add demo

docs/test.js

@@ -0,0 +1,27 @@
+const invodb = require('..')
+
+invodb.database('test.invodb')
+
+let col = invodb.collection('blog')
+if(!col.exist()) col.create();
+
+col.insert({
+    "id": 7,
+    "title": "这是一篇文章",
+    "content": "这是文章内容",
+    "author": "YuhangQ",
+    "category": "数据库",
+    "original-url": null,
+    "tags": ["数据库", "C++", "数据结构"],
+    "parameters": {
+      "hidden": true,
+      "like": 25565,
+    },
+    "comment": [
+      {"username": "YuhangQ", "content": "文章写的真不错！"},
+      {"username": "TechCiel", "content": "能提供下打赏渠道吗？"},
+    ]
+})
+
+let result = col.query({})
+console.log(result)

src/file/page_manager.cpp

@@ -10,6 +10,7 @@ std::fstream PageManager::stream;
 int PageManager::loadDatabase(const char *filename) { 
     Instance().stream.open(filename);
     Instance().stream.seekp(0, std::ios::end);
+
     if(!Instance().stream.is_open()) {
         std::ofstream file(filename, std::fstream::out);
         file.close();
@@ -68,12 +69,13 @@ int PageManager::allocate() {
     }
 
     index = page.getIntStartFrom(4);
+
     //printf("2allocate: %d\n", index);
 
     page.setIntStartFrom(4, index + 1);
     page.save();
     //      allocate block at the end
-//    stream.seekp(0, std::ios::end);
+ //   stream.seekp(0, std::ios::end);
 //    index = stream.tellp() / 1024;
     setPage(index, StoragePage(index));
     return index;