eXtremeDB Unix-Linux Libraries - target/bin

The /target/bin directory under your eXtremeDB installation root directory contains Java archives extremedb.jar and extremedb_jdbc.jar, a python subdirectory and a number of binary libraries described below. The Java archive files are required only for Java applications and JDBC applications. The python subdirectory contains shared object libraries and exdb.py which are required for Python applications.

Python Subdirectory

The /target/bin/python directory contains the eXtremeDB Python implementation source file exdb.py and the following Python shared object libraries:

eXtremeDB.so	The release mode version of the eXtremeDB Python implementation
eXtremeDB_debug.so	The debug mode version of the eXtremeDB Python implementation
eXtremeDB_load.so	The loader functionality that dynamically loads requested runtime modules

Native C Libraries

The native C libraries (upon which the C++, Java and Python wrappers depend) are described in the sections below. Each library is provided in two forms:

• Debug - used during development to aid in finding application level errors; contains several levels of checks for possible erroneous argument values and other error conditions that should be caught and resolved before application deployment; These are easily recognized with the _debug suffix in the filename
• Release - used when the development cycle is completed or when performance comparisons are desired; because most of the checks built into the debug version are removed this version of the libraries performs significantly faster

(Only release mode filenames are shown in the sections below.)

Java and Python applications load shared object versions of the necessary libraries at runtime, but normally C and C++ applications will statically link the appropriate libraries.

Required Libraries

The following tables lists the essential libraries that implement the eXtremeDB functionality. Platform-dependent functionality is implemented in the set of libraries called System Access Layer (SAL) . At least one of the libraries from each of the categories below must be linked to C and C++ applications together with the supporting SAL libraries.

The SAL libraries in the following table implement the indicated functionality for all supported platforms:

libmcosalatomic.a	Atomic operations
libmcosallatches.a	Latches implementations
libmcosaltimer.a	Lo-resolution and hi-resolution timer implementations
libmconet.a	System network layer
libmcosalmem.a	System memory management
libmcosalsmp.a	System mutex, semaphores, threading and other multi-thread/process related code
libmcosaldload.a	System dynamic loader
libmcosalhollow.a	Stub functions for in-memory database single-threaded applications only

Core Runtime

Of the following libraries, libmcolib.a is required for basic eXtremeDB functions and either libmcovtmem.a or libmcovtdsk.a is required depending on whether a persistent database is used:

libmcolib.a	Main database functions
libmcovtmem.a	Virtual Table management for in-memory databases
libmcovtdsk.a	Virtual Table management for persistent and hybrid databases

Memory Device Manager

Depending on the type of database memory device being used, one of the following libraries is required:

libmcomconv.a	Conventional memory device
libmcomalloc.a	Conventional memory device with internal memory allocation by the eXtremeDB runtime
libmcomipc.a	Shared memory device using Unix-Linux IPC
libmcompsx.a	Shared memory device using Unix-Linux POSIX

Transaction Manager

Depending on the choice of Transaction Manager, one of the following libraries is required:

libmcotmursiw.a	MURSIW (MUlti-Read-Single-Write) transaction manager
libmcotmvcc.a	MVCC (Multi Version Concurrency Control) transaction manager
libmcotexcl.a	EXCLusive transaction manager

Concurrency Management

One of the following libraries is required to manage synchronization of database access from multiple threads or processes.

(Note that minimalistic single threaded in-memory database applications, a “hollow” synchronization stub is provided in library libmcosalhollow.a. It has no synchronization code so it is the fastest implementation - but it is valid for single-threaded applications only. If the application links with libmcosalhollow.a then no synchronization library is necessary).

libmcoslnxp.a	POSIX synchronization implementation – faster than SysV-based but applicable only for conventional memory applications (Note that this library is good for multi-process applications if pthread supports that and the operating system is not MacOS)
libmcoslnxs5.a	Pure SysV synchronization implementation – slowest but good for all applications
libmcoslnx.a	SysV with atomic operations. - good for all applications in shared or conventional memory (Note that atomic operations avoid unnecessary kernel calls and can provide better performance.)

Persistent Database Support

All C and C++ applications using the Persistent Storage APIs must link with libmcovtdsk instead of libmcovtmem for "virtual table" control, and, in addition, one of the following libraries is required depending on the file system used:

libmcofuni.a	Unix-Linux file system support
libmcofu98.a	Unix98 file system support
libmcofu98zip.a	LZ Compression and database + mmap
libmcofu98ziplog.a	LZ Compression and sequential log

Utility Functions

Miscellaneous functionality used in eXtremeDB internals are provided in the following libraries. Depending on whether the standard C runtime libraries are used one of these is required:

libmcouwrt.a	Utilities using the C runtime
libmcounrt.a	Utilities without the C runtime

Optional Libraries

The following sections describe optional libraries that are required only for the eXtremeDB features specified:

Dynamic Module Loader [Optional]

The following library provides the capability to dynamically load parts of the eXtremeDB core on request:

libmcoloader.a

Provides the mco_core_load() API to dynamically load parts of the eXtremeDB core on request

Sequence Data Type Support [Optional]

These libraries provide basic sequence data type operations such as reading and inserting sequence data. All applications that use the sequence data type must link with one of the following libraries:

libmcoseq.a	Sequence data type API support
libmcoseqrle.a	Sequence data type with RLE compression API support

Analytics Function Library [Optional]

If, in addition to basic sequence operations, mathematics and statistical functions that operate on sequences are required, applications must link with one of the following libraries:

libmcoseqmath.a	Mathematical and statistical functions operating on sequences
libmcoseqrlemath.a	Mathematical and statistical functions operating on sequences with RLE compression

Active Replication Fabric Support [Optional]

eXtremeDB Active Replication Fabric packages provide the following libraries. All applications that use ARF (IoT) APIs must link with both:

libmcoiotcomm.a	IOT communication library
libmcoiotrepl.a	IOT replication

Transaction Logging APIs [Optional]

The eXtremeDB Transaction Logging APIs are implemented in the following library. All applications that use the Transaction Logging API must link with:

libmcolog.a

Transaction Logging API

In addition, all applications that use the Transaction Logging APIs must link with a File System Wrapper library (see the Persistent Database Support section above)

Backup [Optional]

The following library is provided for applications using the incremental backup feature to backup and restore databases on persistent media:

libmcobackup.a

Incremental backup and restore for in-memory and persistent databases

Serialization [Optional]

The following library is provided for applications using the save / load features to store and retrieve database or class snapshots on persistent media. (Note that this functionality does not require file system wrappers. The save / load features use an abstract stream (implemented by the application) to transfer data to the operating system.)

libmcoseri.a

Serialization (save and load) for all-in-memory databases

Uniform Data Access (UDA) [Optional]

For applications that use the Uniform Data Access functions the following library is required:

libmcouda.a

Required if UDA APIs are used

Debug Error and Tracing Diagnostics [Optional]

The eXtremeDB tracing framework allows applications to output trace and debugging information to a log file. If desired, the following library can be included:

libmcotrace.a

Required if tracing framework is used

Database Calculator [Optional]

The following library is required for applications that use the database calculator:

libmcodbcalc.a

Database Calculator implementation

HTTP Database Viewer [Optional]

The HTTP Viewer requires the following libraries:

libmcoews.a	HTTP server implementation
libmcohv.a	HTTP Database Viewer (without SQL capability)

Cryptography [Optional]

The Database Encryption feature requires one of the following libraries:

libmcocryptaes.a	AES encryption algorithm
libmcocryptstub.a	Empty encryption APIs for custom implementation