[performance] Avoid 2nd file access on lightweightAutoRefresh #1442

When reading file content with force==true it is tried to read that file
from file system. Only if the read fails the existence of that file can
have changed and exception is thrown anyway. We just need to move the
"asyncRefresh" into the exception handler.
Hotspot from JDTs ResourceCompilationUnit.getContents()

fixes #1442

tested by Bug_303517

Author: EcljpseB0T

resources/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/localstore/FileSystemResourceManager.java

@@ -874,6 +874,7 @@ public InputStream read(IFile target, boolean force, IProgressMonitor monitor) t
 		try {
 			return store.openInputStream(EFS.NONE, monitor);
 		} catch (CoreException e) {
+			asyncRefresh(target);
 			if (e.getStatus().getCode() == EFS.ERROR_NOT_EXISTS) {
 				String message = NLS.bind(Messages.localstore_fileNotFound, store.toString());
 				throw new ResourceException(IResourceStatus.RESOURCE_NOT_FOUND, target.getFullPath(), message, e);
@@ -884,23 +885,14 @@ public InputStream read(IFile target, boolean force, IProgressMonitor monitor) t
 
 	private IFileStore getFileStore(IFile target, boolean force) throws ResourceException, CoreException {
 		IFileStore store = getStore(target);
-		if (lightweightAutoRefreshEnabled || !force) {
+		if (!force) {
 			final IFileInfo fileInfo = store.fetchInfo();
-			if (!fileInfo.exists()) {
-				asyncRefresh(target);
-				String message = NLS.bind(Messages.localstore_fileNotFound, store.toString());
-				throw new ResourceException(IResourceStatus.RESOURCE_NOT_FOUND, target.getFullPath(), message, null);
-			}
 			Resource resource = (Resource) target;
 			ResourceInfo info = resource.getResourceInfo(true, false);
-			int flags = resource.getFlags(info);
-			resource.checkExists(flags, true);
 			if (fileInfo.getLastModified() != info.getLocalSyncInfo()) {
 				asyncRefresh(target);
-				if (!force) {
-					String message = NLS.bind(Messages.localstore_resourceIsOutOfSync, target.getFullPath());
-					throw new ResourceException(IResourceStatus.OUT_OF_SYNC_LOCAL, target.getFullPath(), message, null);
-				}
+				String message = NLS.bind(Messages.localstore_resourceIsOutOfSync, target.getFullPath());
+				throw new ResourceException(IResourceStatus.OUT_OF_SYNC_LOCAL, target.getFullPath(), message, null);
 			}
 		}
 		return store;
@@ -912,6 +904,7 @@ public byte[] readAllBytes(IFile target, boolean force, IProgressMonitor monitor
 		try {
 			return store.readAllBytes(EFS.NONE, monitor);
 		} catch (CoreException e) {
+			asyncRefresh(target);
 			if (e.getStatus().getCode() == EFS.ERROR_NOT_EXISTS) {
 				String message = NLS.bind(Messages.localstore_fileNotFound, store.toString());
 				throw new ResourceException(IResourceStatus.RESOURCE_NOT_FOUND, target.getFullPath(), message, e);