Make devhelp parser faster

- stop parsing file when we know we have our function info
  by throwing an exception
- close the InputStream each time after parsing

Change-Id: I1c41b7695b35561eeec687cd9e480d5bc53c597d
Reviewed-on: https://git.eclipse.org/r/30832
Tested-by: Hudson CI
Reviewed-by: Jeff Johnston <jjohnstn@redhat.com>
Tested-by: Jeff Johnston <jjohnstn@redhat.com>

2 files changed, 58 insertions, 27 deletions

diff --git a/libhover/org.eclipse.linuxtools.cdt.libhover.devhelp/src/org/eclipse/linuxtools/internal/cdt/libhover/devhelp/ParseDevHelp.java b/libhover/org.eclipse.linuxtools.cdt.libhover.devhelp/src/org/eclipse/linuxtools/internal/cdt/libhover/devhelp/ParseDevHelp.java
index 47cd9748dc..03b35f05bd 100644
--- a/libhover/org.eclipse.linuxtools.cdt.libhover.devhelp/src/org/eclipse/linuxtools/internal/cdt/libhover/devhelp/ParseDevHelp.java
+++ b/libhover/org.eclipse.linuxtools.cdt.libhover.devhelp/src/org/eclipse/linuxtools/internal/cdt/libhover/devhelp/ParseDevHelp.java
@@ -41,6 +41,7 @@ import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.linuxtools.cdt.libhover.FunctionInfo;
 import org.eclipse.linuxtools.cdt.libhover.LibHoverInfo;
+import org.eclipse.linuxtools.internal.cdt.libhover.devhelp.preferences.FuncFoundSaxException;
 import org.eclipse.linuxtools.internal.cdt.libhover.devhelp.preferences.LibHoverMessages;
 import org.w3c.dom.Document;
 import org.w3c.dom.NamedNodeMap;
@@ -164,6 +165,7 @@ public class ParseDevHelp {
                         descStart = false;
                         parmStart = false;
                         protoStart = false;
+                        throw new FuncFoundSaxException(); // indicate we are done and stop parser
                     }
                 }
                 if (descStart) {
@@ -381,33 +383,40 @@ public class ParseDevHelp {
         }
 
         private void parseLink(Node link, Node name, IPath path, LibHoverInfo libhover) {
-            String linkValue = link.getNodeValue();
-            String[] linkParts = linkValue.split("#"); //$NON-NLS-1$
-            if (linkParts.length == 2) {
-                try {
-                    String nameString = name.getNodeValue();
-                    nameString = nameString.replaceAll("\\(.*\\);+", "").trim(); //$NON-NLS-1$ //$NON-NLS-2$
-                    if (nameString.contains("::") || nameString.startsWith("enum ") //$NON-NLS-1$ //$NON-NLS-2$
-                            || nameString.contains("\"")) { //$NON-NLS-1$
-                        return;
-                    }
-                    InputStream reader = new FileInputStream(path.removeLastSegments(1).toOSString()
-                            + "/" + linkParts[0]); //$NON-NLS-1$
-                    HTMLSaxParser parser = new HTMLSaxParser(linkParts[1], nameString);
-                    parser.parse(new InputSource(reader));
-                    FunctionInfo finfo = parser.getFunctionInfo();
-                    if (finfo != null) {
-                        if (debug) {
-                            System.out.println(parser.toString());
-                        }
-                        libhover.functions.put(parser.getFuncName(), parser.getFunctionInfo());
-                    }
-                } catch (IOException e) {
-                    // ignore
-                } catch (SAXException e) {
-                    e.printStackTrace();
-                }
-            }
+        	String linkValue = link.getNodeValue();
+        	String[] linkParts = linkValue.split("#"); //$NON-NLS-1$
+        	InputStream reader = null;
+        	HTMLSaxParser parser = null;
+        	if (linkParts.length == 2) {
+        		try {
+        			String nameString = name.getNodeValue();
+        			nameString = nameString.replaceAll("\\(.*\\);+", "").trim(); //$NON-NLS-1$ //$NON-NLS-2$
+        			if (nameString.contains("::") || nameString.startsWith("enum ") //$NON-NLS-1$ //$NON-NLS-2$
+        					|| nameString.contains("\"")) { //$NON-NLS-1$
+        				return;
+        			}
+        			reader = new FileInputStream(path.removeLastSegments(1).toOSString()
+        					+ "/" + linkParts[0]); //$NON-NLS-1$
+        			parser = new HTMLSaxParser(linkParts[1], nameString);
+        			try {
+        				parser.parse(new InputSource(reader));
+        			} catch (FuncFoundSaxException e) {
+        				// ignore because this is just how we shorten parse time
+        			}
+        			reader.close();
+        			FunctionInfo finfo = parser.getFunctionInfo();
+        			if (finfo != null) {
+        				if (debug) {
+        					System.out.println(parser.toString());
+        				}
+        				libhover.functions.put(parser.getFuncName(), parser.getFunctionInfo());
+        			}
+        		} catch (IOException e) {
+        			// ignore
+        		} catch (SAXException e) {
+        			e.printStackTrace();
+        		}
+        	}
         }
 
         private void parse(String fileName, IProgressMonitor monitor) {
diff --git a/libhover/org.eclipse.linuxtools.cdt.libhover.devhelp/src/org/eclipse/linuxtools/internal/cdt/libhover/devhelp/preferences/FuncFoundSaxException.java b/libhover/org.eclipse.linuxtools.cdt.libhover.devhelp/src/org/eclipse/linuxtools/internal/cdt/libhover/devhelp/preferences/FuncFoundSaxException.java
new file mode 100644
index 0000000000..ed4d74658d
--- /dev/null
+++ b/libhover/org.eclipse.linuxtools.cdt.libhover.devhelp/src/org/eclipse/linuxtools/internal/cdt/libhover/devhelp/preferences/FuncFoundSaxException.java
@@ -0,0 +1,22 @@
+/*******************************************************************************
+ * Copyright (c) 2014 Red Hat Inc. and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ * Red Hat Inc. - Initial implementation
+ *******************************************************************************/
+package org.eclipse.linuxtools.internal.cdt.libhover.devhelp.preferences;
+
+
+// This class is just to allow us to end parsing devhelp docs once
+// we have found the function we are interested in
+public class FuncFoundSaxException extends RuntimeException {
+	/**
+	 * 
+	 */
+	private static final long serialVersionUID = 1L;
+
+}