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DataDraw
is an ultra-fast persistent database for high performance programs
written in C. It's so fast that many programs keep all their data
in a DataDraw database, even while being manipulated in inner loops of
compute intensive applications. Unlike
slow SQL databases, DataDraw databases are compiled, and directly link
into your C programs. DataDraw databases are resident in memory,
making data manipulation even faster than if they were stored in native
C data structures (really). Further, they can automatically
support infinite undo/redo, greatly simplifying many applications.
DataDraw
databases can be persistent. Modifications to persistent data are
written to disk as they are made, which of course dramatically slows
write times. However, DataDraw databases can also be
volatile. Volatile databases exist only in memory, and only for
the duration that your program needs it. Volatile databases can
be directly manipulated faster than C structures, since data is better
organized in memory to optimize cache performance. DataDraw
supports modular design. An application can have one or more
common persistent databases, and multiple volatile databases to support
various tools' data structures. Classes in a tool's database can
extend classes in the common database. DataDraw
is also 64-bit optimized, allowing programs to run much faster and in
less memory than standard C programs using 64-bit pointers. This
is because DataDraw databases support over 4 billion objects of a
given class with 32-bit object references.
DataDraw
is released under the GNU Library General Public License, Version
2. It costs you nothing to use, and does not restrict your
application in any way. Only the DataDraw program itself is
covered by the license. There is detailed documentation on DataDraw3.0, in OpenOffice open-document format. For those who don't have a recent OpenOffice installation, here's a PDF version. If you have questions, feel free to contact Bill Cox, or post to the mailing list.
Use Cases
If
your application is 99% GUI, and 1% data manipulation, don't use
DataDraw, because that 1% isn't worth automating. If you need to
write a CGI application for the Apache web server with a MySQL
back-end, don't use DataDraw, because the speed DataDraw gives your
application will be wasted. If you don't use data structures more
complex than a tree, don't use DataDraw, because there will be little
for DataDraw to automate. Use
DataDraw when you need speed, efficiency, and/or rich data
structures. Use it for the simplicity it brings your project,
it's automated debugging, persistence, and undo/redo capabilities.
DataDraw
is extensively used in EDA tool development, where speed is critical
and data structures complex. It has, for example, been used in
technology mappers, circuit simulators (both analog and digital),
placers, and routers. DataDraw has been in use since in EDA since
1992, and has matured greatly over that time. DataDraw has also
been used in compiler development.
Internet
servers also benefit from DataDraw. A DataDraw backed application
can process 100X to 1000X more transactions per second than a LAMP
based application. This makes DataDraw a good choice for SIP
servers, BitTorrent, and other applications supporting thousands of
simultaneous connections. Embedded web servers could also benefit
from DataDraw's small memory footprint, power efficient data
manipulation, and ultra-high speed. Telephony applications, and
other CPU intensive tasks are potentially a good fit. Editors of
all kinds are a good fit with DataDraw, because of it's infinite
undo/redo automation.
When to use DataDraw vs MySQL and PHP
LAMP
is a very powerful combination for creating web applications: Linux,
Apache, MySQL, and PHP. Apache provides an incredibly powerful
framework built around a world-class web server. PHP provides a
powerful language for developing web applications rapidly. MySQL
provides a way for these web applications to manage data.
DataDraw is not meant to replace any of this. However, Apache is bloated, PHP is a slow interpreted language, and
MySQL interprets ASCII commands that it reads through sockets that
communicate with PHP. All this slows the system down 100-1000X,
relative to plain old C code. Most applications don't care: if
I'm just trying to sell stuff over the Internet, being able to process
even one transaction per second is probably fine.
DataDraw is for demanding applications for which LAMP is too slow
and/or bloated. While running, a DataDraw application owns the
database, and does not share it with others. That makes it well
suited for implementing some tasks, and not others. For example,
it is well suited for building SQL servers, or BitTorrent trackers, and
embedded servers, but not well suited for Apache modules. In
these cases, consider embedding both DataDraw, and a free, fast, tiny
HTML server, such as the MiniWeb HTTP server, directly in your
application. This will allow you to serve many times more
requests per second, in far less memory.
Benchmarks vs. C++/STL
DataDraw
has been extensively benchmarked against the #1 rival for EDA software
development: C++ using the Standard Template Library. In short DataDraw
smokes C++/STL. In simple depth-first graph traversal, the
graph_benchmark example shows DataDraw based code runs over 15X faster
than the
C++/STL version. It also uses less than half the memory when compiled
in 64-bit mode. Check out the examples directory for current
benchmarks. The difference in runtime is mostly due to L2 data
cashe hit rates, which are 16.6X lower for the DataDraw version.
The DataDraw code also runs 7X faster than the C version!
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L1
Miss Rate
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L2
Miss Rate
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Run
Time
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Memory
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DataDraw
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3.8%
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1.3%
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7.83s
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432MB
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C++/STL
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32.9%
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21.7%
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124.6s
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1.1GB
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Raw
C
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34.4%
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20.4%
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55.2
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702MB
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Installation
DataDraw3.0
is under heavy development, so it is wise to download and compile it
directly from source. Use subversion like this:
$ svn co
https://datadraw.svn.sourceforge.net/svnroot/datadraw/trunk datadraw
However, you are welcome to download a recent source tarball from here. Once you have a datadraw directory, cd into it and type:
$ ./autogen
$ ./configure
$ make
$ su
$ make install
This
should create a 'datadraw' executable, and install it in /usr/local/bin.
You can specify another destination with the --prefix=<dir>
option to configure.
Open-Source Projects Using DataDraw
There
are a few fairly well developed open-source applications using
DataDraw, in addtion to at least three commercial EDA companies using
it for high-performance EDA tool development. The stable
open-source projects
are:
- DataDraw (this project)
- gnetman - an netlist translation tool, compatible with gEDA
- BTSlave - a BitTorrent client
- NetFS - a BitTorrent replacement
Credits
DataDraw
has a long history, dating back to 1992, when Bill Cox wrote verision
1.0 and placed it into the copyleft domain. Since then, others
have contributed to version 2.0, including Bill Falk, Mukesh Lulla,
Brad Pirtle, and John Maushammer.
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