WIP: Design non-static storage class

Author: dhebbeker

lib/storage/storage.cpp

@@ -0,0 +1,35 @@
+#include "storage.hpp"
+#include <iostream>
+
+const esp_partition_t *check_ffat_partition(const char *label); // defined in FFat.cpp
+
+Storage::Storage(const bool formatFsOnFail, const char *const partitionLabel, ESPUSB &usb, fs::F_Fat &fs, const std::size_t blockSize):
+partition(check_ffat_partition(partitionLabel)),
+blockSize(blockSize),
+fs(fs),
+usb(usb)
+{
+  if(!partition){
+    std::cerr << "Error with partition!" << std::endl;
+    return;
+  }
+
+  // initialize file system
+  const auto basePath = rootPath + partitionLabel;
+  constexpr auto maxOpenFiles = 10;
+  if(!fs.begin(formatFsOnFail, basePath.c_str(), maxOpenFiles, partitionLabel)){
+    std::cerr << "File-system initialization failed!" << std::endl;
+    return;
+  }
+  std::cout << "Storage has a size of " << size() << " bytes." << std::endl;
+
+  // subscribe to USB events
+  callbackSubscribers.push_back(this);
+  usb.onEvent(ARDUINO_USB_STARTED_EVENT, callbackUsbStarted_s);
+  usb.onEvent(ARDUINO_USB_STOPPED_EVENT, callbackUsbStopped_s);
+}
+
+std::size_t Storage::size() const
+{
+  return fs.totalBytes();
+}

lib/storage/storage.hpp

@@ -1,17 +1,29 @@
 #pragma once
 #include <FFat.h>
+#include <USB.h>
 #include <USBMSC.h>
 #include <cstddef>
 #include <esp_partition.h>
+#include <optional>
+#include <string>
+#include <vector>
 
 class Storage
 {
   public:
-    void begin(const char *partitionLabel = FFAT_PARTITION_LABEL);
-    void end();
+    Storage(bool formatFsOnFail = false, const char *partitionLabel = FFAT_PARTITION_LABEL, ESPUSB &usb = USB,
+            fs::F_Fat &fs = FFat, std::size_t blockSize = 512);
     bool isFileSystemReady() const;
     void setCallbackFsReady();
     void setCallbackFsBusy();
+    std::size_t size() const;
+    std::string getFileContents(const char *path) const;
+    ~Storage();
+
+    static constexpr std::string rootPath = "/";
+
+  protected:
+    fs::FS &getFileSystem();
 
   private:
     const esp_partition_t *partition;
@@ -20,4 +32,11 @@ class Storage
      */
     USBMSC usbMsc;
     const std::size_t blockSize;
-};
+    fs::F_Fat &fs;
+    ESPUSB &usb;
+    static std::vector<Storage *> callbackSubscribers;
+    static esp_event_handler_t callbackUsbStarted_s;
+    void callbackUsbStarted();
+    static esp_event_handler_t callbackUsbStopped_s;
+    void callbackUsbStopped();
+};