io.questdb.cairo.ColumnVersionReader Maven / Gradle / Ivy
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*
* Copyright (c) 2014-2019 Appsicle
* Copyright (c) 2019-2023 QuestDB
*
* Licensed 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 io.questdb.cairo;
import io.questdb.cairo.vm.Vm;
import io.questdb.cairo.vm.api.MemoryCMR;
import io.questdb.cairo.vm.api.MemoryR;
import io.questdb.cairo.vm.api.MemoryW;
import io.questdb.log.Log;
import io.questdb.log.LogFactory;
import io.questdb.std.*;
import io.questdb.std.datetime.millitime.MillisecondClock;
import io.questdb.std.str.LPSZ;
import java.io.Closeable;
public class ColumnVersionReader implements Closeable, Mutable {
public static final int BLOCK_SIZE = 4;
public static final int BLOCK_SIZE_BYTES = BLOCK_SIZE * Long.BYTES;
public static final int BLOCK_SIZE_MSB = Numbers.msb(BLOCK_SIZE);
// PARTITION_TIMESTAMP_OFFSET = 0;
public static final int COLUMN_INDEX_OFFSET = 1;
public static final int COLUMN_NAME_TXN_OFFSET = 2;
public static final int COLUMN_TOP_OFFSET = 3;
public static final long COL_TOP_DEFAULT_PARTITION = Long.MIN_VALUE;
public static final int OFFSET_VERSION_64 = 0;
public static final int OFFSET_OFFSET_A_64 = OFFSET_VERSION_64 + 8;
public static final int OFFSET_SIZE_A_64 = OFFSET_OFFSET_A_64 + 8;
public static final int OFFSET_OFFSET_B_64 = OFFSET_SIZE_A_64 + 8;
public static final int OFFSET_SIZE_B_64 = OFFSET_OFFSET_B_64 + 8;
public static final int HEADER_SIZE = OFFSET_SIZE_B_64 + 8;
static final int TIMESTAMP_ADDED_PARTITION_OFFSET = COLUMN_TOP_OFFSET;
private final static Log LOG = LogFactory.getLog(ColumnVersionReader.class);
protected final LongList cachedList = new LongList();
private MemoryCMR mem;
private boolean ownMem;
private long version;
@Override
public void clear() {
if (ownMem) {
mem.close();
}
}
@Override
public void close() {
clear();
}
public void dumpTo(MemoryW mem) {
mem.putLong(OFFSET_VERSION_64, version);
boolean areaA = (version & 1L) == 0L;
final long offset = HEADER_SIZE;
mem.putLong(areaA ? OFFSET_OFFSET_A_64 : OFFSET_OFFSET_B_64, offset);
final long size = (long) (cachedList.size() / BLOCK_SIZE) * BLOCK_SIZE_BYTES;
mem.putLong(areaA ? OFFSET_SIZE_A_64 : OFFSET_SIZE_B_64, size);
int i = 0;
long p = offset;
long lim = offset + size;
while (p < lim) {
mem.putLong(p, cachedList.getQuick(i));
mem.putLong(p + COLUMN_INDEX_OFFSET * Long.BYTES, cachedList.getQuick(i + COLUMN_INDEX_OFFSET));
mem.putLong(p + COLUMN_NAME_TXN_OFFSET * Long.BYTES, cachedList.getQuick(i + COLUMN_NAME_TXN_OFFSET));
mem.putLong(p + COLUMN_TOP_OFFSET * Long.BYTES, cachedList.getQuick(i + COLUMN_TOP_OFFSET));
i += BLOCK_SIZE;
p += BLOCK_SIZE_BYTES;
}
}
public LongList getCachedList() {
return cachedList;
}
public long getColumnNameTxn(long partitionTimestamp, int columnIndex) {
int versionRecordIndex = getRecordIndex(partitionTimestamp, columnIndex);
return versionRecordIndex > -1 ? cachedList.getQuick(versionRecordIndex + COLUMN_NAME_TXN_OFFSET) : getDefaultColumnNameTxn(columnIndex);
}
public long getColumnNameTxnByIndex(int versionRecordIndex) {
return versionRecordIndex > -1 ? cachedList.getQuick(versionRecordIndex + COLUMN_NAME_TXN_OFFSET) : -1L;
}
/**
* Checks that column exists in the partition and returns the column top
*
* @param partitionTimestamp timestamp of the partition
* @param columnIndex column index
* @return column top in the partition or -1 if column does not exist in the partition
*/
public long getColumnTop(long partitionTimestamp, int columnIndex) {
// Check if there is explicit record for this partitionTimestamp / columnIndex combination
int recordIndex = getRecordIndex(partitionTimestamp, columnIndex);
if (recordIndex > -1L) {
return cachedList.getQuick(recordIndex + COLUMN_TOP_OFFSET);
}
// Check if column has been already added before this partition
long columnTopDefaultPartition = getColumnTopPartitionTimestamp(columnIndex);
if (columnTopDefaultPartition <= partitionTimestamp) {
return 0;
}
// This column does not exist in the partition
return -1L;
}
public long getColumnTopByIndex(int versionRecordIndex) {
return versionRecordIndex > -1 ? cachedList.getQuick(versionRecordIndex + COLUMN_TOP_OFFSET) : 0L;
}
/**
* Get partition when the column was added first into the table.
* All partitions before that one should not have any data in the column
* All partitions after that will have 0 column top (column fully exists)
* Exception is when O3 commit can overwrite column top for any partition where the column did not exist
* with concrete column top value
*
* @param columnIndex column index
* @return the partition timestamp where column added or Long.MIN_VALUE if column was present from table creation
*/
public long getColumnTopPartitionTimestamp(int columnIndex) {
int index = getRecordIndex(COL_TOP_DEFAULT_PARTITION, columnIndex);
return index > -1 ? getColumnTopByIndex(index) : Long.MIN_VALUE;
}
/**
* Returns the column top without checking that column exists in the partition
*
* @param partitionTimestamp timestamp of the partition
* @param columnIndex column index
* @return column top in the partition or 0 if column does not exist in the partition or column exists with no column top
*/
public long getColumnTopQuick(long partitionTimestamp, int columnIndex) {
int index = getRecordIndex(partitionTimestamp, columnIndex);
return getColumnTopByIndex(index);
}
public long getDefaultColumnNameTxn(int columnIndex) {
int index = getRecordIndex(COL_TOP_DEFAULT_PARTITION, columnIndex);
return index > -1 ? getColumnNameTxnByIndex(index) : -1L;
}
public int getRecordIndex(long partitionTimestamp, int columnIndex) {
int index = cachedList.binarySearchBlock(BLOCK_SIZE_MSB, partitionTimestamp, BinarySearch.SCAN_UP);
if (index > -1) {
final int sz = cachedList.size();
for (; index < sz && cachedList.getQuick(index) == partitionTimestamp; index += BLOCK_SIZE) {
final long thisIndex = cachedList.getQuick(index + COLUMN_INDEX_OFFSET);
if (thisIndex == columnIndex) {
return index;
}
if (thisIndex > columnIndex) {
break;
}
}
}
return -1;
}
public long getVersion() {
return version;
}
public ColumnVersionReader ofRO(FilesFacade ff, LPSZ fileName) {
version = -1;
if (this.mem == null || !ownMem) {
this.mem = Vm.getCMRInstance();
}
this.mem.of(ff, fileName, 0, HEADER_SIZE, MemoryTag.MMAP_TABLE_READER);
ownMem = true;
return this;
}
public void ofRO(MemoryCMR mem) {
if (this.mem != null && ownMem) {
this.mem.close();
}
this.mem = mem;
ownMem = false;
version = -1;
}
public void readSafe(MillisecondClock microsecondClock, long spinLockTimeout) {
final long tick = microsecondClock.getTicks();
while (true) {
long version = unsafeGetVersion();
if (version == this.version) {
return;
}
Unsafe.getUnsafe().loadFence();
final long offset;
final long size;
final boolean areaA = (version & 1L) == 0;
if (areaA) {
offset = mem.getLong(OFFSET_OFFSET_A_64);
size = mem.getLong(OFFSET_SIZE_A_64);
} else {
offset = mem.getLong(OFFSET_OFFSET_B_64);
size = mem.getLong(OFFSET_SIZE_B_64);
}
Unsafe.getUnsafe().loadFence();
if (version == unsafeGetVersion()) {
mem.resize(offset + size);
readUnsafe(offset, size, cachedList, mem);
Unsafe.getUnsafe().loadFence();
if (version == unsafeGetVersion()) {
this.version = version;
LOG.debug().$("read clean version ").$(version).$(", offset ").$(offset).$(", size ").$(size).$();
return;
}
}
if (microsecondClock.getTicks() - tick > spinLockTimeout) {
LOG.error().$("Column Version read timeout [timeout=").$(spinLockTimeout).utf8("ms]").$();
throw CairoException.critical(0).put("Column Version read timeout");
}
Os.pause();
LOG.debug().$("read dirty version ").$(version).$(", retrying").$();
}
}
public long readUnsafe() {
long version = mem.getLong(OFFSET_VERSION_64);
boolean areaA = (version & 1L) == 0L;
long offset = areaA ? mem.getLong(OFFSET_OFFSET_A_64) : mem.getLong(OFFSET_OFFSET_B_64);
long size = areaA ? mem.getLong(OFFSET_SIZE_A_64) : mem.getLong(OFFSET_SIZE_B_64);
mem.resize(offset + size);
readUnsafe(offset, size, cachedList, mem);
return version;
}
private static void readUnsafe(long offset, long areaSize, LongList cachedList, MemoryR mem) {
long lim = offset + areaSize;
mem.extend(lim);
int i = 0;
long p = offset;
assert areaSize % BLOCK_SIZE_BYTES == 0;
cachedList.setPos((int) ((areaSize / BLOCK_SIZE_BYTES) * BLOCK_SIZE));
while (p < lim) {
cachedList.setQuick(i, mem.getLong(p));
cachedList.setQuick(i + COLUMN_INDEX_OFFSET, mem.getLong(p + COLUMN_INDEX_OFFSET * Long.BYTES));
cachedList.setQuick(i + COLUMN_NAME_TXN_OFFSET, mem.getLong(p + COLUMN_NAME_TXN_OFFSET * Long.BYTES));
cachedList.setQuick(i + COLUMN_TOP_OFFSET, mem.getLong(p + COLUMN_TOP_OFFSET * Long.BYTES));
i += BLOCK_SIZE;
p += BLOCK_SIZE_BYTES;
}
}
private long unsafeGetVersion() {
return mem.getLong(OFFSET_VERSION_64);
}
}
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