PowerShell Module designed to optimize the speed of searching an array.
Install-Module -Name FastLookup
See the PowerShell Gallery for the complete details and instructions.
Download FastLookup.zip and extract the contents into C:\Users\[User]\Documents\WindowsPowerShell\modules\FastLookup (you may have to create these directories if they don't exist.)
The FastLookup module creates a hashtable, combining the Values in an array with the Index of the item in the array. Since the Name (or "Key") of the hashtable must be unique, each duplicate result is appended in the hashtable:
PS> $array
Laptop
Workstation
Laptop
Router
PS> $hashtable
Name Value
---- -----
Laptop 0,2
Workstation 1
Router 3
By creating a dictionary of Values and their Index locations, we can find the Values faster in the hashtable without enumerating the entire array. The larger the array, the more significant the performance increase:
Searching for 100 objects in 1,000 row array:
Where-Object: 0 hr, 0 min, 0 sec, 40 ms
Foreach/If Loop: 0 hr, 0 min, 0 sec, 22 ms
FastLookup: 0 hr, 0 min, 0 sec, 84 ms
Searching for 1,000 objects in 10,000 row array:
Where-Object: 0 hr, 0 min, 1 sec, 687 ms
Foreach/If Loop: 0 hr, 0 min, 1 sec, 633 ms
FastLookup: 0 hr, 0 min, 0 sec, 806 ms
Searching for 10,000 objects in 100,000 row array:
Where-Object: 0 hr, 4 min, 18 sec, 366 ms
Foreach/If Loop: 0 hr, 4 min, 14 sec, 148 ms
FastLookup: 0 hr, 0 min, 52 sec, 773 ms
Searching for 100,000 objects in 1,000,000 row array:
Where-Object: 23 hr, 26 min, 31 sec, 789 ms
Foreach/If Loop: 23 hr, 44 min, 12 sec, 430 ms
FastLookup: 1 hr, 37 min, 16 sec, 874 ms
Performance test on Windows 10 x64 (i5-6200U/8GB/SSD)
PS> $array = 1..1000000
PS> $hashtable = New-FastLookup $array
PS> Get-FastLookup -Value 199999 -Array $array -Table $hashtable
PS> $array
DeviceName : Device38
Type : Security Camera
IP : 10.10.128.1
VLAN : VLAN85
Location : Los Angeles
Patch Window : Sunday
DeviceName : Device68
Type : Server
IP : 10.10.128.126
VLAN : VLAN15
Location : Chicago
Patch Window : Sunday
PS> $Hashtable = New-FastLookup -Array $Array -Header "Location"
PS> Get-FastLookup -Value "Chicago" -Array $Array -Table $Hashtable
DeviceName : Device68
Type : Server
IP : 10.10.128.126
VLAN : VLAN15
Location : Chicago
Patch Window : Sunday
- see Test-FastLookup file
- see TODO file
- Blog: