@0: }
michael@0: 
michael@0: // static
michael@0: void
michael@0: XPCNativeInterface::DestroyInstance(XPCNativeInterface* inst)
michael@0: {
michael@0:     inst->~XPCNativeInterface();
michael@0:     delete [] (char*) inst;
michael@0: }
michael@0: 
michael@0: size_t
michael@0: XPCNativeInterface::SizeOfIncludingThis(MallocSizeOf mallocSizeOf)
michael@0: {
michael@0:     return mallocSizeOf(this);
michael@0: }
michael@0: 
michael@0: void
michael@0: XPCNativeInterface::DebugDump(int16_t depth)
michael@0: {
michael@0: #ifdef DEBUG
michael@0:     depth--;
michael@0:     XPC_LOG_ALWAYS(("XPCNativeInterface @ %x", this));
michael@0:         XPC_LOG_INDENT();
michael@0:         XPC_LOG_ALWAYS(("name is %s", GetNameString()));
michael@0:         XPC_LOG_ALWAYS(("mMemberCount is %d", mMemberCount));
michael@0:         XPC_LOG_ALWAYS(("mInfo @ %x", mInfo.get()));
michael@0:         XPC_LOG_OUTDENT();
michael@0: #endif
michael@0: }
michael@0: 
michael@0: /***************************************************************************/
michael@0: // XPCNativeSet
michael@0: 
michael@0: // static
michael@0: XPCNativeSet*
michael@0: XPCNativeSet::GetNewOrUsed(const nsIID* iid)
michael@0: {
michael@0:     AutoJSContext cx;
michael@0:     AutoMarkingNativeSetPtr set(cx);
michael@0: 
michael@0:     AutoMarkingNativeInterfacePtr iface(cx);
michael@0:     iface = XPCNativeInterface::GetNewOrUsed(iid);
michael@0:     if (!iface)
michael@0:         return nullptr;
michael@0: 
michael@0:     XPCNativeSetKey key(nullptr, iface, 0);
michael@0: 
michael@0:     XPCJSRuntime* rt = XPCJSRuntime::Get();
michael@0:     NativeSetMap* map = rt->GetNativeSetMap();
michael@0:     if (!map)
michael@0:         return nullptr;
michael@0: 
michael@0:     set = map->Find(&key);
michael@0: 
michael@0:     if (set)
michael@0:         return set;
michael@0: 
michael@0:     // hacky way to get a XPCNativeInterface** using the AutoPtr
michael@0:     XPCNativeInterface* temp[] = {iface};
michael@0:     set = NewInstance(temp, 1);
michael@0:     if (!set)
michael@0:         return nullptr;
michael@0: 
michael@0:     XPCNativeSet* set2 = map->Add(&key, set);
michael@0:     if (!set2) {
michael@0:         NS_ERROR("failed to add our set!");
michael@0:         DestroyInstance(set);
michael@0:         set = nullptr;
michael@0:     } else if (set2 != set) {
michael@0:         DestroyInstance(set);
michael@0:         set = set2;
michael@0:     }
michael@0: 
michael@0:     return set;
michael@0: }
michael@0: 
michael@0: // static
michael@0: XPCNativeSet*
michael@0: XPCNativeSet::GetNewOrUsed(nsIClassInfo* classInfo)
michael@0: {
michael@0:     AutoJSContext cx;
michael@0:     AutoMarkingNativeSetPtr set(cx);
michael@0:     XPCJSRuntime* rt = XPCJSRuntime::Get();
michael@0: 
michael@0:     ClassInfo2NativeSetMap* map = rt->GetClassInfo2NativeSetMap();
michael@0:     if (!map)
michael@0:         return nullptr;
michael@0: 
michael@0:     set = map->Find(classInfo);
michael@0: 
michael@0:     if (set)
michael@0:         return set;
michael@0: 
michael@0:     nsIID** iidArray = nullptr;
michael@0:     AutoMarkingNativeInterfacePtrArrayPtr interfaceArray(cx);
michael@0:     uint32_t iidCount = 0;
michael@0: 
michael@0:     if (NS_FAILED(classInfo->GetInterfaces(&iidCount, &iidArray))) {
michael@0:         // Note: I'm making it OK for this call to fail so that one can add
michael@0:         // nsIClassInfo to classes implemented in script without requiring this
michael@0:         // method to be implemented.
michael@0: 
michael@0:         // Make sure these are set correctly...
michael@0:         iidArray = nullptr;
michael@0:         iidCount = 0;
michael@0:     }
michael@0: 
michael@0:     MOZ_ASSERT((iidCount && iidArray) || !(iidCount || iidArray), "GetInterfaces returned bad array");
michael@0: 
michael@0:     // !!! from here on we only exit through the 'out' label !!!
michael@0: 
michael@0:     if (iidCount) {
michael@0:         AutoMarkingNativeInterfacePtrArrayPtr
michael@0:             arr(cx, new XPCNativeInterface*[iidCount], iidCount, true);
michael@0: 
michael@0:         interfaceArray = arr;
michael@0: 
michael@0:         XPCNativeInterface** currentInterface = interfaceArray;
michael@0:         nsIID**              currentIID = iidArray;
michael@0:         uint16_t             interfaceCount = 0;
michael@0: 
michael@0:         for (uint32_t i = 0; i < iidCount; i++) {
michael@0:             nsIID* iid = *(currentIID++);
michael@0:             if (!iid) {
michael@0:                 NS_ERROR("Null found in classinfo interface list");
michael@0:                 continue;
michael@0:             }
michael@0: 
michael@0:             XPCNativeInterface* iface =
michael@0:                 XPCNativeInterface::GetNewOrUsed(iid);
michael@0: 
michael@0:             if (!iface) {
michael@0:                 // XXX warn here
michael@0:                 continue;
michael@0:             }
michael@0: 
michael@0:             *(currentInterface++) = iface;
michael@0:             interfaceCount++;
michael@0:         }
michael@0: 
michael@0:         if (interfaceCount) {
michael@0:             set = NewInstance(interfaceArray, interfaceCount);
michael@0:             if (set) {
michael@0:                 NativeSetMap* map2 = rt->GetNativeSetMap();
michael@0:                 if (!map2)
michael@0:                     goto out;
michael@0: 
michael@0:                 XPCNativeSetKey key(set, nullptr, 0);
michael@0: 
michael@0:                 XPCNativeSet* set2 = map2->Add(&key, set);
michael@0:                 if (!set2) {
michael@0:                     NS_ERROR("failed to add our set!");
michael@0:                     DestroyInstance(set);
michael@0:                     set = nullptr;
michael@0:                     goto out;
michael@0:                 }
michael@0:                 if (set2 != set) {
michael@0:                     DestroyInstance(set);
michael@0:                     set = set2;
michael@0:                 }
michael@0:             }
michael@0:         } else
michael@0:             set = GetNewOrUsed(&NS_GET_IID(nsISupports));
michael@0:     } else
michael@0:         set = GetNewOrUsed(&NS_GET_IID(nsISupports));
michael@0: 
michael@0:     if (set) {
michael@0: #ifdef DEBUG
michael@0:         XPCNativeSet* set2 =
michael@0: #endif
michael@0:           map->Add(classInfo, set);
michael@0:         MOZ_ASSERT(set2, "failed to add our set!");
michael@0:         MOZ_ASSERT(set2 == set, "hashtables inconsistent!");
michael@0:     }
michael@0: 
michael@0: out:
michael@0:     if (iidArray)
michael@0:         NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(iidCount, iidArray);
michael@0:     if (interfaceArray)
michael@0:         delete [] interfaceArray.get();
michael@0: 
michael@0:     return set;
michael@0: }
michael@0: 
michael@0: // static
michael@0: void
michael@0: XPCNativeSet::ClearCacheEntryForClassInfo(nsIClassInfo* classInfo)
michael@0: {
michael@0:     XPCJSRuntime* rt = nsXPConnect::GetRuntimeInstance();
michael@0:     ClassInfo2NativeSetMap* map = rt->GetClassInfo2NativeSetMap();
michael@0:     if (map)
michael@0:         map->Remove(classInfo);
michael@0: }
michael@0: 
michael@0: // static
michael@0: XPCNativeSet*
michael@0: XPCNativeSet::GetNewOrUsed(XPCNativeSet* otherSet,
michael@0:                            XPCNativeInterface* newInterface,
michael@0:                            uint16_t position)
michael@0: {
michael@0:     AutoJSContext cx;
michael@0:     AutoMarkingNativeSetPtr set(cx);
michael@0:     XPCJSRuntime* rt = XPCJSRuntime::Get();
michael@0:     NativeSetMap* map = rt->GetNativeSetMap();
michael@0:     if (!map)
michael@0:         return nullptr;
michael@0: 
michael@0:     XPCNativeSetKey key(otherSet, newInterface, position);
michael@0: 
michael@0:     set = map->Find(&key);
michael@0: 
michael@0:     if (set)
michael@0:         return set;
michael@0: 
michael@0:     if (otherSet)
michael@0:         set = NewInstanceMutate(otherSet, newInterface, position);
michael@0:     else
michael@0:         set = NewInstance(&newInterface, 1);
michael@0: 
michael@0:     if (!set)
michael@0:         return nullptr;
michael@0: 
michael@0:     XPCNativeSet* set2 = map->Add(&key, set);
michael@0:     if (!set2) {
michael@0:         NS_ERROR("failed to add our set!");
michael@0:         DestroyInstance(set);
michael@0:         set = nullptr;
michael@0:     } else if (set2 != set) {
michael@0:         DestroyInstance(set);
michael@0:         set = set2;
michael@0:     }
michael@0: 
michael@0:     return set;
michael@0: }
michael@0: 
michael@0: // static
michael@0: XPCNativeSet*
michael@0: XPCNativeSet::GetNewOrUsed(XPCNativeSet* firstSet,
michael@0:                            XPCNativeSet* secondSet,
michael@0:                            bool preserveFirstSetOrder)
michael@0: {
michael@0:     // Figure out how many interfaces we'll need in the new set.
michael@0:     uint32_t uniqueCount = firstSet->mInterfaceCount;
michael@0:     for (uint32_t i = 0; i < secondSet->mInterfaceCount; ++i) {
michael@0:         if (!firstSet->HasInterface(secondSet->mInterfaces[i]))
michael@0:             uniqueCount++;
michael@0:     }
michael@0: 
michael@0:     // If everything in secondSet was a duplicate, we can just use the first
michael@0:     // set.
michael@0:     if (uniqueCount == firstSet->mInterfaceCount)
michael@0:         return firstSet;
michael@0: 
michael@0:     // If the secondSet is just a superset of the first, we can use it provided
michael@0:     // that the caller doesn't care about ordering.
michael@0:     if (!preserveFirstSetOrder && uniqueCount == secondSet->mInterfaceCount)
michael@0:         return secondSet;
michael@0: 
michael@0:     // Ok, darn. Now we have to make a new set.
michael@0:     //
michael@0:     // It would be faster to just create the new set all at once, but that
michael@0:     // would involve wrangling with some pretty hairy code - especially since
michael@0:     // a lot of stuff assumes that sets are created by adding one interface to an
michael@0:     // existing set. So let's just do the slow and easy thing and hope that the
michael@0:     // above optimizations handle the common cases.
michael@0:     XPCNativeSet* currentSet = firstSet;
michael@0:     for (uint32_t i = 0; i < secondSet->mInterfaceCount; ++i) {
michael@0:         XPCNativeInterface* iface = secondSet->mInterfaces[i];
michael@0:         if (!currentSet->HasInterface(iface)) {
michael@0:             // Create a new augmented set, inserting this interface at the end.
michael@0:             uint32_t pos = currentSet->mInterfaceCount;
michael@0:             currentSet = XPCNativeSet::GetNewOrUsed(currentSet, iface, pos);
michael@0:             if (!currentSet)
michael@0:                 return nullptr;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     // We've got the union set. Hand it back to the caller.
michael@0:     MOZ_ASSERT(currentSet->mInterfaceCount == uniqueCount);
michael@0:     return currentSet;
michael@0: }
michael@0: 
michael@0: // static
michael@0: XPCNativeSet*
michael@0: XPCNativeSet::NewInstance(XPCNativeInterface** array,
michael@0:                           uint16_t count)
michael@0: {
michael@0:     XPCNativeSet* obj = nullptr;
michael@0: 
michael@0:     if (!array || !count)
michael@0:         return nullptr;
michael@0: 
michael@0:     // We impose the invariant:
michael@0:     // "All sets have exactly one nsISupports interface and it comes first."
michael@0:     // This is the place where we impose that rule - even if given inputs
michael@0:     // that don't exactly follow the rule.
michael@0: 
michael@0:     XPCNativeInterface* isup = XPCNativeInterface::GetISupports();
michael@0:     uint16_t slots = count+1;
michael@0: 
michael@0:     uint16_t i;
michael@0:     XPCNativeInterface** pcur;
michael@0: 
michael@0:     for (i = 0, pcur = array; i < count; i++, pcur++) {
michael@0:         if (*pcur == isup)
michael@0:             slots--;
michael@0:     }
michael@0: 
michael@0:     // Use placement new to create an object with the right amount of space
michael@0:     // to hold the members array
michael@0:     int size = sizeof(XPCNativeSet);
michael@0:     if (slots > 1)
michael@0:         size += (slots - 1) * sizeof(XPCNativeInterface*);
michael@0:     void* place = new char[size];
michael@0:     if (place)
michael@0:         obj = new(place) XPCNativeSet();
michael@0: 
michael@0:     if (obj) {
michael@0:         // Stick the nsISupports in front and skip additional nsISupport(s)
michael@0:         XPCNativeInterface** inp = array;
michael@0:         XPCNativeInterface** outp = (XPCNativeInterface**) &obj->mInterfaces;
michael@0:         uint16_t memberCount = 1;   // for the one member in nsISupports
michael@0: 
michael@0:         *(outp++) = isup;
michael@0: 
michael@0:         for (i = 0; i < count; i++) {
michael@0:             XPCNativeInterface* cur;
michael@0: 
michael@0:             if (isup == (cur = *(inp++)))
michael@0:                 continue;
michael@0:             *(outp++) = cur;
michael@0:             memberCount += cur->GetMemberCount();
michael@0:         }
michael@0:         obj->mMemberCount = memberCount;
michael@0:         obj->mInterfaceCount = slots;
michael@0:     }
michael@0: 
michael@0:     return obj;
michael@0: }
michael@0: 
michael@0: // static
michael@0: XPCNativeSet*
michael@0: XPCNativeSet::NewInstanceMutate(XPCNativeSet*       otherSet,
michael@0:                                 XPCNativeInterface* newInterface,
michael@0:                                 uint16_t            position)
michael@0: {
michael@0:     XPCNativeSet* obj = nullptr;
michael@0: 
michael@0:     if (!newInterface)
michael@0:         return nullptr;
michael@0:     if (otherSet && position > otherSet->mInterfaceCount)
michael@0:         return nullptr;
michael@0: 
michael@0:     // Use placement new to create an object with the right amount of space
michael@0:     // to hold the members array
michael@0:     int size = sizeof(XPCNativeSet);
michael@0:     if (otherSet)
michael@0:         size += otherSet->mInterfaceCount * sizeof(XPCNativeInterface*);
michael@0:     void* place = new char[size];
michael@0:     if (place)
michael@0:         obj = new(place) XPCNativeSet();
michael@0: 
michael@0:     if (obj) {
michael@0:         if (otherSet) {
michael@0:             obj->mMemberCount = otherSet->GetMemberCount() +
michael@0:                                 newInterface->GetMemberCount();
michael@0:             obj->mInterfaceCount = otherSet->mInterfaceCount + 1;
michael@0: 
michael@0:             XPCNativeInterface** src = otherSet->mInterfaces;
michael@0:             XPCNativeInterface** dest = obj->mInterfaces;
michael@0:             for (uint16_t i = 0; i < obj->mInterfaceCount; i++) {
michael@0:                 if (i == position)
michael@0:                     *dest++ = newInterface;
michael@0:                 else
michael@0:                     *dest++ = *src++;
michael@0:             }
michael@0:         } else {
michael@0:             obj->mMemberCount = newInterface->GetMemberCount();
michael@0:             obj->mInterfaceCount = 1;
michael@0:             obj->mInterfaces[0] = newInterface;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     return obj;
michael@0: }
michael@0: 
michael@0: // static
michael@0: void
michael@0: XPCNativeSet::DestroyInstance(XPCNativeSet* inst)
michael@0: {
michael@0:     inst->~XPCNativeSet();
michael@0:     delete [] (char*) inst;
michael@0: }
michael@0: 
michael@0: size_t
michael@0: XPCNativeSet::SizeOfIncludingThis(MallocSizeOf mallocSizeOf)
michael@0: {
michael@0:     return mallocSizeOf(this);
michael@0: }
michael@0: 
michael@0: void
michael@0: XPCNativeSet::DebugDump(int16_t depth)
michael@0: {
michael@0: #ifdef DEBUG
michael@0:     depth--;
michael@0:     XPC_LOG_ALWAYS(("XPCNativeSet @ %x", this));
michael@0:         XPC_LOG_INDENT();
michael@0: 
michael@0:         XPC_LOG_ALWAYS(("mInterfaceCount of %d", mInterfaceCount));
michael@0:         if (depth) {
michael@0:             for (uint16_t i = 0; i < mInterfaceCount; i++)
michael@0:                 mInterfaces[i]->DebugDump(depth);
michael@0:         }
michael@0:         XPC_LOG_ALWAYS(("mMemberCount of %d", mMemberCount));
michael@0:         XPC_LOG_OUTDENT();
michael@0: #endif
michael@0: }