com.ericsson.otp.erlang
Class OtpInputStream

java.lang.Object
  java.io.InputStream
      java.io.ByteArrayInputStream
          com.ericsson.otp.erlang.OtpInputStream

All Implemented Interfaces:

java.io.Closeable

public class OtpInputStream
extends java.io.ByteArrayInputStream

Provides a stream for decoding Erlang terms from external format.

Note that this class is not synchronized, if you need synchronization you must provide it yourself.

Field Summary

static int

DECODE_INT_LISTS_AS_STRINGS

Fields inherited from class java.io.ByteArrayInputStream

buf, count, mark, pos

Constructor Summary

OtpInputStream(byte[] buf)

OtpInputStream(byte[] buf, int flags)
Create a stream from a buffer containing encoded Erlang terms.

OtpInputStream(byte[] buf, int offset, int length, int flags)
Create a stream from a buffer containing encoded Erlang terms at the given offset and length.

Method Summary

static long	byte_array_to_long(byte[] b, boolean unsigned)
int	getPos() Get the current position in the stream.
int	peek() Alias for peek1()
int	peek1() Look ahead one position in the stream without consuming the byte found there.
int	peek1skip_version()
OtpErlangObject	read_any() Read an arbitrary Erlang term from the stream.
java.lang.String	read_atom() Read an Erlang atom from the stream.
byte[]	read_binary() Read an Erlang binary from the stream.
byte[]	read_bitstr(int[] pad_bits) Read an Erlang bitstr from the stream.
boolean	read_boolean() Read an Erlang atom from the stream and interpret the value as a boolean.
byte	read_byte() Read one byte from the stream.
char	read_char() Read a character from the stream.
OtpErlangObject	read_compressed() Read a compressed term from the stream
double	read_double() Read an Erlang float from the stream.
OtpErlangExternalFun	read_external_fun()
float	read_float() Read an Erlang float from the stream.
OtpErlangFun	read_fun()
int	read_int() Read an integer from the stream.
byte[]	read_integer_byte_array() Read an integer from the stream.
int	read_list_head() Read a list header from the stream.
long	read_long() Read a long from the stream.
long	read_long(boolean unsigned)
int	read_nil() Read an empty list from the stream.
OtpErlangPid	read_pid() Read an Erlang PID from the stream.
OtpErlangPort	read_port() Read an Erlang port from the stream.
OtpErlangRef	read_ref() Read an Erlang reference from the stream.
short	read_short() Read a short from the stream.
java.lang.String	read_string() Read a string from the stream.
int	read_tuple_head() Read a tuple header from the stream.
int	read_uint() Read an unsigned integer from the stream.
long	read_ulong() Read an unsigned long from the stream.
short	read_ushort() Read an unsigned short from the stream.
int	read1() Read a one byte integer from the stream.
int	read1skip_version()
int	read2BE() Read a two byte big endian integer from the stream.
int	read2LE() Read a two byte little endian integer from the stream.
int	read4BE() Read a four byte big endian integer from the stream.
int	read4LE() Read a four byte little endian integer from the stream.
long	readBE(int n) Read a bigendian integer from the stream.
long	readLE(int n) Read a little endian integer from the stream.
int	readN(byte[] buf) Read an array of bytes from the stream.
int	readN(byte[] buf, int off, int len) Read an array of bytes from the stream.
int	setPos(int pos) Set the current position in the stream.

Methods inherited from class java.io.ByteArrayInputStream

available, close, mark, markSupported, read, read, reset, skip

Methods inherited from class java.io.InputStream

read

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DECODE_INT_LISTS_AS_STRINGS

public static int DECODE_INT_LISTS_AS_STRINGS

Constructor Detail

OtpInputStream

public OtpInputStream(byte[] buf)

Parameters:

buf -

OtpInputStream

public OtpInputStream(byte[] buf,
                      int flags)

Create a stream from a buffer containing encoded Erlang terms.

Parameters:

flags -

OtpInputStream

public OtpInputStream(byte[] buf,
                      int offset,
                      int length,
                      int flags)

Create a stream from a buffer containing encoded Erlang terms at the given offset and length.

Parameters:

flags -

Method Detail

getPos

public int getPos()

Get the current position in the stream.

Returns:

the current position in the stream.

setPos

public int setPos(int pos)

Set the current position in the stream.

Parameters:

pos - the position to move to in the stream. If pos indicates a position beyond the end of the stream, the position is move to the end of the stream instead. If pos is negative, the position is moved to the beginning of the stream instead.

Returns:

the previous position in the stream.

readN

public int readN(byte[] buf)
          throws OtpErlangDecodeException

Read an array of bytes from the stream. The method reads at most buf.length bytes from the input stream.

Returns:

the number of bytes read.

Throws:

OtpErlangDecodeException - if the next byte cannot be read.

readN

public int readN(byte[] buf,
                 int off,
                 int len)
          throws OtpErlangDecodeException

Read an array of bytes from the stream. The method reads at most len bytes from the input stream into offset off of the buffer.

Returns:

the number of bytes read.

Throws:

OtpErlangDecodeException - if the next byte cannot be read.

peek

public int peek()
         throws OtpErlangDecodeException

Alias for peek1()

Throws:

OtpErlangDecodeException

peek1

public int peek1()
          throws OtpErlangDecodeException

Look ahead one position in the stream without consuming the byte found there.

Returns:

the next byte in the stream, as an integer.

Throws:

OtpErlangDecodeException - if the next byte cannot be read.

peek1skip_version

public int peek1skip_version()
                      throws OtpErlangDecodeException

Throws:

OtpErlangDecodeException

read1

public int read1()
          throws OtpErlangDecodeException

Read a one byte integer from the stream.

Returns:

the byte read, as an integer.

Throws:

OtpErlangDecodeException - if the next byte cannot be read.

read1skip_version

public int read1skip_version()
                      throws OtpErlangDecodeException

Throws:

OtpErlangDecodeException

read2BE

public int read2BE()
            throws OtpErlangDecodeException

Read a two byte big endian integer from the stream.

Returns:

the bytes read, converted from big endian to an integer.

Throws:

OtpErlangDecodeException - if the next byte cannot be read.

read4BE

public int read4BE()
            throws OtpErlangDecodeException

Read a four byte big endian integer from the stream.

Returns:

the bytes read, converted from big endian to an integer.

Throws:

OtpErlangDecodeException - if the next byte cannot be read.

read2LE

public int read2LE()
            throws OtpErlangDecodeException

Read a two byte little endian integer from the stream.

Returns:

the bytes read, converted from little endian to an integer.

Throws:

OtpErlangDecodeException - if the next byte cannot be read.

read4LE

public int read4LE()
            throws OtpErlangDecodeException

Read a four byte little endian integer from the stream.

Returns:

the bytes read, converted from little endian to an integer.

Throws:

OtpErlangDecodeException - if the next byte cannot be read.

readLE

public long readLE(int n)
            throws OtpErlangDecodeException

Read a little endian integer from the stream.

Parameters:

n - the number of bytes to read

Returns:

the bytes read, converted from little endian to an integer.

Throws:

OtpErlangDecodeException - if the next byte cannot be read.

readBE

public long readBE(int n)
            throws OtpErlangDecodeException

Read a bigendian integer from the stream.

Parameters:

n - the number of bytes to read

Returns:

the bytes read, converted from big endian to an integer.

Throws:

OtpErlangDecodeException - if the next byte cannot be read.

read_boolean

public boolean read_boolean()
                     throws OtpErlangDecodeException

Read an Erlang atom from the stream and interpret the value as a boolean.

Returns:

true if the atom at the current position in the stream contains the value 'true' (ignoring case), false otherwise.

Throws:

OtpErlangDecodeException - if the next term in the stream is not an atom.

read_atom

public java.lang.String read_atom()
                           throws OtpErlangDecodeException

Read an Erlang atom from the stream.

Returns:

a String containing the value of the atom.

Throws:

OtpErlangDecodeException - if the next term in the stream is not an atom.

read_binary

public byte[] read_binary()
                   throws OtpErlangDecodeException

Read an Erlang binary from the stream.

Returns:

a byte array containing the value of the binary.

Throws:

OtpErlangDecodeException - if the next term in the stream is not a binary.

read_bitstr

public byte[] read_bitstr(int[] pad_bits)
                   throws OtpErlangDecodeException

Read an Erlang bitstr from the stream.

Parameters:

pad_bits - an int array whose first element will be set to the number of pad bits in the last byte.

Returns:

a byte array containing the value of the bitstr.

Throws:

OtpErlangDecodeException - if the next term in the stream is not a bitstr.

read_float

public float read_float()
                 throws OtpErlangDecodeException

Read an Erlang float from the stream.

Returns:

the float value.

Throws:

OtpErlangDecodeException - if the next term in the stream is not a float.

read_double

public double read_double()
                   throws OtpErlangDecodeException

Read an Erlang float from the stream.

Returns:

the float value, as a double.

Throws:

OtpErlangDecodeException - if the next term in the stream is not a float.

read_byte

public byte read_byte()
               throws OtpErlangDecodeException

Read one byte from the stream.

Returns:

the byte read.

Throws:

OtpErlangDecodeException - if the next byte cannot be read.

read_char

public char read_char()
               throws OtpErlangDecodeException

Read a character from the stream.

Returns:

the character value.

Throws:

OtpErlangDecodeException - if the next term in the stream is not an integer that can be represented as a char.

read_uint

public int read_uint()
              throws OtpErlangDecodeException

Read an unsigned integer from the stream.

Returns:

the integer value.

Throws:

OtpErlangDecodeException - if the next term in the stream can not be represented as a positive integer.

read_int

public int read_int()
             throws OtpErlangDecodeException

Read an integer from the stream.

Returns:

the integer value.

Throws:

OtpErlangDecodeException - if the next term in the stream can not be represented as an integer.

read_ushort

public short read_ushort()
                  throws OtpErlangDecodeException

Read an unsigned short from the stream.

Returns:

the short value.

Throws:

OtpErlangDecodeException - if the next term in the stream can not be represented as a positive short.

read_short

public short read_short()
                 throws OtpErlangDecodeException

Read a short from the stream.

Returns:

the short value.

Throws:

OtpErlangDecodeException - if the next term in the stream can not be represented as a short.

read_ulong

public long read_ulong()
                throws OtpErlangDecodeException

Read an unsigned long from the stream.

Returns:

the long value.

Throws:

OtpErlangDecodeException - if the next term in the stream can not be represented as a positive long.

read_long

public long read_long()
               throws OtpErlangDecodeException

Read a long from the stream.

Returns:

the long value.

Throws:

OtpErlangDecodeException - if the next term in the stream can not be represented as a long.

read_long

public long read_long(boolean unsigned)
               throws OtpErlangDecodeException

Throws:

OtpErlangDecodeException

read_integer_byte_array

public byte[] read_integer_byte_array()
                               throws OtpErlangDecodeException

Read an integer from the stream.

Returns:

the value as a big endian 2's complement byte array.

Throws:

OtpErlangDecodeException - if the next term in the stream is not an integer.

byte_array_to_long

public static long byte_array_to_long(byte[] b,
                                      boolean unsigned)
                               throws OtpErlangDecodeException

Throws:

OtpErlangDecodeException

read_list_head

public int read_list_head()
                   throws OtpErlangDecodeException

Read a list header from the stream.

Returns:

the arity of the list.

Throws:

OtpErlangDecodeException - if the next term in the stream is not a list.

read_tuple_head

public int read_tuple_head()
                    throws OtpErlangDecodeException

Read a tuple header from the stream.

Returns:

the arity of the tuple.

Throws:

OtpErlangDecodeException - if the next term in the stream is not a tuple.

read_nil

public int read_nil()
             throws OtpErlangDecodeException

Read an empty list from the stream.

Returns:

zero (the arity of the list).

Throws:

OtpErlangDecodeException - if the next term in the stream is not an empty list.

read_pid

public OtpErlangPid read_pid()
                      throws OtpErlangDecodeException

Read an Erlang PID from the stream.

Returns:

the value of the PID.

Throws:

OtpErlangDecodeException - if the next term in the stream is not an Erlang PID.

read_port

public OtpErlangPort read_port()
                        throws OtpErlangDecodeException

Read an Erlang port from the stream.

Returns:

the value of the port.

Throws:

OtpErlangDecodeException - if the next term in the stream is not an Erlang port.

read_ref

public OtpErlangRef read_ref()
                      throws OtpErlangDecodeException

Read an Erlang reference from the stream.

Returns:

the value of the reference

Throws:

OtpErlangDecodeException - if the next term in the stream is not an Erlang reference.

read_fun

public OtpErlangFun read_fun()
                      throws OtpErlangDecodeException

Throws:

OtpErlangDecodeException

read_external_fun

public OtpErlangExternalFun read_external_fun()
                                       throws OtpErlangDecodeException

Throws:

OtpErlangDecodeException

read_string

public java.lang.String read_string()
                             throws OtpErlangDecodeException

Read a string from the stream.

Returns:

the value of the string.

Throws:

OtpErlangDecodeException - if the next term in the stream is not a string.

read_compressed

public OtpErlangObject read_compressed()
                                throws OtpErlangDecodeException

Read a compressed term from the stream

Returns:

the resulting uncompressed term.

Throws:

OtpErlangDecodeException - if the next term in the stream is not a compressed term.

read_any

public OtpErlangObject read_any()
                         throws OtpErlangDecodeException

Read an arbitrary Erlang term from the stream.

Returns:

the Erlang term.

Throws:

OtpErlangDecodeException - if the stream does not contain a known Erlang type at the next position.