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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 19:33:14 +0000
commit36d22d82aa202bb199967e9512281e9a53db42c9 (patch)
tree105e8c98ddea1c1e4784a60a5a6410fa416be2de /storage/Variant.h
parentInitial commit. (diff)
downloadfirefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz
firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip
Adding upstream version 115.7.0esr.upstream/115.7.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'storage/Variant.h')
-rw-r--r--storage/Variant.h435
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
+ * 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 mozilla_storage_Variant_h__
+#define mozilla_storage_Variant_h__
+
+#include <utility>
+
+#include "nsIVariant.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+#define VARIANT_BASE_IID \
+ { /* 78888042-0fa3-4f7a-8b19-7996f99bf1aa */ \
+ 0x78888042, 0x0fa3, 0x4f7a, { \
+ 0x8b, 0x19, 0x79, 0x96, 0xf9, 0x9b, 0xf1, 0xaa \
+ } \
+ }
+
+/**
+ * This class is used by the storage module whenever an nsIVariant needs to be
+ * returned. We provide traits for the basic sqlite types to make use easier.
+ * The following types map to the indicated sqlite type:
+ * int64_t -> INTEGER (use IntegerVariant)
+ * double -> FLOAT (use FloatVariant)
+ * nsString -> TEXT (use TextVariant)
+ * nsCString -> TEXT (use UTF8TextVariant)
+ * uint8_t[] -> BLOB (use BlobVariant)
+ * nullptr -> NULL (use NullVariant)
+ *
+ * The kvstore component also reuses this class as a common implementation
+ * of a simple threadsafe variant for the storage of primitive values only.
+ * The BooleanVariant type has been introduced for kvstore use cases and should
+ * be enhanced to provide full boolean variant support for mozStorage.
+ *
+ * Bug 1494102 tracks that work.
+ */
+
+namespace mozilla {
+namespace storage {
+
+////////////////////////////////////////////////////////////////////////////////
+//// Base Class
+
+class Variant_base : public nsIVariant {
+ public:
+ NS_DECL_THREADSAFE_ISUPPORTS
+ NS_DECL_NSIVARIANT
+ NS_DECLARE_STATIC_IID_ACCESSOR(VARIANT_BASE_IID)
+
+ protected:
+ virtual ~Variant_base() = default;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(Variant_base, VARIANT_BASE_IID)
+
+////////////////////////////////////////////////////////////////////////////////
+//// Traits
+
+/**
+ * Generics
+ */
+
+template <typename DataType>
+struct variant_traits {
+ static inline uint16_t type() { return nsIDataType::VTYPE_EMPTY; }
+};
+
+template <typename DataType, bool Adopting = false>
+struct variant_storage_traits {
+ typedef DataType ConstructorType;
+ typedef DataType StorageType;
+ static inline void storage_conversion(const ConstructorType aData,
+ StorageType* _storage) {
+ *_storage = aData;
+ }
+
+ static inline void destroy(const StorageType& _storage) {}
+};
+
+#define NO_CONVERSION return NS_ERROR_CANNOT_CONVERT_DATA;
+
+template <typename DataType, bool Adopting = false>
+struct variant_boolean_traits {
+ typedef typename variant_storage_traits<DataType, Adopting>::StorageType
+ StorageType;
+ static inline nsresult asBool(const StorageType&, bool*) { NO_CONVERSION }
+};
+
+template <typename DataType, bool Adopting = false>
+struct variant_integer_traits {
+ typedef typename variant_storage_traits<DataType, Adopting>::StorageType
+ StorageType;
+ static inline nsresult asInt32(const StorageType&, int32_t*) { NO_CONVERSION }
+ static inline nsresult asInt64(const StorageType&, int64_t*) { NO_CONVERSION }
+};
+
+template <typename DataType, bool Adopting = false>
+struct variant_float_traits {
+ typedef typename variant_storage_traits<DataType, Adopting>::StorageType
+ StorageType;
+ static inline nsresult asDouble(const StorageType&, double*) { NO_CONVERSION }
+};
+
+template <typename DataType, bool Adopting = false>
+struct variant_text_traits {
+ typedef typename variant_storage_traits<DataType, Adopting>::StorageType
+ StorageType;
+ static inline nsresult asUTF8String(const StorageType&, nsACString&) {
+ NO_CONVERSION
+ }
+ static inline nsresult asString(const StorageType&, nsAString&) {
+ NO_CONVERSION
+ }
+};
+
+template <typename DataType, bool Adopting = false>
+struct variant_blob_traits {
+ typedef typename variant_storage_traits<DataType, Adopting>::StorageType
+ StorageType;
+ static inline nsresult asArray(const StorageType&, uint16_t*, uint32_t*,
+ void**) {
+ NO_CONVERSION
+ }
+};
+
+#undef NO_CONVERSION
+
+/**
+ * BOOLEAN type
+ */
+
+template <>
+struct variant_traits<bool> {
+ static inline uint16_t type() { return nsIDataType::VTYPE_BOOL; }
+};
+template <>
+struct variant_boolean_traits<bool> {
+ static inline nsresult asBool(bool aValue, bool* _result) {
+ *_result = aValue;
+ return NS_OK;
+ }
+
+ // NB: It might be worth also providing conversions to int types.
+
+ // NB: It'd be nice to implement asBool conversions for 0 and 1, too.
+ // That would let us clean up some conversions in Places, such as:
+ // https://searchfox.org/mozilla-central/rev/0640ea80fbc8d48f8b197cd363e2535c95a15eb3/toolkit/components/places/SQLFunctions.cpp#564-565
+ // https://searchfox.org/mozilla-central/rev/0640ea80fbc8d48f8b197cd363e2535c95a15eb3/toolkit/components/places/SQLFunctions.cpp#1057
+ // https://searchfox.org/mozilla-central/rev/0640ea80fbc8d48f8b197cd363e2535c95a15eb3/toolkit/components/places/nsNavHistory.cpp#3189
+};
+
+/**
+ * INTEGER types
+ */
+
+template <>
+struct variant_traits<int64_t> {
+ static inline uint16_t type() { return nsIDataType::VTYPE_INT64; }
+};
+template <>
+struct variant_integer_traits<int64_t> {
+ static inline nsresult asInt32(int64_t aValue, int32_t* _result) {
+ if (aValue > INT32_MAX || aValue < INT32_MIN)
+ return NS_ERROR_CANNOT_CONVERT_DATA;
+
+ *_result = static_cast<int32_t>(aValue);
+ return NS_OK;
+ }
+ static inline nsresult asInt64(int64_t aValue, int64_t* _result) {
+ *_result = aValue;
+ return NS_OK;
+ }
+};
+// xpcvariant just calls get double for integers...
+template <>
+struct variant_float_traits<int64_t> {
+ static inline nsresult asDouble(int64_t aValue, double* _result) {
+ *_result = double(aValue);
+ return NS_OK;
+ }
+};
+
+/**
+ * FLOAT types
+ */
+
+template <>
+struct variant_traits<double> {
+ static inline uint16_t type() { return nsIDataType::VTYPE_DOUBLE; }
+};
+template <>
+struct variant_float_traits<double> {
+ static inline nsresult asDouble(double aValue, double* _result) {
+ *_result = aValue;
+ return NS_OK;
+ }
+};
+
+/**
+ * TEXT types
+ */
+
+template <>
+struct variant_traits<nsString> {
+ static inline uint16_t type() { return nsIDataType::VTYPE_ASTRING; }
+};
+template <>
+struct variant_storage_traits<nsString> {
+ typedef const nsAString& ConstructorType;
+ typedef nsString StorageType;
+ static inline void storage_conversion(ConstructorType aText,
+ StorageType* _outData) {
+ *_outData = aText;
+ }
+ static inline void destroy(const StorageType& _outData) {}
+};
+template <>
+struct variant_text_traits<nsString> {
+ static inline nsresult asUTF8String(const nsString& aValue,
+ nsACString& _result) {
+ CopyUTF16toUTF8(aValue, _result);
+ return NS_OK;
+ }
+ static inline nsresult asString(const nsString& aValue, nsAString& _result) {
+ _result = aValue;
+ return NS_OK;
+ }
+};
+
+template <>
+struct variant_traits<nsCString> {
+ static inline uint16_t type() { return nsIDataType::VTYPE_UTF8STRING; }
+};
+template <>
+struct variant_storage_traits<nsCString> {
+ typedef const nsACString& ConstructorType;
+ typedef nsCString StorageType;
+ static inline void storage_conversion(ConstructorType aText,
+ StorageType* _outData) {
+ *_outData = aText;
+ }
+ static inline void destroy(const StorageType& aData) {}
+};
+template <>
+struct variant_text_traits<nsCString> {
+ static inline nsresult asUTF8String(const nsCString& aValue,
+ nsACString& _result) {
+ _result = aValue;
+ return NS_OK;
+ }
+ static inline nsresult asString(const nsCString& aValue, nsAString& _result) {
+ CopyUTF8toUTF16(aValue, _result);
+ return NS_OK;
+ }
+};
+
+/**
+ * BLOB types
+ */
+
+template <>
+struct variant_traits<uint8_t[]> {
+ static inline uint16_t type() { return nsIDataType::VTYPE_ARRAY; }
+};
+template <>
+struct variant_storage_traits<uint8_t[], false> {
+ typedef std::pair<const void*, int> ConstructorType;
+ typedef FallibleTArray<uint8_t> StorageType;
+ static inline void storage_conversion(ConstructorType aBlob,
+ StorageType* _outData) {
+ _outData->Clear();
+ (void)_outData->AppendElements(static_cast<const uint8_t*>(aBlob.first),
+ aBlob.second, fallible);
+ }
+ static inline void destroy(const StorageType& _outData) {}
+};
+template <>
+struct variant_storage_traits<uint8_t[], true> {
+ typedef std::pair<uint8_t*, int> ConstructorType;
+ typedef std::pair<uint8_t*, int> StorageType;
+ static inline void storage_conversion(ConstructorType aBlob,
+ StorageType* _outData) {
+ *_outData = aBlob;
+ }
+ static inline void destroy(StorageType& aData) {
+ if (aData.first) {
+ free(aData.first);
+ aData.first = nullptr;
+ }
+ }
+};
+template <>
+struct variant_blob_traits<uint8_t[], false> {
+ static inline nsresult asArray(FallibleTArray<uint8_t>& aData,
+ uint16_t* _type, uint32_t* _size,
+ void** _result) {
+ // For empty blobs, we return nullptr.
+ if (aData.Length() == 0) {
+ *_result = nullptr;
+ *_type = nsIDataType::VTYPE_UINT8;
+ *_size = 0;
+ return NS_OK;
+ }
+
+ // Otherwise, we copy the array.
+ *_result = moz_xmemdup(aData.Elements(), aData.Length() * sizeof(uint8_t));
+
+ // Set type and size
+ *_type = nsIDataType::VTYPE_UINT8;
+ *_size = aData.Length();
+ return NS_OK;
+ }
+};
+
+template <>
+struct variant_blob_traits<uint8_t[], true> {
+ static inline nsresult asArray(std::pair<uint8_t*, int>& aData,
+ uint16_t* _type, uint32_t* _size,
+ void** _result) {
+ // For empty blobs, we return nullptr.
+ if (aData.second == 0) {
+ *_result = nullptr;
+ *_type = nsIDataType::VTYPE_UINT8;
+ *_size = 0;
+ return NS_OK;
+ }
+
+ // Otherwise, transfer the data out.
+ *_result = aData.first;
+ aData.first = nullptr;
+ MOZ_ASSERT(*_result); // We asked for it twice, better not use adopting!
+
+ // Set type and size
+ *_type = nsIDataType::VTYPE_UINT8;
+ *_size = aData.second;
+ return NS_OK;
+ }
+};
+
+/**
+ * nullptr type
+ */
+
+class NullVariant : public Variant_base {
+ public:
+ uint16_t GetDataType() override { return nsIDataType::VTYPE_EMPTY; }
+
+ NS_IMETHOD GetAsAUTF8String(nsACString& _str) override {
+ // Return a void string.
+ _str.SetIsVoid(true);
+ return NS_OK;
+ }
+
+ NS_IMETHOD GetAsAString(nsAString& _str) override {
+ // Return a void string.
+ _str.SetIsVoid(true);
+ return NS_OK;
+ }
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//// Template Implementation
+
+template <typename DataType, bool Adopting = false>
+class Variant final : public Variant_base {
+ ~Variant() { variant_storage_traits<DataType, Adopting>::destroy(mData); }
+
+ public:
+ explicit Variant(
+ const typename variant_storage_traits<DataType, Adopting>::ConstructorType
+ aData) {
+ variant_storage_traits<DataType, Adopting>::storage_conversion(aData,
+ &mData);
+ }
+
+ uint16_t GetDataType() override { return variant_traits<DataType>::type(); }
+
+ NS_IMETHOD GetAsBool(bool* _boolean) override {
+ return variant_boolean_traits<DataType, Adopting>::asBool(mData, _boolean);
+ }
+
+ NS_IMETHOD GetAsInt32(int32_t* _integer) override {
+ return variant_integer_traits<DataType, Adopting>::asInt32(mData, _integer);
+ }
+
+ NS_IMETHOD GetAsInt64(int64_t* _integer) override {
+ return variant_integer_traits<DataType, Adopting>::asInt64(mData, _integer);
+ }
+
+ NS_IMETHOD GetAsDouble(double* _double) override {
+ return variant_float_traits<DataType, Adopting>::asDouble(mData, _double);
+ }
+
+ NS_IMETHOD GetAsAUTF8String(nsACString& _str) override {
+ return variant_text_traits<DataType, Adopting>::asUTF8String(mData, _str);
+ }
+
+ NS_IMETHOD GetAsAString(nsAString& _str) override {
+ return variant_text_traits<DataType, Adopting>::asString(mData, _str);
+ }
+
+ NS_IMETHOD GetAsArray(uint16_t* _type, nsIID*, uint32_t* _size,
+ void** _data) override {
+ return variant_blob_traits<DataType, Adopting>::asArray(mData, _type, _size,
+ _data);
+ }
+
+ private:
+ typename variant_storage_traits<DataType, Adopting>::StorageType mData;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+//// Handy typedefs! Use these for the right mapping.
+
+// Currently, BooleanVariant is only useful for kvstore.
+// Bug 1494102 tracks implementing full boolean variant support for mozStorage.
+typedef Variant<bool> BooleanVariant;
+
+typedef Variant<int64_t> IntegerVariant;
+typedef Variant<double> FloatVariant;
+typedef Variant<nsString> TextVariant;
+typedef Variant<nsCString> UTF8TextVariant;
+typedef Variant<uint8_t[], false> BlobVariant;
+typedef Variant<uint8_t[], true> AdoptedBlobVariant;
+
+} // namespace storage
+} // namespace mozilla
+
+#include "Variant_inl.h"
+
+#endif // mozilla_storage_Variant_h__