Diff: features/storage/blockdevice/BufferedBlockDevice.h

Revision:

0:5b88d5760320

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/features/storage/blockdevice/BufferedBlockDevice.h	Tue Dec 17 23:23:45 2019 +0000
@@ -0,0 +1,197 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2018 ARM Limited
+ *
+ * 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.
+ */
+
+/** \addtogroup storage */
+/** @{*/
+
+#ifndef MBED_BUFFERED_BLOCK_DEVICE_H
+#define MBED_BUFFERED_BLOCK_DEVICE_H
+
+#include "BlockDevice.h"
+
+namespace mbed {
+
+/** Block device for allowing minimal read and program sizes (of 1) for the underlying BD,
+ *  using a buffer on the heap.
+ */
+class BufferedBlockDevice : public BlockDevice {
+public:
+    /** Lifetime of a memory-buffered block device wrapping an underlying block device
+     *
+     *  @param bd        Block device to back the BufferedBlockDevice
+     */
+    BufferedBlockDevice(BlockDevice *bd);
+
+    /** Lifetime of the memory-buffered block device
+     */
+    virtual ~BufferedBlockDevice();
+
+    /** Initialize a buffered-memory block device and its underlying block device
+     *
+     *  @return         0 on success or a negative error code on failure
+     */
+    virtual int init();
+
+    /** Deinitialize the buffered-memory block device and its underlying block device
+     *
+     *  @return         0 on success or a negative error code on failure
+     */
+    virtual int deinit();
+
+    /** Ensure that data on the underlying storage block device is in sync with the
+     *  memory-buffered block device
+     *
+     *  @return         0 on success or a negative error code on failure
+     */
+    virtual int sync();
+
+    /** Read blocks from the memory-buffered block device
+     *
+     *  @param buffer   Buffer to read blocks into
+     *  @param addr     Address of block to begin reading from
+     *  @param size     Size to read in bytes, must be a multiple of read block size
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
+
+    /** Program data to the memory-buffered block device
+     *
+     *  The write address blocks must be erased prior to being programmed.
+     *
+     *  @param buffer   Buffer of data to write to blocks
+     *  @param addr     Address of block to begin writing to
+     *  @param size     Size to write in bytes, must be a multiple of program block size
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
+
+    /** Erase blocks from the memory-buffered block device
+     *
+     *  The state of an erased block is undefined until it has been programmed,
+     *  unless get_erase_value returns a non-negative byte value.
+     *
+     *  @param addr     Address of block to begin erasing
+     *  @param size     Size to erase in bytes, must be a multiple of erase block size
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int erase(bd_addr_t addr, bd_size_t size);
+
+    /** Mark blocks as no longer in use
+     *
+     *  This function provides a hint to the underlying block device that a region of blocks
+     *  is no longer in use and may be erased without side effects. Erase must still be called
+     *  before programming, but trimming allows flash-translation-layers to schedule erases when
+     *  the device is not busy.
+     *
+     *  @param addr     Address of block to mark as unused
+     *  @param size     Size to mark as unused in bytes, must be a multiple of erase block size
+     *  @return         0 on success, negative error code on failure
+     */
+    virtual int trim(bd_addr_t addr, bd_size_t size);
+
+    /** Get the size of a readable block
+     *
+     *  @return         Size of a readable block in bytes
+     */
+    virtual bd_size_t get_read_size() const;
+
+    /** Get the size of a programmable block
+     *
+     *  @return         Size of a programmable block in bytes
+     *  @note Must be a multiple of the read size
+     */
+    virtual bd_size_t get_program_size() const;
+
+    /** Get the size of an erasable block
+     *
+     *  @return         Size of an erasable block in bytes
+     *  @note Must be a multiple of the program size
+     */
+    virtual bd_size_t get_erase_size() const;
+
+    /** Get the size of an erasable block of a given address
+     *
+     *  @param addr     Address within the erasable block
+     *  @return         Size of an erasable block in bytes
+     *  @note Must be a multiple of the program size
+     */
+    virtual bd_size_t get_erase_size(bd_addr_t addr) const;
+
+    /** Get the value of storage data after being erased
+     *
+     *  If get_erase_value returns a non-negative byte value, the underlying
+     *  storage is set to that value when erased, and storage containing
+     *  that value can be programmed without another erase.
+     *
+     *  @return         The value of storage when erased, or -1 if you can't
+     *                  rely on the value of erased storage
+     */
+    virtual int get_erase_value() const;
+
+    /** Get the total size of the underlying device
+     *
+     *  @return         Size of the underlying device in bytes
+     */
+    virtual bd_size_t size() const;
+
+    /** Get the underlying BlockDevice class type
+     *
+     *  @return         A string representing the underlying BlockDevice class type
+     */
+    virtual const char *get_type() const;
+
+protected:
+    BlockDevice *_bd;
+    bd_size_t _bd_program_size;
+    bd_size_t _bd_read_size;
+    bd_size_t _bd_size;
+    bd_size_t _write_cache_addr;
+    bool _write_cache_valid;
+    uint8_t *_write_cache;
+    uint8_t *_read_buf;
+    uint32_t _init_ref_count;
+    bool _is_initialized;
+
+#if !(DOXYGEN_ONLY)
+    /** Flush data in cache
+     *
+     *  @return         0 on success or a negative error code on failure
+     */
+    int flush();
+
+    /** Invalidate write cache
+     *
+     *  @return         none
+     */
+    void invalidate_write_cache();
+#endif //#if !(DOXYGEN_ONLY)
+};
+} // namespace mbed
+
+// Added "using" for backwards compatibility
+#ifndef MBED_NO_GLOBAL_USING_DIRECTIVE
+using mbed::BufferedBlockDevice;
+#endif
+
+#endif
+
+/** @}*/