2023.08.25_쥬용지에

5주차(2023.08.25)/Simple_FTL_ZHU YJ.c

@@ -0,0 +1,146 @@
+#include <stdio.h>
+#include <string.h>
+
+#define TOTAL_BLOCKS 256
+#define PAGES_PER_BLOCK 16
+#define PAGE_SIZE 4096
+
+typedef struct {
+    char data[PAGE_SIZE];
+} Page;
+
+typedef struct {
+    Page pages[PAGES_PER_BLOCK];
+    int valid[PAGES_PER_BLOCK]; 
+} Block;
+
+Block flash[TOTAL_BLOCKS];
+
+int L2P[TOTAL_BLOCKS];
+int P2L[TOTAL_BLOCKS]; 
+
+void initFTL() { 
+    for (int i = 0; i < TOTAL_BLOCKS; i++) {
+        L2P[i] = -1;
+        P2L[i] = -1;
+        for (int j = 0; j < PAGES_PER_BLOCK; j++) {
+            flash[i].valid[j] = 0;
+        }
+    }
+}
+
+int allocateBlock() { 
+    for (int i = 0; i < TOTAL_BLOCKS; i++) {
+        if (L2P[i] == -1 && P2L[i] == -1) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+int invalidPagesInBlock(int block) { 
+    int count = 0;
+    for (int j = 0; j < PAGES_PER_BLOCK; j++) {
+        if (flash[block].valid[j] == 0) {
+            count++;
+        }
+    }
+    return count;
+}
+
+void eraseBlock(int logicalBlock) {
+    int physicalBlock = L2P[logicalBlock];
+    if (physicalBlock != -1) {
+        for (int j = 0; j < PAGES_PER_BLOCK; j++) {
+            memset(flash[physicalBlock].pages[j].data, 0, PAGE_SIZE);
+            flash[physicalBlock].valid[j] = 0;
+        }
+        L2P[logicalBlock] = -1;
+        P2L[physicalBlock] = -1;
+    }
+}
+
+void garbageCollector() {
+    int targetBlock = -1;
+    int maxInvalidPages = -1;
+
+    for (int i = 0; i < TOTAL_BLOCKS; i++) {
+        int currentInvalidPages = invalidPagesInBlock(i);
+        if (currentInvalidPages > maxInvalidPages) {
+            targetBlock = i;
+            maxInvalidPages = currentInvalidPages;
+        }
+    }
+
+    if (targetBlock != -1) {
+        eraseBlock(P2L[targetBlock]);
+    }
+}
+
+void readPage(int logicalBlock, int page, char *buffer) {
+    int physicalBlock = L2P[logicalBlock];
+    if (physicalBlock != -1 && flash[physicalBlock].valid[page]) {
+    memcpy(buffer, flash[physicalBlock].pages[page].data, PAGE_SIZE);
+} else {
+    memset(buffer, 0, PAGE_SIZE);
+}
+}
+
+void writePage(int logicalBlock, int page, char *buffer) {
+    int physicalBlock = L2P[logicalBlock];
+    if (physicalBlock == -1) {
+        physicalBlock = allocateBlock();
+        if (physicalBlock == -1) {
+            garbageCollector();
+            physicalBlock = allocateBlock();
+        }
+        L2P[logicalBlock] = physicalBlock;
+        P2L[physicalBlock] = logicalBlock;
+    }
+
+    if (flash[physicalBlock].valid[page] == 0) {
+        memcpy(flash[physicalBlock].pages[page].data, buffer, PAGE_SIZE);
+        flash[physicalBlock].valid[page] = 1;
+    } else {
+        flash[physicalBlock].valid[page] = 0;
+        int newPhysicalBlock = allocateBlock();
+        if (newPhysicalBlock == -1) {
+            garbageCollector();
+            newPhysicalBlock = allocateBlock();
+        }
+        for (int j = 0; j < PAGES_PER_BLOCK; j++) {
+            if (flash[physicalBlock].valid[j]) {
+                memcpy(flash[newPhysicalBlock].pages[j].data, flash[physicalBlock].pages[j].data, PAGE_SIZE);
+                flash[newPhysicalBlock].valid[j] = 1;
+            }
+        }
+        eraseBlock(logicalBlock);
+        L2P[logicalBlock] = newPhysicalBlock;
+        P2L[newPhysicalBlock] = logicalBlock;
+
+        memcpy(flash[newPhysicalBlock].pages[page].data, buffer, PAGE_SIZE);
+        flash[newPhysicalBlock].valid[page] = 1;
+    }
+}
+
+int main() {
+    initFTL();
+
+    char buffer[PAGE_SIZE] = "Hello";
+    char readBuffer[PAGE_SIZE];
+
+    writePage(10, 5, buffer);
+    readPage(10, 5, readBuffer);
+    printf("Read data: %s\n", readBuffer);
+
+    strcpy(buffer, "World");
+    writePage(10, 5, buffer);
+    readPage(10, 5, readBuffer);
+    printf("Read data: %s\n", readBuffer);
+
+    eraseBlock(10);
+    readPage(10, 5, readBuffer);
+    printf("Read data: %s\n", readBuffer);
+
+    return 0;
+}