avoid listing directories who's content is never used
diff --git a/WHATSNEW b/WHATSNEW
index 67c8f00..8990ec2 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -44,6 +44,11 @@
* <ftp> now supports FTPs.
Github Pull Request #170
+ * DirectoryScanner avoids listing directory contents when it known it
+ will never use the information retrieved. This may improve
+ performance in some special cases.
+ Bugzilla Report 66048
+
Changes from Ant 1.10.11 TO Ant 1.10.12
=======================================
diff --git a/src/main/org/apache/tools/ant/DirectoryScanner.java b/src/main/org/apache/tools/ant/DirectoryScanner.java
index 045fdbf..b7f6479 100644
--- a/src/main/org/apache/tools/ant/DirectoryScanner.java
+++ b/src/main/org/apache/tools/ant/DirectoryScanner.java
@@ -1126,12 +1126,16 @@
private void processSlowScan(final String[] arr) {
for (String element : arr) {
final TokenizedPath path = new TokenizedPath(element);
- if (!couldHoldIncluded(path) || contentsExcluded(path)) {
+ if (!scanDuringFastScan(path)) {
scandir(new File(basedir, element), path, false);
}
}
}
+ private boolean scanDuringFastScan(TokenizedPath path) {
+ return couldHoldIncluded(path) && !contentsExcluded(path);
+ }
+
/**
* Scan the given directory for files and directories. Found files and
* directories are placed in their respective collections, based on the
@@ -1236,7 +1240,18 @@
final String name = vpath + newFile;
final TokenizedPath newPath = new TokenizedPath(path, newFile);
final File file = new File(dir, newFile);
- final String[] children = file.list();
+ final String[] children;
+
+ // don't invoke file.list() if we know we never use the children
+ if (fast // slow scan scans everything anyway
+ && file.isDirectory() // otherwise we need list() to know whether this is a directory
+ && !scanDuringFastScan(newPath) // otherwise we'd invoke scandir
+ ) {
+ children = new String[0];
+ } else {
+ children = file.list();
+ }
+
if (children == null || (children.length == 0 && file.isFile())) {
if (isIncluded(newPath)) {
accountForIncludedFile(newPath, file);
@@ -1263,7 +1278,7 @@
} else {
everythingIncluded = false;
dirsNotIncluded.addElement(name);
- if (fast && couldHoldIncluded(newPath) && !contentsExcluded(newPath)) {
+ if (fast && scanDuringFastScan(newPath)) {
scandir(file, newPath, fast, children, directoryNamesFollowed);
}
}
@@ -1298,7 +1313,7 @@
private void accountForIncludedDir(final TokenizedPath name, final File file,
final boolean fast) {
processIncluded(name, file, dirsIncluded, dirsExcluded, dirsDeselected);
- if (fast && couldHoldIncluded(name) && !contentsExcluded(name)) {
+ if (fast && scanDuringFastScan(name)) {
scandir(file, name, fast);
}
}
@@ -1308,7 +1323,7 @@
final String[] children,
final Deque<String> directoryNamesFollowed) {
processIncluded(name, file, dirsIncluded, dirsExcluded, dirsDeselected);
- if (fast && couldHoldIncluded(name) && !contentsExcluded(name)) {
+ if (fast && scanDuringFastScan(name)) {
scandir(file, name, fast, children, directoryNamesFollowed);
}
}
@@ -1319,7 +1334,7 @@
private void accountForNotFollowedSymlink(final TokenizedPath name, final File file) {
if (!isExcluded(name) && (isIncluded(name)
- || (file.isDirectory() && couldHoldIncluded(name) && !contentsExcluded(name)))) {
+ || (file.isDirectory() && scanDuringFastScan(name)))) {
notFollowedSymlinks.add(file.getAbsolutePath());
}
}
