Add proper implementation of methods in JnaUtils.

Implement the methods getFilemode and setFilemode
in JnaUtils. Not using the libc names as we don't
necessarily use JNA and because it is not necessarily
a one to one mapping.

1 files changed, 226 insertions, 0 deletions

diff --git a/src/main/java/com/gitblit/utils/JnaUtils.java b/src/main/java/com/gitblit/utils/JnaUtils.java
new file mode 100644
index 00000000..b7d7209f
--- /dev/null
+++ b/src/main/java/com/gitblit/utils/JnaUtils.java
@@ -0,0 +1,226 @@
+/*
+ * Copyright 2013 gitblit.com.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.gitblit.utils;
+
+import com.sun.jna.Library;
+import com.sun.jna.Native;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Collection of static methods to access native OS library functionality.
+ *
+ * @author Florian Zschocke
+ */
+public class JnaUtils {
+	public static final int S_IFMT =   0170000;
+	public static final int S_IFIFO =  0010000;
+	public static final int S_IFCHR =  0020000;
+	public static final int S_IFDIR =  0040000;
+	public static final int S_IFBLK =  0060000;
+	public static final int S_IFREG =  0100000;
+	public static final int S_IFLNK =  0120000;
+	public static final int S_IFSOCK = 0140000;
+
+	public static final int S_ISUID =  0004000;
+	public static final int S_ISGID =  0002000;
+	public static final int S_ISVTX =  0001000;
+
+	public static final int S_IRWXU =  0000700;
+	public static final int S_IRUSR =  0000400;
+	public static final int S_IWUSR =  0000200;
+	public static final int S_IXUSR =  0000100;
+	public static final int S_IRWXG =  0000070;
+	public static final int S_IRGRP =  0000040;
+	public static final int S_IWGRP =  0000020;
+	public static final int S_IXGRP =  0000010;
+	public static final int S_IRWXO =  0000007;
+	public static final int S_IROTH =  0000004;
+	public static final int S_IWOTH =  0000002;
+	public static final int S_IXOTH =  0000001;
+
+
+	private static final Logger LOGGER = LoggerFactory.getLogger(JGitUtils.class);
+
+	private static UnixCLibrary unixlibc = null;
+
+
+	public static boolean isWindows()
+	{
+		return System.getProperty("os.name").toLowerCase().startsWith("windows");
+	}
+
+
+	private interface UnixCLibrary extends Library {
+		public int chmod(String path, int mode);
+	}
+
+
+	public static int setFilemode(File path, int mode)
+	{
+		return setFilemode(path.getAbsolutePath(), mode);
+	}
+
+	public static int setFilemode(String path, int mode)
+	{
+		if (isWindows()) {
+			throw new UnsupportedOperationException("The method JnaUtils.getFilemode is not supported under Windows.");
+		}
+
+		return getUnixCLibrary().chmod(path, mode);
+	}
+
+
+
+	public static int getFilemode(File path)
+	{
+		return getFilemode(path.getAbsolutePath());
+	}
+
+	public static int getFilemode(String path)
+	{
+		if (isWindows()) {
+			throw new UnsupportedOperationException("The method JnaUtils.getFilemode is not supported under Windows.");
+		}
+
+
+		int mode = 0;
+
+		// Use a Runtime, because implementing stat() via JNA is just too much trouble.
+		String lsLine = runProcessLs(path);
+		if (lsLine == null) {
+			LOGGER.debug("Could not get file information for path " + path);
+			return -1;
+		}
+
+		Pattern p = Pattern.compile("^(([-bcdlsp])([-r][-w][-xSs])([-r][-w][-xSs])([-r][-w][-xTt])) ");
+		Matcher m = p.matcher(lsLine);
+		if ( !m.lookingAt() ) {
+			LOGGER.debug("Could not parse valid file mode information for path " + path);
+			return -1;
+		}
+
+		// Parse mode string to mode bits
+		String group = m.group(2);
+		switch (group.charAt(0)) {
+		case 'p' :
+			mode |= 0010000; break;
+		case 'c':
+			mode |= 0020000; break;
+		case 'd':
+			mode |= 0040000; break;
+		case 'b':
+			mode |= 0060000; break;
+		case '-':
+			mode |= 0100000; break;
+		case 'l':
+			mode |= 0120000; break;
+		case 's':
+			mode |= 0140000; break;
+		}
+
+		for ( int i = 0; i < 3; i++) {
+			group = m.group(3 + i);
+			switch (group.charAt(0)) {
+			case 'r':
+				mode |= (0400 >> i*3); break;
+			case '-':
+				break;
+			}
+
+			switch (group.charAt(1)) {
+			case 'w':
+				mode |= (0200 >> i*3); break;
+			case '-':
+				break;
+			}
+
+			switch (group.charAt(2)) {
+			case 'x':
+				mode |= (0100 >> i*3); break;
+			case 'S':
+				mode |= (04000 >> i); break;
+			case 's':
+				mode |= (0100 >> i*3);
+				mode |= (04000 >> i); break;
+			case 'T':
+				mode |= 01000; break;
+			case 't':
+				mode |= (0100 >> i*3);
+				mode |= 01000; break;
+			case '-':
+				break;
+			}
+		}
+
+		return mode;
+	}
+
+
+	private static String runProcessLs(String path)
+	{
+		String cmd = "ls -ldO " + path;
+		Runtime rt = Runtime.getRuntime();
+		Process pr = null;
+		InputStreamReader ir = null;
+		BufferedReader br = null;
+		String output = null;
+
+		try {
+			pr = rt.exec(cmd);
+			ir = new InputStreamReader(pr.getInputStream());
+			br = new BufferedReader(ir);
+
+			output = br.readLine();
+
+			while (br.readLine() != null) ; // Swallow remaining output
+		}
+		catch (IOException e) {
+			LOGGER.debug("Exception while running unix command '" + cmd + "': " + e);
+		}
+		finally {
+			if (pr != null) try { pr.waitFor();	} catch (Exception ignored) {}
+
+			if (br != null) try { br.close(); } catch (Exception ignored) {}
+			if (ir != null) try { ir.close(); } catch (Exception ignored) {}
+
+			if (pr != null) try { pr.getOutputStream().close();	} catch (Exception ignored) {}
+			if (pr != null) try { pr.getInputStream().close();	} catch (Exception ignored) {}
+			if (pr != null) try { pr.getErrorStream().close();	} catch (Exception ignored) {}
+		}
+
+		return output;
+	}
+
+
+	private static UnixCLibrary getUnixCLibrary()
+	{
+		if (unixlibc == null) {
+			unixlibc = (UnixCLibrary) Native.loadLibrary("c", UnixCLibrary.class);
+			if (unixlibc == null) throw new RuntimeException("Could not initialize native C library.");
+		}
+		return unixlibc;
+	}
+
+}