Feature: performance test case

perf/string_to_hex_perf_test.cpp

@@ -0,0 +1,97 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+// Function declarations
+void byteArrayToHexString_point(const unsigned char* byteArray, size_t length, char* hexString);
+void byteArrayToHexString_snprintf(const unsigned char* byteArray, size_t length, char* hexString);
+void byteArrayToHexString_idx(const unsigned char* byteArray, size_t length, char* hexString);
+
+int main() {
+    // Example large byte array
+    size_t length = 256; // 1 million bytes
+    unsigned char *byteArray = (unsigned char*)malloc(length * sizeof(unsigned char));
+    for (size_t i = 0; i < length; i++) {
+        byteArray[i] = i % 256; // Filling with example data
+    }
+
+    // Allocate memory for the hex string (2 characters per byte + 1 for the null terminator)
+    char* hexString = (char*)malloc((length * 2 + 1) * sizeof(char));
+    if (hexString == NULL || byteArray == NULL) {
+        fprintf(stderr, "Memory allocation failed\n");
+        return EXIT_FAILURE;
+    }
+
+    int loop_times=1000;
+
+    // Measure the time taken for the conversion
+    clock_t start = clock();
+    for(int i=0; i<loop_times; i++)
+    {
+    	byteArrayToHexString_point(byteArray, length, hexString);
+    }
+    clock_t end = clock();
+
+    // Print the time taken
+    double time_spent = (double)(end - start) / CLOCKS_PER_SEC;
+    printf("byteArrayToHexString_point Time taken: %f seconds\n", time_spent/loop_times);
+
+    start = clock();
+    for(int i=0; i<loop_times; i++)
+    {
+	    byteArrayToHexString_snprintf(byteArray, length, hexString);
+    }
+    end = clock();
+
+    // Print the time taken
+    time_spent = (double)(end - start) / CLOCKS_PER_SEC;
+    printf("byteArrayToHexString_snprintf: Time taken: %f seconds\n", time_spent/loop_times);
+
+    start = clock();
+    for(int i=0; i<loop_times; i++)
+    {
+	    byteArrayToHexString_idx(byteArray, length, hexString);
+    }
+    end = clock();
+
+    // Print the time taken
+    time_spent = (double)(end - start) / CLOCKS_PER_SEC;
+    printf("byteArrayToHexString_idx Time taken: %f seconds\n", time_spent/loop_times);
+
+
+
+    // Free the allocated memory
+    free(hexString);
+    free(byteArray);
+
+    return 0;
+}
+
+// Function to convert byte array to hex string
+void byteArrayToHexString_point(const unsigned char* byteArray, size_t length, char* hexString) {
+    const char hexChars[] = "0123456789abcdef";
+    char* ptr = hexString;
+    
+    for (size_t i = 0; i < length; i++) {
+        *ptr++ = hexChars[(byteArray[i] >> 4) & 0x0F];
+        *ptr++ = hexChars[byteArray[i] & 0x0F];
+    }
+    *ptr = '\0';  // Null-terminate the string
+}
+
+// Function to convert byte array to hex string
+void byteArrayToHexString_snprintf(const unsigned char* byteArray, size_t length, char* hexString) {
+    for (size_t i = 0; i < length; i++) {
+        sprintf(hexString + (i * 2), "%02x", byteArray[i]);
+    }
+    hexString[length * 2] = '\0';  // Null-terminate the string
+}
+
+void byteArrayToHexString_idx(const unsigned char* byteArray, size_t length, char* hexString) {
+    const char hexChars[] = "0123456789abcdef";
+    for (size_t i = 0; i < length; i++) {
+        hexString[i * 2] = hexChars[(byteArray[i] >> 4) & 0x0F];
+        hexString[i * 2 + 1] = hexChars[byteArray[i] & 0x0F];
+    }
+    hexString[length * 2] = '\0';  // Null-terminate the string
+}