private void reportProblem(Exception e) {
StringBuilder sb = new StringBuilder();
sb.append("Halted log file reading at file 0x")
.append(Long.toHexString(window.currentFileNum()))
.append(" offset 0x")
.append(Long.toHexString(nextEntryOffset))
.append(" offset(decimal)=")
.append(nextEntryOffset)
.append(" prev=0x")
.append(Long.toHexString(currentEntryPrevOffset));
if (currentEntryHeader != null) {
LogEntryType problemType = LogEntryType.findType(currentEntryHeader.getType());
sb.append(":\nentry=")
.append(problemType)
.append("type=")
.append(currentEntryHeader.getType())
.append(",version=")
.append(currentEntryHeader.getVersion())
.append(")\nprev=0x")
.append(Long.toHexString(currentEntryPrevOffset))
.append("\nsize=")
.append(currentEntryHeader.getItemSize())
.append("\nNext entry should be at 0x")
.append(
Long.toHexString(
nextEntryOffset
+ currentEntryHeader.getSize()
+ currentEntryHeader.getItemSize()));
}
LoggerUtils.traceAndLogException(envImpl, "FileReader", "readNextEntry", sb.toString(), e);
}
/** Copy the required number of bytes into the save buffer. */
private void copyToSaveBuffer(int bytesNeeded) {
/* How much can we get from this current read buffer? */
int bytesFromThisBuffer;
if (bytesNeeded <= window.remaining()) {
bytesFromThisBuffer = bytesNeeded;
} else {
bytesFromThisBuffer = window.remaining();
}
/* Gather it all into this save buffer. */
ByteBuffer temp;
/* Make sure the save buffer is big enough. */
if (saveBuffer.capacity() - threadSafeBufferPosition(saveBuffer) < bytesFromThisBuffer) {
/* Grow the save buffer. */
temp = ByteBuffer.allocate(saveBuffer.capacity() + bytesFromThisBuffer);
threadSafeBufferFlip(saveBuffer);
temp.put(saveBuffer);
saveBuffer = temp;
}
/*
* Bulk copy only the required section from the read buffer into the
* save buffer. We need from readBuffer.position() to
* readBuffer.position() + bytesFromThisBuffer
*/
temp = window.getBuffer().slice();
temp.limit(bytesFromThisBuffer);
saveBuffer.put(temp);
window.incrementBufferPosition(bytesFromThisBuffer);
}
/**
* Try to read a specified number of bytes.
*
* @param amountToRead is the number of bytes we need
* @param collectData is true if we need to actually look at the data. If false, we know we're
* skipping this entry, and all we need to do is to count until we get to the right spot.
* @return a byte buffer positioned at the head of the desired portion, or null if we reached eof.
*/
private ByteBuffer readData(int amountToRead, boolean collectData)
throws ChecksumException, EOFException, FileNotFoundException, DatabaseException {
int alreadyRead = 0;
ByteBuffer completeBuffer = null;
saveBuffer.clear();
while ((alreadyRead < amountToRead) && !eof) {
int bytesNeeded = amountToRead - alreadyRead;
if (window.hasRemaining()) {
/* There's data in the window, process it. */
if (collectData) {
/*
* Save data in a buffer for processing.
*/
if ((alreadyRead > 0) || (window.remaining() < bytesNeeded)) {
/* We need to piece an entry together. */
copyToSaveBuffer(bytesNeeded);
alreadyRead = threadSafeBufferPosition(saveBuffer);
completeBuffer = saveBuffer;
} else {
/* A complete entry is available in this buffer. */
completeBuffer = window.getBuffer();
alreadyRead = amountToRead;
}
} else {
/*
* We're not processing the data, so need to save it. just
* move buffer positions.
*/
int positionIncrement =
(window.remaining() > bytesNeeded) ? bytesNeeded : window.remaining();
alreadyRead += positionIncrement;
window.incrementBufferPosition(positionIncrement);
completeBuffer = window.getBuffer();
}
} else {
/*
* Look for more data.
*/
if (window.fillNext(singleFile, bytesNeeded)) {
/* This call to fillNext slid the window to a new file. */
nextEntryOffset = 0;
}
}
}
/* Flip the save buffer just in case we've been accumulating in it. */
threadSafeBufferFlip(saveBuffer);
return completeBuffer;
}
void startSwitchingToReadMode(ReadWindow window) {
readCacheStatus = READ_CACHE_STATUS.SWITCHINGTOREADMODE;
i2cDevice.enableI2cReadMode(window.getIregFirst(), window.getCreg());
enabledReadMode = true;
// Remember what we actually told the controller
readWindowSentToController = window;
readWindowSentToControllerInitialized = true;
setActionFlag = true; // causes an I2C read to happen
queueFullWrite = true; // for just the mode bytes
queueRead = true; // read the mode byte so we can tell when the switch is done
dirtyModeCacheStatus();
}
/** Helper for determining the starting position and opening up a file at the desired location. */
protected void initStartingPosition(long endOfFileLsn, Long ignoreSingleFileNumber) {
eof = false;
if (forward) {
/*
* Start off at the startLsn. If that's null, start at the
* beginning of the log. If there are no log files, set eof.
*/
if (startLsn != DbLsn.NULL_LSN) {
window.initAtFileStart(startLsn);
} else {
Long firstNum = fileManager.getFirstFileNum();
if (firstNum == null) {
eof = true;
} else {
window.initAtFileStart(DbLsn.makeLsn(firstNum, 0));
}
}
/*
* After we read the first entry, the currentEntry will point here.
*/
nextEntryOffset = window.getEndOffset();
} else {
/*
* Make the read buffer look like it's positioned off the end of
* the file. Initialize the first LSN we want to read. When
* traversing the log backwards, we always start at the very end.
*/
assert startLsn != DbLsn.NULL_LSN;
window.initAtFileStart(endOfFileLsn);
/*
* currentEntryPrevOffset points to the entry we want to start out
* reading when going backwards. If it's 0, the entry we want to
* read is in a different file.
*/
if (DbLsn.getFileNumber(startLsn) == DbLsn.getFileNumber(endOfFileLsn)) {
currentEntryPrevOffset = DbLsn.getFileOffset(startLsn);
} else {
currentEntryPrevOffset = 0;
}
currentEntryOffset = DbLsn.getFileOffset(endOfFileLsn);
}
}
/** TBW */
protected void handleGapInBackwardsScan(long prevFileNum) {
throw new EnvironmentFailureException(
envImpl,
EnvironmentFailureReason.LOG_INTEGRITY,
"Cannot read backward over cleaned file"
+ " from "
+ window.currentFileNum()
+ " to "
+ prevFileNum);
}
/**
* Ensure that the next target is in the window. The default behavior is that the next target is
* the next, following entry, so we can assume that it's in the window. All we have to do is to
* check if we've gone past the specified end point.
*
* @throws DatabaseException
* @throws FileNotFoundException
* @throws ChecksumException
*/
protected void setForwardPosition()
throws EOFException, DatabaseException, ChecksumException, FileNotFoundException {
if (finishLsn != DbLsn.NULL_LSN) {
/* The next log entry has passed the end LSN. */
long nextLsn = DbLsn.makeLsn(window.currentFileNum(), nextEntryOffset);
if (DbLsn.compareTo(nextLsn, finishLsn) >= 0) {
throw new EOFException();
}
}
}
/**
* Add the entry bytes to the checksum and check the value. This method must be called with the
* buffer positioned at the start of the entry.
*/
private void validateChecksum(ByteBuffer dataBuffer, boolean isChecksumTarget)
throws ChecksumException {
if (!doChecksumOnRead) {
return;
}
if (!isChecksumTarget) {
return;
}
cksumValidator.update(dataBuffer, currentEntryHeader.getItemSize());
cksumValidator.validate(
currentEntryHeader.getChecksum(), window.currentFileNum(), currentEntryOffset);
}
/** Set the set of registers that we will read and read and read again on every hardware cycle */
@Override
public void setReadWindow(ReadWindow newWindow) {
synchronized (this.concurrentClientLock) {
synchronized (this.callbackLock) {
if (this.readWindow == null
|| !this.readWindow.isOkToRead()
|| !this.readWindow.sameAsIncludingMode(newWindow)) {
// Remember the new window, but get a fresh copy so we can implement the read mode policy
this.readWindow = newWindow.freshCopy();
assertTrue(!BuildConfig.DEBUG || this.readWindow.isOkToRead());
// Let others know of the update
this.readWindowChanged = true;
}
}
}
}
/** Returns the number of reads since the last time this method was called. */
public int getAndResetNReads() {
return window.getAndResetNReads();
}
/**
* Ensure that the next target is in the window. The default behavior is that the next target is
* the next previous entry.
*
* @throws DatabaseException
*/
protected void setBackwardPosition()
throws ChecksumException, FileNotFoundException, EOFException, DatabaseException {
/*
* currentEntryPrevOffset is the entry before the current entry.
* currentEntryOffset is the entry we just read (or the end of the
* file if we're starting out.
*/
if ((currentEntryPrevOffset != 0) && window.containsOffset(currentEntryPrevOffset)) {
/* The next log entry has passed the start LSN. */
long nextLsn = DbLsn.makeLsn(window.currentFileNum(), currentEntryPrevOffset);
if (finishLsn != DbLsn.NULL_LSN) {
if (DbLsn.compareTo(nextLsn, finishLsn) == -1) {
throw new EOFException(
"finish="
+ DbLsn.getNoFormatString(finishLsn)
+ "next="
+ DbLsn.getNoFormatString(nextLsn));
}
}
/* This log entry starts in this buffer, just reposition. */
window.positionBuffer(currentEntryPrevOffset);
} else {
/*
* The start of the log entry is not in this read buffer so
* we must fill the buffer again.
*
* 1) The target log entry is in a different file from the
* current window's file. Move the window to the previous
* file and start the read from the target LSN.
*
* 2) The target log entry is the same file but the log entry
* is larger than the read chunk size. Start the next read
* buffer from the target LSN. It's going to take multiple
* reads to get the log entry, and we might as well get as
* much as possible.
*
* 3) In the same file, and the log entry fits within one
* read buffer. Try to position the next buffer chunk so the
* target entry is held within the buffer, all the way at the
* end. That way, since we're reading backwards, there will be
* more buffered data available for following reads.
*/
long nextFile;
long nextWindowStart;
long nextTarget;
if (currentEntryPrevOffset == 0) {
/* Case 1: Go to another file. */
currentEntryPrevOffset = fileManager.getFileHeaderPrevOffset(window.currentFileNum());
Long prevFileNum = fileManager.getFollowingFileNum(window.currentFileNum(), false);
if (prevFileNum == null) {
throw new EOFException("No file following " + window.currentFileNum());
}
/*
* Check finishLSN before proceeding, in case we should stop
* the search before attempting to set the file reader to a
* position in the previous file. In [#22407] we threw a
* spurious EFE complaining that we cannot read backwards over
* a cleaned file because the previous file had been cleaned
* away.
*/
if (finishLsn != DbLsn.NULL_LSN && prevFileNum < DbLsn.getFileNumber(finishLsn)) {
throw new EOFException(
"finish="
+ DbLsn.getNoFormatString(finishLsn)
+ " nextFile=0x"
+ Long.toHexString(prevFileNum));
}
if (window.currentFileNum() - prevFileNum.longValue() != 1) {
handleGapInBackwardsScan(prevFileNum);
}
nextFile = prevFileNum;
nextWindowStart = currentEntryPrevOffset;
nextTarget = currentEntryPrevOffset;
} else if ((currentEntryOffset - currentEntryPrevOffset) > window.capacity()) {
/*
* Case 2: The entry is in the same file, but is bigger
* than one buffer. Position it at the front of the buffer.
*/
nextFile = window.currentFileNum();
nextWindowStart = currentEntryPrevOffset;
nextTarget = currentEntryPrevOffset;
} else {
/*
* Case 3: In same file, but not in this buffer. The target
* entry will fit in one buffer.
*/
nextFile = window.currentFileNum();
long newPosition = currentEntryOffset - window.capacity();
nextWindowStart = (newPosition < 0) ? 0 : newPosition;
nextTarget = currentEntryPrevOffset;
}
/* The next log entry has passed the start LSN. */
long nextLsn = DbLsn.makeLsn(nextFile, currentEntryPrevOffset);
if (finishLsn != DbLsn.NULL_LSN) {
if (DbLsn.compareTo(nextLsn, finishLsn) == -1) {
throw new EOFException(
"finish="
+ DbLsn.getNoFormatString(finishLsn)
+ " next="
+ DbLsn.getNoFormatString(nextLsn));
}
}
window.slideAndFill(nextFile, nextWindowStart, nextTarget, forward);
}
/* The current entry will start at this offset. */
currentEntryOffset = currentEntryPrevOffset;
}
/** Get LSN of the last entry read. */
public long getLastLsn() {
return DbLsn.makeLsn(window.currentFileNum(), currentEntryOffset);
}
public long getNRepeatIteratorReads() {
return window.getNRepeatIteratorReads();
}
