Faster compilation of themes

- Ability to provided precompiled themes in the datamodel
- Check that a precompiled theme is still up-to-date based on a signature

setup/compiler.class.inc.php

@@ -2701,6 +2701,7 @@ EOF;
 				'variables' => array(),
 				'imports' => array(),
 				'stylesheets' => array(),
+				'precompiled_stylesheet' => '',
 			);
 
 			/** @var \DOMNodeList $oVariables */
@@ -2726,7 +2727,7 @@ EOF;
 				$sStylesheetId = $oStylesheet->getAttribute('id');
 				$aThemeParameters['stylesheets'][$sStylesheetId] = $oStylesheet->GetText();
 			}
-
+			$aThemeParameters['precompiled_stylesheet'] = $oTheme->GetChildText('precompiled_stylesheet', '');
 			$aThemes[$sThemeId] = $aThemeParameters;
 		}
 
@@ -2738,6 +2739,7 @@ EOF;
 		}
 
 		// Compile themes
+		$fStart = microtime(true);
 		foreach($aThemes as $sThemeId => $aThemeParameters)
 		{
 			$sThemeDir = $sThemesDir.$sThemeId;
@@ -2745,10 +2747,21 @@ EOF;
 			{
 				SetupUtils::builddir($sThemeDir);
 			}
-
-
+			// Check if a precompiled version of the theme is supplied
+			$sPrecompiledFile = $sTempTargetDir.$aThemeParameters['precompiled_stylesheet'];
+			if (file_exists($sPrecompiledFile))
+			{
+				copy($sPrecompiledFile, $sThemeDir.'/main.css');
+				// Make sure that the copy of the precompiled file is older than any other files to force a validation of the signature
+				touch($sThemeDir.'/main.css', 1577836800 /* 2020-01-01 00:00:00 */);
+			}
+			else if ($sPrecompiledFile != '')
+			{
+				$this->Log("Precompiled file not found: '$sPrecompiledFile'");
+			}
 			ThemeHandler::CompileTheme($sThemeId, $aThemeParameters, $aImportsPaths, $sTempTargetDir);
 		}
+		$this->Log(sprintf('Themes compilation took: %.3f ms for %d themes.', (microtime(true) - $fStart)*1000.0, count($aThemes)));
 	}
 
 	/**