Update readme.md

readme.md

@@ -1,11 +1,12 @@
 # Implementation
 
-1. Allocate and Deallocate Physical Pages
-	**Functionality**:
+####	1. Allocate and Deallocate Physical Pages
+**Functionality**:
 
 -   `allocatePhysicalPage()` uses `mmap` to allocate a 4KB physical page.
 -   Destructor `~MemoryManager()` uses `munmap` to deallocate physical pages.
 
+**Code**:
 ```
 void* allocatePhysicalPage() {
     void* page = mmap(nullptr, PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
@@ -25,3 +26,27 @@ MemoryManager::~MemoryManager() {
     }
 }
 ```
+
+#### Data and Metadata Size Constraints
+-   **Slot Size**: Each slot is defined to have a total size of 8 bytes.
+- **Metadata**: Each slot contains 2 bytes of metadata.
+		-    `virtualPageId` uses 15 bits.
+		-   `occupiedFlg` uses 1 bit.
+
+Given these constraints, the remaining space in each slot is available for data storage.
+
+-   **Data Size**: 8 bytes (total slot size) - 2 bytes (metadata) = 6 bytes available for data.
+
+**Details:**
+
+**Slot Size Definition (8B)**:
+```static constexpr size_t SLOT_SIZE = 8; // 8 bytes per slot```
+
+**Metadata Structure (2B)**:
+```
+struct ArrMetadata {
+    uint16_t virtualPageId : 15; // 15 bits for virtualPageId
+    bool occupiedFlg : 1;        // 1 bit for the occupied flag
+};
+```
+"Using `uint16_t`, normally occupies 16 bits (2B). But by using 15 bits for `virtualPageId` and 1 bit for `occupiedFlg` as bit-fields in `ArrMetadata`, a compact metadata size of 2 bytes per slot was achieved, leaving 6 bytes for data storage."