diff options
Diffstat (limited to 'xpcom/ds/nsVariant.h')
| -rw-r--r-- | xpcom/ds/nsVariant.h | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/xpcom/ds/nsVariant.h b/xpcom/ds/nsVariant.h new file mode 100644 index 0000000000..8de1fe4618 --- /dev/null +++ b/xpcom/ds/nsVariant.h @@ -0,0 +1,223 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef nsVariant_h +#define nsVariant_h + +#include "nsIVariant.h" +#include "nsStringFwd.h" +#include "mozilla/Attributes.h" +#include "nsCycleCollectionParticipant.h" + +/** + * Map the nsAUTF8String, nsUTF8String classes to the nsACString and + * nsCString classes respectively for now. These defines need to be removed + * once Jag lands his nsUTF8String implementation. + */ +#define nsAUTF8String nsACString +#define nsUTF8String nsCString +#define PromiseFlatUTF8String PromiseFlatCString + +/** + * nsDiscriminatedUnion is a class that nsIVariant implementors can use + * to hold the underlying data. + */ + +class nsDiscriminatedUnion { + public: + nsDiscriminatedUnion() : mType(nsIDataType::VTYPE_EMPTY) { + u.mInt8Value = '\0'; + } + nsDiscriminatedUnion(const nsDiscriminatedUnion&) = delete; + nsDiscriminatedUnion(nsDiscriminatedUnion&&) = delete; + + ~nsDiscriminatedUnion() { Cleanup(); } + + nsDiscriminatedUnion& operator=(const nsDiscriminatedUnion&) = delete; + nsDiscriminatedUnion& operator=(nsDiscriminatedUnion&&) = delete; + + void Cleanup(); + + uint16_t GetType() const { return mType; } + + [[nodiscard]] nsresult ConvertToInt8(uint8_t* aResult) const; + [[nodiscard]] nsresult ConvertToInt16(int16_t* aResult) const; + [[nodiscard]] nsresult ConvertToInt32(int32_t* aResult) const; + [[nodiscard]] nsresult ConvertToInt64(int64_t* aResult) const; + [[nodiscard]] nsresult ConvertToUint8(uint8_t* aResult) const; + [[nodiscard]] nsresult ConvertToUint16(uint16_t* aResult) const; + [[nodiscard]] nsresult ConvertToUint32(uint32_t* aResult) const; + [[nodiscard]] nsresult ConvertToUint64(uint64_t* aResult) const; + [[nodiscard]] nsresult ConvertToFloat(float* aResult) const; + [[nodiscard]] nsresult ConvertToDouble(double* aResult) const; + [[nodiscard]] nsresult ConvertToBool(bool* aResult) const; + [[nodiscard]] nsresult ConvertToChar(char* aResult) const; + [[nodiscard]] nsresult ConvertToWChar(char16_t* aResult) const; + + [[nodiscard]] nsresult ConvertToID(nsID* aResult) const; + + [[nodiscard]] nsresult ConvertToAString(nsAString& aResult) const; + [[nodiscard]] nsresult ConvertToAUTF8String(nsAUTF8String& aResult) const; + [[nodiscard]] nsresult ConvertToACString(nsACString& aResult) const; + [[nodiscard]] nsresult ConvertToString(char** aResult) const; + [[nodiscard]] nsresult ConvertToWString(char16_t** aResult) const; + [[nodiscard]] nsresult ConvertToStringWithSize(uint32_t* aSize, + char** aStr) const; + [[nodiscard]] nsresult ConvertToWStringWithSize(uint32_t* aSize, + char16_t** aStr) const; + + [[nodiscard]] nsresult ConvertToISupports(nsISupports** aResult) const; + [[nodiscard]] nsresult ConvertToInterface(nsIID** aIID, + void** aInterface) const; + [[nodiscard]] nsresult ConvertToArray(uint16_t* aType, nsIID* aIID, + uint32_t* aCount, void** aPtr) const; + + [[nodiscard]] nsresult SetFromVariant(nsIVariant* aValue); + + void SetFromInt8(uint8_t aValue); + void SetFromInt16(int16_t aValue); + void SetFromInt32(int32_t aValue); + void SetFromInt64(int64_t aValue); + void SetFromUint8(uint8_t aValue); + void SetFromUint16(uint16_t aValue); + void SetFromUint32(uint32_t aValue); + void SetFromUint64(uint64_t aValue); + void SetFromFloat(float aValue); + void SetFromDouble(double aValue); + void SetFromBool(bool aValue); + void SetFromChar(char aValue); + void SetFromWChar(char16_t aValue); + void SetFromID(const nsID& aValue); + void SetFromAString(const nsAString& aValue); + void SetFromAUTF8String(const nsAUTF8String& aValue); + void SetFromACString(const nsACString& aValue); + [[nodiscard]] nsresult SetFromString(const char* aValue); + [[nodiscard]] nsresult SetFromWString(const char16_t* aValue); + void SetFromISupports(nsISupports* aValue); + void SetFromInterface(const nsIID& aIID, nsISupports* aValue); + [[nodiscard]] nsresult SetFromArray(uint16_t aType, const nsIID* aIID, + uint32_t aCount, void* aValue); + [[nodiscard]] nsresult SetFromStringWithSize(uint32_t aSize, + const char* aValue); + [[nodiscard]] nsresult SetFromWStringWithSize(uint32_t aSize, + const char16_t* aValue); + + // Like SetFromWStringWithSize, but leaves the string uninitialized. It does + // does write the null-terminator. + void AllocateWStringWithSize(uint32_t aSize); + + void SetToVoid(); + void SetToEmpty(); + void SetToEmptyArray(); + + void Traverse(nsCycleCollectionTraversalCallback& aCb) const; + + private: + [[nodiscard]] nsresult ToManageableNumber( + nsDiscriminatedUnion* aOutData) const; + void FreeArray(); + [[nodiscard]] bool String2ID(nsID* aPid) const; + [[nodiscard]] nsresult ToString(nsACString& aOutString) const; + + public: + union { + int8_t mInt8Value; + int16_t mInt16Value; + int32_t mInt32Value; + int64_t mInt64Value; + uint8_t mUint8Value; + uint16_t mUint16Value; + uint32_t mUint32Value; + uint64_t mUint64Value; + float mFloatValue; + double mDoubleValue; + bool mBoolValue; + char mCharValue; + char16_t mWCharValue; + nsIID mIDValue; + nsAString* mAStringValue; + nsAUTF8String* mUTF8StringValue; + nsACString* mCStringValue; + struct { + // This is an owning reference that cannot be an nsCOMPtr because + // nsDiscriminatedUnion needs to be POD. AddRef/Release are manually + // called on this. + nsISupports* MOZ_OWNING_REF mInterfaceValue; + nsIID mInterfaceID; + } iface; + struct { + nsIID mArrayInterfaceID; + void* mArrayValue; + uint32_t mArrayCount; + uint16_t mArrayType; + } array; + struct { + char* mStringValue; + uint32_t mStringLength; + } str; + struct { + char16_t* mWStringValue; + uint32_t mWStringLength; + } wstr; + } u; + uint16_t mType; +}; + +/** + * nsVariant implements the generic variant support. The xpcom module registers + * a factory (see NS_VARIANT_CONTRACTID in nsIVariant.idl) that will create + * these objects. They are created 'empty' and 'writable'. + * + * nsIVariant users won't usually need to see this class. + */ +class nsVariantBase : public nsIWritableVariant { + public: + NS_DECL_NSIVARIANT + NS_DECL_NSIWRITABLEVARIANT + + nsVariantBase(); + + protected: + ~nsVariantBase() = default; + + nsDiscriminatedUnion mData; + bool mWritable; +}; + +class nsVariant final : public nsVariantBase { + public: + NS_DECL_ISUPPORTS + + nsVariant() = default; + + private: + ~nsVariant() = default; +}; + +class nsVariantCC final : public nsVariantBase { + public: + NS_DECL_CYCLE_COLLECTING_ISUPPORTS + NS_DECL_CYCLE_COLLECTION_CLASS(nsVariantCC) + + nsVariantCC() = default; + + private: + ~nsVariantCC() = default; +}; + +/** + * Users of nsIVariant should be using the contractID and not this CID. + * - see NS_VARIANT_CONTRACTID in nsIVariant.idl. + */ + +#define NS_VARIANT_CID \ + { /* 0D6EA1D0-879C-11d5-90EF-0010A4E73D9A */ \ + 0xd6ea1d0, 0x879c, 0x11d5, { \ + 0x90, 0xef, 0x0, 0x10, 0xa4, 0xe7, 0x3d, 0x9a \ + } \ + } + +#endif // nsVariant_h |