--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/org/tmatesoft/hg/internal/StoragePathHelper.java	Mon Jan 24 03:14:45 2011 +0100
@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2011 TMate Software Ltd
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * For information on how to redistribute this software under
+ * the terms of a license other than GNU General Public License
+ * contact TMate Software at support@svnkit.com
+ */
+package org.tmatesoft.hg.internal;
+
+import java.util.Arrays;
+import java.util.TreeSet;
+
+import org.tmatesoft.hg.repo.HgRepository;
+import org.tmatesoft.hg.util.PathRewrite;
+
+/**
+ * @see http://mercurial.selenic.com/wiki/CaseFoldingPlan
+ * 
+ * @author Artem Tikhomirov
+ * @author TMate Software Ltd.
+ */
+class StoragePathHelper implements PathRewrite {
+	
+	private final boolean store;
+	private final boolean fncache;
+	private final boolean dotencode;
+
+	public StoragePathHelper(boolean isStore, boolean isFncache, boolean isDotencode) {
+		store = isStore;
+		fncache = isFncache;
+		dotencode = isDotencode;
+	}
+
+	// FIXME document what path argument is, whether it includes .i or .d, and whether it's 'normalized' (slashes) or not.
+	// since .hg/store keeps both .i files and files without extension (e.g. fncache), guees, for data == false 
+	// we shall assume path has extension
+	// FIXME much more to be done, see store.py:_hybridencode
+	public String rewrite(String path) {
+		final String STR_STORE = "store/";
+		final String STR_DATA = "data/";
+		final String STR_DH = "dh/";
+		
+		path = path.replace(".hg/", ".hg.hg/").replace(".i/", ".i.hg/").replace(".d/", ".d.hg/");
+		StringBuilder sb = new StringBuilder(path.length() << 1);
+		if (store || fncache) {
+			// encodefilename
+			final String reservedChars = "\\:*?\"<>|";
+			// in fact, \\ is unlikely to match, ever - we've replaced all of them already, above. Just regards to store.py 
+			int x;
+			char[] hexByte = new char[2];
+			for (int i = 0; i < path.length(); i++) {
+				final char ch = path.charAt(i);
+				if (ch >= 'a' && ch <= 'z') {
+					sb.append(ch); // POIRAE
+				} else if (ch >= 'A' && ch <= 'Z') {
+					sb.append('_');
+					sb.append(Character.toLowerCase(ch)); // Perhaps, (char) (((int) ch) + 32)? Even better, |= 0x20? 
+				} else if ( (x = reservedChars.indexOf(ch)) != -1) {
+					sb.append('~');
+					sb.append(toHexByte(reservedChars.charAt(x), hexByte));
+				} else if ((ch >= '~' /*126*/ && ch <= 255) || ch < ' ' /*32*/) {
+					sb.append('~');
+					sb.append(toHexByte(ch, hexByte));
+				} else if (ch == '_') {
+					// note, encoding from store.py:_buildencodefun and :_build_lower_encodefun
+					// differ in the way they process '_' (latter doesn't escape it)
+					sb.append('_');
+					sb.append('_');
+				} else {
+					sb.append(ch);
+				}
+			}
+			// auxencode
+			if (fncache) {
+				x = 0; // last segment start
+				final TreeSet<String> windowsReservedFilenames = new TreeSet<String>();
+				windowsReservedFilenames.addAll(Arrays.asList("con prn aux nul com1 com2 com3 com4 com5 com6 com7 com8 com9 lpt1 lpt2 lpt3 lpt4 lpt5 lpt6 lpt7 lpt8 lpt9".split(" "))); 
+				do {
+					int i = sb.indexOf("/", x);
+					if (i == -1) {
+						i = sb.length();
+					}
+					// windows reserved filenames are at least of length 3 
+					if (i - x >= 3) {
+						boolean found = false;
+						if (i-x == 3) {
+							found = windowsReservedFilenames.contains(sb.subSequence(x, i));
+						} else if (sb.charAt(x+3) == '.') { // implicit i-x > 3
+							found = windowsReservedFilenames.contains(sb.subSequence(x, x+3));
+						} else if (i-x > 4 && sb.charAt(x+4) == '.') {
+							found = windowsReservedFilenames.contains(sb.subSequence(x, x+4));
+						}
+						if (found) {
+							sb.setCharAt(x, '~');
+							sb.insert(x+1, toHexByte(sb.charAt(x+2), hexByte));
+							i += 2;
+						}
+					}
+					if (dotencode && (sb.charAt(x) == '.' || sb.charAt(x) == ' ')) {
+						sb.insert(x+1, toHexByte(sb.charAt(x), hexByte));
+						sb.setCharAt(x, '~'); // setChar *after* charAt/insert to get ~2e, not ~7e for '.'
+						i += 2;
+					}
+					x = i+1;
+				} while (x < sb.length());
+			}
+		}
+		final int MAX_PATH_LEN_IN_HGSTORE = 120;
+		if (fncache && (sb.length() + STR_DATA.length() > MAX_PATH_LEN_IN_HGSTORE)) {
+			throw HgRepository.notImplemented(); // FIXME digest and fncache use
+		}
+		if (store) {
+			sb.insert(0, STR_STORE + STR_DATA);
+		}
+		sb.append(".i");
+		return sb.toString();
+	}
+
+	private static char[] toHexByte(int ch, char[] buf) {
+		assert buf.length > 1;
+		final String hexDigits = "0123456789abcdef";
+		buf[0] = hexDigits.charAt((ch & 0x00F0) >>> 4);
+		buf[1] = hexDigits.charAt(ch & 0x0F);
+		return buf;
+	}
+}