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cannonicalize all accesses to indexMetadataMap.
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patch by jbellis; reviewed by Jun Rao for CASSANDRA-153

git-svn-id: https://svn.apache.org/repos/asf/incubator/cassandra/trunk@773726 13f79535-47bb-0310-9956-ffa450edef68
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@jbellis
jbellis committed May 11, 2009
1 parent 69bc7e9 commit dfa41ec
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Showing 2 changed files with 79 additions and 49 deletions.
124 changes: 77 additions & 47 deletions src/java/org/apache/cassandra/io/SSTable.java
View file
Expand Up @@ -42,7 +42,6 @@
import org.apache.cassandra.utils.BloomFilter;
import org.apache.cassandra.utils.FileUtils;
import org.apache.cassandra.utils.LogUtil;
import org.apache.cassandra.dht.IPartitioner;

/**
* This class is built on top of the SequenceFile. It stores
Expand Down Expand Up @@ -198,7 +197,7 @@ public static int indexInterval()
* We do this so that we don't read the index file into memory multiple
* times.
*/
static Map<String, List<KeyPositionInfo>> indexMetadataMap_ = new Hashtable<String, List<KeyPositionInfo>>();
static IndexMap indexMetadataMap_ = new IndexMap();

/**
* This method deletes both the specified data file
Expand Down Expand Up @@ -348,7 +347,7 @@ public static boolean isKeyInFile(String clientKey, String filename)
* ctor to read the data in this file.
*/
public SSTable(String dataFileName, IPartitioner partitioner) throws IOException
{
{
dataFile_ = dataFileName;
partitioner_ = partitioner;
init();
Expand All @@ -359,7 +358,7 @@ public SSTable(String dataFileName, IPartitioner partitioner) throws IOException
* version for non DB writes to the SSTable.
*/
public SSTable(String directory, String filename, IPartitioner partitioner) throws IOException
{
{
dataFile_ = directory + System.getProperty("file.separator") + filename + "-Data.db";
partitioner_ = partitioner;
blockIndex_ = new TreeMap<String, BlockMetadata>(partitioner_.getReverseDecoratedKeyComparator());
Expand Down Expand Up @@ -660,58 +659,43 @@ public void append(String decoratedKey, byte[] value) throws IOException
public static Coordinate getCoordinates(String decoratedKey, IFileReader dataReader, IPartitioner partitioner) throws IOException
{
List<KeyPositionInfo> indexInfo = indexMetadataMap_.get(dataReader.getFileName());
int size = (indexInfo == null) ? 0 : indexInfo.size();
long start = 0L;
assert indexInfo != null && indexInfo.size() > 0;
long start = 0L;
long end;
if ( size > 0 )
int index = Collections.binarySearch(indexInfo, new KeyPositionInfo(decoratedKey, partitioner));
if ( index < 0 )
{
int index = Collections.binarySearch(indexInfo, new KeyPositionInfo(decoratedKey, partitioner));
if ( index < 0 )
/*
* We are here which means that the requested
* key is not an index.
*/
index = (++index)*(-1);
/*
* This means key is not present at all. Hence
* a scan is in order.
*/
start = (index == 0) ? 0 : indexInfo.get(index - 1).position();
if ( index < indexInfo.size())
{
/*
* We are here which means that the requested
* key is not an index.
*/
index = (++index)*(-1);
/*
* This means key is not present at all. Hence
* a scan is in order.
*/
start = (index == 0) ? 0 : indexInfo.get(index - 1).position();
if ( index < size )
{
end = indexInfo.get(index).position();
}
else
{
/* This is the Block Index in the file. */
end = start;
}
end = indexInfo.get(index).position();
}
else
{
/*
* If we are here that means the key is in the index file
* and we can retrieve it w/o a scan. In reality we would
* like to have a retreive(key, fromPosition) but for now
* we use scan(start, start + 1) - a hack.
*/
start = indexInfo.get(index).position();
/* This is the Block Index in the file. */
end = start;
}
}
else
{
/*
* We are here which means there are less than
* 128 keys in the system and hence our only recourse
* is a linear scan from start to finish. Automatically
* use memory mapping since we have a huge file and very
* few keys.
* If we are here that means the key is in the index file
* and we can retrieve it w/o a scan. In reality we would
* like to have a retreive(key, fromPosition) but for now
* we use scan(start, start + 1) - a hack.
*/
end = dataReader.getEOF();
}

start = indexInfo.get(index).position();
end = start;
}
return new Coordinate(start, end);
}

Expand Down Expand Up @@ -798,9 +782,9 @@ public void closeRename(BloomFilter bf) throws IOException
String tmpDataFile = dataFile_;
String dataFileName = dataFile_.replace("-" + temporaryFile_,"");
File dataFile = new File(dataFile_);
dataFile.renameTo(new File(dataFileName));
dataFile_ = dataFileName;
/* Now repair the in memory index associated with the old name */
dataFile.renameTo(new File(dataFileName));
dataFile_ = dataFileName;
/* Now repair the in memory index associated with the old name */
List<KeyPositionInfo> keyPositionInfos = SSTable.indexMetadataMap_.remove(tmpDataFile);
SSTable.indexMetadataMap_.put(dataFile_, keyPositionInfos);
}
Expand Down Expand Up @@ -829,5 +813,51 @@ private void close(byte[] footer, int size) throws IOException
dataWriter_.writeDirect(BasicUtilities.longToByteArray(bloomFilterRelativePosition));
dataWriter_.close();
}
}
}

/**
* wraps a Map to ensure that all filenames used as keys are cannonicalized.
* (Note that cannonical paths are cached by the JDK so the performance hit is negligible.)
*/
static class IndexMap
{
private final Hashtable<String, List<KeyPositionInfo>> hashtable = new Hashtable<String, List<KeyPositionInfo>>();

private String cannonicalize(String filename)
{
try
{
return new File(filename).getCanonicalPath();
}
catch (IOException e)
{
throw new RuntimeException(e);
}
}

public List<KeyPositionInfo> get(String filename)
{
return hashtable.get(cannonicalize(filename));
}

public List<KeyPositionInfo> put(String filename, List<KeyPositionInfo> value)
{
return hashtable.put(cannonicalize(filename), value);
}

public void clear()
{
hashtable.clear();
}

public Set<String> keySet()
{
return hashtable.keySet();
}

public List<KeyPositionInfo> remove(String filename)
{
return hashtable.remove(cannonicalize(filename));
}
}
}
4 changes: 2 additions & 2 deletions test/unit/org/apache/cassandra/io/SSTableTest.java
View file
Expand Up @@ -29,7 +29,7 @@ public void testSingleWrite() throws IOException {
ssTable.close(bf);

// verify
SSTable.indexMetadataMap_.clear();
SSTable.indexMetadataMap_.clear(); // force reloading the index
ssTable = new SSTable(f.getPath() + "-Data.db", new OrderPreservingPartitioner());
FileStruct fs = new FileStruct(SequenceFile.bufferedReader(ssTable.dataFile_, 128 * 1024), new OrderPreservingPartitioner());
fs.seekTo(key);
Expand Down Expand Up @@ -60,7 +60,7 @@ public void testManyWrites() throws IOException {
ssTable.close(bf);

// verify
SSTable.indexMetadataMap_.clear();
SSTable.indexMetadataMap_.clear(); // force reloading the index
List<String> keys = new ArrayList(map.keySet());
Collections.shuffle(keys);
ssTable = new SSTable(f.getPath() + "-Data.db", new OrderPreservingPartitioner());
Expand Down

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