An attempt to understand good ways to organize, transform and move data around in a modern computer.
A package containing implementations of various ways of storing lexicons for fast access, update and removal.
The following tests were performed using the following hardware/software :
- Intel Xeon E31230 (4 core) @ 3.2 GHz machine with 8 GB RAM
- Windows 7 Enterprise 64-bit OS
- Eclipse Java EE IDE (version: Juno Service Release 2)
- Eclipse Memory Analyzer Version 1.3.0
Time/space characteristics for complete ingestion of a sample lexicon containing 178691 words :
| Method | Time with I/O (in seconds) | Time without I/O (in seconds) | Memory Footprint |
|---|---|---|---|
| Ternary Search Tree (direct implementation) | 0.07 | 0.07 | 12.1 MB |
| Ternary Search Tree (using array-based maps) | 0.45 | 0.5 | 27.6 MB |
| Hash Array Mapped Trie | 0.18 | 0.15 | 13.4 MB |
| CTrie (Concurrent Hash Trie)a | 0.11b | 0.09b | 19 MB |
| HashSet | 0.03 | 16 MB | |
| Collections.synchronizedSet(HashSet) OR Collections.newSetFromMap(ConcurrentHashMap) | 0.06 |
Running time for Nth word containment test from the same lexicon (after ingestion) :
| Method | Time (in seconds) |
|---|---|
| Ternary Search Tree (direct implementation) | 0.01 |
| Ternary Search Tree (using array-based maps) | failed |
| Hash Array Mapped Trie | 0.02 |
| CTrie | 0.01b |
| HashSet | 0.006 |
| Collections.synchronizedSet(HashSet) OR Collections.newSetFromMap(ConcurrentHashMap) | 0.005 |
a CTries are concurrent, lock-free versions of Hash Array Mapped Tries.
b Ingestion was performed sequentially (i.e. no concurrency was used)
Licensed under the ISC License : http://en.wikipedia.org/wiki/ISC_license
Copyright (c) 2014, Paul Varkey
Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.