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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing, software
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*/
package org.apache.hadoop.hbase.wal;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.HBaseInterfaceAudience;
import org.apache.hadoop.hbase.PrivateCellUtil;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.RegionInfo;
import org.apache.hadoop.hbase.codec.Codec;
import org.apache.hadoop.hbase.io.HeapSize;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.ClassSize;
import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.hadoop.hbase.shaded.protobuf.generated.WALProtos;
import org.apache.hadoop.hbase.shaded.protobuf.generated.WALProtos.CompactionDescriptor;
import org.apache.hadoop.hbase.shaded.protobuf.generated.WALProtos.FlushDescriptor;
import org.apache.hadoop.hbase.shaded.protobuf.generated.WALProtos.RegionEventDescriptor;
/**
* Used in HBase's transaction log (WAL) to represent a collection of edits (Cell/KeyValue objects)
* that came in as a single transaction. All the edits for a given transaction are written out as a
* single record, in PB format, followed (optionally) by Cells written via the WALCellEncoder.
* This class is LimitedPrivate for CPs to read-only. The {@link #add} methods are
* classified as private methods, not for use by CPs.
*
* A particular WALEdit 'type' is the 'meta' type used to mark key operational
* events in the WAL such as compaction, flush, or region open. These meta types do not traverse
* hbase memstores. They are edits made by the hbase system rather than edit data submitted by
* clients. They only show in the WAL. These 'Meta' types have not been formally specified
* (or made into an explicit class type). They evolved organically. HBASE-8457 suggests codifying
* a WALEdit 'type' by adding a type field to WALEdit that gets serialized into the WAL. TODO.
* Would have to work on the consumption-side. Reading WALs on replay we seem to consume
* a Cell-at-a-time rather than by WALEdit. We are already in the below going out of our
* way to figure particular types -- e.g. if a compaction, replay, or close meta Marker -- during
* normal processing so would make sense to do this. Current system is an awkward marking of Cell
* columnfamily as {@link #METAFAMILY} and then setting qualifier based off meta edit type. For
* replay-time where we read Cell-at-a-time, there are utility methods below for figuring
* meta type. See also
* {@link #createBulkLoadEvent(RegionInfo, WALProtos.BulkLoadDescriptor)}, etc., for where we
* create meta WALEdit instances.
*
* WALEdit will accumulate a Set of all column family names referenced by the Cells
* {@link #add(Cell)}'d. This is an optimization. Usually when loading a WALEdit, we have the
* column family name to-hand.. just shove it into the WALEdit if available. Doing this, we can
* save on a parse of each Cell to figure column family down the line when we go to add the
* WALEdit to the WAL file. See the hand-off in FSWALEntry Constructor.
* @see WALKey
*/
// TODO: Do not expose this class to Coprocessors. It has set methods. A CP might meddle.
@InterfaceAudience.LimitedPrivate({ HBaseInterfaceAudience.REPLICATION,
HBaseInterfaceAudience.COPROC })
public class WALEdit implements HeapSize {
// Below defines are for writing WALEdit 'meta' Cells..
// TODO: Get rid of this system of special 'meta' Cells. See HBASE-8457. It suggests
// adding a type to WALEdit itself for use denoting meta Edits and their types.
public static final byte [] METAFAMILY = Bytes.toBytes("METAFAMILY");
/**
* @deprecated Since 2.3.0. Not used.
*/
@Deprecated
public static final byte [] METAROW = Bytes.toBytes("METAROW");
/**
* @deprecated Since 2.3.0. Make it protected, internal-use only. Use
* {@link #isCompactionMarker(Cell)}
*/
@Deprecated
@InterfaceAudience.Private
public static final byte[] COMPACTION = Bytes.toBytes("HBASE::COMPACTION");
/**
* @deprecated Since 2.3.0. Make it protected, internal-use only.
*/
@Deprecated
@InterfaceAudience.Private
public static final byte [] FLUSH = Bytes.toBytes("HBASE::FLUSH");
/**
* Qualifier for region event meta 'Marker' WALEdits start with the
* {@link #REGION_EVENT_PREFIX} prefix ('HBASE::REGION_EVENT::'). After the prefix,
* we note the type of the event which we get from the RegionEventDescriptor protobuf
* instance type (A RegionEventDescriptor protobuf instance is written as the meta Marker
* Cell value). Adding a type suffix means we do not have to deserialize the protobuf to
* figure out what type of event this is.. .just read the qualifier suffix. For example,
* a close region event descriptor will have a qualifier of HBASE::REGION_EVENT::REGION_CLOSE.
* See WAL.proto and the EventType in RegionEventDescriptor protos for all possible
* event types.
*/
private static final String REGION_EVENT_STR = "HBASE::REGION_EVENT";
private static final String REGION_EVENT_PREFIX_STR = REGION_EVENT_STR + "::";
private static final byte [] REGION_EVENT_PREFIX = Bytes.toBytes(REGION_EVENT_PREFIX_STR);
/**
* @deprecated Since 2.3.0. Remove. Not for external use. Not used.
*/
@Deprecated
public static final byte [] REGION_EVENT = Bytes.toBytes(REGION_EVENT_STR);
/**
* We use this define figuring if we are carrying a close event.
*/
private static final byte [] REGION_EVENT_CLOSE =
createRegionEventDescriptorQualifier(RegionEventDescriptor.EventType.REGION_CLOSE);
@InterfaceAudience.Private
public static final byte [] BULK_LOAD = Bytes.toBytes("HBASE::BULK_LOAD");
private final transient boolean replay;
private ArrayList cells;
/**
* All the Cell families in cells. Updated by {@link #add(Cell)} and
* {@link #add(Map)}. This Set is passed to the FSWALEntry so it does not have
* to recalculate the Set of families in a transaction; makes for a bunch of CPU savings.
*/
private Set families = null;
public WALEdit() {
this(1, false);
}
/**
* @deprecated since 2.0.1 and will be removed in 4.0.0. Use {@link #WALEdit(int, boolean)}
* instead.
* @see #WALEdit(int, boolean)
* @see HBASE-20781
*/
@Deprecated
public WALEdit(boolean replay) {
this(1, replay);
}
/**
* @deprecated since 2.0.1 and will be removed in 4.0.0. Use {@link #WALEdit(int, boolean)}
* instead.
* @see #WALEdit(int, boolean)
* @see HBASE-20781
*/
@Deprecated
public WALEdit(int cellCount) {
this(cellCount, false);
}
/**
* @param cellCount Pass so can pre-size the WALEdit. Optimization.
*/
public WALEdit(int cellCount, boolean isReplay) {
this.replay = isReplay;
cells = new ArrayList<>(cellCount);
}
private Set getOrCreateFamilies() {
if (this.families == null) {
this.families = new TreeSet<>(Bytes.BYTES_COMPARATOR);
}
return this.families;
}
/**
* For use by FSWALEntry ONLY. An optimization.
* @return All families in {@link #getCells()}; may be null.
*/
public Set getFamilies() {
return this.families;
}
/**
* @return True is f is {@link #METAFAMILY}
* @deprecated Since 2.3.0. Do not expose. Make protected.
*/
@Deprecated
public static boolean isMetaEditFamily(final byte [] f) {
return Bytes.equals(METAFAMILY, f);
}
/**
* Replaying WALs can read Cell-at-a-time so need this method in those cases.
*/
public static boolean isMetaEditFamily(Cell cell) {
return CellUtil.matchingFamily(cell, METAFAMILY);
}
/**
* @return True if this is a meta edit; has one edit only and its columnfamily
* is {@link #METAFAMILY}.
*/
public boolean isMetaEdit() {
return this.families != null && this.families.size() == 1 && this.families.contains(METAFAMILY);
}
/**
* @return True when current WALEdit is created by log replay. Replication skips WALEdits from
* replay.
*/
public boolean isReplay() {
return this.replay;
}
@InterfaceAudience.Private
public WALEdit add(Cell cell, byte [] family) {
getOrCreateFamilies().add(family);
return addCell(cell);
}
@InterfaceAudience.Private
public WALEdit add(Cell cell) {
// We clone Family each time we add a Cell. Expensive but safe. For CPU savings, use
// add(Map) or add(Cell, family).
return add(cell, CellUtil.cloneFamily(cell));
}
public boolean isEmpty() {
return cells.isEmpty();
}
public int size() {
return cells.size();
}
public ArrayList getCells() {
return cells;
}
/**
* This is not thread safe.
* This will change the WALEdit and shouldn't be used unless you are sure that nothing
* else depends on the contents being immutable.
*
* @param cells the list of cells that this WALEdit now contains.
*/
@InterfaceAudience.Private
// Used by replay.
public void setCells(ArrayList cells) {
this.cells = cells;
this.families = null;
}
/**
* Reads WALEdit from cells.
* @param cellDecoder Cell decoder.
* @param expectedCount Expected cell count.
* @return Number of KVs read.
*/
public int readFromCells(Codec.Decoder cellDecoder, int expectedCount) throws IOException {
cells.clear();
cells.ensureCapacity(expectedCount);
while (cells.size() < expectedCount && cellDecoder.advance()) {
add(cellDecoder.current());
}
return cells.size();
}
@Override
public long heapSize() {
long ret = ClassSize.ARRAYLIST;
for (Cell cell : cells) {
ret += cell.heapSize();
}
return ret;
}
public long estimatedSerializedSizeOf() {
long ret = 0;
for (Cell cell: cells) {
ret += PrivateCellUtil.estimatedSerializedSizeOf(cell);
}
return ret;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("[#edits: ").append(cells.size()).append(" = <");
for (Cell cell : cells) {
sb.append(cell);
sb.append("; ");
}
sb.append(">]");
return sb.toString();
}
public static WALEdit createFlushWALEdit(RegionInfo hri, FlushDescriptor f) {
KeyValue kv = new KeyValue(getRowForRegion(hri), METAFAMILY, FLUSH,
EnvironmentEdgeManager.currentTime(), f.toByteArray());
return new WALEdit().add(kv, METAFAMILY);
}
public static FlushDescriptor getFlushDescriptor(Cell cell) throws IOException {
return CellUtil.matchingColumn(cell, METAFAMILY, FLUSH)?
FlushDescriptor.parseFrom(CellUtil.cloneValue(cell)): null;
}
/**
* @return A meta Marker WALEdit that has a single Cell whose value is the passed in
* regionEventDesc serialized and whose row is this region,
* columnfamily is {@link #METAFAMILY} and qualifier is
* {@link #REGION_EVENT_PREFIX} + {@link RegionEventDescriptor#getEventType()};
* for example HBASE::REGION_EVENT::REGION_CLOSE.
*/
public static WALEdit createRegionEventWALEdit(RegionInfo hri,
RegionEventDescriptor regionEventDesc) {
return createRegionEventWALEdit(getRowForRegion(hri), regionEventDesc);
}
@InterfaceAudience.Private
public static WALEdit createRegionEventWALEdit(byte [] rowForRegion,
RegionEventDescriptor regionEventDesc) {
KeyValue kv = new KeyValue(rowForRegion, METAFAMILY,
createRegionEventDescriptorQualifier(regionEventDesc.getEventType()),
EnvironmentEdgeManager.currentTime(), regionEventDesc.toByteArray());
return new WALEdit().add(kv, METAFAMILY);
}
/**
* @return Cell qualifier for the passed in RegionEventDescriptor Type; e.g. we'll
* return something like a byte array with HBASE::REGION_EVENT::REGION_OPEN in it.
*/
@InterfaceAudience.Private
public static byte [] createRegionEventDescriptorQualifier(RegionEventDescriptor.EventType t) {
return Bytes.toBytes(REGION_EVENT_PREFIX_STR + t.toString());
}
/**
* Public so can be accessed from regionserver.wal package.
* @return True if this is a Marker Edit and it is a RegionClose type.
*/
public boolean isRegionCloseMarker() {
return isMetaEdit() && PrivateCellUtil.matchingQualifier(this.cells.get(0),
REGION_EVENT_CLOSE, 0, REGION_EVENT_CLOSE.length);
}
/**
* @return Returns a RegionEventDescriptor made by deserializing the content of the
* passed in cell, IFF the cell is a RegionEventDescriptor
* type WALEdit.
*/
public static RegionEventDescriptor getRegionEventDescriptor(Cell cell) throws IOException {
return CellUtil.matchingColumnFamilyAndQualifierPrefix(cell, METAFAMILY, REGION_EVENT_PREFIX)?
RegionEventDescriptor.parseFrom(CellUtil.cloneValue(cell)): null;
}
/**
* @return A Marker WALEdit that has c serialized as its value
*/
public static WALEdit createCompaction(final RegionInfo hri, final CompactionDescriptor c) {
byte [] pbbytes = c.toByteArray();
KeyValue kv = new KeyValue(getRowForRegion(hri), METAFAMILY, COMPACTION,
EnvironmentEdgeManager.currentTime(), pbbytes);
return new WALEdit().add(kv, METAFAMILY); //replication scope null so this won't be replicated
}
public static byte[] getRowForRegion(RegionInfo hri) {
byte[] startKey = hri.getStartKey();
if (startKey.length == 0) {
// empty row key is not allowed in mutations because it is both the start key and the end key
// we return the smallest byte[] that is bigger (in lex comparison) than byte[0].
return new byte[] {0};
}
return startKey;
}
/**
* Deserialized and returns a CompactionDescriptor is the KeyValue contains one.
* @param kv the key value
* @return deserialized CompactionDescriptor or null.
*/
public static CompactionDescriptor getCompaction(Cell kv) throws IOException {
return isCompactionMarker(kv)? CompactionDescriptor.parseFrom(CellUtil.cloneValue(kv)): null;
}
/**
* Returns true if the given cell is a serialized {@link CompactionDescriptor}
*
* @see #getCompaction(Cell)
*/
public static boolean isCompactionMarker(Cell cell) {
return CellUtil.matchingColumn(cell, METAFAMILY, COMPACTION);
}
/**
* Create a bulk loader WALEdit
*
* @param hri The RegionInfo for the region in which we are bulk loading
* @param bulkLoadDescriptor The descriptor for the Bulk Loader
* @return The WALEdit for the BulkLoad
*/
public static WALEdit createBulkLoadEvent(RegionInfo hri,
WALProtos.BulkLoadDescriptor bulkLoadDescriptor) {
KeyValue kv = new KeyValue(getRowForRegion(hri), METAFAMILY, BULK_LOAD,
EnvironmentEdgeManager.currentTime(), bulkLoadDescriptor.toByteArray());
return new WALEdit().add(kv, METAFAMILY);
}
/**
* Deserialized and returns a BulkLoadDescriptor from the passed in Cell
* @param cell the key value
* @return deserialized BulkLoadDescriptor or null.
*/
public static WALProtos.BulkLoadDescriptor getBulkLoadDescriptor(Cell cell) throws IOException {
return CellUtil.matchingColumn(cell, METAFAMILY, BULK_LOAD)?
WALProtos.BulkLoadDescriptor.parseFrom(CellUtil.cloneValue(cell)): null;
}
/**
* Append the given map of family->edits to a WALEdit data structure.
* This does not write to the WAL itself.
* Note that as an optimization, we will stamp the Set of column families into the WALEdit
* to save on our having to calculate column families subsequently down in the actual WAL
* writing.
*
* @param familyMap map of family->edits
*/
public void add(Map> familyMap) {
for (Map.Entry> e: familyMap.entrySet()) {
// 'foreach' loop NOT used. See HBASE-12023 "...creates too many iterator objects."
int listSize = e.getValue().size();
// Add all Cells first and then at end, add the family rather than call {@link #add(Cell)}
// and have it clone family each time. Optimization!
for (int i = 0; i < listSize; i++) {
addCell(e.getValue().get(i));
}
addFamily(e.getKey());
}
}
private void addFamily(byte [] family) {
getOrCreateFamilies().add(family);
}
private WALEdit addCell(Cell cell) {
this.cells.add(cell);
return this;
}
}
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