From 1c1544f5297f88bbbcbbad2d21c4ec7b62bb9a28 Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Tue, 30 Aug 2011 16:10:02 +0200
Subject: Implement uniform handle management across all databases
Also use the auto_handle template instead of the raw handle in connection,
statement, and result classes. This removes a lot of brittle "exception
safety guarantee" code that we had in those classes.
---
odb/sqlite/auto-handle.hxx | 103 +++++++++++++++++++++++++++++++++++++++++++++
odb/sqlite/connection.cxx | 20 ++++-----
odb/sqlite/connection.hxx | 11 +++--
odb/sqlite/statement.cxx | 5 ++-
odb/sqlite/statement.hxx | 11 ++---
5 files changed, 129 insertions(+), 21 deletions(-)
create mode 100644 odb/sqlite/auto-handle.hxx
diff --git a/odb/sqlite/auto-handle.hxx b/odb/sqlite/auto-handle.hxx
new file mode 100644
index 0000000..60b1ea9
--- /dev/null
+++ b/odb/sqlite/auto-handle.hxx
@@ -0,0 +1,103 @@
+// file : odb/sqlite/auto-handle.hxx
+// author : Constantin Michael <constantin@codesynthesis.com>
+// copyright : Copyright (c) 2005-2011 Code Synthesis Tools CC
+// license : GNU GPL v2; see accompanying LICENSE file
+
+#ifndef ODB_SQLITE_AUTO_HANDLE_HXX
+#define ODB_SQLITE_AUTO_HANDLE_HXX
+
+#include <odb/pre.hxx>
+
+#include <cassert>
+#include <sqlite3.h>
+
+#include <odb/sqlite/version.hxx>
+
+namespace odb
+{
+ namespace sqlite
+ {
+ template <typename H>
+ struct handle_traits;
+
+ template <>
+ struct handle_traits<sqlite3>
+ {
+ static void
+ release (sqlite3* h)
+ {
+ if (sqlite3_close (h) == SQLITE_BUSY)
+ {
+ // Connection has outstanding prepared statements.
+ //
+ assert (false);
+ }
+ }
+ };
+
+ template <>
+ struct handle_traits<sqlite3_stmt>
+ {
+ static void
+ release (sqlite3_stmt* h)
+ {
+ sqlite3_finalize (h);
+ }
+ };
+
+ template <typename H>
+ class auto_handle
+ {
+ public:
+ auto_handle (H* h = 0)
+ : h_ (h)
+ {
+ }
+
+ ~auto_handle ()
+ {
+ if (h_ != 0)
+ handle_traits<H>::release (h_);
+ }
+
+ H*
+ get () const
+ {
+ return h_;
+ }
+
+ void
+ reset (H* h = 0)
+ {
+ if (h_ != 0)
+ handle_traits<H>::release (h_);
+
+ h_ = h;
+ }
+
+ H*
+ release ()
+ {
+ H* h (h_);
+ h_ = 0;
+ return h;
+ }
+
+ operator H* ()
+ {
+ return h_;
+ }
+
+ private:
+ auto_handle (const auto_handle&);
+ auto_handle& operator= (const auto_handle&);
+
+ private:
+ H* h_;
+ };
+ }
+}
+
+#include <odb/post.hxx>
+
+#endif // ODB_SQLITE_AUTO_HANDLE_HXX
diff --git a/odb/sqlite/connection.cxx b/odb/sqlite/connection.cxx
index 68b57f9..7b16547 100644
--- a/odb/sqlite/connection.cxx
+++ b/odb/sqlite/connection.cxx
@@ -29,15 +29,6 @@ namespace odb
namespace sqlite
{
connection::
- ~connection ()
- {
- statement_cache_.reset (); // Free prepared statements.
-
- if (sqlite3_close (handle_) == SQLITE_BUSY)
- assert (false); // Connection has outstanding prepared statements.
- }
-
- connection::
connection (database_type& db, int extra_flags)
: odb::connection (db),
db_ (db),
@@ -58,7 +49,11 @@ namespace odb
if ((f & SQLITE_OPEN_FULLMUTEX) == 0)
f |= SQLITE_OPEN_NOMUTEX;
- if (int e = sqlite3_open_v2 (n.c_str (), &handle_, f, 0))
+ sqlite3* h (0);
+ int e (sqlite3_open_v2 (n.c_str (), &h, f, 0));
+ handle_.reset (h);
+
+ if (e != SQLITE_OK)
{
if (handle_ == 0)
throw bad_alloc ();
@@ -98,6 +93,11 @@ namespace odb
statement_cache_.reset (new statement_cache_type (*this));
}
+ connection::
+ ~connection ()
+ {
+ }
+
transaction_impl* connection::
begin ()
{
diff --git a/odb/sqlite/connection.hxx b/odb/sqlite/connection.hxx
index e487e6b..c1133eb 100644
--- a/odb/sqlite/connection.hxx
+++ b/odb/sqlite/connection.hxx
@@ -21,6 +21,8 @@
#include <odb/sqlite/version.hxx>
#include <odb/sqlite/forward.hxx>
#include <odb/sqlite/transaction-impl.hxx>
+#include <odb/sqlite/auto-handle.hxx>
+
#include <odb/sqlite/details/export.hxx>
namespace odb
@@ -102,7 +104,12 @@ namespace odb
private:
database_type& db_;
- sqlite3* handle_;
+ auto_handle<sqlite3> handle_;
+
+ // Keep statement_cache_ after handle_ so that it is destroyed before
+ // the connection is closed.
+ //
+ std::auto_ptr<statement_cache_type> statement_cache_;
// Unlock notification machinery.
//
@@ -120,8 +127,6 @@ namespace odb
private:
friend class statement;
statement* statements_;
-
- std::auto_ptr<statement_cache_type> statement_cache_;
};
}
}
diff --git a/odb/sqlite/statement.cxx b/odb/sqlite/statement.cxx
index 0fe52f3..d0020d5 100644
--- a/odb/sqlite/statement.cxx
+++ b/odb/sqlite/statement.cxx
@@ -31,10 +31,11 @@ namespace odb
init (const char* s, std::size_t n)
{
int e;
+ sqlite3_stmt* stmt (0);
while ((e = sqlite3_prepare_v2 (conn_.handle (),
s,
static_cast<int> (n),
- &stmt_,
+ &stmt,
0)) == SQLITE_LOCKED)
{
conn_.wait ();
@@ -43,6 +44,8 @@ namespace odb
if (e != SQLITE_OK)
translate_error (e, conn_);
+ stmt_.reset (stmt);
+
active_ = false;
cached_ = false;
diff --git a/odb/sqlite/statement.hxx b/odb/sqlite/statement.hxx
index 5ddb56b..1d48cd4 100644
--- a/odb/sqlite/statement.hxx
+++ b/odb/sqlite/statement.hxx
@@ -20,6 +20,8 @@
#include <odb/sqlite/version.hxx>
#include <odb/sqlite/binding.hxx>
#include <odb/sqlite/connection.hxx>
+#include <odb/sqlite/auto-handle.hxx>
+
#include <odb/sqlite/details/export.hxx>
namespace odb
@@ -131,19 +133,14 @@ namespace odb
finilize ()
{
list_remove ();
-
- if (stmt_ != 0)
- {
- sqlite3_finalize (stmt_);
- stmt_ = 0;
- }
+ stmt_.reset ();
}
protected:
friend class connection;
connection& conn_;
- sqlite3_stmt* stmt_;
+ auto_handle<sqlite3_stmt> stmt_;
bool active_;
bool cached_;
--
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