From cfe042dd41a05c8eaef6126203a6f1e3763bc1c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Rombauts?= <sebastien.rombauts@gmail.com>
Date: Tue, 17 Apr 2012 07:06:41 +0200
Subject: [PATCH] Added the dealocation of the reference counter

- Suppressed the exception that can be thrown in those two destructors:
- Added documentation of those destructors
---
 TODO.txt                    | 3 +++
 src/SQLiteC++/Column.cpp    | 8 +++++++-
 src/SQLiteC++/Column.h      | 2 +-
 src/SQLiteC++/Statement.cpp | 6 ++++++
 src/SQLiteC++/Statement.h   | 2 +-
 5 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/TODO.txt b/TODO.txt
index 16ea28d..98ba451 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -5,6 +5,9 @@ Missing features in v0.3.0:
 - Blob
 - getColumnByName ? std::map getRow() ?
 
+Missing documentation in v0.3.0:
+- Help for the new helper functions
+
 Advanced missing features:
 - batch mode managing multiple queries semicolon separated ? 
 - Function ?
diff --git a/src/SQLiteC++/Column.cpp b/src/SQLiteC++/Column.cpp
index e672392..281fa1a 100644
--- a/src/SQLiteC++/Column.cpp
+++ b/src/SQLiteC++/Column.cpp
@@ -24,15 +24,21 @@ Column::Column(sqlite3* apSQLite, sqlite3_stmt* apStmt, unsigned int* apStmtRefC
     (*mpStmtRefCount)++;
 }
 
+// Finalize and unregister the SQL query from the SQLite Database Connection.
 Column::~Column(void) throw() // nothrow
 {
+    // Decrement and check the reference counter
     (*mpStmtRefCount)--;
     if (0 == *mpStmtRefCount)
     {
+        // When count reaches zero, dealloc and finalize the statement
+        delete mpStmtRefCount;
+
         int ret = sqlite3_finalize(mpStmt);
         if (SQLITE_OK != ret)
         {
-            throw SQLite::Exception(sqlite3_errmsg(mpSQLite));
+            // Never throw an exception in a destructor
+            //std::cout << sqlite3_errmsg(mpSQLite);
         }
         mpStmt = NULL;
     }
diff --git a/src/SQLiteC++/Column.h b/src/SQLiteC++/Column.h
index fa87ab5..e1432f1 100644
--- a/src/SQLiteC++/Column.h
+++ b/src/SQLiteC++/Column.h
@@ -76,7 +76,7 @@ private:
 private:
     sqlite3*        mpSQLite;       //!< Pointer to SQLite Database Connection Handle
     sqlite3_stmt*   mpStmt;         //!< Pointer to SQLite Statement Object
-    unsigned int*   mpStmtRefCount; //!< Pointer to the reference counter of the (shared) Statement Object
+    unsigned int*   mpStmtRefCount; //!< Pointer to the reference counter of the Statement Object (to share it with a Statement object)
     int             mIndex;         //!< Index of the column in the row of result
 };
 
diff --git a/src/SQLiteC++/Statement.cpp b/src/SQLiteC++/Statement.cpp
index 533b8f4..e2cc5c2 100644
--- a/src/SQLiteC++/Statement.cpp
+++ b/src/SQLiteC++/Statement.cpp
@@ -28,6 +28,7 @@ Statement::Statement(Database &aDatabase, const char* apQuery) : // throw(SQLite
     int ret = sqlite3_prepare_v2(mpSQLite, mQuery.c_str(), mQuery.size(), &mpStmt, NULL);
     check(ret);
     mColumnCount = sqlite3_column_count(mpStmt);
+    // Initialize the reference counter of the Statement Object : used to share the mpStmt with Column objects
     mpStmtRefCount = new unsigned int;
     *mpStmtRefCount = 1;
 }
@@ -35,9 +36,13 @@ Statement::Statement(Database &aDatabase, const char* apQuery) : // throw(SQLite
 // Finalize and unregister the SQL query from the SQLite Database Connection.
 Statement::~Statement(void) throw() // nothrow
 {
+    // Decrement and check the reference counter
     (*mpStmtRefCount)--;
     if (0 == *mpStmtRefCount)
     {
+        // When count reaches zero, dealloc and finalize the statement
+        delete mpStmtRefCount;
+
         int ret = sqlite3_finalize(mpStmt);
         if (SQLITE_OK != ret)
         {
@@ -189,6 +194,7 @@ Column Statement::getColumn(const int aIndex) const // throw(SQLite::Exception)
         throw SQLite::Exception("Column index out of range");
     }
 
+    // Share the Statement Object handle with the new Column created
     return Column(mpSQLite, mpStmt, mpStmtRefCount, aIndex);
 }
 
diff --git a/src/SQLiteC++/Statement.h b/src/SQLiteC++/Statement.h
index 757c2f4..32eb9f0 100644
--- a/src/SQLiteC++/Statement.h
+++ b/src/SQLiteC++/Statement.h
@@ -176,7 +176,7 @@ private:
 
 private:
     sqlite3_stmt*   mpStmt;         //!< Pointer to SQLite Statement Object
-    unsigned int*   mpStmtRefCount; //!< Pointer to the reference counter of the (shared) Statement Object
+    unsigned int*   mpStmtRefCount; //!< Pointer to the reference counter of the Statement Object (to share it with Column objects)
     sqlite3*        mpSQLite;       //!< Pointer to SQLite Database Connection Handle
     std::string     mQuery;         //!< UTF-8 SQL Query
     int             mColumnCount;   //!< Number of column in the result of the prepared statement