/**
* Copyright 2012 Twitter, Inc.
*
* 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 parquet.column.impl;
import static parquet.bytes.BytesInput.concat;
import java.io.IOException;
import parquet.Log;
import parquet.bytes.BytesUtils;
import parquet.column.ColumnDescriptor;
import parquet.column.ColumnWriter;
import parquet.column.ParquetProperties;
import parquet.column.ParquetProperties.WriterVersion;
import parquet.column.page.DictionaryPage;
import parquet.column.page.PageWriter;
import parquet.column.values.ValuesWriter;
import parquet.column.values.boundedint.DevNullValuesWriter;
import parquet.column.values.dictionary.DictionaryValuesWriter.PlainBinaryDictionaryValuesWriter;
import parquet.column.values.dictionary.DictionaryValuesWriter.PlainDoubleDictionaryValuesWriter;
import parquet.column.values.dictionary.DictionaryValuesWriter.PlainFloatDictionaryValuesWriter;
import parquet.column.values.dictionary.DictionaryValuesWriter.PlainIntegerDictionaryValuesWriter;
import parquet.column.values.dictionary.DictionaryValuesWriter.PlainLongDictionaryValuesWriter;
import parquet.column.values.plain.BooleanPlainValuesWriter;
import parquet.column.values.plain.FixedLenByteArrayPlainValuesWriter;
import parquet.column.values.plain.PlainValuesWriter;
import parquet.column.values.rle.RunLengthBitPackingHybridValuesWriter;
import parquet.io.ParquetEncodingException;
import parquet.io.api.Binary;
/**
* Writes (repetition level, definition level, value) triplets and deals with writing pages to the underlying layer.
*
* @author Julien Le Dem
*
*/
final class ColumnWriterImpl implements ColumnWriter {
private static final Log LOG = Log.getLog(ColumnWriterImpl.class);
private static final boolean DEBUG = Log.DEBUG;
private static final int INITIAL_COUNT_FOR_SIZE_CHECK = 100;
private final ColumnDescriptor path;
private final PageWriter pageWriter;
private final long pageSizeThreshold;
private ValuesWriter repetitionLevelColumn;
private ValuesWriter definitionLevelColumn;
private ValuesWriter dataColumn;
private int valueCount;
private int valueCountForNextSizeCheck;
public ColumnWriterImpl(
ColumnDescriptor path,
PageWriter pageWriter,
int pageSizeThreshold,
int initialSizePerCol,
int dictionaryPageSizeThreshold,
boolean enableDictionary,
WriterVersion writerVersion) {
this.path = path;
this.pageWriter = pageWriter;
this.pageSizeThreshold = pageSizeThreshold;
// initial check of memory usage. So that we have enough data to make an initial prediction
this.valueCountForNextSizeCheck = INITIAL_COUNT_FOR_SIZE_CHECK;
ParquetProperties parquetProps = new ParquetProperties(dictionaryPageSizeThreshold, writerVersion, enableDictionary);
this.repetitionLevelColumn = ParquetProperties.getColumnDescriptorValuesWriter(path.getMaxRepetitionLevel(), initialSizePerCol);
this.definitionLevelColumn = ParquetProperties.getColumnDescriptorValuesWriter(path.getMaxDefinitionLevel(), initialSizePerCol);
this.dataColumn = parquetProps.getValuesWriter(path, initialSizePerCol);
}
private void log(Object value, int r, int d) {
LOG.debug(path + " " + value + " r:" + r + " d:" + d);
}
/**
* Counts how many values have been written and checks the memory usage to flush the page when we reach the page threshold.
*
* We measure the memory used when we reach the mid point toward our estimated count.
* We then update the estimate and flush the page if we reached the threshold.
*
* That way we check the memory size log2(n) times.
*
*/
private void accountForValueWritten() {
++ valueCount;
if (valueCount > valueCountForNextSizeCheck) {
// not checking the memory used for every value
long memSize = repetitionLevelColumn.getBufferedSize()
+ definitionLevelColumn.getBufferedSize()
+ dataColumn.getBufferedSize();
if (memSize > pageSizeThreshold) {
// we will write the current page and check again the size at the predicted middle of next page
valueCountForNextSizeCheck = valueCount / 2;
writePage();
} else {
// not reached the threshold, will check again midway
valueCountForNextSizeCheck = (int)(valueCount + ((float)valueCount * pageSizeThreshold / memSize)) / 2 + 1;
}
}
}
private void writePage() {
if (DEBUG) LOG.debug("write page");
try {
pageWriter.writePage(
concat(repetitionLevelColumn.getBytes(), definitionLevelColumn.getBytes(), dataColumn.getBytes()),
valueCount,
repetitionLevelColumn.getEncoding(),
definitionLevelColumn.getEncoding(),
dataColumn.getEncoding());
} catch (IOException e) {
throw new ParquetEncodingException("could not write page for " + path, e);
}
repetitionLevelColumn.reset();
definitionLevelColumn.reset();
dataColumn.reset();
valueCount = 0;
}
@Override
public void writeNull(int repetitionLevel, int definitionLevel) {
if (DEBUG) log(null, repetitionLevel, definitionLevel);
repetitionLevelColumn.writeInteger(repetitionLevel);
definitionLevelColumn.writeInteger(definitionLevel);
accountForValueWritten();
}
@Override
public void write(double value, int repetitionLevel, int definitionLevel) {
if (DEBUG) log(value, repetitionLevel, definitionLevel);
repetitionLevelColumn.writeInteger(repetitionLevel);
definitionLevelColumn.writeInteger(definitionLevel);
dataColumn.writeDouble(value);
accountForValueWritten();
}
@Override
public void write(float value, int repetitionLevel, int definitionLevel) {
if (DEBUG) log(value, repetitionLevel, definitionLevel);
repetitionLevelColumn.writeInteger(repetitionLevel);
definitionLevelColumn.writeInteger(definitionLevel);
dataColumn.writeFloat(value);
accountForValueWritten();
}
@Override
public void write(Binary value, int repetitionLevel, int definitionLevel) {
if (DEBUG) log(value, repetitionLevel, definitionLevel);
repetitionLevelColumn.writeInteger(repetitionLevel);
definitionLevelColumn.writeInteger(definitionLevel);
dataColumn.writeBytes(value);
accountForValueWritten();
}
@Override
public void write(boolean value, int repetitionLevel, int definitionLevel) {
if (DEBUG) log(value, repetitionLevel, definitionLevel);
repetitionLevelColumn.writeInteger(repetitionLevel);
definitionLevelColumn.writeInteger(definitionLevel);
dataColumn.writeBoolean(value);
accountForValueWritten();
}
@Override
public void write(int value, int repetitionLevel, int definitionLevel) {
if (DEBUG) log(value, repetitionLevel, definitionLevel);
repetitionLevelColumn.writeInteger(repetitionLevel);
definitionLevelColumn.writeInteger(definitionLevel);
dataColumn.writeInteger(value);
accountForValueWritten();
}
@Override
public void write(long value, int repetitionLevel, int definitionLevel) {
if (DEBUG) log(value, repetitionLevel, definitionLevel);
repetitionLevelColumn.writeInteger(repetitionLevel);
definitionLevelColumn.writeInteger(definitionLevel);
dataColumn.writeLong(value);
accountForValueWritten();
}
@Override
public void flush() {
if (valueCount > 0) {
writePage();
}
final DictionaryPage dictionaryPage = dataColumn.createDictionaryPage();
if (dictionaryPage != null) {
if (DEBUG) LOG.debug("write dictionary");
try {
pageWriter.writeDictionaryPage(dictionaryPage);
} catch (IOException e) {
throw new ParquetEncodingException("could not write dictionary page for " + path, e);
}
dataColumn.resetDictionary();
}
}
@Override
public long getBufferedSizeInMemory() {
return repetitionLevelColumn.getBufferedSize()
+ definitionLevelColumn.getBufferedSize()
+ dataColumn.getBufferedSize()
+ pageWriter.getMemSize();
}
public long allocatedSize() {
return repetitionLevelColumn.getAllocatedSize()
+ definitionLevelColumn.getAllocatedSize()
+ dataColumn.getAllocatedSize()
+ pageWriter.allocatedSize();
}
public String memUsageString(String indent) {
StringBuilder b = new StringBuilder(indent).append(path).append(" {\n");
b.append(repetitionLevelColumn.memUsageString(indent + " r:")).append("\n");
b.append(definitionLevelColumn.memUsageString(indent + " d:")).append("\n");
b.append(dataColumn.memUsageString(indent + " data:")).append("\n");
b.append(pageWriter.memUsageString(indent + " pages:")).append("\n");
b.append(indent).append(String.format(" total: %,d/%,d", getBufferedSizeInMemory(), allocatedSize())).append("\n");
b.append(indent).append("}\n");
return b.toString();
}
}