System and Method for Scalable File Filtering Using Wildcards
A system monitors access to a computer file via a dynamically changeable non-heterogeneous collection load balanced across two hash tables. User activity is monitored on a target device to detect a user entered pattern including a wildcard character, selects one of the two hash tables, and calculates an index for the selected hash table based on the user entered pattern. The index is used to access the selected hash table to receive a stored pattern. The hash tables each have a plurality of entries, and each entry includes a list of one or more patterns that have the same hash index but different pattern values sorted by length in characters from longest to shortest. The first hash table is a direct hash table, and the second hash table is a reverse hash table.
1 . A system for monitoring access to a computer file, comprising:
a dynamically changeable non-heterogeneous collection load balanced across a first hash table and a second hash table;
a target device comprising a first processor and a first memory configured to contain non-transitory instructions, that when executed, perform the steps of:
monitoring user activity on the target device to detect a user entered pattern comprising a wildcard character;
based upon the user entered pattern, selecting a selected hash table consisting of one of the first hash table and the second hash table;
with a hash function, calculating an index for the selected hash table based on the user entered pattern; and
accessing the selected hash table with the index to receive a stored pattern,
wherein the first hash table comprises a direct hash table and the second hash table comprises a reverse hash table.
2 . The system of claim 1 , wherein the monitoring step is performed by an agent installed in the target device as an operating system (OS) daemon.
3 . The system of claim 1 , further configured to perform the steps of:
if the pattern matches an entry in the collection, generating an alert to a system administrator of the target device.
4 . The system of claim 1 , wherein the collection comprises a list of target computer file pathnames and the pattern comprises at least a partial file pathname.
5 . The system of claim 4 , wherein if the file access data matches a file in the list of target computer file pathnames, further comprising a step of generating an alert to a system administrator of the target device.
6 . The system of claim 1 , wherein selecting the selected hash table comprises determining a position of the wildcard character within the user entered pattern.
7 . The system of claim 1 , wherein accessing the selected hash table comprises an incremental search.