--- parser3/src/include/Attic/pa_db_table.h	2001/10/26 06:40:25	1.2
+++ parser3/src/include/Attic/pa_db_table.h	2001/10/29 08:23:49	1.7
@@ -4,19 +4,21 @@
 	Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)
 	Author: Alexander Petrosyan <paf@design.ru> (http://design.ru/paf)
 
-	$Id: pa_db_table.h,v 1.2 2001/10/26 06:40:25 paf Exp $
+	$Id: pa_db_table.h,v 1.7 2001/10/29 08:23:49 paf Exp $
 */
 
 #ifndef PA_DB_TABLE_H
 #define PA_DB_TABLE_H
 
 #include "pa_config_includes.h"
-#include "pa_pool.h"
-#include "pa_db_connection.h"
 #include "pa_globals.h"
+#include "pa_pool.h"
 
-#ifdef HAVE_DB_H
+#ifdef DB2
 #	include <db.h>
+#	if DB_VERSION_MAJOR != 2
+#		error Parser needs DB 2.x.x version of libdb to compile
+#	endif
 #endif
 
 // defines
@@ -25,6 +27,9 @@
 
 // forwards
 
+class DB_Connection;
+
+class DB_Table_ptr;
 class DB_Transaction;
 class DB_Cursor;
 
@@ -32,72 +37,42 @@ class DB_Cursor;
 
 /// DB table. handy wrapper around low level <db.h> calls
 class DB_Table : public Pooled {
-	friend DB_Transaction;
-	friend DB_Cursor;
+	friend class DB_Table_ptr;
+	friend class DB_Transaction;
+	friend class DB_Cursor;
 public:
 
-	DB_Table(Pool& pool, const String& afile_spec, DB_Connection& aconnection);
+	DB_Table(Pool& apool, const String& afile_name, DB_Connection& aconnection);
+	~DB_Table();
+
+	const String& file_name() { return ffile_name; }
 
-	void set_services(Pool *aservices_pool) {
-		time_used=time(0); // they started to use at this time
-		fservices_pool=aservices_pool;
-	}
 	bool expired(time_t older_dies) {
-		return time_used<older_dies;
+		return !used && time_used<older_dies;
 	}
 
-	void close() {
-		fconnection.close_table(ffile_spec, *this);
-	}
+	void put(DB_Transaction *t, const String& key, const String& data, time_t time_to_die);
+	String *get(DB_Transaction *t, Pool& pool, const String& key);
+	void remove(DB_Transaction *t, const String& key);
+
+private: // table usage methods
+
+	void use();
+	void unuse();
 
-	bool connected() { return db!=0; }
-	void connect();
-	void disconnect();	
-	bool ping() { return errors==0; }
+private: // table usage data
 
-	void put(const String& key, const String& data, time_t time_to_die);
-	String *get(const String& key);
-	void remove(const String& key);
+	int used;
 
 private:
 
 	DB_Connection& fconnection;
 	DB_ENV& dbenv;
-	const String& ffile_spec; const char *file_spec_cstr;
+	const String& ffile_name; const char *file_name_cstr;
 	Pool *fservices_pool;
 	DB *db;
-	int errors;
-	DB_TXN *ftid; bool ftid_has_parent;
 	time_t time_used;
 
-private: // transaction
-
-	/// commits current transaction, restores previous transaction handle
-	void commit_restore(DB_TXN *atid, bool atid_has_parent) { 
-		if(ftid && !atid_has_parent) // it's parent responsibility to do that
-			check("txn_commit", &ffile_spec, txn_commit(ftid)); 
-
-		ftid=atid;
-		ftid_has_parent=atid_has_parent;
-	}
-	
-	/// rolls current transaction back, restores previous transaction handle
-	void rollback_restore(DB_TXN *atid, bool atid_has_parent) {
-		if(ftid && !atid_has_parent) // it's parent responsibility to do that
-			check("txn_abort", &ffile_spec, txn_abort(ftid));
-
-		ftid=atid;
-		ftid_has_parent=atid_has_parent;
-	}
-	
-	/// stars new current trunsaction @returns previous transaction handle
-	void transaction_begin_save(DB_TXN *& rtid, bool& rtid_has_parent) {
-		rtid=ftid;
-		rtid_has_parent=ftid_has_parent;
-		check("txn_begin", &ffile_spec, ::txn_begin(dbenv.tx_info, rtid, &ftid));
-		ftid_has_parent=rtid!=0;
-	}
-	
 private:
 
 	void check(const char *operation, const String *source, int error);
@@ -106,43 +81,90 @@ private:
 	/// pass empty dbt, would fill it from string
 	void key_string_to_dbt(const String& key_string, DBT& key_result);
 	/// @returns new string
-	String& key_dbt_to_string(const DBT& key_dbt);
+	String& key_dbt_to_string(Pool& pool, const DBT& key_dbt);
 	/// pass empty dbt, would fill it from string
 	void data_string_to_dbt(const String& data_string,  time_t time_to_die, 
 		DBT& data_result);
 	/// @returns new string if it not expired
-	String *data_dbt_to_string(const DBT& data_dbt);
+	String *data_dbt_to_string(Pool& pool, const DBT& data_dbt);
 
 };
 
+/// Auto-object used to track DB_Table usage
+class DB_Table_ptr {
+	DB_Table *ftable;
+public:
+	explicit DB_Table_ptr(DB_Table *atable) : ftable(atable) {
+		ftable->use();
+	}
+	~DB_Table_ptr() {
+		ftable->unuse();
+	}
+	DB_Table* operator->() {
+		return ftable;
+	}
+	DB_Table& operator*() {
+		return *ftable;
+	}
+
+	// copying
+	DB_Table_ptr(const DB_Table_ptr& src) : ftable(src.ftable) {
+		ftable->use();
+	}
+	DB_Table_ptr& operator =(const DB_Table_ptr& src) {
+		// may do without this=src check
+		ftable->unuse();
+		ftable=src.ftable;
+		ftable->use();
+
+		return *this;
+	}
+};
+
 ///	Auto-object used for temporary changing DB_Table::tid.
 class DB_Transaction {
-	DB_Table& ftable;
-	bool marked_to_rollback;
-	DB_TXN *saved_tid; bool saved_tid_has_parent;
 public:
-	DB_Transaction(DB_Table& atable) : ftable(atable), marked_to_rollback(false) {
-		atable.transaction_begin_save(saved_tid, saved_tid_has_parent);
+
+	DB_Transaction(Pool& apool, DB_Table& atable, DB_Transaction *& aparent_ref);
+	~DB_Transaction();
+	DB_TXN *id() { return fid; }
+	void mark_to_rollback();
+
+	void put(const String& key, const String& data, time_t time_to_die) {
+		ftable.put(this, key, data, time_to_die);
+	}
+	String *get(const String& key) {
+		return ftable.get(this, fpool, key);
 	}
-	~DB_Transaction() { 
-		if(marked_to_rollback)
-			ftable.rollback_restore(saved_tid, saved_tid_has_parent);
-		else
-			ftable.commit_restore(saved_tid, saved_tid_has_parent);
+	void remove(const String& key) {
+		ftable.remove(this, key);
 	}
-	void mark_to_rollback() {
-		marked_to_rollback=true;
+
+private:
+
+	void check(const char *operation, const String *source, int error) {
+		ftable.check(operation, source, error);
 	}
+
+private:
+
+	Pool& fpool;
+	DB_Table& ftable;
+	DB_Transaction *parent;
+	DB_Transaction *& fparent_ref;
+	DB_TXN *fid;
+	bool marked_to_rollback;
+
 };
 
 /// DB cursor. handy wrapper around low level <db.h> calls
 class DB_Cursor {
-	friend DB_Table;
 public:
-	DB_Cursor(DB_Table& atable, const String *asource);
+	DB_Cursor(DB_Table& atable, DB_Transaction *transaction, const String *asource);
 	~DB_Cursor();
 	/// pass empty strings to key&data, would fill them
-	bool get(String *& key, String *& data, u_int32_t flags);
+	bool get(Pool& pool, String *& key, String *& data, u_int32_t flags);
+	bool move(u_int32_t flags);
 	void remove(u_int32_t flags);
 private:
 	const String *fsource;
@@ -153,12 +175,12 @@ private:
 		ftable.check(operation, source, error);
 	}
 	/// @returns new string
-	String& key_dbt_to_string(DBT& key_dbt) {
-		return ftable.key_dbt_to_string(key_dbt);
+	String& key_dbt_to_string(Pool& pool, DBT& key_dbt) {
+		return ftable.key_dbt_to_string(pool, key_dbt);
 	}
 	/// @returns new string if it not expired
-	String *data_dbt_to_string(const DBT& data_dbt) {	
-		return ftable.data_dbt_to_string(data_dbt);
+	String *data_dbt_to_string(Pool& pool, const DBT& data_dbt) {	
+		return ftable.data_dbt_to_string(pool, data_dbt);
 	}
 };