Enable FileListingService to properly traverse symlinks-to-directories

Bug: 7048633
Change-Id: I85d4780286a663ab75555049f21b7215e45870d0

1 files changed, 68 insertions, 8 deletions

diff --git a/ddms/libs/ddmlib/src/com/android/ddmlib/FileListingService.java b/ddms/libs/ddmlib/src/com/android/ddmlib/FileListingService.java
index d731a4d..97c57b9 100644
--- a/ddms/libs/ddmlib/src/com/android/ddmlib/FileListingService.java
+++ b/ddms/libs/ddmlib/src/com/android/ddmlib/FileListingService.java
@@ -88,8 +88,13 @@ public final class FileListingService {
     /**
      * Regexp pattern to parse the result from ls.
      */
-    private static Pattern sLsPattern = Pattern.compile(
-        "^([bcdlsp-][-r][-w][-xsS][-r][-w][-xsS][-r][-w][-xstST])\\s+(\\S+)\\s+(\\S+)\\s+([\\d\\s,]*)\\s+(\\d{4}-\\d\\d-\\d\\d)\\s+(\\d\\d:\\d\\d)\\s+(.*)$"); //$NON-NLS-1$
+    private static final Pattern LS_L_PATTERN = Pattern.compile(
+            "^([bcdlsp-][-r][-w][-xsS][-r][-w][-xsS][-r][-w][-xstST])\\s+(\\S+)\\s+(\\S+)\\s+" +
+            "([\\d\\s,]*)\\s+(\\d{4}-\\d\\d-\\d\\d)\\s+(\\d\\d:\\d\\d)\\s+(.*)$"); //$NON-NLS-1$
+
+    private static final Pattern LS_LD_PATTERN = Pattern.compile(
+                    "d[rwx-]{9}\\s+\\S+\\s+\\S+\\s+[0-9-]{10}\\s+\\d{2}:\\d{2}$"); //$NON-NLS-1$
+
 
     private Device mDevice;
     private FileEntry mRoot;
@@ -261,13 +266,20 @@ public final class FileListingService {
         }
 
         /**
-         * Returns true if the entry is a directory, false otherwise;
+         * Returns the Entry type as an int, which will match one of the TYPE_(...) constants
          */
         public int getType() {
             return type;
         }
 
         /**
+         * Sets a new type.
+         */
+        public void setType(int type) {
+            this.type = type;
+        }
+
+        /**
          * Returns if the entry is a folder or a link to a folder.
          */
         public boolean isDirectory() {
@@ -404,7 +416,7 @@ public final class FileListingService {
         }
     }
 
-    private class LsReceiver extends MultiLineReceiver {
+    private static class LsReceiver extends MultiLineReceiver {
 
         private ArrayList<FileEntry> mEntryList;
         private ArrayList<String> mLinkList;
@@ -438,7 +450,7 @@ public final class FileListingService {
                 }
 
                 // run the line through the regexp
-                Matcher m = sLsPattern.matcher(line);
+                Matcher m = LS_L_PATTERN.matcher(line);
                 if (m.matches() == false) {
                     continue;
                 }
@@ -567,8 +579,50 @@ public final class FileListingService {
             return false;
         }
 
-        public void finishLinks() {
-            // TODO Handle links in the listing service
+        /**
+         * Determine if any symlinks in the <code entries> list are links-to-directories, and if so
+         * mark them as such.  This allows us to traverse them properly later on.
+         */
+        public void finishLinks(IDevice device, ArrayList<FileEntry> entries)
+                throws TimeoutException, AdbCommandRejectedException,
+                ShellCommandUnresponsiveException, IOException {
+            final int[] nLines = {0};
+            MultiLineReceiver receiver = new MultiLineReceiver() {
+                @Override
+                public void processNewLines(String[] lines) {
+                    for (String line : lines) {
+                        Matcher m = LS_LD_PATTERN.matcher(line);
+                        if (m.matches()) {
+                            nLines[0]++;
+                        }
+                    }
+                }
+
+                @Override
+                public boolean isCancelled() {
+                    return false;
+                }
+            };
+
+            for (FileEntry entry : entries) {
+                if (entry.getType() != TYPE_LINK) continue;
+
+                // We simply need to determine whether the referent is a directory or not.
+                // We do this by running `ls -ld ${link}/`.  If the referent exists and is a
+                // directory, we'll see the normal directory listing.  Otherwise, we'll see an
+                // error of some sort.
+                nLines[0] = 0;
+
+                final String command = String.format("ls -l -d %s%s", entry.getFullEscapedPath(),
+                        FILE_SEPARATOR);
+
+                device.executeShellCommand(command, receiver);
+
+                if (nLines[0] > 0) {
+                    // We saw lines matching the directory pattern, so it's a directory!
+                    entry.setType(TYPE_DIRECTORY_LINK);
+                }
+            }
         }
     }
 
@@ -773,6 +827,12 @@ public final class FileListingService {
         try {
             // create the command
             String command = "ls -l " + entry.getFullEscapedPath(); //$NON-NLS-1$
+            if (entry.isDirectory()) {
+                // If we expect a file to behave like a directory, we should stick a "/" at the end.
+                // This is a good habit, and is mandatory for symlinks-to-directories, which will
+                // otherwise behave like symlinks.
+                command += FILE_SEPARATOR;
+            }
 
             // create the receiver object that will parse the result from ls
             LsReceiver receiver = new LsReceiver(entry, entryList, linkList);
@@ -781,7 +841,7 @@ public final class FileListingService {
             mDevice.executeShellCommand(command, receiver);
 
             // finish the process of the receiver to handle links
-            receiver.finishLinks();
+            receiver.finishLinks(mDevice, entryList);
         } finally {
             // at this point we need to refresh the viewer
             entry.fetchTime = System.currentTimeMillis();