org.apache.hadoop.hive.serde2.io.TimestampWritable Maven / Gradle / Ivy
The newest version!
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.hadoop.hive.serde2.io;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.sql.Timestamp;
import java.time.format.DateTimeFormatter;
import java.util.Date;
import org.apache.hadoop.hive.common.type.HiveDecimal;
import org.apache.hadoop.hive.ql.util.TimestampUtils;
import org.apache.hadoop.hive.serde2.ByteStream.RandomAccessOutput;
import org.apache.hadoop.hive.serde2.lazybinary.LazyBinaryUtils;
import org.apache.hadoop.hive.serde2.lazybinary.LazyBinaryUtils.VInt;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.io.WritableUtils;
/**
* TimestampWritable
* Writable equivalent of java.sq.Timestamp
*
* Timestamps are of the format
* YYYY-MM-DD HH:MM:SS.[fff...]
*
* We encode Unix timestamp in seconds in 4 bytes, using the MSB to signify
* whether the timestamp has a fractional portion.
*
* The fractional portion is reversed, and encoded as a VInt
* so timestamps with less precision use fewer bytes.
*
* 0.1 -> 1
* 0.01 -> 10
* 0.001 -> 100
*
*/
public class TimestampWritable implements WritableComparable {
static final public byte[] nullBytes = {0x0, 0x0, 0x0, 0x0};
private static final int DECIMAL_OR_SECOND_VINT_FLAG = 0x80000000;
private static final int LOWEST_31_BITS_OF_SEC_MASK = 0x7fffffff;
private static final long SEVEN_BYTE_LONG_SIGN_FLIP = 0xff80L << 48;
/** The maximum number of bytes required for a TimestampWritable */
public static final int MAX_BYTES = 13;
public static final int BINARY_SORTABLE_LENGTH = 11;
public static final DateTimeFormatter DATE_TIME_FORMAT = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
private Timestamp timestamp = new Timestamp(0);
/**
* true if data is stored in timestamp field rather than byte arrays.
* allows for lazy conversion to bytes when necessary
* false otherwise
*/
private boolean bytesEmpty;
private boolean timestampEmpty;
/* Allow use of external byte[] for efficiency */
private byte[] currentBytes;
private final byte[] internalBytes = new byte[MAX_BYTES];
private byte[] externalBytes;
private int offset;
/* Constructors */
public TimestampWritable() {
bytesEmpty = false;
currentBytes = internalBytes;
offset = 0;
clearTimestamp();
}
public TimestampWritable(byte[] bytes, int offset) {
set(bytes, offset);
}
public TimestampWritable(TimestampWritable t) {
this(t.getBytes(), 0);
}
public TimestampWritable(Timestamp t) {
set(t);
}
public void set(byte[] bytes, int offset) {
externalBytes = bytes;
this.offset = offset;
bytesEmpty = false;
currentBytes = externalBytes;
clearTimestamp();
}
public void setTime(long time) {
timestamp.setTime(time);
bytesEmpty = true;
timestampEmpty = false;
}
public void set(Timestamp t) {
if (t == null) {
timestamp.setTime(0);
timestamp.setNanos(0);
return;
}
timestamp.setTime(t.getTime());
timestamp.setNanos(t.getNanos());
bytesEmpty = true;
timestampEmpty = false;
}
public void set(TimestampWritable t) {
if (t.bytesEmpty) {
set(t.getTimestamp());
return;
}
if (t.currentBytes == t.externalBytes) {
set(t.currentBytes, t.offset);
} else {
set(t.currentBytes, 0);
}
}
public static void updateTimestamp(Timestamp timestamp, long secondsAsMillis, int nanos) {
((Date) timestamp).setTime(secondsAsMillis);
timestamp.setNanos(nanos);
}
public void setInternal(long secondsAsMillis, int nanos) {
// This is our way of documenting that we are MUTATING the contents of
// this writable's internal timestamp.
updateTimestamp(timestamp, secondsAsMillis, nanos);
bytesEmpty = true;
timestampEmpty = false;
}
private void clearTimestamp() {
timestampEmpty = true;
}
public void writeToByteStream(RandomAccessOutput byteStream) {
checkBytes();
byteStream.write(currentBytes, offset, getTotalLength());
}
/**
*
* @return seconds corresponding to this TimestampWritable
*/
public long getSeconds() {
if (!timestampEmpty) {
return TimestampUtils.millisToSeconds(timestamp.getTime());
} else if (!bytesEmpty) {
return TimestampWritable.getSeconds(currentBytes, offset);
} else {
throw new IllegalStateException("Both timestamp and bytes are empty");
}
}
/**
*
* @return nanoseconds in this TimestampWritable
*/
public int getNanos() {
if (!timestampEmpty) {
return timestamp.getNanos();
} else if (!bytesEmpty) {
return hasDecimalOrSecondVInt() ?
TimestampWritable.getNanos(currentBytes, offset + 4) : 0;
} else {
throw new IllegalStateException("Both timestamp and bytes are empty");
}
}
/**
* @return length of serialized TimestampWritable data. As a side effect, populates the internal
* byte array if empty.
*/
int getTotalLength() {
checkBytes();
return getTotalLength(currentBytes, offset);
}
public static int getTotalLength(byte[] bytes, int offset) {
int len = 4;
if (hasDecimalOrSecondVInt(bytes[offset])) {
int firstVIntLen = WritableUtils.decodeVIntSize(bytes[offset + 4]);
len += firstVIntLen;
if (hasSecondVInt(bytes[offset + 4])) {
len += WritableUtils.decodeVIntSize(bytes[offset + 4 + firstVIntLen]);
}
}
return len;
}
public Timestamp getTimestamp() {
if (timestampEmpty) {
populateTimestamp();
}
return timestamp;
}
/**
* Used to create copies of objects
* @return a copy of the internal TimestampWritable byte[]
*/
public byte[] getBytes() {
checkBytes();
int len = getTotalLength();
byte[] b = new byte[len];
System.arraycopy(currentBytes, offset, b, 0, len);
return b;
}
/**
* @return byte[] representation of TimestampWritable that is binary
* sortable (7 bytes for seconds, 4 bytes for nanoseconds)
*/
public byte[] getBinarySortable() {
byte[] b = new byte[BINARY_SORTABLE_LENGTH];
int nanos = getNanos();
// We flip the highest-order bit of the seven-byte representation of seconds to make negative
// values come before positive ones.
long seconds = getSeconds() ^ SEVEN_BYTE_LONG_SIGN_FLIP;
sevenByteLongToBytes(seconds, b, 0);
intToBytes(nanos, b, 7);
return b;
}
/**
* Given a byte[] that has binary sortable data, initialize the internal
* structures to hold that data
* @param bytes the byte array that holds the binary sortable representation
* @param binSortOffset offset of the binary-sortable representation within the buffer.
*/
public void setBinarySortable(byte[] bytes, int binSortOffset) {
// Flip the sign bit (and unused bits of the high-order byte) of the seven-byte long back.
long seconds = readSevenByteLong(bytes, binSortOffset) ^ SEVEN_BYTE_LONG_SIGN_FLIP;
int nanos = bytesToInt(bytes, binSortOffset + 7);
int firstInt = (int) seconds;
boolean hasSecondVInt = seconds < 0 || seconds > Integer.MAX_VALUE;
if (nanos != 0 || hasSecondVInt) {
firstInt |= DECIMAL_OR_SECOND_VINT_FLAG;
} else {
firstInt &= LOWEST_31_BITS_OF_SEC_MASK;
}
intToBytes(firstInt, internalBytes, 0);
setNanosBytes(nanos, internalBytes, 4, hasSecondVInt);
if (hasSecondVInt) {
LazyBinaryUtils.writeVLongToByteArray(internalBytes,
4 + WritableUtils.decodeVIntSize(internalBytes[4]),
seconds >> 31);
}
currentBytes = internalBytes;
this.offset = 0;
}
/**
* The data of TimestampWritable can be stored either in a byte[]
* or in a Timestamp object. Calling this method ensures that the byte[]
* is populated from the Timestamp object if previously empty.
*/
private void checkBytes() {
if (bytesEmpty) {
// Populate byte[] from Timestamp
convertTimestampToBytes(timestamp, internalBytes, 0);
offset = 0;
currentBytes = internalBytes;
bytesEmpty = false;
}
}
/**
*
* @return double representation of the timestamp, accurate to nanoseconds
*/
public double getDouble() {
double seconds, nanos;
if (bytesEmpty) {
seconds = TimestampUtils.millisToSeconds(timestamp.getTime());
nanos = timestamp.getNanos();
} else {
seconds = getSeconds();
nanos = getNanos();
}
return seconds + nanos / 1000000000;
}
public static long getLong(Timestamp timestamp) {
return timestamp.getTime() / 1000;
}
public void readFields(DataInput in) throws IOException {
in.readFully(internalBytes, 0, 4);
if (TimestampWritable.hasDecimalOrSecondVInt(internalBytes[0])) {
in.readFully(internalBytes, 4, 1);
int len = (byte) WritableUtils.decodeVIntSize(internalBytes[4]);
if (len > 1) {
in.readFully(internalBytes, 5, len-1);
}
long vlong = LazyBinaryUtils.readVLongFromByteArray(internalBytes, 4);
if (vlong < -1000000000 || vlong > 999999999) {
throw new IOException(
"Invalid first vint value (encoded nanoseconds) of a TimestampWritable: " + vlong +
", expected to be between -1000000000 and 999999999.");
// Note that -1000000000 is a valid value corresponding to a nanosecond timestamp
// of 999999999, because if the second VInt is present, we use the value
// (-reversedNanoseconds - 1) as the second VInt.
}
if (vlong < 0) {
// This indicates there is a second VInt containing the additional bits of the seconds
// field.
in.readFully(internalBytes, 4 + len, 1);
int secondVIntLen = (byte) WritableUtils.decodeVIntSize(internalBytes[4 + len]);
if (secondVIntLen > 1) {
in.readFully(internalBytes, 5 + len, secondVIntLen - 1);
}
}
}
currentBytes = internalBytes;
this.offset = 0;
}
public void write(DataOutput out) throws IOException {
checkBytes();
out.write(currentBytes, offset, getTotalLength());
}
public int compareTo(TimestampWritable t) {
checkBytes();
long s1 = this.getSeconds();
long s2 = t.getSeconds();
if (s1 == s2) {
int n1 = this.getNanos();
int n2 = t.getNanos();
if (n1 == n2) {
return 0;
}
return n1 - n2;
} else {
return s1 < s2 ? -1 : 1;
}
}
@Override
public boolean equals(Object o) {
return compareTo((TimestampWritable) o) == 0;
}
@Override
public String toString() {
if (timestampEmpty) {
populateTimestamp();
}
if (timestamp.getNanos() > 0) {
return timestamp.toString();
}
return timestamp.toLocalDateTime().format(DATE_TIME_FORMAT);
}
@Override
public int hashCode() {
long seconds = getSeconds();
seconds <<= 30; // the nanosecond part fits in 30 bits
seconds |= getNanos();
return (int) ((seconds >>> 32) ^ seconds);
}
private void populateTimestamp() {
long seconds = getSeconds();
int nanos = getNanos();
timestamp.setTime(seconds * 1000);
timestamp.setNanos(nanos);
}
/** Static methods **/
/**
* Gets seconds stored as integer at bytes[offset]
* @param bytes
* @param offset
* @return the number of seconds
*/
public static long getSeconds(byte[] bytes, int offset) {
int lowest31BitsOfSecondsAndFlag = bytesToInt(bytes, offset);
if (lowest31BitsOfSecondsAndFlag >= 0 || // the "has decimal or second VInt" flag is not set
!hasSecondVInt(bytes[offset + 4])) {
// The entire seconds field is stored in the first 4 bytes.
return lowest31BitsOfSecondsAndFlag & LOWEST_31_BITS_OF_SEC_MASK;
}
// We compose the seconds field from two parts. The lowest 31 bits come from the first four
// bytes. The higher-order bits come from the second VInt that follows the nanos field.
return ((long) (lowest31BitsOfSecondsAndFlag & LOWEST_31_BITS_OF_SEC_MASK)) |
(LazyBinaryUtils.readVLongFromByteArray(bytes,
offset + 4 + WritableUtils.decodeVIntSize(bytes[offset + 4])) << 31);
}
public static int getNanos(byte[] bytes, int offset) {
VInt vInt = LazyBinaryUtils.threadLocalVInt.get();
LazyBinaryUtils.readVInt(bytes, offset, vInt);
int val = vInt.value;
if (val < 0) {
// This means there is a second VInt present that specifies additional bits of the timestamp.
// The reversed nanoseconds value is still encoded in this VInt.
val = -val - 1;
}
int len = (int) Math.floor(Math.log10(val)) + 1;
// Reverse the value
int tmp = 0;
while (val != 0) {
tmp *= 10;
tmp += val % 10;
val /= 10;
}
val = tmp;
if (len < 9) {
val *= Math.pow(10, 9 - len);
}
return val;
}
/**
* Writes a Timestamp's serialized value to byte array b at the given offset
* @param t to convert to bytes
* @param b destination byte array
* @param offset destination offset in the byte array
*/
public static void convertTimestampToBytes(Timestamp t, byte[] b,
int offset) {
long millis = t.getTime();
int nanos = t.getNanos();
long seconds = TimestampUtils.millisToSeconds(millis);
boolean hasSecondVInt = seconds < 0 || seconds > Integer.MAX_VALUE;
boolean hasDecimal = setNanosBytes(nanos, b, offset+4, hasSecondVInt);
int firstInt = (int) seconds;
if (hasDecimal || hasSecondVInt) {
firstInt |= DECIMAL_OR_SECOND_VINT_FLAG;
} else {
firstInt &= LOWEST_31_BITS_OF_SEC_MASK;
}
intToBytes(firstInt, b, offset);
if (hasSecondVInt) {
LazyBinaryUtils.writeVLongToByteArray(b,
offset + 4 + WritableUtils.decodeVIntSize(b[offset + 4]),
seconds >> 31);
}
}
/**
* Given an integer representing nanoseconds, write its serialized
* value to the byte array b at offset
*
* @param nanos
* @param b
* @param offset
* @return
*/
private static boolean setNanosBytes(int nanos, byte[] b, int offset, boolean hasSecondVInt) {
int decimal = 0;
if (nanos != 0) {
int counter = 0;
while (counter < 9) {
decimal *= 10;
decimal += nanos % 10;
nanos /= 10;
counter++;
}
}
if (hasSecondVInt || decimal != 0) {
// We use the sign of the reversed-nanoseconds field to indicate that there is a second VInt
// present.
LazyBinaryUtils.writeVLongToByteArray(b, offset, hasSecondVInt ? (-decimal - 1) : decimal);
}
return decimal != 0;
}
public HiveDecimal getHiveDecimal() {
if (timestampEmpty) {
populateTimestamp();
}
return getHiveDecimal(timestamp);
}
public static HiveDecimal getHiveDecimal(Timestamp timestamp) {
// The BigDecimal class recommends not converting directly from double to BigDecimal,
// so we convert through a string...
Double timestampDouble = TimestampUtils.getDouble(timestamp);
HiveDecimal result = HiveDecimal.create(timestampDouble.toString());
return result;
}
/**
* Converts the time in seconds or milliseconds to a timestamp.
* @param time time in seconds or in milliseconds
* @return the timestamp
*/
public static Timestamp longToTimestamp(long time, boolean intToTimestampInSeconds) {
// If the time is in seconds, converts it to milliseconds first.
return new Timestamp(intToTimestampInSeconds ? time * 1000 : time);
}
public static void setTimestamp(Timestamp t, byte[] bytes, int offset) {
long seconds = getSeconds(bytes, offset);
t.setTime(seconds * 1000);
if (hasDecimalOrSecondVInt(bytes[offset])) {
t.setNanos(getNanos(bytes, offset + 4));
} else {
t.setNanos(0);
}
}
public static Timestamp createTimestamp(byte[] bytes, int offset) {
Timestamp t = new Timestamp(0);
TimestampWritable.setTimestamp(t, bytes, offset);
return t;
}
private static boolean hasDecimalOrSecondVInt(byte b) {
return (b >> 7) != 0;
}
private static boolean hasSecondVInt(byte b) {
return WritableUtils.isNegativeVInt(b);
}
private final boolean hasDecimalOrSecondVInt() {
return hasDecimalOrSecondVInt(currentBytes[offset]);
}
public final boolean hasDecimal() {
return hasDecimalOrSecondVInt() || currentBytes[offset + 4] != -1;
// If the first byte of the VInt is -1, the VInt itself is -1, indicating that there is a
// second VInt but the nanoseconds field is actually 0.
}
/**
* Writes value into dest at offset
* @param value
* @param dest
* @param offset
*/
private static void intToBytes(int value, byte[] dest, int offset) {
dest[offset] = (byte) ((value >> 24) & 0xFF);
dest[offset+1] = (byte) ((value >> 16) & 0xFF);
dest[offset+2] = (byte) ((value >> 8) & 0xFF);
dest[offset+3] = (byte) (value & 0xFF);
}
/**
* Writes value into dest at offset as a seven-byte
* serialized long number.
*/
static void sevenByteLongToBytes(long value, byte[] dest, int offset) {
dest[offset] = (byte) ((value >> 48) & 0xFF);
dest[offset+1] = (byte) ((value >> 40) & 0xFF);
dest[offset+2] = (byte) ((value >> 32) & 0xFF);
dest[offset+3] = (byte) ((value >> 24) & 0xFF);
dest[offset+4] = (byte) ((value >> 16) & 0xFF);
dest[offset+5] = (byte) ((value >> 8) & 0xFF);
dest[offset+6] = (byte) (value & 0xFF);
}
/**
*
* @param bytes
* @param offset
* @return integer represented by the four bytes in bytes
* beginning at offset
*/
private static int bytesToInt(byte[] bytes, int offset) {
return ((0xFF & bytes[offset]) << 24)
| ((0xFF & bytes[offset+1]) << 16)
| ((0xFF & bytes[offset+2]) << 8)
| (0xFF & bytes[offset+3]);
}
static long readSevenByteLong(byte[] bytes, int offset) {
// We need to shift everything 8 bits left and then shift back to populate the sign field.
return (((0xFFL & bytes[offset]) << 56)
| ((0xFFL & bytes[offset+1]) << 48)
| ((0xFFL & bytes[offset+2]) << 40)
| ((0xFFL & bytes[offset+3]) << 32)
| ((0xFFL & bytes[offset+4]) << 24)
| ((0xFFL & bytes[offset+5]) << 16)
| ((0xFFL & bytes[offset+6]) << 8)) >> 8;
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy