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+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 2009 Oracle.  All rights reserved.
+ *
+ * $Id$
+ */
+
+#ifndef _DB_STL_CONTAINER_H__
+#define _DB_STL_CONTAINER_H__
+
+#include "dbstl_common.h"
+#include "dbstl_resource_manager.h"
+#include <assert.h>
+
+START_NS(dbstl)
+
+class ResourceManager;
+
+//////////////////////////////////////////////////////////////////////////
+//////////////////////////////////////////////////////////////////////////
+//
+// db_container class definition
+//
+// This class's begin_txn, commit/abort_txn is used to wrap each DB related
+// operation inside dbstl. When auto commit is enabled, each operation will
+// be auto committed before returning, and aborted when an exception is thrown.
+//
+// It also contains members to hold all needed parameters and flags for
+// transaction and cursor related calls.
+//
+// Container classes will inherit from this class. Each container will enclose
+// every db related operation with db_container::begin_txn and
+// db_container::commit_txn, and if exception is not caught, abort_txn()
+// should be called.
+
+/** \defgroup dbstl_containers dbstl container classes
+A dbstl container is very much like a C++ STL container. It stores a 
+collection of data items, or key/data pairs. 
+Each container is backed by a Berkeley DB database created in an explicit
+database environment or an internal private environment; And the database
+itself can be created explicitly with all kinds of configurations, or
+by dbstl internally. For each type of container, some specific type of 
+database and/or configurations must be used or specified to the database
+and its environment. dbstl will check the database and environment conform 
+to the requirement. When users don't have a chance to specify a container's
+backing database and environment, like in copy constructors, dbstl will
+create proper databases and/or environment for it. There are two helper 
+functions to make it easier to create/open an environment or database, they
+are dbstl::open_db() and dbstl::open_env();
+\sa dbstl::open_db() dbstl::open_env() db_vector db_map db_multimap db_set 
+db_multiset
+*/
+
+/** \ingroup dbstl_containers
+@{
+This class is the base class for all db container classes, you don't directly
+use this class, but all container classes inherit from this class, so you need
+to know the methods that can be accessed via concrete container classes.
+This class is also used to support auto commit transactions. Autocommit is
+enabled when DB_AUTO_COMMIT is set to the database or database environment
+handle and the environment is transactional.
+
+Inside dbstl, there are transactions begun and committed/aborted if the backing
+database and/or environment requires auto commit, and there are cursors
+opened internally, and you can set the flags used by the transaction and cursor
+functions via set functions of this class.
+
+All dbstl containers are fully multi-threaded, you should not need any
+synchronization to use them in the correct way, but this class is not thread
+safe, access to its members are not proctected by any mutex because the data
+members of this class are supposed to be set before they are used, 
+and remain read only afterwards. If this is not the case, you must synchronize
+the access.
+*/
+class _exported db_container
+{
+private:
+	// By default these flags are 0, users should configure these values
+	// on container initialization.
+	//
+	u_int32_t txn_begin_flags_, commit_flags_;
+	mutable u_int32_t cursor_oflags_;
+
+	// Berkeley DB database handle for each container. Subclasses do not
+	// need to define it.
+	//
+	Db *pdb_;
+
+	// Berkeley DB environment handle in which the db handle is opened.
+	DbEnv *dbenv_;
+
+	// db_map_iterator<> needs to know whether the container is a
+	// db_(multi)set or not
+	//
+	bool is_set_;
+
+	// Determined automatically, by inspecting users the Berkeley DB
+	// database and environment configuration options.
+	//
+	bool auto_commit_;
+
+	// If exisiting random temporary database name generation mechanism is
+	// still causing name clashes, users can set this global suffix number
+	// which will be append to each temporary database file name and by 
+	// default it is 0. there is a dbstl::set_global_dbfile_suffix_number
+	// to do so.
+	static u_int32_t g_db_file_suffix_;
+	friend void set_global_dbfile_suffix_number(u_int32_t);
+protected:
+
+	// Does not clone or copy data from database parameter.
+	// Return the db file name back in the dbfname parameter.
+	// We construct a default database name the user can rename it using
+	// either DbEnv::dbrename or Db::rename.
+	//
+	Db* clone_db_config(Db *dbp, std::string &dbfname);
+	Db* clone_db_config(Db *dbp);
+
+	// Store the name into name parameter whose length is n. Return -1 if
+	// not enough space.
+	int construct_db_file_name(std::string &filename) const;
+
+	// Check that this container and cntnr are backed by different databases
+	// and if any one of them is using transactions, both should be in the
+	// same transactional environment.
+	// Called by all deriving classes' methods
+	// which have a container parameter.
+	void verify_db_handles(const db_container &cntnr) const;
+
+	void open_db_handles(Db *&pdb, DbEnv *&penv, DBTYPE dbtype,
+	    u_int32_t oflags, u_int32_t sflags);
+
+	inline void set_is_set(bool b)
+	{
+		is_set_ = b;
+	}
+
+	inline bool is_set() const
+	{
+		return is_set_;
+	}
+
+	// Database and environment handles and autocommit and is_set_ are 
+	// not assigned, because they are the nature of my own db, not 
+	// that of dbctnr.
+	inline const db_container &operator=(const db_container & dbctnr)
+	{
+		ASSIGNMENT_PREDCOND(dbctnr)
+		txn_begin_flags_ = dbctnr.txn_begin_flags_;
+		commit_flags_ = dbctnr.commit_flags_;
+		cursor_oflags_ = dbctnr.cursor_oflags_;
+		return dbctnr;
+	}
+
+public:
+	/// Default constructor.
+	db_container();
+
+	/// Copy constructor.
+	/// The new container will be backed by another database within the
+	/// same environment unless dbctnr's backing database is in its own
+	/// internal private environment. The name of the database is coined
+	/// based on current time and thread id and some random number. If
+	/// this is still causing naming clashes, you can set a suffix number
+	/// via "set_global_dbfile_suffix_number" function; And following db
+	/// file will suffix this number in the file name for additional 
+	/// randomness. And the suffix will be incremented after each such use.
+	/// You can change the file name via DbEnv::rename.
+	/// If dbctnr is using an anonymous database, the newly constructed
+	/// container will also use an anonymous one.
+	/// \param dbctnr The container to initialize this container.
+	db_container(const db_container &dbctnr);
+
+	/**
+	This constructor is not directly called by the user, but invoked by
+	constructors of concrete container classes. The statement about the
+	parameters applies to constructors of all container classes.
+	\param dbp Database handle. dbp is supposed to be opened inside envp.
+	Each dbstl container is backed by a Berkeley DB database, so dbstl 
+	will create an internal anonymous database if dbp is NULL. 
+	\param envp Environment handle. And envp can also be NULL, meaning the
+	dbp handle may be created in its internal private environment.
+	*/
+	db_container(Db *dbp, DbEnv *envp);
+
+	/// The backing database is not closed in this function. It is closed
+	/// when current thread exits and the database is no longer referenced
+	/// by any other container instances in this process. 
+	/// In order to make the reference counting work alright, you must call
+	/// register_db(Db*) and register_db_env(DbEnv*) correctly.
+	/// \sa register_db(Db*) register_db_env(DbEnv*) 
+	virtual ~db_container(){}
+
+	/// \name Get and set functions for data members.
+	/// Note that these functions are not thread safe, because all data 
+	/// members of db_container are supposed to be set on container 
+	/// construction and initialization, and remain read only afterwards.
+	//@{
+	/// Get the backing database's open flags.
+	/// \return The backing database's open flags.
+	inline u_int32_t get_db_open_flags()   const
+	{
+		u_int32_t oflags;
+		pdb_->get_open_flags(&oflags);
+		return oflags;
+	}
+
+	/// Get the backing database's flags that are set via Db::set_flags()
+	/// function.
+	/// \return Flags set to this container's database handle.
+	inline u_int32_t get_db_set_flags()   const
+	{
+		u_int32_t oflags;
+		pdb_->get_flags(&oflags);
+		return oflags;
+	}
+
+	/// Get the backing database's handle. 
+	/// \return The backing database handle of this container.
+	inline Db* get_db_handle() const
+	{
+		return pdb_;
+	}
+
+	/// Get the backing database environment's handle. 
+	/// \return The backing database environment handle of this container.
+	inline DbEnv* get_db_env_handle()  const
+	{
+		return dbenv_;
+	}
+
+	/** 
+	Set the underlying database's handle, and optionally environment 
+	handle if the environment has also changed. That is, users can change
+	the container object's underlying database while the object is alive.
+	dbstl will verify that the handles set conforms to the concrete 
+	container's requirement to Berkeley DB database/environment handles.
+	\param dbp The database handle to set.
+	\param newenv The database environment handle to set.
+	*/
+	void set_db_handle(Db *dbp, DbEnv *newenv = NULL);
+
+	/** Set the flags required by the Berkeley DB functions 
+	DbEnv::txn_begin(), DbTxn::commit() and DbEnv::cursor(). These flags
+	will be set to this container's auto commit member functions when 
+	auto commit transaction is used, except that cursor_oflags is set to 
+	the Dbc::cursor when creating an iterator for this container.
+	By default the three flags are all zero.
+	You can also set the values of the flags individually by using the 
+	appropriate set functions in this class. The corresponding get 
+	functions return the flags actually used.
+	\param txn_begin_flags Flags to be set to DbEnv::txn_begin().
+	\param commit_flags Flags to be set to DbTxn::commit().
+	\param cursor_open_flags Flags to be set to Db::cursor().
+	*/
+	inline void set_all_flags(u_int32_t txn_begin_flags,
+	    u_int32_t commit_flags, u_int32_t cursor_open_flags)
+	{
+		this->txn_begin_flags_ = txn_begin_flags;
+		this->commit_flags_ = commit_flags;
+		this->cursor_oflags_ = cursor_open_flags;
+	}
+
+	/// Set flag of DbEnv::txn_begin() call.
+	/// \param flag Flags to be set to DbEnv::txn_begin().
+	inline void set_txn_begin_flags(u_int32_t flag )
+	{
+		txn_begin_flags_ = flag;
+	}
+
+	/// Get flag of DbEnv::txn_begin() call.
+	/// \return Flags to be set to DbEnv::txn_begin().
+	inline u_int32_t get_txn_begin_flags()  const
+	{
+		return txn_begin_flags_;
+	}
+
+	/// Set flag of DbTxn::commit() call.
+	/// \param flag Flags to be set to DbTxn::commit().
+	inline void set_commit_flags(u_int32_t flag)
+	{
+		commit_flags_ = flag;
+	}
+
+	/// Get flag of DbTxn::commit() call.
+	/// \return Flags to be set to DbTxn::commit().
+	inline u_int32_t get_commit_flags()  const
+	{
+		return commit_flags_;
+	}
+
+	/// Get flag of Db::cursor() call.
+	/// \return Flags to be set to Db::cursor().
+	inline u_int32_t get_cursor_open_flags()  const
+	{
+		return cursor_oflags_;
+	}
+
+	/// Set flag of Db::cursor() call.
+	/// \param flag Flags to be set to Db::cursor().
+	inline void set_cursor_open_flags(u_int32_t flag)
+	{
+		cursor_oflags_ = flag;
+	}
+	//@} // getter_setters
+
+protected:
+	void init_members();
+	void init_members(Db *pdb, DbEnv *env);
+	void init_members(const db_container&cnt);
+	// Called internally by concrete container constructors. Verification
+	// is done by the specialized constructors
+	void set_db_handle_int(Db *dbp, DbEnv *envp)
+	{
+		this->pdb_ = dbp;
+		this->dbenv_ = envp;
+	}
+
+	// Child classes override this function to check the db and environment
+	// handles are correctly configured.
+	virtual const char* verify_config(Db* pdb, DbEnv* penv) const
+	{
+		if (pdb != NULL && ((pdb->get_create_flags() & 
+		    DB_CXX_NO_EXCEPTIONS) == 0))
+			return 
+"Db and DbEnv object must be constructed with DB_CXX_NO_EXCEPTIONS flag set.";
+
+		if (penv != NULL && ((penv->get_create_flags() & 
+		    DB_CXX_NO_EXCEPTIONS) == 0))
+			return 
+"Db and DbEnv object must be constructed with DB_CXX_NO_EXCEPTIONS flag set.";
+		return NULL;
+	}
+
+	// Use db and dbenv_ to determine whether to enable autocommit. If
+	// DB_AUTOCOMMIT is set on dbenv_ or db and dbenv_ is transactional,
+	// that db should be autocommit.
+	//
+	void set_auto_commit(Db* db);
+
+	// Begin a transaction. Used to make a container's db related
+	// operations auto commit when the operation completes and abort
+	// when the operation fails. If there is already a transaction for this
+	// container's environment, then that transaction is used. If the
+	// transaction was created by DB STL, its reference count is
+	// incremented (user created and external transactions are not
+	// reference counted because they can be nested.).
+	inline DbTxn* begin_txn() const
+	{
+		DbTxn *txn = NULL;
+
+		if (this->auto_commit_) {
+			txn = ResourceManager::instance()->begin_txn(
+			    this->txn_begin_flags_, dbenv_, 0);
+		}
+		return txn;
+	}
+
+	inline void commit_txn()  const
+	{
+		if (this->auto_commit_) {
+			ResourceManager::instance()->
+			    commit_txn(pdb_->get_env(), this->commit_flags_);
+		}
+	}
+
+	inline void abort_txn() const
+	{
+		if (this->auto_commit_)
+			ResourceManager::instance()->
+			    abort_txn(pdb_->get_env());
+	}
+
+	inline DbTxn *current_txn() const
+	{
+		return ResourceManager::instance()->
+		    current_txn(pdb_->get_env());
+	}
+}; // db_container
+/** @} */ // dbstl_containers
+
+/// \addtogroup dbstl_helper_classes
+//@{
+/// Bulk retrieval configuration helper class. Used by the begin() function of
+/// a container.
+class _exported BulkRetrievalOption
+{
+public:
+	enum Option {BulkRetrieval, NoBulkRetrieval};
+
+protected:
+	Option bulk_retrieve;
+	u_int32_t bulk_buf_sz_;
+
+	inline BulkRetrievalOption()
+	{
+		bulk_retrieve = NoBulkRetrieval;
+		bulk_buf_sz_ = DBSTL_BULK_BUF_SIZE;
+	}
+
+public:
+	inline BulkRetrievalOption(Option bulk_retrieve1, 
+	    u_int32_t bulk_buf_sz = DBSTL_BULK_BUF_SIZE)
+	{
+		this->bulk_retrieve = bulk_retrieve1;
+		this->bulk_buf_sz_ = bulk_buf_sz;
+	}
+
+	// The following two static members should best be const, but this is
+	// impossible because in C++ this definition is a function declaration:
+	// const static BulkRetrievalOption BulkRetrieval(BulkRetrieval);
+	// i.e. const static members can only be inited with default copy
+	// constructor.
+	//
+  	// Static data members can't be compiled into a .lib for a dll on
+  	// Windows, code using the static members will have link error---
+  	// unresolved symbols, so we have to use a static function here.
+ 	/// This function indicates that you need a bulk retrieval iterator, 
+ 	/// and it can be also used to optionally set the bulk read buffer size.
+  	inline static BulkRetrievalOption bulk_retrieval(
+  	    u_int32_t bulk_buf_sz = DBSTL_BULK_BUF_SIZE)
+  	{
+  		return BulkRetrievalOption(BulkRetrieval, bulk_buf_sz);
+  	}
+  
+ 	/// This function indicates that you do not need a bulk retrieval 
+ 	/// iterator.
+  	inline static BulkRetrievalOption no_bulk_retrieval()
+  	{
+  		return BulkRetrievalOption(NoBulkRetrieval, 0);
+  	}
+  
+ 	/// Equality comparison.
+  	inline bool operator==(const BulkRetrievalOption& bro) const
+  	{
+  		return bulk_retrieve == bro.bulk_retrieve;
+  	}
+  
+ 	/// Assignment operator.
+  	inline void operator=(BulkRetrievalOption::Option opt)
+  	{
+  		bulk_retrieve = opt;
+  	}
+  
+ 	/// Return the buffer size set to this object.
+ 	inline u_int32_t bulk_buf_size()
+  	{
+  		return bulk_buf_sz_;
+  	}
+};
+//@}
+
+/// \addtogroup dbstl_helper_classes
+//@{
+/// Read-modify-write cursor configuration helper class. Used by each begin()
+/// function of all containers.
+class _exported ReadModifyWriteOption
+{
+protected:
+	enum Option{ReadModifyWrite, NoReadModifyWrite};
+	Option rmw;
+
+	inline ReadModifyWriteOption(Option rmw1)
+	{
+		this->rmw = rmw1;
+	}
+
+	inline ReadModifyWriteOption()
+	{
+		rmw = NoReadModifyWrite;
+	}
+
+public:
+	/// Assignment operator.
+	inline void operator=(ReadModifyWriteOption::Option rmw1)
+	{
+		this->rmw = rmw1;
+	}
+
+	/// Equality comparison.
+	inline bool operator==(const ReadModifyWriteOption &rmw1) const
+	{
+		return this->rmw == rmw1.rmw;
+	}
+
+	/// Call this function to tell the container's begin() function that
+	/// you need a read-modify-write iterator.
+	inline static ReadModifyWriteOption read_modify_write()
+	{
+		return ReadModifyWriteOption(ReadModifyWrite);
+	}
+
+	/// Call this function to tell the container's begin() function that
+	/// you do not need a read-modify-write iterator. This is the default
+	/// value for the parameter of any container's begin() function.
+	inline static ReadModifyWriteOption no_read_modify_write()
+	{
+		return ReadModifyWriteOption(NoReadModifyWrite);
+	}
+
+};
+//@} // dbstl_helper_classes
+
+// The classes in the Berkeley DB C++ API do not expose data and p_ member.
+// Extend the class to provide this functionality, rather than altering the
+// internal implementations.
+//
+class _exported DbstlMultipleIterator : protected DbMultipleIterator
+{
+protected:
+	DbstlMultipleIterator(const Dbt &dbt) : DbMultipleIterator(dbt) {}
+public:
+	u_int32_t get_pointer()
+	{
+		u_int32_t off;
+		off = (u_int32_t)((u_int8_t*)p_ - data_);
+		return off;
+	}
+
+	inline void set_pointer(u_int32_t offset)
+	{
+		p_ = (u_int32_t*)(data_ + offset);
+	}
+
+};
+
+class _exported DbstlMultipleKeyDataIterator : public DbstlMultipleIterator
+{
+public:
+	DbstlMultipleKeyDataIterator(const Dbt &dbt)
+	    : DbstlMultipleIterator(dbt) {}
+	bool next(Dbt &key, Dbt &data);
+};
+
+class _exported DbstlMultipleRecnoDataIterator : public DbstlMultipleIterator
+{
+public:
+	DbstlMultipleRecnoDataIterator(const Dbt &dbt)
+	   : DbstlMultipleIterator(dbt) {}
+	bool next(db_recno_t &recno, Dbt &data);
+};
+
+class _exported DbstlMultipleDataIterator : public DbstlMultipleIterator
+{
+public:
+	DbstlMultipleDataIterator(const Dbt &dbt)
+	    : DbstlMultipleIterator(dbt) {}
+	bool next(Dbt &data);
+};
+
+// These classes are used to give data values meaningful default
+// initializations. They are only necessary for types that do not have a
+// reasonable default constructor - explicitly char *, wchar_t * and T*.
+// The string types don't have a reasonable default initializer since we store
+// the underlying content, not a pointer.
+// So we fully instantiate types for T* and const T* and set the pointers to
+// NULL and leave other types intact.
+template <Typename T>
+class DbstlInitializeDefault
+{
+public:
+	DbstlInitializeDefault(T&){}
+};
+
+template <Typename T>
+class DbstlInitializeDefault<T *>
+{
+public:
+	DbstlInitializeDefault(T *& t){t = NULL;}
+};
+
+template <Typename T>
+class DbstlInitializeDefault<const T *>
+{
+public:
+	DbstlInitializeDefault(const T *& t){t = NULL;}
+};
+
+END_NS
+
+#endif //_DB_STL_CONTAINER_H__