/**
* Tries to lock all local shards for the given index. If any of the shard locks can't be acquired
* an {@link LockObtainFailedException} is thrown and all previously acquired locks are released.
*
* @param index the index to lock shards for
* @param lockTimeoutMS how long to wait for acquiring the indices shard locks
* @return the {@link ShardLock} instances for this index.
* @throws IOException if an IOException occurs.
*/
public List<ShardLock> lockAllForIndex(
Index index, @IndexSettings Settings settings, long lockTimeoutMS) throws IOException {
final Integer numShards = settings.getAsInt(IndexMetaData.SETTING_NUMBER_OF_SHARDS, null);
if (numShards == null || numShards <= 0) {
throw new IllegalArgumentException("settings must contain a non-null > 0 number of shards");
}
logger.trace("locking all shards for index {} - [{}]", index, numShards);
List<ShardLock> allLocks = new ArrayList<>(numShards);
boolean success = false;
long startTimeNS = System.nanoTime();
try {
for (int i = 0; i < numShards; i++) {
long timeoutLeftMS =
Math.max(0, lockTimeoutMS - TimeValue.nsecToMSec((System.nanoTime() - startTimeNS)));
allLocks.add(shardLock(new ShardId(index, i), timeoutLeftMS));
}
success = true;
} finally {
if (success == false) {
logger.trace("unable to lock all shards for index {}", index);
IOUtils.closeWhileHandlingException(allLocks);
}
}
return allLocks;
}
/**
* Read block from file.
*
* @param file - File to read.
* @param off - Marker position in file to start read from if {@code -1} read last blockSz bytes.
* @param blockSz - Maximum number of chars to read.
* @param lastModified - File last modification time.
* @return Read file block.
* @throws IOException In case of error.
*/
public static VisorFileBlock readBlock(File file, long off, int blockSz, long lastModified)
throws IOException {
RandomAccessFile raf = null;
try {
long fSz = file.length();
long fLastModified = file.lastModified();
long pos = off >= 0 ? off : Math.max(fSz - blockSz, 0);
// Try read more that file length.
if (fLastModified == lastModified && fSz != 0 && pos >= fSz)
throw new IOException(
"Trying to read file block with wrong offset: " + pos + " while file size: " + fSz);
if (fSz == 0)
return new VisorFileBlock(file.getPath(), pos, fLastModified, 0, false, EMPTY_FILE_BUF);
else {
int toRead = Math.min(blockSz, (int) (fSz - pos));
byte[] buf = new byte[toRead];
raf = new RandomAccessFile(file, "r");
raf.seek(pos);
int cntRead = raf.read(buf, 0, toRead);
if (cntRead != toRead)
throw new IOException(
"Count of requested and actually read bytes does not match [cntRead="
+ cntRead
+ ", toRead="
+ toRead
+ ']');
boolean zipped = buf.length > 512;
return new VisorFileBlock(
file.getPath(), pos, fSz, fLastModified, zipped, zipped ? zipBytes(buf) : buf);
}
} finally {
U.close(raf, null);
}
}
