feat(db): add size api for meta

Former-commit-id: 0b240dbf664348f65a70e57a5d545857469ad37b

cpp/src/db/DBMetaImpl.cpp

@@ -476,20 +476,11 @@ Status DBMetaImpl::archive_files() {
         }
         if (criteria == "disk") {
             size_t G = 1024*1024*1024UL;
-            long unsigned int sum = 0;
-            try {
-                auto sum_c = ConnectorPtr->sum(
-                        &GroupFileSchema::rows,
-                        where(
-                            c(&GroupFileSchema::file_type) != (int)GroupFileSchema::TO_DELETE
-                        ));
-                sum = *sum_c;
-            } catch (std::exception & e) {
-                LOG(DEBUG) << e.what();
-                throw e;
-            }
+            long sum = 0;
+            size(sum);
+
             // PXU TODO: refactor rows
-            auto to_delete = sum - limit*G/sizeof(float);
+            auto to_delete = (sum - limit*G)/sizeof(float);
             discard_files_of_size(to_delete);
         }
     }
@@ -497,6 +488,22 @@ Status DBMetaImpl::archive_files() {
     return Status::OK();
 }
 
+Status DBMetaImpl::size(long& result) {
+    try {
+        auto sum_c = ConnectorPtr->sum(
+                &GroupFileSchema::rows,
+                where(
+                    c(&GroupFileSchema::file_type) != (int)GroupFileSchema::TO_DELETE
+                    ));
+        result = *sum_c*sizeof(float);
+    } catch (std::exception & e) {
+        LOG(DEBUG) << e.what();
+        throw e;
+    }
+
+    return Status::OK();
+}
+
 Status DBMetaImpl::discard_files_of_size(long to_discard_size) {
     LOG(DEBUG) << "Abort to discard size=" << to_discard_size;
     if (to_discard_size <= 0) {

cpp/src/db/DBMetaImpl.h

@@ -52,6 +52,8 @@ public:
 
     virtual Status archive_files() override;
 
+    virtual Status size(long& result) override;
+
     virtual Status cleanup() override;
 
     virtual Status cleanup_ttl_files(uint16_t seconds) override;

cpp/src/db/LocalMetaImpl.cpp

@@ -261,6 +261,11 @@ Status LocalMetaImpl::drop_all() {
     return Status::OK();
 }
 
+Status LocalMetaImpl::size(long& result) {
+    // PXU TODO
+    return Status::OK();
+}
+
 Status LocalMetaImpl::count(const std::string& group_id, long& result) {
     // PXU TODO
     return Status::OK();

cpp/src/db/LocalMetaImpl.h

@@ -55,6 +55,8 @@ public:
 
     virtual Status drop_all() override;
 
+    virtual Status size(long& result) override;
+
 private:
 
     Status GetGroupMetaInfoByPath(const std::string& path, GroupSchema& group_info);

cpp/src/db/Meta.h

@@ -93,6 +93,8 @@ public:
     virtual Status files_to_merge(const std::string& group_id,
             DatePartionedGroupFilesSchema& files) = 0;
 
+    virtual Status size(long& result) = 0;
+
     virtual Status archive_files() = 0;
 
     virtual Status files_to_index(GroupFilesSchema&) = 0;