Avoid useless computation of getMatchingRegexpAssociated that uses

Pattern (time consumming)

Goal :

Improve performance

See : https://pasteboard.co/7EJ61d3sSu5Y.png and
https://pasteboard.co/KvGgdDU7Macb.png

Why :

In ContentTypeMatcher for findContentTypeFor(String fileName) we take
the first result of currentCatalog.findContentTypesFor(this, fileName);
so if there is a result on selectMatchingByName(context, allByFileName,
Collections.emptySet(), fileName, IContentType.FILE_NAME_SPEC);
there is no need to compute selectMatchingByName(context,
allByFileExtension, selectedByName, fileExtension,
IContentType.FILE_EXTENSION_SPEC);
because it won't be used if there is no policy to reorder the results.

Author: RoiSoleil

runtime/bundles/org.eclipse.core.contenttype/src/org/eclipse/core/internal/content/ContentTypeCatalog.java

@@ -14,6 +14,9 @@
  *******************************************************************************/
 package org.eclipse.core.internal.content;
 
+import static java.util.Optional.empty;
+import static java.util.Optional.of;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.Reader;
@@ -28,6 +31,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Optional;
 import java.util.Set;
 import java.util.regex.Pattern;
 import org.eclipse.core.runtime.CoreException;
@@ -409,7 +413,7 @@ IContentType[] findContentTypesFor(ContentTypeMatcher matcher, InputStream conte
 	}
 
 	IContentType[] findContentTypesFor(ContentTypeMatcher matcher, final String fileName) {
-		IContentType[] selected = concat(internalFindContentTypesSorted(matcher, fileName, policyConstantGeneralIsBetter));
+		IContentType[] selected = concat(internalFindContentTypesSorted(matcher, fileName, policyConstantGeneralIsBetter ,false));
 		// give the policy a chance to change the results
 		ISelectionPolicy policy = matcher.getPolicy();
 		if (policy != null) {
@@ -418,6 +422,15 @@ IContentType[] findContentTypesFor(ContentTypeMatcher matcher, final String file
 		return selected;
 	}
 
+	Optional<IContentType> findFirstContentTypeFor(ContentTypeMatcher matcher, final String fileName) {
+		ISelectionPolicy policy = matcher.getPolicy();
+		IContentType[] selected = concat(internalFindContentTypesSorted(matcher, fileName, policyConstantGeneralIsBetter, policy == null));
+		// give the policy a chance to change the results
+		if (policy != null)
+			selected = applyPolicy(policy, selected, true, false);
+		return selected.length != 0 ? of(selected[0]) : empty();
+	}
+
 	synchronized public IContentType[] getAllContentTypes() {
 		List<ContentType> result = new ArrayList<>(contentTypes.size());
 		for (IContentType iContentType : contentTypes.values()) {
@@ -555,7 +568,7 @@ private IContentType[] internalFindContentTypesFor(ContentTypeMatcher matcher, I
 			indeterminatePolicy = policyConstantGeneralIsBetter;
 			validPolicy = policyConstantSpecificIsBetter;
 		} else {
-			subset = internalFindContentTypesSorted(matcher, fileName, policyLexicographical);
+			subset = internalFindContentTypesSorted(matcher, fileName, policyLexicographical, false);
 			indeterminatePolicy = policyGeneralIsBetter;
 			validPolicy = policySpecificIsBetter;
 		}
@@ -590,7 +603,7 @@ private IContentType[] internalFindContentTypesFor(ContentTypeMatcher matcher, I
 	 * @return all matching content types in the preferred order
 	 * @see IContentTypeManager#findContentTypesFor(String)
 	 */
-	synchronized private IContentType[][] internalFindContentTypesSorted(ContentTypeMatcher matcher, final String fileName, Comparator<IContentType> sortingPolicy) {
+	synchronized private IContentType[][] internalFindContentTypesSorted(ContentTypeMatcher matcher, final String fileName, Comparator<IContentType> sortingPolicy, boolean quickFinish) {
 		IScopeContext context = matcher.getContext();
 		IContentType[][] result = { NO_CONTENT_TYPES, NO_CONTENT_TYPES, NO_CONTENT_TYPES };
 
@@ -609,6 +622,9 @@ synchronized private IContentType[][] internalFindContentTypesSorted(ContentType
 		result[0] = selectedByName.toArray(new IContentType[selectedByName.size()]);
 		if (result[0].length > 1) {
 			Arrays.sort(result[0], sortingPolicy);
+			if (quickFinish) {
+				return result;
+			}
 		}
 
 		final String fileExtension = ContentTypeManager.getFileExtension(fileName);
@@ -628,6 +644,9 @@ synchronized private IContentType[][] internalFindContentTypesSorted(ContentType
 		}
 		if (result[1].length > 1) {
 			Arrays.sort(result[1], sortingPolicy);
+			if (quickFinish) {
+				return result;
+			}
 		}
 
 		final Set<ContentType> allByFilePattern;

runtime/bundles/org.eclipse.core.contenttype/src/org/eclipse/core/internal/content/ContentTypeMatcher.java

@@ -14,11 +14,19 @@
  *******************************************************************************/
 package org.eclipse.core.internal.content;
 
-import java.io.*;
-import java.util.*;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.Reader;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
 import java.util.regex.Pattern;
 import org.eclipse.core.runtime.QualifiedName;
-import org.eclipse.core.runtime.content.*;
+import org.eclipse.core.runtime.content.IContentDescription;
+import org.eclipse.core.runtime.content.IContentType;
+import org.eclipse.core.runtime.content.IContentTypeManager;
+import org.eclipse.core.runtime.content.IContentTypeMatcher;
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.eclipse.core.runtime.preferences.IScopeContext;
 import org.osgi.service.prefs.BackingStoreException;
@@ -47,8 +55,9 @@ public IContentType findContentTypeFor(InputStream contents, String fileName) th
 	public IContentType findContentTypeFor(String fileName) {
 		// basic implementation just gets all content types
 		ContentTypeCatalog currentCatalog = getCatalog();
-		IContentType[] associated = currentCatalog.findContentTypesFor(this, fileName);
-		return associated.length == 0 ? null : new ContentTypeHandler((ContentType) associated[0], currentCatalog.getGeneration());
+		return currentCatalog.findFirstContentTypeFor(this, fileName)
+				.map(contentType -> new ContentTypeHandler((ContentType) contentType, currentCatalog.getGeneration()))
+				.orElse(null);
 	}
 
 	@Override