Mercurial > jhg
changeset 112:d488c7638b87
Prototype Filter support with keyword filter as a playground
author | Artem Tikhomirov <tikhomirov.artem@gmail.com> |
---|---|
date | Tue, 01 Feb 2011 00:21:08 +0100 (2011-01-31) |
parents | 32e794c599d7 |
children | 67ae317408c9 |
files | TODO src/org/tmatesoft/hg/internal/Filter.java src/org/tmatesoft/hg/internal/KeywordFilter.java |
diffstat | 3 files changed, 305 insertions(+), 0 deletions(-) [+] |
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--- a/TODO Tue Feb 01 00:19:31 2011 +0100 +++ b/TODO Tue Feb 01 00:21:08 2011 +0100 @@ -34,6 +34,7 @@ * Tags are read and can be queried (cmdline Log does) - keywords + - filter with context. filters shall have weight (to allow certain filter come first) - newlines
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/org/tmatesoft/hg/internal/Filter.java Tue Feb 01 00:21:08 2011 +0100 @@ -0,0 +1,36 @@ +/* + * 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.nio.ByteBuffer; + +import org.tmatesoft.hg.core.Path; +import org.tmatesoft.hg.repo.HgRepository; + +/** + * + * @author Artem Tikhomirov + * @author TMate Software Ltd. + */ +public interface Filter { + + ByteBuffer filter(ByteBuffer src); + + interface Factory { + Filter create(HgRepository hgRepo, Path path); + } +}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/org/tmatesoft/hg/internal/KeywordFilter.java Tue Feb 01 00:21:08 2011 +0100 @@ -0,0 +1,268 @@ +/* + * 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.io.File; +import java.io.FileInputStream; +import java.io.FileOutputStream; +import java.nio.ByteBuffer; +import java.util.TreeMap; + +import org.tmatesoft.hg.core.Path; +import org.tmatesoft.hg.repo.HgRepository; + +/** + * + * @author Artem Tikhomirov + * @author TMate Software Ltd. + */ +public class KeywordFilter implements Filter { + private final boolean isExpanding; + private final TreeMap<String,String> keywords; + private final int minBufferLen; + + /** + * + * @param expand <code>true</code> to expand keywords, <code>false</code> to shrink + */ + private KeywordFilter(boolean expand) { + isExpanding = expand; + keywords = new TreeMap<String,String>(); + keywords.put("Id", "Id"); + keywords.put("Revision", "Revision"); + keywords.put("Author", "Author"); + int l = 0; + for (String s : keywords.keySet()) { + if (s.length() > l) { + l = s.length(); + } + } + // FIXME later may implement #filter() not to read full kw value (just "$kw:"). However, limit of maxLen + 2 would keep valid. + // for buffers less then minBufferLen, there are chances #filter() implementation would never end + // (i.e. for input "$LongestKey"$ + minBufferLen = l + 2 + (isExpanding ? 0 : 120 /*any reasonable constant for max possible kw value length*/); + } + + /** + * @param src buffer ready to be read + * @return buffer ready to be read and original buffer's position modified to reflect consumed bytes. IOW, if source buffer + * on return has remaining bytes, they are assumed not-read (not processed) and next chunk passed to filter is supposed to + * start with them + */ + public ByteBuffer filter(ByteBuffer src) { + if (src.capacity() < minBufferLen) { + throw new IllegalStateException(String.format("Need buffer of at least %d bytes to ensure filter won't hang", minBufferLen)); + } + ByteBuffer rv = null; + int keywordStart = -1; + int x = src.position(); + while (x < src.limit()) { + if (keywordStart == -1) { + int i = indexOf(src, '$', x, false); + if (i == -1) { + if (rv == null) { + return src; + } else { + copySlice(src, x, src.limit(), rv); + rv.flip(); + src.position(src.limit()); + return rv; + } + } + keywordStart = i; + // fall-through + } + if (keywordStart >= 0) { + int i = indexOf(src, '$', keywordStart+1, true); + if (i == -1) { + // end of buffer reached + if (rv == null) { + if (keywordStart == x) { + // FIXME in fact, x might be equal to keywordStart and to src.position() here ('$' is first character in the buffer, + // and there are no other '$' not eols till the end of the buffer). This would lead to deadlock (filter won't consume any + // bytes). To prevent this, either shall copy bytes [keywordStart..buffer.limit()) to local buffer and use it on the next invocation, + // or add lookup of the keywords right after first '$' is found (do not wait for closing '$'). For now, large enough src buffer would be sufficient + // not to run into such situation + throw new IllegalStateException("Try src buffer of a greater size"); + } + rv = ByteBuffer.allocateDirect(keywordStart - x); + } + // copy all from source till latest possible kw start + copySlice(src, x, keywordStart, rv); + rv.flip(); + // and tell caller we've consumed only to the potential kw start + src.position(keywordStart); + return rv; + } else if (src.get(i) == '$') { + // end of keyword, or start of a new one. + String keyword; + if ((keyword = matchKeyword(src, keywordStart, i)) != null) { + if (rv == null) { + rv = ByteBuffer.allocateDirect(isExpanding ? src.capacity() * 4 : src.capacity()); + } + copySlice(src, x, keywordStart+1, rv); + rv.put(keyword.getBytes()); + if (isExpanding) { + rv.put((byte) ':'); + rv.put((byte) ' '); + expandKeywordValue(keyword, rv); + rv.put((byte) ' '); + } + rv.put((byte) '$'); + keywordStart = -1; + x = i+1; + continue; + } else { + if (rv != null) { + // we've already did some substitution, thus need to copy bytes we've scanned. + copySlice(src, x, i, rv); + } // no else in attempt to avoid rv creation if no real kw would be found + keywordStart = i; + x = i; // '$' at i wasn't consumed, hence x points to i, not i+1. This is to avoid problems with case: "sdfsd $ asdfs $Id$ sdf" + continue; + } + } else { + assert src.get(i) == '\n' || src.get(i) == '\r'; + // line break + if (rv != null) { + copySlice(src, x, i+1, rv); + } + x = i+1; + keywordStart = -1; // Wasn't keyword, really + continue; // try once again + } + } + } + if (keywordStart != -1) { + if (rv == null) { + // no expansion happened yet, and we have potential kw start + rv = ByteBuffer.allocateDirect(keywordStart - src.position()); + copySlice(src, src.position(), keywordStart, rv); + } + src.position(keywordStart); + } + if (rv != null) { + rv.flip(); + return rv; + } + return src; + } + + /** + * @param keyword + * @param rv + */ + private void expandKeywordValue(String keyword, ByteBuffer rv) { + if ("Id".equals(keyword)) { + rv.put(identityString().getBytes()); + } else if ("Revision".equals(keyword)) { + rv.put(revision()); + } else if ("Author".equals(keyword)) { + rv.put(username().getBytes()); + } + } + + private String matchKeyword(ByteBuffer src, int kwStart, int kwEnd) { + assert kwEnd - kwStart - 1 > 0; + assert src.get(kwStart) == src.get(kwEnd) && src.get(kwEnd) == '$'; + char[] chars = new char[kwEnd - kwStart - 1]; + int i; + for (i = 0; i < chars.length; i++) { + char c = (char) src.get(kwStart + 1 + i); + if (c == ':') { + break; + } + chars[i] = c; + } + String kw = new String(chars, 0, i); + return keywords.get(kw); + } + + // copies part of the src buffer, [from..to). doesn't modify src position + private static void copySlice(ByteBuffer src, int from, int to, ByteBuffer dst) { + if (to > src.limit()) { + throw new IllegalArgumentException("Bad right boundary"); + } + if (dst.remaining() < to - from) { + throw new IllegalArgumentException("Not enough room in the destination buffer"); + } + for (int i = from; i < to; i++) { + dst.put(src.get(i)); + } + } + + private static int indexOf(ByteBuffer b, char ch, int from, boolean newlineBreaks) { + for (int i = from; i < b.limit(); i++) { + byte c = b.get(i); + if (ch == c) { + return i; + } + if (newlineBreaks && (c == '\n' || c == '\r')) { + return i; + } + } + return -1; + } + + private String identityString() { + return "sample/file.txt, asd"; + } + + private byte[] revision() { + return "1234567890ab".getBytes(); + } + + private String username() { + /* ui.py: username() + Searched in this order: $HGUSER, [ui] section of hgrcs, $EMAIL + and stop searching if one of these is set. + If not found and ui.askusername is True, ask the user, else use + ($LOGNAME or $USER or $LNAME or $USERNAME) + "@full.hostname". + */ + return "<Sample> sample@sample.org"; + } + + public static class Factory implements Filter.Factory { + + public Filter create(HgRepository hgRepo, Path path) { + return new KeywordFilter(true); + } + } + + + public static void main(String[] args) throws Exception { + FileInputStream fis = new FileInputStream(new File("/temp/kwoutput.txt")); + FileOutputStream fos = new FileOutputStream(new File("/temp/kwoutput2.txt")); + ByteBuffer b = ByteBuffer.allocateDirect(256); + KeywordFilter kwFilter = new KeywordFilter(false); + while (fis.getChannel().read(b) != -1) { + b.flip(); // get ready to be read + ByteBuffer f = kwFilter.filter(b); + fos.getChannel().write(f); + if (b.hasRemaining()) { + ByteBuffer remaining = b.slice(); + b.clear(); + b.put(remaining); + } else { + b.clear(); + } + } + fis.close(); + fos.flush(); + fos.close(); + } +}