From 99e16b7cf676d2c7d168792fd794342ae28db3bc Mon Sep 17 00:00:00 2001
From: YuhangQ <i@yuhangq.com>
Date: Wed, 3 Nov 2021 09:39:13 +0800
Subject: [PATCH] add cache

---
 .idea/.name                  |  1 +
 .idea/misc.xml               |  4 +++
 CMakeLists.txt               |  2 +-
 invodb/file/page_manager.cpp | 11 +++++++-
 invodb/file/page_manager.h   |  4 ++-
 invodb/main.cpp              | 11 +++-----
 invodb/models/cache.h        | 52 ++++++++++++++++++++++++++++++++++++
 7 files changed, 75 insertions(+), 10 deletions(-)
 create mode 100644 .idea/.name
 create mode 100644 .idea/misc.xml
 create mode 100644 invodb/models/cache.h

diff --git a/.idea/.name b/.idea/.name
new file mode 100644
index 0000000..96275ad
--- /dev/null
+++ b/.idea/.name
@@ -0,0 +1 @@
+InvoDB
\ No newline at end of file
diff --git a/.idea/misc.xml b/.idea/misc.xml
new file mode 100644
index 0000000..79b3c94
--- /dev/null
+++ b/.idea/misc.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="CMakeWorkspace" PROJECT_DIR="$PROJECT_DIR$" />
+</project>
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 778b760..d741eb3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,4 +11,4 @@ include_directories(./invodb)
 
 add_executable(InvoDB
         invodb/main.cpp
-        invodb/main.h invodb/file/page_manager.cpp invodb/file/page_manager.h invodb/models/collection.cpp invodb/models/collection.h invodb/file/storage_page.cpp invodb/file/storage_page.h invodb/utils/logger.h invodb/utils/uuid.h invodb/btree/node.h invodb/btree/btree.h invodb/index/index.cpp invodb/index/index.h invodb/btree/list.h invodb/index/query.cpp invodb/index/query.h)
+        invodb/main.h invodb/file/page_manager.cpp invodb/file/page_manager.h invodb/models/collection.cpp invodb/models/collection.h invodb/file/storage_page.cpp invodb/file/storage_page.h invodb/utils/logger.h invodb/utils/uuid.h invodb/btree/node.h invodb/btree/btree.h invodb/index/index.cpp invodb/index/index.h invodb/btree/list.h invodb/index/query.cpp invodb/index/query.h invodb/models/cache.h)
diff --git a/invodb/file/page_manager.cpp b/invodb/file/page_manager.cpp
index 0b79ccb..f4c911e 100644
--- a/invodb/file/page_manager.cpp
+++ b/invodb/file/page_manager.cpp
@@ -10,6 +10,13 @@ int PageManager::loadDatabase(const char *filename) {
 }
 
 StoragePage PageManager::getPage(const int &index) {
+
+    if(cache.exist(index)) {
+        static int cnt = 0;
+        printf("%d\n", ++cnt);
+        return cache.get(index);
+    }
+
     StoragePage page(index);
     // 调整指针位置
     stream.clear();
@@ -19,10 +26,12 @@ StoragePage PageManager::getPage(const int &index) {
 }
 
 void PageManager::setPage(const int &index, const StoragePage &page) {
+
+    cache.put(index, page);
+
     stream.clear();
     stream.seekg(index * 1024);
     stream.write(page, 1024);
-    stream.flush();
 }
 
 int PageManager::allocate() {
diff --git a/invodb/file/page_manager.h b/invodb/file/page_manager.h
index 0b3aa90..0382015 100644
--- a/invodb/file/page_manager.h
+++ b/invodb/file/page_manager.h
@@ -11,6 +11,7 @@
 
 #include "storage_page.h"
 #include "json/json.hpp"
+#include "models/cache.h"
 
 class PageManager {
 public:
@@ -28,8 +29,9 @@ public:
 private:
     std::map<int, StoragePage> map;
     std::fstream stream;
+    LRUCache<int, StoragePage> cache;
     // 私有化实现单例
-    PageManager() {}
+    PageManager():cache(LRUCache<int, StoragePage>(50000)) {}
     ~PageManager() {}
     PageManager(const PageManager&);
     PageManager& operator=(const PageManager&);
diff --git a/invodb/main.cpp b/invodb/main.cpp
index 3740796..f523155 100644
--- a/invodb/main.cpp
+++ b/invodb/main.cpp
@@ -29,7 +29,7 @@ int main() {
         col = &Collection::getCollection("hello");
     }
 
-    //testAndBenchmark(10000);
+
 
 
     nlohmann::json j = nlohmann::json::parse(R"(
@@ -42,19 +42,16 @@ int main() {
         "id": 3
     },
     "array": ["1", "2", "3"]
+}
     )");
 
 
-    try {
     col->insert(j);
-    }catch(const char * s ){
-        puts(s);
-    }
-
-    printf("?");
 
     col->remove(j);
 
+    testAndBenchmark(100000);
+
     return 0;
 }
 
diff --git a/invodb/models/cache.h b/invodb/models/cache.h
new file mode 100644
index 0000000..4805a44
--- /dev/null
+++ b/invodb/models/cache.h
@@ -0,0 +1,52 @@
+//
+// Created by i on 2021/11/2.
+//
+
+#ifndef INVODBCACHEH
+#define INVODBCACHEH
+
+#include <list>
+#include <map>
+
+template<typename KT, typename VT>
+class LRUCache {
+public:
+    LRUCache(int capacity) : capacity(capacity) {}
+
+    bool exist(KT const &key) {
+        return hash.find(key) != hash.end();
+    }
+
+    VT get(KT const &key) {
+        if (hash.find(key) == hash.end())
+            throw "cache error";
+        else {
+            VT value = hash[key]->second;
+            ls.erase(hash[key]);
+            ls.push_front(std::make_pair(key, value));
+            hash[key] = ls.begin();
+            return value;
+        }
+    }
+
+    void put(KT const &key, VT const &value) {
+        if (hash.find(key) != hash.end()) {
+            ls.erase(hash[key]);
+        }
+        else if (ls.size() >= capacity) {
+            hash.erase(ls.back().first);
+            ls.pop_back();
+        }
+        ls.push_front(std::make_pair(key, value));
+        hash[key] = ls.begin();
+    }
+
+private:
+    int capacity;
+    std::list<std::pair<KT, VT>> ls;
+    std::unordered_map<KT, typename std::list<std::pair<KT, VT>>::iterator> hash;
+};
+
+
+
+#endif //INVODBCACHEH