IOUtils (hudi-io 0.15.0 API)

java.lang.Object
- org.apache.hudi.io.util.IOUtils

```
public class IOUtils
extends Object
```
Util methods on I/O.

Constructor Summary

Constructors
Constructor and Description

IOUtils()

Constructors
Constructor and Description
`IOUtils()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static String`	`bytesToString(byte[] bytes, int offset, int length)`
`static int`	`compareTo(byte[] bytes1, byte[] bytes2)` Lexicographically compares two byte arrays.
`static int`	`compareTo(byte[] bytes1, int offset1, int length1, byte[] bytes2, int offset2, int length2)` Lexicographically compares two byte arrays.
`static byte[]`	`copy(byte[] bytes, int offset, int length)`
`static void`	`copy(InputStream inputStream, OutputStream outputStream)`
`static int`	`decodeVarLongSize(byte value)` Parses the first byte of a variable-length encoded number (integer or long value) to determine total number of bytes representing the number on disk.
`static int`	`decodeVarLongSizeOnDisk(byte[] bytes, int offset)` Parses the first byte of a variable-length encoded number (integer or long value) to determine total number of bytes representing the number on disk.
`static DataInputStream`	`getDataInputStream(ByteBuffer byteBuffer)`
`static int`	`hashCode(byte[] bytes, int offset, int length)`
`static int`	`indexOf(byte[] array, byte[] target)` Returns the start position of the first occurrence of the specified `target` within `array`, or `-1` if there is no such occurrence.
`static boolean`	`isNegativeVarLong(byte value)` Given the first byte of a variable-length encoded number, determines the sign.
`static byte[]`	`readAsByteArray(InputStream input, int outputSize)`
`static int`	`readFully(InputStream inputStream, byte[] targetByteArray, int offset, int length)` Reads the data fully from the `InputStream` to the byte array.
`static int`	`readInt(byte[] bytes, int offset)` Reads four bytes starting from the offset in the input and returns `int` value.
`static long`	`readLong(byte[] bytes, int offset)` Reads eight bytes starting from the offset in the input and returns `long` value.
`static short`	`readShort(byte[] bytes, int offset)` Reads two bytes starting from the offset in the input and returns `short` value.
`static long`	`readVarLong(byte[] bytes, int offset)` Reads a variable-length encoded number from input bytes and returns it.
`static long`	`readVarLong(byte[] bytes, int offset, int varLongSizeOnDisk)` Reads a variable-length encoded number from input bytes and the decoded size on disk, and returns it.
`static byte[]`	`toBytes(ByteBuffer buf)` Returns a new byte array, copied from the given `buf`, from the index 0 (inclusive) to the limit (exclusive), regardless of the current position.
`static byte[]`	`toBytes(int val)` Converts an int value to a byte array using big-endian.
`static byte[]`	`toBytes(long val)` Converts a long value to a byte array using big-endian.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - IOUtils
```
public IOUtils()
```
- Method Detail
  - readInt
```
public static int readInt(byte[] bytes,
                          int offset)
```
    Reads four bytes starting from the offset in the input and returns int value.
    
    Parameters:
    
    bytes - input byte array.
    
    offset - offset to start reading.
    
    Returns:
    
    the int value.
  - readLong
```
public static long readLong(byte[] bytes,
                            int offset)
```
    Reads eight bytes starting from the offset in the input and returns long value.
    
    Parameters:
    
    bytes - input byte array.
    
    offset - offset to start reading.
    
    Returns:
    
    the long value.
  - readShort
```
public static short readShort(byte[] bytes,
                              int offset)
```
    Reads two bytes starting from the offset in the input and returns short value.
    
    Parameters:
    
    bytes - input byte array.
    
    offset - offset to start reading.
    
    Returns:
    
    the short value.
  - decodeVarLongSizeOnDisk
```
public static int decodeVarLongSizeOnDisk(byte[] bytes,
                                          int offset)
```
    Parses the first byte of a variable-length encoded number (integer or long value) to determine total number of bytes representing the number on disk.
    
    Parameters:
    
    bytes - input byte array of the encoded number.
    
    offset - offset to start reading.
    
    Returns:
    
    the total number of bytes (1 to 9) on disk.
  - decodeVarLongSize
```
public static int decodeVarLongSize(byte value)
```
    Parses the first byte of a variable-length encoded number (integer or long value) to determine total number of bytes representing the number on disk.
    
    Parameters:
    
    value - the first byte of the encoded number.
    
    Returns:
    
    the total number of bytes (1 to 9) on disk.
  - readVarLong
```
public static long readVarLong(byte[] bytes,
                               int offset)
```
    Reads a variable-length encoded number from input bytes and returns it.
    
    Parameters:
    
    bytes - input byte array.
    
    offset - offset to start reading.
    
    Returns:
    
    decoded long from the input.
  - readVarLong
```
public static long readVarLong(byte[] bytes,
                               int offset,
                               int varLongSizeOnDisk)
```
    Reads a variable-length encoded number from input bytes and the decoded size on disk, and returns it.
    
    Parameters:
    
    bytes - input byte array.
    
    offset - offset to start reading.
    
    varLongSizeOnDisk - the total number of bytes (1 to 9) on disk.
    
    Returns:
    
    decoded long from the input.
  - isNegativeVarLong
```
public static boolean isNegativeVarLong(byte value)
```
    Given the first byte of a variable-length encoded number, determines the sign.
    
    Parameters:
    
    value - the first byte.
    
    Returns:
    
    is the value negative.
  - copy
```
public static byte[] copy(byte[] bytes,
                          int offset,
                          int length)
```
    Parameters:
    
    bytes - input byte array.
    
    offset - offset to start reading.
    
    length - length of bytes to copy.
    
    Returns:
    
    a new copy of the byte array.
  - compareTo
```
public static int compareTo(byte[] bytes1,
                            byte[] bytes2)
```
    Lexicographically compares two byte arrays.
    
    Parameters:
    
    bytes1 - left operand.
    
    bytes2 - right operand.
    
    Returns:
    
    0 if equal, < 0 if left is less than right, etc.
  - compareTo
```
public static int compareTo(byte[] bytes1,
                            int offset1,
                            int length1,
                            byte[] bytes2,
                            int offset2,
                            int length2)
```
    Lexicographically compares two byte arrays.
    
    Parameters:
    
    bytes1 - left operand.
    
    bytes2 - right operand.
    
    offset1 - where to start comparing in the left buffer.
    
    offset2 - where to start comparing in the right buffer.
    
    length1 - how much to compare from the left buffer.
    
    length2 - how much to compare from the right buffer.
    
    Returns:
    
    0 if equal, < 0 if left is less than right, > 0 otherwise.
  - indexOf
```
public static int indexOf(byte[] array,
                          byte[] target)
```
    Returns the start position of the first occurrence of the specified target within array, or -1 if there is no such occurrence.
    More formally, returns the lowest index i such that the range [i, i + target.length) in array contains exactly the same elements as target.
    
    Parameters:
    
    array - the array to search for the sequence target.
    
    target - the array to search for as a sub-sequence of array.
    
    Returns:
    
    the start position if found; -1 if there is no such occurrence.
  - bytesToString
```
public static String bytesToString(byte[] bytes,
                                   int offset,
                                   int length)
```
    Parameters:
    
    bytes - input byte array.
    
    offset - offset to start reading.
    
    length - length of bytes to read.
    
    Returns:
    
    String value based on the byte array.
  - toBytes
```
public static byte[] toBytes(int val)
```
    Converts an int value to a byte array using big-endian.
    
    Parameters:
    
    val - value to convert.
    
    Returns:
    
    the byte array.
  - toBytes
```
public static byte[] toBytes(long val)
```
    Converts a long value to a byte array using big-endian.
    
    Parameters:
    
    val - value to convert.
    
    Returns:
    
    the byte array.
  - hashCode
```
public static int hashCode(byte[] bytes,
                           int offset,
                           int length)
```
    Parameters:
    
    bytes - byte array to hash.
    
    offset - offset to start hashing.
    
    length - length of bytes to hash.
    
    Returns:
    
    the generated hash code.
  - readFully
```
public static int readFully(InputStream inputStream,
                            byte[] targetByteArray,
                            int offset,
                            int length)
                     throws IOException
```
    Reads the data fully from the InputStream to the byte array.
    
    Parameters:
    
    inputStream - InputStream containing the data.
    
    targetByteArray - target byte array.
    
    offset - offset in the target byte array to start to write data.
    
    length - maximum amount of data to write.
    
    Returns:
    
    size of bytes read.
    
    Throws:
    
    IOException - upon error.
  - readAsByteArray
```
public static byte[] readAsByteArray(InputStream input,
                                     int outputSize)
                              throws IOException
```
    Throws:
    
    IOException
  - copy
```
public static void copy(InputStream inputStream,
                        OutputStream outputStream)
                 throws IOException
```
    Throws:
    
    IOException
  - getDataInputStream
```
public static DataInputStream getDataInputStream(ByteBuffer byteBuffer)
```
    Parameters:
    
    byteBuffer - ByteBuffer containing the bytes.
    
    Returns:
    
    DataInputStream based on the byte buffer.
  - toBytes
```
public static byte[] toBytes(ByteBuffer buf)
```
    Returns a new byte array, copied from the given buf, from the index 0 (inclusive) to the limit (exclusive), regardless of the current position. The position and the other index parameters are not changed.
    
    Parameters:
    
    buf - a byte buffer.
    
    Returns:
    
    the byte array.

Class IOUtils

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

IOUtils

Method Detail

readInt

readLong

readShort

decodeVarLongSizeOnDisk

decodeVarLongSize

readVarLong

readVarLong

isNegativeVarLong

copy

compareTo

compareTo

indexOf

bytesToString

toBytes

toBytes

hashCode

readFully

readAsByteArray

copy

getDataInputStream

toBytes