Functions/GenXdev.FileSystem/ReadJsonWithRetry.ps1
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Part of PowerShell module : GenXdev.FileSystem Original cmdlet filename : ReadJsonWithRetry.ps1 Original author : René Vaessen / GenXdev Version : 1.300.2025 ################################################################################ Copyright (c) René Vaessen / GenXdev Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. ################################################################################> ############################################################################### <# .SYNOPSIS Reads JSON file with retry logic and automatic lock cleanup. .DESCRIPTION Attempts to read a JSON file with retry logic to handle concurrent access. Implements automatic cleanup of stale lock files. Returns empty hashtable if file doesn't exist. .PARAMETER FilePath The path to the JSON file to read. .PARAMETER MaxRetries Maximum number of retry attempts. Defaults to 10. .PARAMETER RetryDelayMs Delay in milliseconds between retries. Defaults to 200. #> function ReadJsonWithRetry { [CmdletBinding()] param( [Parameter(Mandatory = $true)] [string]$FilePath, [Parameter(Mandatory = $false)] [int]$MaxRetries = 10, [Parameter(Mandatory = $false)] [int]$RetryDelayMs = 200 ) # return empty hashtable if file doesn't exist if (-not (Microsoft.PowerShell.Management\Test-Path -LiteralPath $FilePath)) { return @{} } # construct lock file path $lockFile = "${FilePath}.lock" # attempt to read with retries for ($attempt = 0; $attempt -lt $MaxRetries; $attempt++) { try { # clean up stale lock files older than 30 seconds if (Microsoft.PowerShell.Management\Test-Path -LiteralPath $lockFile) { $lockInfo = [System.IO.FileInfo]::new($lockFile) $ageSeconds = ([DateTime]::Now - $lockInfo.LastWriteTime).TotalSeconds if ($ageSeconds -gt 30) { Microsoft.PowerShell.Utility\Write-Verbose ` "Removing stale lock file: $lockFile (age: ${ageSeconds}s)" Microsoft.PowerShell.Management\Remove-Item ` -LiteralPath $lockFile ` -Force ` -ErrorAction SilentlyContinue } } # read and parse json file $content = Microsoft.PowerShell.Management\Get-Content ` -LiteralPath $FilePath ` -Raw ` -ErrorAction Stop if ([string]::IsNullOrWhiteSpace($content)) { return @{} } $data = $content | Microsoft.PowerShell.Utility\ConvertFrom-Json ` -AsHashtable ` -ErrorAction Stop return $data } catch { # log retry attempt Microsoft.PowerShell.Utility\Write-Verbose ` "Read attempt $($attempt + 1) failed: $($_.Exception.Message)" # wait before retry unless this is the last attempt if ($attempt -lt ($MaxRetries - 1)) { Microsoft.PowerShell.Utility\Start-Sleep ` -Milliseconds $RetryDelayMs } else { # final attempt failed, throw error throw "Failed to read JSON file after ${MaxRetries} attempts: $_" } } } } |