Best throughput tracker with chunksize

include/shred.h

@@ -16,9 +16,28 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <string.h>
+#include <chrono>
 
-#define CHUNK_SIZE 1024 * 1024 * 32 // amount of bytes that are overwritten at once --> 32MB
-#define TFNG_DATA_SIZE CHUNK_SIZE   // amount of bytes used by tfng
+// Adaptive chunk size optimization - uncomment to enable
+#define ADAPTIVE_CHUNK_SIZE
+
+// Chunk size configuration
+#define CHUNK_SIZE_START 1024 * 1024 * 32 // Starting chunk size: 32MB
+#define CHUNK_SIZE_MIN 1024 * 1024 * 4 // Minimum chunk size: 4MB
+#define CHUNK_SIZE_MAX 1024 * 1024 * 128 // Maximum chunk size: 128MB
+#define CHUNK_SIZE_STEP_UP 1024 * 1024 * 2 // Increase step: 2MB
+#define CHUNK_SIZE_STEP_DOWN 1024 * 1024 * 4 // Decrease step: 4MB
+#define CHUNK_MEASURE_INTERVAL 64 // Measure performance every 64 chunks
+
+#ifdef ADAPTIVE_CHUNK_SIZE
+// Use max buffer size when adaptive mode is enabled
+#define CHUNK_SIZE CHUNK_SIZE_MAX
+#define TFNG_DATA_SIZE CHUNK_SIZE_MAX
+#else
+// Use fixed chunk size when adaptive mode is disabled
+#define CHUNK_SIZE CHUNK_SIZE_START
+#define TFNG_DATA_SIZE CHUNK_SIZE
+#endif
 
 // #define DEMO_DRIVE_SIZE 1024*1024*256L // 256MB
 // #define DEMO_DRIVE_SIZE 1024*1024*1024L // 1GB
@@ -33,22 +52,47 @@ protected:
 public:
     Shred();
     ~Shred();
-    int shredDrive(Drive *drive, int *ipSignalFd);
+    int shredDrive(Drive* drive, int* ipSignalFd);
 
 private:
     fileDescriptor randomSrcFileDiscr;
     fileDescriptor driveFileDiscr;
+
+#ifdef ADAPTIVE_CHUNK_SIZE
+    unsigned char* caTfngData; // Dynamic buffer allocation for adaptive mode
+    unsigned char* caReadBuffer; // Dynamic buffer allocation for adaptive mode
+#else
     unsigned char caTfngData[TFNG_DATA_SIZE];
     unsigned char caReadBuffer[CHUNK_SIZE];
+#endif
+
     unsigned long ulDriveByteSize;
     unsigned long ulDriveByteOverallCount = 0; // all bytes shredded in all iterations + checking -> used for progress calculation
     double d32Percent = 0.0;
     double d32TmpPercent = 0.0;
 
+#ifdef ADAPTIVE_CHUNK_SIZE
+    // Adaptive chunk size optimization members
+    size_t currentChunkSize;
+    size_t bestChunkSize;
+    unsigned int chunkCounter;
+    std::chrono::high_resolution_clock::time_point measurementStartTime;
+    double bestThroughputMBps;
+    double lastThroughputMBps;
+    unsigned long bytesWrittenInMeasurement;
+    bool throughputIncreasing;
+
+    // Adaptive methods
+    void startMeasurement();
+    void evaluateThroughput(Drive* drive);
+    void adjustChunkSize(Drive* drive);
+    size_t getCurrentChunkSize() const;
+#endif
+
     inline double calcProgress();
     int iRewindDrive(fileDescriptor file);
     long getDriveSizeInBytes(fileDescriptor file);
-    unsigned int uiCalcChecksum(fileDescriptor file, Drive *drive, int *ipSignalFd);
+    unsigned int uiCalcChecksum(fileDescriptor file, Drive* drive, int* ipSignalFd);
     void cleanup();
 };