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-rw-r--r--xpcom/ds/nsVariant.h223
1 files changed, 223 insertions, 0 deletions
diff --git a/xpcom/ds/nsVariant.h b/xpcom/ds/nsVariant.h
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+/* -*- 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