From 350bfdb5ea9b4f7e50746c50a46d8032cbc5a104 Mon Sep 17 00:00:00 2001
From: Kelly Rauchenberger <fefferburbia@gmail.com>
Date: Wed, 8 Nov 2017 14:53:26 -0500
Subject: Created database versioning system

Also added an ANALYZE statement to the end of the datafile generation
process. This generates information that allows sqlite to sometimes come
up with a better query plan, and in many cases can significant speed up
queries. This constitutes a minor database update, but because this is
the first version that uses the database versioning system, older
versions are essentially incompatible.

refs #2
---
 lib/database.cpp | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

(limited to 'lib/database.cpp')

diff --git a/lib/database.cpp b/lib/database.cpp
index a4d056d..fe64763 100644
--- a/lib/database.cpp
+++ b/lib/database.cpp
@@ -1,7 +1,9 @@
 #include "database.h"
 #include <sqlite3.h>
 #include <stdexcept>
+#include <sstream>
 #include "query.h"
+#include "version.h"
 
 namespace verbly {
 
@@ -17,6 +19,35 @@ namespace verbly {
 
       throw database_error("Could not open verbly datafile", errmsg);
     }
+
+    std::string queryString = "SELECT major, minor FROM version";
+
+    sqlite3_stmt* ppstmt;
+    if (sqlite3_prepare_v2(ppdb_, queryString.c_str(), queryString.length(), &ppstmt, NULL) != SQLITE_OK)
+    {
+      std::string errorMsg = sqlite3_errmsg(ppdb_);
+      sqlite3_finalize(ppstmt);
+
+      throw database_error("Error reading database version", errorMsg);
+    }
+
+    if (sqlite3_step(ppstmt) != SQLITE_ROW)
+    {
+      std::string errorMsg = sqlite3_errmsg(ppdb_);
+      sqlite3_finalize(ppstmt);
+
+      throw database_error("Error reading database version", errorMsg);
+    }
+
+    major_ = sqlite3_column_int(ppstmt, 0);
+    minor_ = sqlite3_column_int(ppstmt, 1);
+
+    sqlite3_finalize(ppstmt);
+
+    if (major_ != DATABASE_MAJOR_VERSION)
+    {
+      throw database_version_mismatch(DATABASE_MAJOR_VERSION, major_);
+    }
   }
 
   database::database(database&& other) : database()
@@ -135,4 +166,15 @@ namespace verbly {
     return result;
   }
 
+  std::string database_version_mismatch::generateMessage(int right, int wrong)
+  {
+    std::ostringstream msgbuilder;
+    msgbuilder << "Incompatible database version: needed ";
+    msgbuilder << right;
+    msgbuilder << ", found ";
+    msgbuilder << wrong;
+
+    return msgbuilder.str();
+  }
+
 };
-- 
cgit 1.4.1