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StorageAPI: Add different "modes" for reading binary and string data …
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…into an buffer (C++ API only)
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@Maschell
Maschell committed Feb 23, 2024
1 parent 9664b8e commit a760e2f
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Showing 2 changed files with 176 additions and 47 deletions.
101 changes: 66 additions & 35 deletions include/wups/storage.h
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Original file line number Diff line number Diff line change
Expand Up @@ -676,6 +676,15 @@ namespace WUPSStorageAPI {
static constexpr WUPSStorageItemTypes value = WUPS_STORAGE_ITEM_BINARY;
};

/**
* @enum GetOptions
* Enumerates options for retrieving items from storage.
*/
enum GetOptions {
RESIZE_EXISTING_BUFFER, /**< Resizes the given buffer to the item size before loading an item from storage */
USE_EXISTING_BUFFER, /**< Does not resize the buffer before loading an item from storage */
};

/**
* @brief Gets a string representation of the specified storage status.
* @param err The storage error status.
Expand Down Expand Up @@ -864,11 +873,12 @@ namespace WUPSStorageAPI {
* @param parent The parent storage item. Can be NULL to refer to the root of the storage.
* @param key The key under which the value is stored.
* @param[out] outValue A reference to the variable where the retrieved value will be stored.
* @param options additional options, see @GetOptions for more information
* @return WUPSStorageError WUPS_STORAGE_ERROR_SUCCESS on success, otherwise an appropriate error code.
* \see WUPSStorageAPI_GetItem
*/
template<typename T>
inline WUPSStorageError GetEx(wups_storage_item parent, std::string_view key, T &outValue) noexcept;
inline WUPSStorageError GetEx(wups_storage_item parent, std::string_view key, T &outValue, GetOptions options = RESIZE_EXISTING_BUFFER) noexcept;

/**
* @brief Retrieves a signed 32-bit integer value from a storage item.
Expand All @@ -878,12 +888,13 @@ namespace WUPSStorageAPI {
* @param parent The parent storage item. Can be NULL to refer to the root of the storage.
* @param key The key under which the value is stored.
* @param[out] outValue A reference to the variable where the retrieved value will be stored.
* @param options unused parameter
* @return WUPSStorageError Returns `WUPS_STORAGE_ERROR_SUCCESS` on success, otherwise an appropriate error code.
* \see WUPSStorageAPI_GetS32
* \see WUPSStorageAPI_GetItem
*/
template<>
inline WUPSStorageError GetEx<int32_t>(wups_storage_item parent, std::string_view key, int32_t &outValue) noexcept {
inline WUPSStorageError GetEx<int32_t>(wups_storage_item parent, std::string_view key, int32_t &outValue, GetOptions options) noexcept {
return WUPSStorageAPI_GetS32(parent, key.data(), &outValue);
}

Expand All @@ -895,12 +906,13 @@ namespace WUPSStorageAPI {
* @param parent The parent storage item. Can be NULL to refer to the root of the storage.
* @param key The key under which the value is stored.
* @param[out] outValue A reference to the variable where the retrieved value will be stored.
* @param options unused parameter
* @return WUPSStorageError Returns `WUPS_STORAGE_ERROR_SUCCESS` on success, otherwise an appropriate error code.
* \see WUPSStorageAPI_GetS64
* \see WUPSStorageAPI_GetItem
*/
template<>
inline WUPSStorageError GetEx<int64_t>(wups_storage_item parent, std::string_view key, int64_t &outValue) noexcept {
inline WUPSStorageError GetEx<int64_t>(wups_storage_item parent, std::string_view key, int64_t &outValue, GetOptions options) noexcept {
return WUPSStorageAPI_GetS64(parent, key.data(), &outValue);
}

Expand All @@ -912,12 +924,13 @@ namespace WUPSStorageAPI {
* @param parent The parent storage item. Can be NULL to refer to the root of the storage.
* @param key The key under which the value is stored.
* @param[out] outValue A reference to the variable where the retrieved value will be stored.
* @param options unused parameter
* @return WUPSStorageError Returns `WUPS_STORAGE_ERROR_SUCCESS` on success, otherwise an appropriate error code.
* \see WUPSStorageAPI_GetU32
* \see WUPSStorageAPI_GetItem
*/
template<>
inline WUPSStorageError GetEx<uint32_t>(wups_storage_item parent, std::string_view key, uint32_t &outValue) noexcept {
inline WUPSStorageError GetEx<uint32_t>(wups_storage_item parent, std::string_view key, uint32_t &outValue, GetOptions options) noexcept {
return WUPSStorageAPI_GetU32(parent, key.data(), &outValue);
}

Expand All @@ -929,12 +942,13 @@ namespace WUPSStorageAPI {
* @param parent The parent storage item. Can be NULL to refer to the root of the storage.
* @param key The key under which the value is stored.
* @param[out] outValue A reference to the variable where the retrieved value will be stored.
* @param options unused parameter
* @return WUPSStorageError Returns `WUPS_STORAGE_ERROR_SUCCESS` on success, otherwise an appropriate error code.
* \see WUPSStorageAPI_GetU64
* \see WUPSStorageAPI_GetItem
*/
template<>
inline WUPSStorageError GetEx<uint64_t>(wups_storage_item parent, std::string_view key, uint64_t &outValue) noexcept {
inline WUPSStorageError GetEx<uint64_t>(wups_storage_item parent, std::string_view key, uint64_t &outValue, GetOptions options) noexcept {
return WUPSStorageAPI_GetU64(parent, key.data(), &outValue);
}

Expand All @@ -946,12 +960,13 @@ namespace WUPSStorageAPI {
* @param parent The parent storage item. Can be NULL to refer to the root of the storage.
* @param key The key under which the value is stored.
* @param[out] outValue A reference to the variable where the retrieved value will be stored.
* @param options unused parameter
* @return WUPSStorageError Returns `WUPS_STORAGE_ERROR_SUCCESS` on success, otherwise an appropriate error code.
* \see WUPSStorageAPI_GetBool
* \see WUPSStorageAPI_GetItem
*/
template<>
inline WUPSStorageError GetEx<bool>(wups_storage_item parent, std::string_view key, bool &outValue) noexcept {
inline WUPSStorageError GetEx<bool>(wups_storage_item parent, std::string_view key, bool &outValue, GetOptions options) noexcept {
return WUPSStorageAPI_GetBool(parent, key.data(), &outValue);
}

Expand All @@ -963,12 +978,13 @@ namespace WUPSStorageAPI {
* @param parent The parent storage item. Can be NULL to refer to the root of the storage.
* @param key The key under which the value is stored.
* @param[out] outValue A reference to the variable where the retrieved value will be stored.
* @param options unused parameter
* @return WUPSStorageError Returns `WUPS_STORAGE_ERROR_SUCCESS` on success, otherwise an appropriate error code.
* \see WUPSStorageAPI_GetFloat
* \see WUPSStorageAPI_GetItem
*/
template<>
inline WUPSStorageError GetEx<float>(wups_storage_item parent, std::string_view key, float &outValue) noexcept {
inline WUPSStorageError GetEx<float>(wups_storage_item parent, std::string_view key, float &outValue, GetOptions options) noexcept {
return WUPSStorageAPI_GetFloat(parent, key.data(), &outValue);
}

Expand All @@ -980,12 +996,13 @@ namespace WUPSStorageAPI {
* @param parent The parent storage item. Can be NULL to refer to the root of the storage.
* @param key The key under which the value is stored.
* @param[out] outValue A reference to the variable where the retrieved value will be stored.
* @param options unused parameter
* @return WUPSStorageError Returns `WUPS_STORAGE_ERROR_SUCCESS` on success, otherwise an appropriate error code.
* \see WUPSStorageAPI_GetFloat
* \see WUPSStorageAPI_GetItem
*/
template<>
inline WUPSStorageError GetEx<double>(wups_storage_item parent, std::string_view key, double &outValue) noexcept {
inline WUPSStorageError GetEx<double>(wups_storage_item parent, std::string_view key, double &outValue, GetOptions options) noexcept {
return WUPSStorageAPI_GetDouble(parent, key.data(), &outValue);
}

Expand All @@ -999,6 +1016,7 @@ namespace WUPSStorageAPI {
* @param parent The parent storage item. Can be NULL to refer to the root of the storage.
* @param key The key under which the value is stored.
* @param[out] outValue A reference to the variable where the retrieved enum value will be stored.
* @param options unused parameter
* @return WUPSStorageError Returns WUPS_STORAGE_ERROR_SUCCESS on success, otherwise an appropriate error code.
*
* @note This function assumes that the enum type is of size sizeof(uint32_t).
Expand All @@ -1007,40 +1025,46 @@ namespace WUPSStorageAPI {
* \see WUPSStorageAPI_GetItem
*/
template<typename T>
inline WUPSStorageError GetEx(wups_storage_item parent, std::string_view key, T &outValue) noexcept {
inline WUPSStorageError GetEx(wups_storage_item parent, std::string_view key, T &outValue, GetOptions options) noexcept {
static_assert(sizeof(T) == sizeof(uint32_t) && std::is_enum<T>::value, "T must be an enum of size sizeof(uint32_t)");
return WUPSStorageAPI_GetU32(parent, key.data(), (uint32_t *) &outValue);
}

/**
* @brief Retrieves a vector of uint8_t from storage.
*
* This template specialization of the GetEx function retrieves a vector of uint8_t from the storage.
* It first checks if the outValue vector is empty (size == 0).
* If it is, it retrieves the size of the data and resizes the outValue vector to that size. Otherwise the existing vector (size) will the be used.
* Then, it retrieves the binary data from the storage using the WUPSStorageAPI_GetBinary function.
* If the retrieval is successful, the outValue vector is resized to the size of the retrieved data.
* If the retrieval fails, the outValue vector is resized to 0.
* This template specialization of the GetEx function retrieves a vector of uint8_t from the storage. \n
* Before getting the actual data, the buffer might be prepared depending on the given option parameter: \n
* - USE_EXISTING_BUFFER: the buffer will not be resized to the item size before getting the item. The caller has to make sure the buffer is big enough. \n
* - RESIZE_EXISTING_BUFFER: the buffer will be resized to the actual item size before getting the item. \n
* Then, it retrieves the binary data from the storage using the WUPSStorageAPI_GetBinary function. \n
* If the retrieval is successful, the outValue vector is resized to the size of the retrieved data. \n
* If the retrieval fails, the outValue vector is resized to 0. \n
*
* @param parent The parent storage item. Can be NULL to refer to the root of the storage.
* @param key The key under which the data is stored.
* @param[out] outValue A reference to the vector where the retrieved data will be stored. Will be resized to fit the data only if it's empty.
* @param options Defines how the given outValue buffer is used.
* @return WUPSStorageError WUPS_STORAGE_ERROR_SUCCESS on success, otherwise an appropriate error code.
*
* @see WUPSStorageAPI_GetBinary
* @see WUPSStorageAPI_GetItemSize
*/
template<>
inline WUPSStorageError GetEx<std::vector<uint8_t>>(wups_storage_item parent, std::string_view key, std::vector<uint8_t> &outValue) noexcept {
inline WUPSStorageError GetEx<std::vector<uint8_t>>(wups_storage_item parent, std::string_view key, std::vector<uint8_t> &outValue, GetOptions options) noexcept {
uint32_t outSize = 0;

if (outValue.empty()) {
uint32_t resizeToSize = 0;
auto r = WUPSStorageAPI_GetItemSize(parent, key.data(), WUPS_STORAGE_ITEM_BINARY, &resizeToSize);
if (r == WUPS_STORAGE_ERROR_SUCCESS) {
outValue.resize(resizeToSize);
} else {
return r;
switch (options) {
case USE_EXISTING_BUFFER:
break;
case RESIZE_EXISTING_BUFFER: {
uint32_t resizeToSize = 0;
auto r = WUPSStorageAPI_GetItemSize(parent, key.data(), WUPS_STORAGE_ITEM_BINARY, &resizeToSize);
if (r == WUPS_STORAGE_ERROR_SUCCESS) {
outValue.resize(resizeToSize);
} else {
return r;
}
}
}

Expand All @@ -1056,29 +1080,35 @@ namespace WUPSStorageAPI {
/**
* @brief Retrieves a string value from a storage item with the given key.
*
* If the input `outValue` is empty, the function first retrieves the size of the stored data using `WUPSStorageAPI_GetItemSize`.
* Before getting the actual data, the string might be resized to fit the data depending on the given option parameter: \n
* - USE_EXISTING_BUFFER: the string will not be resized to the item size before getting the item. The caller has to make sure the string is already big enough. \n
* - RESIZE_EXISTING_BUFFER: the string will be resized to the actual string size before getting the item. \n
* If the retrieval is successful, the function resizes `outValue` to the retrieved size.
* Then, it calls `WUPSStorageAPI_GetString` to retrieve the string from the storage item.
* If the retrieval is successful, the function resizes `outValue` to remove the null terminator.
*
* @param parent The parent storage item. Can be `NULL` to refer to the root of the storage.
* @param key The key under which the string is stored.
* @param[out] outValue A reference to a `std::string` object where the retrieved string will be stored. Will be resized to fit the data only if it's empty.
* @param options Defines how the given outValue buffer is used.
* @return WUPSStorageError WUPS_STORAGE_ERROR_SUCCESS on success, otherwise an appropriate error code.
*
* @see WUPSStorageAPI_GetBinary
* @see WUPSStorageAPI_GetString
*/
template<>
inline WUPSStorageError GetEx<std::string>(wups_storage_item parent, std::string_view key, std::string &outValue) noexcept {
inline WUPSStorageError GetEx<std::string>(wups_storage_item parent, std::string_view key, std::string &outValue, GetOptions options) noexcept {
uint32_t outSize = 0;
if (outValue.empty()) {
uint32_t resizeToSize = 0;
auto r = WUPSStorageAPI_GetItemSize(parent, key.data(), WUPS_STORAGE_ITEM_STRING, &resizeToSize);
if (r == WUPS_STORAGE_ERROR_SUCCESS) {
outValue.resize(resizeToSize);
} else {
return r;
switch (options) {
case USE_EXISTING_BUFFER:
break;
case RESIZE_EXISTING_BUFFER: {
uint32_t resizeToSize = 0;
auto r = WUPSStorageAPI_GetItemSize(parent, key.data(), WUPS_STORAGE_ITEM_STRING, &resizeToSize);
if (r == WUPS_STORAGE_ERROR_SUCCESS) {
outValue.resize(resizeToSize);
} else {
return r;
}
}
}

Expand All @@ -1102,14 +1132,15 @@ namespace WUPSStorageAPI {
*
* @param key The key under which the value is stored.
* @param[out] outValue A reference to the variable where the retrieved value will be stored.
* @param[optional] options Defines how a given buffer might be used, only relevant for certain item types (e.g. strings or buffer). Default value is RESIZE_EXISTING_BUFFER.
* @return WUPSStorageError WUPS_STORAGE_ERROR_SUCCESS on success, otherwise an appropriate error code.
*
* @see WUPSStorageAPI_GetItem
* @see GetEx
*/
template<typename T>
inline WUPSStorageError Get(std::string_view key, T &outValue) noexcept {
return GetEx(nullptr, key.data(), outValue);
inline WUPSStorageError Get(std::string_view key, T &outValue, GetOptions options = RESIZE_EXISTING_BUFFER) noexcept {
return GetEx(nullptr, key.data(), outValue, options);
}

/**
Expand Down
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