feat: return data version on each query

include/silo/common/data_version.h

@@ -0,0 +1,17 @@
+#ifndef SILO_INCLUDE_SILO_COMMON_DATAVERSION_H_
+#define SILO_INCLUDE_SILO_COMMON_DATAVERSION_H_
+
+#include <string>
+
+class DataVersion {
+  public:
+   explicit DataVersion(const std::string& data_version = "");
+   [[nodiscard]] std::string toString() const;
+
+   static std::string mineDataVersion();
+
+  private:
+   std::string data_version;
+};
+
+#endif  // SILO_INCLUDE_SILO_COMMON_DATAVERSION_H_

include/silo/database.h

@@ -1,6 +1,7 @@
 #ifndef SILO_DATABASE_H
 #define SILO_DATABASE_H
 
+#include <silo/common/data_version.h>
 #include <cstddef>
 #include <cstdint>
 #include <filesystem>
@@ -36,9 +37,6 @@ struct PreprocessingConfig;
 namespace silo {
 
 class Database {
-  private:
-   PangoLineageAliasLookup alias_key;
-
   public:
    silo::config::DatabaseConfig database_config;
    std::vector<DatabasePartition> partitions;
@@ -62,7 +60,13 @@ class Database {
 
    [[nodiscard]] const PangoLineageAliasLookup& getAliasKey() const;
 
+   void setDataVersion(const DataVersion& data_version);
+   DataVersion getDataVersion() const;
+
   private:
+   PangoLineageAliasLookup alias_key;
+   DataVersion data_version_;
+
    void build(
       const preprocessing::PreprocessingConfig& preprocessing_config,
       const preprocessing::Partitions& partition_descriptor,

include/silo_api/query_handler.h

@@ -14,9 +14,13 @@ namespace silo_api {
 class QueryHandler : public RestResource {
   private:
    const silo::query_engine::QueryEngine& query_engine;
+   const std::string data_version;
 
   public:
-   explicit QueryHandler(const silo::query_engine::QueryEngine& query_engine);
+   explicit QueryHandler(
+      const silo::query_engine::QueryEngine& query_engine,
+      std::string data_version
+   );
 
    void post(Poco::Net::HTTPServerRequest& request, Poco::Net::HTTPServerResponse& response)
       override;

src/silo/common/data_version.cpp

@@ -0,0 +1,16 @@
+#include "silo/common/data_version.h"
+
+#include <chrono>
+
+std::string DataVersion::mineDataVersion() {
+   const auto now = std::chrono::system_clock::now();
+   const auto now_as_time_t = std::chrono::system_clock::to_time_t(now);
+   return std::to_string(now_as_time_t);
+}
+
+DataVersion::DataVersion(const std::string& data_version)
+    : data_version(data_version) {}
+
+std::string DataVersion::toString() const {
+   return data_version;
+}

src/silo/common/data_version.test.cpp

@@ -0,0 +1,19 @@
+#include "silo/common/data_version.h"
+
+#include <gtest/gtest.h>
+
+TEST(DataVersion, shouldMineDataVersionFromUnixTime) {
+   const auto mined_version = DataVersion::mineDataVersion();
+   EXPECT_EQ(mined_version.size(), 10);
+   EXPECT_EQ(mined_version[0], '1');
+}
+
+TEST(DataVersion, shouldConstructFromVersionString) {
+   const auto version = DataVersion("1234567890");
+   EXPECT_EQ(version.toString(), "1234567890");
+}
+
+TEST(DataVersion, shouldConstructWithDefaultVersion) {
+   const auto version = DataVersion();
+   EXPECT_EQ(version.toString(), "");
+}

src/silo/database.cpp

@@ -2,6 +2,7 @@
 
 #include <array>
 #include <atomic>
+#include <chrono>
 #include <deque>
 #include <filesystem>
 #include <fstream>
@@ -143,6 +144,8 @@ void Database::build(
 
    SPDLOG_INFO("Build took {} ms", micros);
    SPDLOG_INFO("database info: {}", getDatabaseInfo());
+
+   setDataVersion(DataVersion(DataVersion::mineDataVersion()));
 }
 
 using RoaringStatistics = roaring::api::roaring_statistics_t;
@@ -367,6 +370,12 @@ std::map<std::string, std::vector<AA_SYMBOL>> Database::getAASequences() const {
    return aa_sequences_map;
 }
 
+void saveDataVersion(const Database& database, const std::string& save_directory) {
+   std::ofstream data_version_file(save_directory + "data_version.silo");
+   const auto data_version = database.getDataVersion().toString();
+   data_version_file << data_version;
+}
+
 void Database::saveDatabaseState(const std::string& save_directory) {
    const std::string database_config_filename = save_directory + "database_config.yaml";
    database_config.writeConfig(database_config_filename);
@@ -414,6 +423,15 @@ void Database::saveDatabaseState(const std::string& save_directory) {
       }
    });
    SPDLOG_INFO("Finished saving partitions", partitions.size());
+
+   saveDataVersion(*this, save_directory);
+}
+
+DataVersion loadDataVersion(const std::string& save_directory) {
+   std::ifstream data_version_file(save_directory + "data_version.silo");
+   std::string data_version;
+   data_version_file >> data_version;
+   return DataVersion(data_version);
 }
 
 Database Database::loadDatabaseState(const std::string& save_directory) {
@@ -482,6 +500,10 @@ Database Database::loadDatabaseState(const std::string& save_directory) {
          }
       }
    );
+
+   SPDLOG_INFO("Loading data_version from {}", save_directory + "data_version.silo");
+   database.setDataVersion(loadDataVersion(save_directory));
+
    return database;
 }
 
@@ -641,4 +663,13 @@ void Database::finalizeInsertionIndexes() {
 
 Database::Database() = default;
 
+void Database::setDataVersion(const DataVersion& data_version) {
+   SPDLOG_DEBUG("Set data version to {}", data_version.toString());
+   data_version_ = data_version;
+}
+
+DataVersion Database::getDataVersion() const {
+   return data_version_;
+}
+
 }  // namespace silo

src/silo_api/query_handler.cpp

@@ -15,8 +15,12 @@
 
 namespace silo_api {
 
-QueryHandler::QueryHandler(const silo::query_engine::QueryEngine& query_engine)
-    : query_engine(query_engine) {}
+QueryHandler::QueryHandler(
+   const silo::query_engine::QueryEngine& query_engine,
+   std::string data_version
+)
+    : query_engine(query_engine),
+      data_version(std::move(data_version)) {}
 
 void QueryHandler::post(
    Poco::Net::HTTPServerRequest& request,
@@ -29,10 +33,11 @@ void QueryHandler::post(
    SPDLOG_INFO("received query: {}", query);
 
    response.setContentType("application/json");
-
    try {
       const auto query_result = query_engine.executeQuery(query);
 
+      response.set("Data-Version", data_version);
+
       std::ostream& out_stream = response.send();
       out_stream << nlohmann::json(query_result);
    } catch (const silo::QueryParseException& ex) {

src/silo_api/request_handler_factory.cpp

@@ -36,7 +36,7 @@ Poco::Net::HTTPRequestHandler* SiloRequestHandlerFactory::routeRequest(
       return new silo_api::InfoHandler(database);
    }
    if (path == "/query") {
-      return new silo_api::QueryHandler(query_engine);
+      return new silo_api::QueryHandler(query_engine, database.getDataVersion().toString());
    }
    return new silo_api::NotFoundHandler;
 }