.NET Core cross-platform, in-memory, full text search library for building search engines

Coresearch uses an inverted index with a boosted trie data structure for indexing atomic search criterion from content to resources. Trie algorithm makes Coresearch more elastic and allows both exact word querying and operations like fuzzy search, wildcards and character matching. Entire trie structure is stored in memory for better performance. The entire project was written as a learning project so be aware of putting in on the production 😉

• Efficient inverted index algorithm (mapping from content to resources)
• Uses Prefix Tree (Trie) data structure for quick search and horizontal scaling
• Exact search with super fast O(k) worst case time, where k is the key length
• Wildcard search for recursive depth-first search tree traversal
• Character match search with deep level k+1
• Simple command line tool and library
• Cross-platform, runs on Linux, MacOS and Windows
• Easily handle large amount of different resources

Trie on Wikipedia

source <string path> <string extension>
alias: load

example:

> source ./ *.txt

get <string key>
alias: search

example:

> search cars
output:
<resource names for key cars>

Query modes:

• Question mark (?) is for select of all resource names belong to children of specific node (if any).
• Wildcard sign (*) is for select of all resource names recursively under specific prefix.
• Exact matching (without any sign) produces equal output as get/search command.

query <string prefix> <query mode: . or *>

example 1:

> query c ?
output: 
<resource names for keys: ca, cb, c5, co, c1, ...>

example 2:

> query c *
output: 
<resource names for keys: ca, cabbage, c4a541, cars, cardio, cantaloupe, ...>

example 3:

> query cars
output: 
<resource names for key cars>

add <string resource name> <string content>
alias: insert

example:

> add english-dict.txt house 

delete <string key>

example:

> delete sport

echo <string content>

example:

> echo hello
output:
hello

debug <bool>

example:

> debug true

flush

example:

> flush

info

example:

> flush
output:
Nodes in trie: 4651175
Words inserted: 15513389
Resource files: 2227
Memory usage: 1044944640 bytes

clear

example:

> clear

Turn debug mode

--debug <bool>
-d

Set max size of memory (in bytes)

--memory-limit <int>
-m

Pre-process every word before insert

--normalize <bool>
-n

Pattern for removing unwanted characters, used for each word before insert

--pattern <regex>
-p

Load data from specific path at start

--source <string>
-s

Set extension for loading data at start

--extension <string>
-e

coresearch is licensed under the MIT.