René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"ConvertFrom-JSON high memory consumption","articleBody":"Steps to reproduce\r\n------------------\r\n\r\n```powershell\r\n$JSON = @\"\r\n{\r\n  \"configGlossary:installationAt\": \"Philadelphia, PA\",\r\n  \"configGlossary:adminEmail\": \"ksm@pobox.com\",\r\n  \"configGlossary:poweredBy\": \"Cofax\",\r\n  \"configGlossary:poweredByIcon\": \"\\/images\\/cofax.gif\",\r\n  \"configGlossary:staticPath\": \"\\/content\\/static\",\r\n  \"templateProcessorClass\": \"org.cofax.WysiwygTemplate\",\r\n  \"templateLoaderClass\": \"org.cofax.FilesTemplateLoader\",\r\n  \"templatePath\": \"templates\",\r\n  \"templateOverridePath\": \"\",\r\n  \"defaultListTemplate\": \"listTemplate.htm\",\r\n  \"defaultFileTemplate\": \"articleTemplate.htm\",\r\n  \"useJSP\": false,\r\n  \"jspListTemplate\": \"listTemplate.jsp\",\r\n  \"jspFileTemplate\": \"articleTemplate.jsp\",\r\n  \"cachePackageTagsTrack\": 200,\r\n  \"cachePackageTagsStore\": 200,\r\n  \"cachePackageTagsRefresh\": 60,\r\n  \"cacheTemplatesTrack\": 100,\r\n  \"cacheTemplatesStore\": 50,\r\n  \"cacheTemplatesRefresh\": 15,\r\n  \"cachePagesTrack\": 200,\r\n  \"cachePagesStore\": 100,\r\n  \"cachePagesRefresh\": 10,\r\n  \"cachePagesDirtyRead\": 10,\r\n  \"searchEngineListTemplate\": \"forSearchEnginesList.htm\",\r\n  \"searchEngineFileTemplate\": \"forSearchEngines.htm\",\r\n  \"searchEngineRobotsDb\": \"WEB-INF\\/robots.db\",\r\n  \"useDataStore\": true,\r\n  \"dataStoreClass\": \"org.cofax.SqlDataStore\",\r\n  \"redirectionClass\": \"org.cofax.SqlRedirection\",\r\n  \"dataStoreName\": \"cofax\",\r\n  \"dataStoreDriver\": \"com.microsoft.jdbc.sqlserver.SQLServerDriver\",\r\n  \"dataStoreUrl\": \"jdbc:microsoft:sqlserver:\\/\\/LOCALHOST:1433;DatabaseName=goon\",\r\n  \"dataStoreUser\": \"sa\",\r\n  \"dataStorePassword\": \"dataStoreTestQuery\",\r\n  \"dataStoreTestQuery\": \"SET NOCOUNT ON;select test='test';\",\r\n  \"dataStoreLogFile\": \"\\/usr\\/local\\/tomcat\\/logs\\/datastore.log\",\r\n  \"dataStoreInitConns\": 10,\r\n  \"dataStoreMaxConns\": 100,\r\n  \"dataStoreConnUsageLimit\": 100,\r\n  \"dataStoreLogLevel\": \"debug\",\r\n  \"maxUrlLength\": 500\r\n}\r\n\"@\r\n\r\n$Count = 39999\r\n$jsonarr = \"[\" + (($json + \",\") * $Count) + $json + \"]\"\r\n[system.gc]::Collect()\r\nwrite-host \"\"\r\nwrite-host \"\"\r\nwrite-host \"JSON -- Objects: $($Count + 1)\"\r\nwrite-host \"JSON -- Length:  $($jsonarr.length / 1024 / 1024 ) Megabytes\"\r\n\r\n$BeforeMemory = $((get-process -pid $PID).WorkingSet)\r\n[void] (convertfrom-json $jsonarr)\r\n$AfterMemory = $((get-process -pid $PID).WorkingSet)\r\n\r\n$MemoryDiff = $AfterMemory - $BeforeMemory\r\n\r\nwrite-host \"Memory Usage -- Before:     $($BeforeMemory  / 1024 / 1024) Megabytes\"\r\nwrite-host \"Memory Usage -- After:      $($AfterMemory  / 1024 / 1024) Megabytes\"\r\nwrite-host \"Memory Usage -- Difference: $($MemoryDiff  / 1024 / 1024) Megabytes\"\r\nwrite-host \"Memory Usage -- Multiple:   $($MemoryDiff / $jsonarr.length)\"\r\n\r\n```\r\noutput:\r\n```\r\nJSON -- Objects: 40000\r\nJSON -- Length:  67.4819955825806 Megabytes\r\nMemory Usage -- Before:     210.8359375 Megabytes\r\nMemory Usage -- After:      1240.90625 Megabytes\r\nMemory Usage -- Difference: 1030.0703125 Megabytes\r\nMemory Usage -- Multiple:   15.2643724241892\r\n```\r\nActual behavior\r\n-----------------\r\nPowershell Core ends up with 1 GB of memory used and peaks to 1.6 GB of memory utilization during convertfrom-json\r\n\r\nExpected behavior\r\n-----------------\r\n\r\nPowershell Core shouldn't need 1.6 gigabytes of memory to deserialize a 65MB JSON file.\r\n\r\nEnvironment data\r\n----------------\r\n\r\n\u003c!-- provide the output of $PSVersionTable --\u003e\r\n\r\n```powershell\r\nName                           Value\r\n----                           -----\r\nPSVersion                      6.1.0-preview.3\r\nPSEdition                      Core\r\nGitCommitId                    v6.1.0-preview.3\r\nOS                             Microsoft Windows 10.0.17134\r\nPlatform                       Win32NT\r\nPSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}\r\nPSRemotingProtocolVersion      2.3\r\nSerializationVersion           1.1.0.1\r\nWSManStackVersion              3.0\r\n```\r\n","author":{"url":"https://github.com/strawgate","@type":"Person","name":"strawgate"},"datePublished":"2018-09-03T17:39:17.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":22},"url":"https://github.com/7698/PowerShell/issues/7698"}