io.questdb.cairo.sql.PageFrame Maven / Gradle / Ivy
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*
* Copyright (c) 2014-2019 Appsicle
* Copyright (c) 2019-2024 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.
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package io.questdb.cairo.sql;
import io.questdb.cairo.BitmapIndexReader;
/**
* Represents a contiguous fragment of a table partition.
*
* When it comes to data access, page frames should not be used directly
* as it's only valid for partitions in the native format. Instead,
* a combination of {@link PageFrameAddressCache} and {@link PageFrameMemoryPool}
* should be used.
*/
public interface PageFrame {
/**
* Page frame belonging to a partition in native QDB format.
*/
byte NATIVE_FORMAT = 0;
/**
* Page frame belonging to a partition in Apache Parquet format.
*/
byte PARQUET_FORMAT = 1;
/**
* Auxiliary index page for variable-length column types, such as Varchar, String, and Binary.
*
* Can be called only for frames in native format.
*
* @param columnIndex index of variable length column
* @return contiguous memory address containing offsets for variable value entries
*/
long getAuxPageAddress(int columnIndex);
/**
* Return the size of the page frame aux vector in bytes.
*
* Can be called only for frames in native format.
*
* @param columnIndex index of column
* @return size of column in bytes
*/
long getAuxPageSize(int columnIndex);
BitmapIndexReader getBitmapIndexReader(int columnIndex, int direction);
/**
* The count of columns in the page frame. In some cases it is possible to have
* page frame with no columns.
*
* @return column count
*/
int getColumnCount();
/**
* Returns page frame format.
*
* Possible values: {@link #NATIVE_FORMAT} and {@link #PARQUET_FORMAT}.
*/
byte getFormat();
/**
* Return the address of the start of the page frame or if this page represents
* a column top (a column that was added to the table when other columns already
* had data) then return 0.
*
* Can be called only for frames in native format.
*
* @param columnIndex index of column
* @return address of column or 0 if column is empty
*/
long getPageAddress(int columnIndex);
/**
* Return the size of the page frame data vector in bytes.
*
* Can be called only for frames in native format.
*
* @param columnIndex index of column
* @return size of column in bytes
*/
long getPageSize(int columnIndex);
/**
* Return high row index within the frame's partition, exclusive.
*/
long getPartitionHi();
/**
* Return index of the partition the frame belongs to.
*/
int getPartitionIndex();
/**
* Return low row index within the frame's partition, inclusive.
*/
long getPartitionLo();
}