| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.solr.update; |
| |
| import java.io.File; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.io.RandomAccessFile; |
| import java.nio.ByteBuffer; |
| import java.nio.channels.Channels; |
| import java.nio.channels.FileChannel; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.HashMap; |
| import java.util.LinkedHashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.concurrent.atomic.AtomicInteger; |
| |
| import org.apache.lucene.util.BytesRef; |
| import org.apache.solr.common.SolrException; |
| import org.apache.solr.common.SolrInputDocument; |
| import org.apache.solr.common.util.DataInputInputStream; |
| import org.apache.solr.common.util.FastInputStream; |
| import org.apache.solr.common.util.FastOutputStream; |
| import org.apache.solr.common.util.JavaBinCodec; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Log Format: List{Operation, Version, ...} |
| * ADD, VERSION, DOC |
| * DELETE, VERSION, ID_BYTES |
| * DELETE_BY_QUERY, VERSION, String |
| * |
| * TODO: keep two files, one for [operation, version, id] and the other for the actual |
| * document data. That way we could throw away document log files more readily |
| * while retaining the smaller operation log files longer (and we can retrieve |
| * the stored fields from the latest documents from the index). |
| * |
| * This would require keeping all source fields stored of course. |
| * |
| * This would also allow to not log document data for requests with commit=true |
| * in them (since we know that if the request succeeds, all docs will be committed) |
| * |
| */ |
| public class TransactionLog { |
| public static Logger log = LoggerFactory.getLogger(TransactionLog.class); |
| final boolean debug = log.isDebugEnabled(); |
| final boolean trace = log.isTraceEnabled(); |
| |
| public final static String END_MESSAGE="SOLR_TLOG_END"; |
| |
| long id; |
| File tlogFile; |
| RandomAccessFile raf; |
| FileChannel channel; |
| OutputStream os; |
| FastOutputStream fos; // all accesses to this stream should be synchronized on "this" (The TransactionLog) |
| int numRecords; |
| |
| protected volatile boolean deleteOnClose = true; // we can delete old tlogs since they are currently only used for real-time-get (and in the future, recovery) |
| |
| AtomicInteger refcount = new AtomicInteger(1); |
| Map<String,Integer> globalStringMap = new HashMap<>(); |
| List<String> globalStringList = new ArrayList<>(); |
| |
| long snapshot_size; |
| int snapshot_numRecords; |
| |
| // write a BytesRef as a byte array |
| JavaBinCodec.ObjectResolver resolver = new JavaBinCodec.ObjectResolver() { |
| @Override |
| public Object resolve(Object o, JavaBinCodec codec) throws IOException { |
| if (o instanceof BytesRef) { |
| BytesRef br = (BytesRef)o; |
| codec.writeByteArray(br.bytes, br.offset, br.length); |
| return null; |
| } |
| return o; |
| } |
| }; |
| |
| public class LogCodec extends JavaBinCodec { |
| public LogCodec(JavaBinCodec.ObjectResolver resolver) { |
| super(resolver); |
| } |
| |
| @Override |
| public void writeExternString(String s) throws IOException { |
| if (s == null) { |
| writeTag(NULL); |
| return; |
| } |
| |
| // no need to synchronize globalStringMap - it's only updated before the first record is written to the log |
| Integer idx = globalStringMap.get(s); |
| if (idx == null) { |
| // write a normal string |
| writeStr(s); |
| } else { |
| // write the extern string |
| writeTag(EXTERN_STRING, idx); |
| } |
| } |
| |
| @Override |
| public String readExternString(DataInputInputStream fis) throws IOException { |
| int idx = readSize(fis); |
| if (idx != 0) {// idx != 0 is the index of the extern string |
| // no need to synchronize globalStringList - it's only updated before the first record is written to the log |
| return globalStringList.get(idx - 1); |
| } else {// idx == 0 means it has a string value |
| // this shouldn't happen with this codec subclass. |
| throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Corrupt transaction log"); |
| } |
| } |
| |
| |
| } |
| |
| |
| TransactionLog(File tlogFile, Collection<String> globalStrings) { |
| this(tlogFile, globalStrings, false); |
| } |
| |
| TransactionLog(File tlogFile, Collection<String> globalStrings, boolean openExisting) { |
| boolean success = false; |
| try { |
| if (debug) { |
| log.debug("New TransactionLog file=" + tlogFile + ", exists=" + tlogFile.exists() + ", size=" + tlogFile.length() + ", openExisting=" + openExisting); |
| } |
| |
| this.tlogFile = tlogFile; |
| raf = new RandomAccessFile(this.tlogFile, "rw"); |
| long start = raf.length(); |
| channel = raf.getChannel(); |
| os = Channels.newOutputStream(channel); |
| fos = new FastOutputStream(os, new byte[65536], 0); |
| // fos = FastOutputStream.wrap(os); |
| |
| if (openExisting) { |
| if (start > 0) { |
| readHeader(null); |
| raf.seek(start); |
| assert channel.position() == start; |
| fos.setWritten(start); // reflect that we aren't starting at the beginning |
| assert fos.size() == channel.size(); |
| } else { |
| addGlobalStrings(globalStrings); |
| } |
| } else { |
| if (start > 0) { |
| log.error("New transaction log already exists:" + tlogFile + " size=" + raf.length()); |
| } |
| assert start==0; |
| if (start > 0) { |
| raf.setLength(0); |
| } |
| addGlobalStrings(globalStrings); |
| } |
| |
| success = true; |
| |
| } catch (IOException e) { |
| throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e); |
| } finally { |
| if (!success && raf != null) { |
| try { |
| raf.close(); |
| } catch (Exception e) { |
| log.error("Error closing tlog file (after error opening)", e); |
| } |
| } |
| } |
| } |
| |
| // for subclasses |
| protected TransactionLog() {} |
| |
| /** Returns the number of records in the log (currently includes the header and an optional commit). |
| * Note: currently returns 0 for reopened existing log files. |
| */ |
| public int numRecords() { |
| synchronized (this) { |
| return this.numRecords; |
| } |
| } |
| |
| public boolean endsWithCommit() throws IOException { |
| long size; |
| synchronized (this) { |
| fos.flush(); |
| size = fos.size(); |
| } |
| |
| |
| // the end of the file should have the end message (added during a commit) plus a 4 byte size |
| byte[] buf = new byte[ END_MESSAGE.length() ]; |
| long pos = size - END_MESSAGE.length() - 4; |
| if (pos < 0) return false; |
| ChannelFastInputStream is = new ChannelFastInputStream(channel, pos); |
| is.read(buf); |
| for (int i=0; i<buf.length; i++) { |
| if (buf[i] != END_MESSAGE.charAt(i)) return false; |
| } |
| return true; |
| } |
| |
| /** takes a snapshot of the current position and number of records |
| * for later possible rollback, and returns the position */ |
| public long snapshot() { |
| synchronized (this) { |
| snapshot_size = fos.size(); |
| snapshot_numRecords = numRecords; |
| return snapshot_size; |
| } |
| } |
| |
| // This could mess with any readers or reverse readers that are open, or anything that might try to do a log lookup. |
| // This should only be used to roll back buffered updates, not actually applied updates. |
| public void rollback(long pos) throws IOException { |
| synchronized (this) { |
| assert snapshot_size == pos; |
| fos.flush(); |
| raf.setLength(pos); |
| fos.setWritten(pos); |
| assert fos.size() == pos; |
| numRecords = snapshot_numRecords; |
| } |
| } |
| |
| |
| public long writeData(Object o) { |
| LogCodec codec = new LogCodec(resolver); |
| try { |
| long pos = fos.size(); // if we had flushed, this should be equal to channel.position() |
| codec.init(fos); |
| codec.writeVal(o); |
| return pos; |
| } catch (IOException e) { |
| throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e); |
| } |
| } |
| |
| |
| private void readHeader(FastInputStream fis) throws IOException { |
| // read existing header |
| fis = fis != null ? fis : new ChannelFastInputStream(channel, 0); |
| LogCodec codec = new LogCodec(resolver); |
| Map header = (Map)codec.unmarshal(fis); |
| |
| fis.readInt(); // skip size |
| |
| // needed to read other records |
| |
| synchronized (this) { |
| globalStringList = (List<String>)header.get("strings"); |
| globalStringMap = new HashMap<>(globalStringList.size()); |
| for (int i=0; i<globalStringList.size(); i++) { |
| globalStringMap.put( globalStringList.get(i), i+1); |
| } |
| } |
| } |
| |
| protected void addGlobalStrings(Collection<String> strings) { |
| if (strings == null) return; |
| int origSize = globalStringMap.size(); |
| for (String s : strings) { |
| Integer idx = null; |
| if (origSize > 0) { |
| idx = globalStringMap.get(s); |
| } |
| if (idx != null) continue; // already in list |
| globalStringList.add(s); |
| globalStringMap.put(s, globalStringList.size()); |
| } |
| assert globalStringMap.size() == globalStringList.size(); |
| } |
| |
| Collection<String> getGlobalStrings() { |
| synchronized (this) { |
| return new ArrayList<>(globalStringList); |
| } |
| } |
| |
| protected void writeLogHeader(LogCodec codec) throws IOException { |
| long pos = fos.size(); |
| assert pos == 0; |
| |
| Map header = new LinkedHashMap<String,Object>(); |
| header.put("SOLR_TLOG",1); // a magic string + version number |
| header.put("strings",globalStringList); |
| codec.marshal(header, fos); |
| |
| endRecord(pos); |
| } |
| |
| protected void endRecord(long startRecordPosition) throws IOException { |
| fos.writeInt((int)(fos.size() - startRecordPosition)); |
| numRecords++; |
| } |
| |
| private void checkWriteHeader(LogCodec codec, SolrInputDocument optional) throws IOException { |
| |
| // Unsynchronized access. We can get away with an unsynchronized access here |
| // since we will never get a false non-zero when the position is in fact 0. |
| // rollback() is the only function that can reset to zero, and it blocks updates. |
| if (fos.size() != 0) return; |
| |
| synchronized (this) { |
| if (fos.size() != 0) return; // check again while synchronized |
| if (optional != null) { |
| addGlobalStrings(optional.getFieldNames()); |
| } |
| writeLogHeader(codec); |
| } |
| } |
| |
| int lastAddSize; |
| |
| public long write(AddUpdateCommand cmd, int flags) { |
| LogCodec codec = new LogCodec(resolver); |
| SolrInputDocument sdoc = cmd.getSolrInputDocument(); |
| |
| try { |
| checkWriteHeader(codec, sdoc); |
| |
| // adaptive buffer sizing |
| int bufSize = lastAddSize; // unsynchronized access of lastAddSize should be fine |
| bufSize = Math.min(1024*1024, bufSize+(bufSize>>3)+256); |
| |
| MemOutputStream out = new MemOutputStream(new byte[bufSize]); |
| codec.init(out); |
| codec.writeTag(JavaBinCodec.ARR, 3); |
| codec.writeInt(UpdateLog.ADD | flags); // should just take one byte |
| codec.writeLong(cmd.getVersion()); |
| codec.writeSolrInputDocument(cmd.getSolrInputDocument()); |
| lastAddSize = (int)out.size(); |
| |
| synchronized (this) { |
| long pos = fos.size(); // if we had flushed, this should be equal to channel.position() |
| assert pos != 0; |
| |
| /*** |
| System.out.println("###writing at " + pos + " fos.size()=" + fos.size() + " raf.length()=" + raf.length()); |
| if (pos != fos.size()) { |
| throw new RuntimeException("ERROR" + "###writing at " + pos + " fos.size()=" + fos.size() + " raf.length()=" + raf.length()); |
| } |
| ***/ |
| |
| out.writeAll(fos); |
| endRecord(pos); |
| // fos.flushBuffer(); // flush later |
| return pos; |
| } |
| |
| } catch (IOException e) { |
| // TODO: reset our file pointer back to "pos", the start of this record. |
| throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "Error logging add", e); |
| } |
| } |
| |
| public long writeDelete(DeleteUpdateCommand cmd, int flags) { |
| LogCodec codec = new LogCodec(resolver); |
| |
| try { |
| checkWriteHeader(codec, null); |
| |
| BytesRef br = cmd.getIndexedId(); |
| |
| MemOutputStream out = new MemOutputStream(new byte[20 + br.length]); |
| codec.init(out); |
| codec.writeTag(JavaBinCodec.ARR, 3); |
| codec.writeInt(UpdateLog.DELETE | flags); // should just take one byte |
| codec.writeLong(cmd.getVersion()); |
| codec.writeByteArray(br.bytes, br.offset, br.length); |
| |
| synchronized (this) { |
| long pos = fos.size(); // if we had flushed, this should be equal to channel.position() |
| assert pos != 0; |
| out.writeAll(fos); |
| endRecord(pos); |
| // fos.flushBuffer(); // flush later |
| return pos; |
| } |
| |
| } catch (IOException e) { |
| throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e); |
| } |
| |
| } |
| |
| public long writeDeleteByQuery(DeleteUpdateCommand cmd, int flags) { |
| LogCodec codec = new LogCodec(resolver); |
| try { |
| checkWriteHeader(codec, null); |
| |
| MemOutputStream out = new MemOutputStream(new byte[20 + (cmd.query.length())]); |
| codec.init(out); |
| codec.writeTag(JavaBinCodec.ARR, 3); |
| codec.writeInt(UpdateLog.DELETE_BY_QUERY | flags); // should just take one byte |
| codec.writeLong(cmd.getVersion()); |
| codec.writeStr(cmd.query); |
| |
| synchronized (this) { |
| long pos = fos.size(); // if we had flushed, this should be equal to channel.position() |
| out.writeAll(fos); |
| endRecord(pos); |
| // fos.flushBuffer(); // flush later |
| return pos; |
| } |
| } catch (IOException e) { |
| throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e); |
| } |
| |
| } |
| |
| |
| public long writeCommit(CommitUpdateCommand cmd, int flags) { |
| LogCodec codec = new LogCodec(resolver); |
| synchronized (this) { |
| try { |
| long pos = fos.size(); // if we had flushed, this should be equal to channel.position() |
| |
| if (pos == 0) { |
| writeLogHeader(codec); |
| pos = fos.size(); |
| } |
| codec.init(fos); |
| codec.writeTag(JavaBinCodec.ARR, 3); |
| codec.writeInt(UpdateLog.COMMIT | flags); // should just take one byte |
| codec.writeLong(cmd.getVersion()); |
| codec.writeStr(END_MESSAGE); // ensure these bytes are (almost) last in the file |
| |
| endRecord(pos); |
| |
| fos.flush(); // flush since this will be the last record in a log fill |
| assert fos.size() == channel.size(); |
| |
| return pos; |
| } catch (IOException e) { |
| throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e); |
| } |
| } |
| } |
| |
| |
| /* This method is thread safe */ |
| public Object lookup(long pos) { |
| // A negative position can result from a log replay (which does not re-log, but does |
| // update the version map. This is OK since the node won't be ACTIVE when this happens. |
| if (pos < 0) return null; |
| |
| try { |
| // make sure any unflushed buffer has been flushed |
| synchronized (this) { |
| // TODO: optimize this by keeping track of what we have flushed up to |
| fos.flushBuffer(); |
| /*** |
| System.out.println("###flushBuffer to " + fos.size() + " raf.length()=" + raf.length() + " pos="+pos); |
| if (fos.size() != raf.length() || pos >= fos.size() ) { |
| throw new RuntimeException("ERROR" + "###flushBuffer to " + fos.size() + " raf.length()=" + raf.length() + " pos="+pos); |
| } |
| ***/ |
| } |
| |
| ChannelFastInputStream fis = new ChannelFastInputStream(channel, pos); |
| LogCodec codec = new LogCodec(resolver); |
| return codec.readVal(fis); |
| } catch (IOException e) { |
| throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e); |
| } |
| } |
| |
| public void incref() { |
| int result = refcount.incrementAndGet(); |
| if (result <= 1) { |
| throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, "incref on a closed log: " + this); |
| } |
| } |
| |
| public boolean try_incref() { |
| return refcount.incrementAndGet() > 1; |
| } |
| |
| public void decref() { |
| if (refcount.decrementAndGet() == 0) { |
| close(); |
| } |
| } |
| |
| /** returns the current position in the log file */ |
| public long position() { |
| synchronized (this) { |
| return fos.size(); |
| } |
| } |
| |
| public void finish(UpdateLog.SyncLevel syncLevel) { |
| if (syncLevel == UpdateLog.SyncLevel.NONE) return; |
| try { |
| synchronized (this) { |
| fos.flushBuffer(); |
| } |
| |
| if (syncLevel == UpdateLog.SyncLevel.FSYNC) { |
| // Since fsync is outside of synchronized block, we can end up with a partial |
| // last record on power failure (which is OK, and does not represent an error... |
| // we just need to be aware of it when reading). |
| raf.getFD().sync(); |
| } |
| |
| } catch (IOException e) { |
| throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e); |
| } |
| } |
| |
| protected void close() { |
| try { |
| if (debug) { |
| log.debug("Closing tlog" + this); |
| } |
| |
| synchronized (this) { |
| fos.flush(); |
| fos.close(); |
| } |
| |
| if (deleteOnClose) { |
| tlogFile.delete(); |
| } |
| } catch (IOException e) { |
| throw new SolrException(SolrException.ErrorCode.SERVER_ERROR, e); |
| } |
| } |
| |
| public void forceClose() { |
| if (refcount.get() > 0) { |
| log.error("Error: Forcing close of " + this); |
| refcount.set(0); |
| close(); |
| } |
| } |
| |
| @Override |
| public String toString() { |
| return "tlog{file=" + tlogFile.toString() + " refcount=" + refcount.get() + "}"; |
| } |
| |
| public long getLogSize() { |
| if (tlogFile != null) { |
| return tlogFile.length(); |
| } |
| return 0; |
| } |
| |
| /** Returns a reader that can be used while a log is still in use. |
| * Currently only *one* LogReader may be outstanding, and that log may only |
| * be used from a single thread. */ |
| public LogReader getReader(long startingPos) { |
| return new LogReader(startingPos); |
| } |
| |
| /** Returns a single threaded reverse reader */ |
| public ReverseReader getReverseReader() throws IOException { |
| return new FSReverseReader(); |
| } |
| |
| public class LogReader { |
| private ChannelFastInputStream fis; |
| private LogCodec codec = new LogCodec(resolver); |
| |
| public LogReader(long startingPos) { |
| incref(); |
| fis = new ChannelFastInputStream(channel, startingPos); |
| } |
| |
| // for classes that extend |
| protected LogReader() {} |
| |
| /** Returns the next object from the log, or null if none available. |
| * |
| * @return The log record, or null if EOF |
| * @throws IOException If there is a low-level I/O error. |
| */ |
| public Object next() throws IOException, InterruptedException { |
| long pos = fis.position(); |
| |
| |
| synchronized (TransactionLog.this) { |
| if (trace) { |
| log.trace("Reading log record. pos="+pos+" currentSize="+fos.size()); |
| } |
| |
| if (pos >= fos.size()) { |
| return null; |
| } |
| |
| fos.flushBuffer(); |
| } |
| |
| if (pos == 0) { |
| readHeader(fis); |
| |
| // shouldn't currently happen - header and first record are currently written at the same time |
| synchronized (TransactionLog.this) { |
| if (fis.position() >= fos.size()) { |
| return null; |
| } |
| pos = fis.position(); |
| } |
| } |
| |
| Object o = codec.readVal(fis); |
| |
| // skip over record size |
| int size = fis.readInt(); |
| assert size == fis.position() - pos - 4; |
| |
| return o; |
| } |
| |
| public void close() { |
| decref(); |
| } |
| |
| @Override |
| public String toString() { |
| synchronized (TransactionLog.this) { |
| return "LogReader{" + "file=" + tlogFile + ", position=" + fis.position() + ", end=" + fos.size() + "}"; |
| } |
| } |
| |
| } |
| |
| public abstract class ReverseReader { |
| |
| |
| |
| /** Returns the next object from the log, or null if none available. |
| * |
| * @return The log record, or null if EOF |
| * @throws IOException If there is a low-level I/O error. |
| */ |
| public abstract Object next() throws IOException; |
| |
| /* returns the position in the log file of the last record returned by next() */ |
| public abstract long position(); |
| public abstract void close(); |
| |
| @Override |
| public abstract String toString() ; |
| |
| |
| } |
| |
| public class FSReverseReader extends ReverseReader { |
| ChannelFastInputStream fis; |
| private LogCodec codec = new LogCodec(resolver) { |
| @Override |
| public SolrInputDocument readSolrInputDocument(DataInputInputStream dis) { |
| // Given that the SolrInputDocument is last in an add record, it's OK to just skip |
| // reading it completely. |
| return null; |
| } |
| }; |
| |
| int nextLength; // length of the next record (the next one closer to the start of the log file) |
| long prevPos; // where we started reading from last time (so prevPos - nextLength == start of next record) |
| |
| public FSReverseReader() throws IOException { |
| incref(); |
| |
| long sz; |
| synchronized (TransactionLog.this) { |
| fos.flushBuffer(); |
| sz = fos.size(); |
| assert sz == channel.size(); |
| } |
| |
| fis = new ChannelFastInputStream(channel, 0); |
| if (sz >=4) { |
| // readHeader(fis); // should not be needed |
| prevPos = sz - 4; |
| fis.seek(prevPos); |
| nextLength = fis.readInt(); |
| } |
| } |
| |
| |
| /** Returns the next object from the log, or null if none available. |
| * |
| * @return The log record, or null if EOF |
| * @throws IOException If there is a low-level I/O error. |
| */ |
| public Object next() throws IOException { |
| if (prevPos <= 0) return null; |
| |
| long endOfThisRecord = prevPos; |
| |
| int thisLength = nextLength; |
| |
| long recordStart = prevPos - thisLength; // back up to the beginning of the next record |
| prevPos = recordStart - 4; // back up 4 more to read the length of the next record |
| |
| if (prevPos <= 0) return null; // this record is the header |
| |
| long bufferPos = fis.getBufferPos(); |
| if (prevPos >= bufferPos) { |
| // nothing to do... we're within the current buffer |
| } else { |
| // Position buffer so that this record is at the end. |
| // For small records, this will cause subsequent calls to next() to be within the buffer. |
| long seekPos = endOfThisRecord - fis.getBufferSize(); |
| seekPos = Math.min(seekPos, prevPos); // seek to the start of the record if it's larger then the block size. |
| seekPos = Math.max(seekPos, 0); |
| fis.seek(seekPos); |
| fis.peek(); // cause buffer to be filled |
| } |
| |
| fis.seek(prevPos); |
| nextLength = fis.readInt(); // this is the length of the *next* record (i.e. closer to the beginning) |
| |
| // TODO: optionally skip document data |
| Object o = codec.readVal(fis); |
| |
| // assert fis.position() == prevPos + 4 + thisLength; // this is only true if we read all the data (and we currently skip reading SolrInputDocument |
| |
| return o; |
| } |
| |
| /* returns the position in the log file of the last record returned by next() */ |
| public long position() { |
| return prevPos + 4; // skip the length |
| } |
| |
| public void close() { |
| decref(); |
| } |
| |
| @Override |
| public String toString() { |
| synchronized (TransactionLog.this) { |
| return "LogReader{" + "file=" + tlogFile + ", position=" + fis.position() + ", end=" + fos.size() + "}"; |
| } |
| } |
| |
| |
| } |
| |
| } |
| |
| |
| |
| class ChannelFastInputStream extends FastInputStream { |
| private FileChannel ch; |
| |
| public ChannelFastInputStream(FileChannel ch, long chPosition) { |
| // super(null, new byte[10],0,0); // a small buffer size for testing purposes |
| super(null); |
| this.ch = ch; |
| super.readFromStream = chPosition; |
| } |
| |
| @Override |
| public int readWrappedStream(byte[] target, int offset, int len) throws IOException { |
| ByteBuffer bb = ByteBuffer.wrap(target, offset, len); |
| int ret = ch.read(bb, readFromStream); |
| return ret; |
| } |
| |
| public void seek(long position) throws IOException { |
| if (position <= readFromStream && position >= getBufferPos()) { |
| // seek within buffer |
| pos = (int)(position - getBufferPos()); |
| } else { |
| // long currSize = ch.size(); // not needed - underlying read should handle (unless read never done) |
| // if (position > currSize) throw new EOFException("Read past EOF: seeking to " + position + " on file of size " + currSize + " file=" + ch); |
| readFromStream = position; |
| end = pos = 0; |
| } |
| assert position() == position; |
| } |
| |
| /** where is the start of the buffer relative to the whole file */ |
| public long getBufferPos() { |
| return readFromStream - end; |
| } |
| |
| public int getBufferSize() { |
| return buf.length; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| ch.close(); |
| } |
| |
| @Override |
| public String toString() { |
| return "readFromStream="+readFromStream +" pos="+pos +" end="+end + " bufferPos="+getBufferPos() + " position="+position() ; |
| } |
| } |
| |
| |
