updates
Dependencies: BLE_API mbed-dev-bin nRF51822
Fork of microbit-dal-eddystone by
Diff: inc/drivers/MicroBitStorage.h
- Revision:
- 1:8aa5cdb4ab67
- Child:
- 3:d86a4ddc1867
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/inc/drivers/MicroBitStorage.h Thu Apr 07 01:33:22 2016 +0100 @@ -0,0 +1,233 @@ +/* +The MIT License (MIT) + +Copyright (c) 2016 British Broadcasting Corporation. +This software is provided by Lancaster University by arrangement with the BBC. + +Permission is hereby granted, free of charge, to any person obtaining a +copy of this software and associated documentation files (the "Software"), +to deal in the Software without restriction, including without limitation +the rights to use, copy, modify, merge, publish, distribute, sublicense, +and/or sell copies of the Software, and to permit persons to whom the +Software is furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL +THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING +FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +DEALINGS IN THE SOFTWARE. +*/ + +#ifndef MICROBIT_STORAGE_H +#define MICROBIT_STORAGE_H + +#include "mbed.h" +#include "MicroBitConfig.h" +#include "ManagedString.h" +#include "ErrorNo.h" + +#define MICROBIT_STORAGE_MAGIC 0xCAFE + +#define MICROBIT_STORAGE_BLOCK_SIZE 48 +#define MICROBIT_STORAGE_KEY_SIZE 16 +#define MICROBIT_STORAGE_VALUE_SIZE MICROBIT_STORAGE_BLOCK_SIZE - MICROBIT_STORAGE_KEY_SIZE + +#define MICROBIT_STORAGE_STORE_PAGE_OFFSET 17 //Use the page just above the BLE Bond Data. +#define MICROBIT_STORAGE_SCRATCH_PAGE_OFFSET 19 //Use the page just below the BLE Bond Data. + +struct KeyValuePair +{ + uint8_t key[MICROBIT_STORAGE_KEY_SIZE] = { 0 }; + uint8_t value[MICROBIT_STORAGE_VALUE_SIZE] = { 0 }; +}; + +struct KeyValueStore +{ + uint32_t magic; + uint32_t size; + + KeyValueStore(uint32_t magic, uint32_t size) + { + this->magic = magic; + this->size = size; + } + + KeyValueStore() + { + this->magic = 0; + this->size = 0; + } +}; + + +/** + * Class definition for the MicroBitStorage class. + * This allows reading and writing of small blocks of data to FLASH memory. + * + * This class operates as a key value store, it allows the retrieval, addition + * and deletion of KeyValuePairs. + * + * The first 8 bytes are reserved for the KeyValueStore struct which gives core + * information such as the number of KeyValuePairs in the store, and whether the + * store has been initialised. + * + * After the KeyValueStore struct, KeyValuePairs are arranged contiguously until + * the end of the block used as persistent storage. + * + * |-------8-------|--------48-------|-----|---------48--------| + * | KeyValueStore | KeyValuePair[0] | ... | KeyValuePair[N-1] | + * |---------------|-----------------|-----|-------------------| + */ +class MicroBitStorage +{ + /** + * Function for copying words from one location to another. + * + * @param from the address to copy data from. + * + * @param to the address to copy the data to. + * + * @param sizeInWords the number of words to copy + */ + void flashCopy(uint32_t* from, uint32_t* to, int sizeInWords); + + /** + * Function for populating the scratch page with a KeyValueStore. + * + * @param store the KeyValueStore struct to write to the scratch page. + */ + void scratchKeyValueStore(KeyValueStore store); + + /** + * Function for populating the scratch page with a KeyValuePair. + * + * @param pair the KeyValuePair struct to write to the scratch page. + * + * @param flashPointer the pointer in flash where this KeyValuePair resides. This pointer + * is used to determine the offset into the scratch page, where the KeyValuePair should + * be written. + */ + void scratchKeyValuePair(KeyValuePair pair, uint32_t* flashPointer); + + public: + + /** + * Default constructor. + * + * Creates an instance of MicroBitStorage which acts like a KeyValueStore + * that allows the retrieval, addition and deletion of KeyValuePairs. + */ + MicroBitStorage(); + + /** + * Writes the given number of bytes to the address specified. + * + * @param buffer the data to write. + * + * @param address the location in memory to write to. + * + * @param length the number of bytes to write. + * + * @note currently not implemented. + */ + int writeBytes(uint8_t *buffer, uint32_t address, int length); + + /** + * Method for erasing a page in flash. + * + * @param page_address Address of the first word in the page to be erased. + */ + void flashPageErase(uint32_t * page_address); + + /** + * Method for writing a word of data in flash with a value. + * + * @param address Address of the word to change. + * + * @param value Value to be written to flash. + */ + void flashWordWrite(uint32_t * address, uint32_t value); + + /** + * Places a given key, and it's corresponding value into flash at the earliest + * available point. + * + * @param key the unique name that should be used as an identifier for the given data. + * The key is presumed to be null terminated. + * + * @param data a pointer to the beginning of the data to be persisted. + * + * @return MICROBIT_OK on success, or MICROBIT_NO_RESOURCES if the storage page is full + */ + int put(const char* key, uint8_t* data); + + /** + * Places a given key, and it's corresponding value into flash at the earliest + * available point. + * + * @param key the unique name that should be used as an identifier for the given data. + * + * @param data a pointer to the beginning of the data to be persisted. + * + * @return MICROBIT_OK on success, or MICROBIT_NO_RESOURCES if the storage page is full + */ + int put(ManagedString key, uint8_t* data); + + /** + * Retreives a KeyValuePair identified by a given key. + * + * @param key the unique name used to identify a KeyValuePair in flash. + * + * @return a pointer to a heap allocated KeyValuePair struct, this pointer will be + * NULL if the key was not found in storage. + * + * @note it is up to the user to free memory after use. + */ + KeyValuePair* get(const char* key); + + /** + * Retreives a KeyValuePair identified by a given key. + * + * @param key the unique name used to identify a KeyValuePair in flash. + * + * @return a pointer to a heap allocated KeyValuePair struct, this pointer will be + * NULL if the key was not found in storage. + * + * @note it is up to the user to free memory after use. + */ + KeyValuePair* get(ManagedString key); + + /** + * Removes a KeyValuePair identified by a given key. + * + * @param key the unique name used to identify a KeyValuePair in flash. + * + * @return MICROBIT_OK on success, or MICROBIT_NO_DATA if the given key + * was not found in flash. + */ + int remove(const char* key); + + /** + * Removes a KeyValuePair identified by a given key. + * + * @param key the unique name used to identify a KeyValuePair in flash. + * + * @return MICROBIT_OK on success, or MICROBIT_NO_DATA if the given key + * was not found in flash. + */ + int remove(ManagedString key); + + /** + * The size of the flash based KeyValueStore. + * + * @return the number of entries in the key value store + */ + int size(); +}; + +#endif