Object Database

Object Database is a C++14 library providing a key-value store using a shared memory-mapped file, where the key and value can be objects of various types and can be accessed directly by the clients from Shared Memory. The database allows multiple synchronized read/write from different processes.

Project Status

• Work In Progress

Features

Dependencies

• Boost interprocess, filesystem

Example Usage

C++ API

odb::ObjectDatabase db("/tmp/example.odb");
// Write
const auto success = db.Insert<std::string, double>("my_dict", "my_key", 49.5);
// Read
const auto my_value = db.Read<std::string, double>("my_dict", "my_key");
// Get a const reference directly to the value. To get a reference the client has to lock the dict for the lifetime of the reference
db.ReadLockDict("my_dict");
const auto& my_ref_value = db.GetSharedNoLock<std::string, double>("my_dict", "my_key");
db.ReadUnLockDict("my_dict");
// Get a non-const reference directly to the value. To get a reference the client has to lock the dict for the lifetime of the reference
db.LockDict("my_dict");
auto& my_ref_value = db.GetSharedNoLock<std::string, double>("my_dict", "my_key");
db.UnLockDict("my_dict");

Command Line Interface

# insert
odb_cli -i -f filename -d <dict_id> -k <key_type_id> -K <key> -v <value_type_id> -V <value>
# read
odb_cli -f filename -d <dict_id> -k <key_type_id> -K <key> -v <value_type_id>

key_type_id and value_type_id are value id for defined types as follows:

Type	id
int	1
char	2
bool	3
unsigned int	4
double	5
float	6
short	7
unsigned long	8
string	9

Adding Custom Types

TODO

• Provide callbacks for when a dict is changed