数据库文件页管理器完成

invodb/io/page_manager.cpp

@@ -6,18 +6,31 @@
 
 int PageManager::loadDatabase(const char *filename) {
     stream.open(filename);
-
-    printf("%d", stream.is_open());
-
-    stream << "hello" << std::endl;
     stream.flush();
     return 0;
 }
 
 StoragePage& PageManager::getPage(const int &index) {
+
     StoragePage page;
     // 调整指针位置
-    stream.seekg((index - 1) << 2);
+    stream.clear();
+    stream.seekg(index * 4096);
     stream.read(page, 4096);
     return page;
 }
+
+void PageManager::setPage(const int &index, const StoragePage &page) {
+    stream.clear();
+    stream.seekg(index * 4096);
+    stream.write(page, 4096);
+}
+
+void StoragePage::print() {
+    for(int i=0; i<16; i++) {
+        for(int j=0; j<256; j++) {
+            printf("%u ", page[i * 16 + j]);
+        }
+        printf("\n");
+    }
+}

invodb/io/page_manager.h

@@ -7,15 +7,15 @@
 
 #include <iostream>
 #include <fstream>
+#include <cstring>
 
 class StoragePage {
 public:
+    void print();
+    StoragePage() { memset(page, 0, sizeof(page)); }
     char& operator[] (int index) { return this->page[index]; }
-    operator const char *() { return this->page; }
+    operator const char *() const { return this->page; }
     operator char *() { return this->page; }
-    ~StoragePage() {
-        printf("我被回收了");
-    }
 private:
     char page[4096];
 };
@@ -29,12 +29,13 @@ public:
     int loadDatabase(const char *filename);
     StoragePage& getPage(const int &index);
     void setPage(const int &index, const StoragePage &page);
+
 private:
     std::fstream stream;
 
     // 私有化实现单例
-    PageManager();
-    ~PageManager();
+    PageManager() {}
+    ~PageManager() {}
     PageManager(const PageManager&);
     PageManager& operator=(const PageManager&);
 };

invodb/main.cpp

@@ -9,7 +9,9 @@ int main() {
     PageManager& manager = PageManager::Instance();
     manager.loadDatabase("test.invodb");
 
-    manager.getPage(0);
+    StoragePage page = manager.getPage(1);
+
+    for(int i=0; i<100; i++) printf("%c", page[i]);
 
     return 0;
 }

invodb/main.h

@@ -7,6 +7,5 @@
 
 #include <iostream>
 #include "io/page_manager.h"
-#include "io/virtual_storage.h"
 
 #endif //INVODB_MAIN_H