package com.subgraph.orchid;
public interface Cell {
/** Command constant for a PADDING type cell. */
final static int PADDING = 0;
/** Command constant for a CREATE type cell. */
final static int CREATE = 1;
/** Command constant for a CREATED type cell. */
final static int CREATED = 2;
/** Command constant for a RELAY type cell. */
final static int RELAY = 3;
/** Command constant for a DESTROY type cell. */
final static int DESTROY = 4;
/** Command constant for a CREATE_FAST type cell. */
final static int CREATE_FAST = 5;
/** Command constant for a CREATED_FAST type cell. */
final static int CREATED_FAST = 6;
/** Command constant for a VERSIONS type cell. */
final static int VERSIONS = 7;
/** Command constant for a NETINFO type cell. */
final static int NETINFO = 8;
/** Command constant for a RELAY_EARLY type cell. */
final static int RELAY_EARLY = 9;
final static int VPADDING = 128;
final static int CERTS = 129;
final static int AUTH_CHALLENGE = 130;
final static int AUTHENTICATE = 131;
final static int AUTHORIZE = 132;
final static int ERROR_NONE = 0;
final static int ERROR_PROTOCOL = 1;
final static int ERROR_INTERNAL = 2;
final static int ERROR_REQUESTED = 3;
final static int ERROR_HIBERNATING = 4;
final static int ERROR_RESOURCELIMIT = 5;
final static int ERROR_CONNECTFAILED = 6;
final static int ERROR_OR_IDENTITY = 7;
final static int ERROR_OR_CONN_CLOSED = 8;
final static int ERROR_FINISHED = 9;
final static int ERROR_TIMEOUT = 10;
final static int ERROR_DESTROYED = 11;
final static int ERROR_NOSUCHSERVICE = 12;
final static int ADDRESS_TYPE_HOSTNAME = 0x00;
final static int ADDRESS_TYPE_IPV4 = 0x04;
final static int ADRESS_TYPE_IPV6 = 0x06;
/**
* The fixed size of a standard cell.
*/
final static int CELL_LEN = 512;
/**
* The length of a standard cell header.
*/
final static int CELL_HEADER_LEN = 3;
/**
* The header length for a variable length cell (ie: VERSIONS)
*/
final static int CELL_VAR_HEADER_LEN = 5;
/**
* The length of the payload space in a standard cell.
*/
final static int CELL_PAYLOAD_LEN = CELL_LEN - CELL_HEADER_LEN;
/**
* Return the circuit id field from this cell.
*
* @return The circuit id field of this cell.
*/
int getCircuitId();
/**
* Return the command field from this cell.
*
* @return The command field of this cell.
*/
int getCommand();
/**
* Set the internal pointer to the first byte after the cell header.
*/
void resetToPayload();
/**
* Return the next byte from the cell and increment the internal pointer by one byte.
*
* @return The byte at the current pointer location.
*/
int getByte();
/**
* Return the byte at the specified offset into the cell.
*
* @param index The cell offset.
* @return The byte at the specified offset.
*/
int getByteAt(int index);
/**
* Return the next 16-bit big endian value from the cell and increment the internal pointer by two bytes.
*
* @return The 16-bit short value at the current pointer location.
*/
int getShort();
/**
* Return the 16-bit big endian value at the specified offset into the cell.
*
* @param index The cell offset.
* @return The 16-bit short value at the specified offset.
*/
int getShortAt(int index);
/**
* Return the next 32-bit big endian value from the cell and increment the internal pointer by four bytes.
*
* @return The 32-bit integer value at the current pointer location.
*/
int getInt();
/**
* Copy <code>buffer.length</code> bytes from the cell into <code>buffer</code>. The data is copied starting
* from the current internal pointer location and afterwards the internal pointer is incremented by <code>buffer.length</code>
* bytes.
*
* @param buffer The array of bytes to copy the cell data into.
*/
void getByteArray(byte[] buffer);
/**
* Return the number of bytes already packed (for outgoing cells) or unpacked (for incoming cells). This is
* equivalent to the internal pointer position.
*
* @return The number of bytes already consumed from this cell.
*/
int cellBytesConsumed();
/**
* Return the number of bytes remaining between the current internal pointer and the end of the cell. If fields
* are being added to a new cell for transmission then this value indicates the remaining space in bytes for
* adding new data. If fields are being read from a received cell then this value describes the number of bytes
* which can be read without overflowing the cell.
*
* @return The number of payload bytes remaining in this cell.
*/
int cellBytesRemaining();
/**
* Store a byte at the current pointer location and increment the pointer by one byte.
*
* @param value The byte value to store.
*/
void putByte(int value);
/**
* Store a byte at the specified offset into the cell.
*
* @param index The offset in bytes into the cell.
* @param value The byte value to store.
*/
void putByteAt(int index, int value);
/**
* Store a 16-bit short value in big endian order at the current pointer location and
* increment the pointer by two bytes.
*
* @param value The 16-bit short value to store.
*/
void putShort(int value);
/**
* Store a 16-bit short value in big endian byte order at the specified offset into the cell
* and increment the pointer by two bytes.
*
* @param index The offset in bytes into the cell.
* @param value The 16-bit short value to store.
*/
void putShortAt(int index, int value);
/**
* Store a 32-bit integer value in big endian order at the current pointer location and
* increment the pointer by 4 bytes.
*
* @param value The 32-bit integer value to store.
*/
void putInt(int value);
/**
* Store the entire array <code>data</code> at the current pointer location and increment
* the pointer by <code>data.length</code> bytes.
*
* @param data The array of bytes to store in the cell.
*/
void putByteArray(byte[] data);
/**
* Store <code>length</code> bytes of the byte array <code>data</code> starting from
* <code>offset</code> into the array at the current pointer location and increment
* the pointer by <code>length</code> bytes.
*
* @param data The source array of bytes.
* @param offset The offset into the source array.
* @param length The number of bytes from the source array to store.
*/
void putByteArray(byte[] data, int offset, int length);
/**
* Return the entire cell data as a raw array of bytes. For all cells except
* <code>VERSIONS</code>, this array will be exactly <code>CELL_LEN</code> bytes long.
*
* @return The cell data as an array of bytes.
*/
byte[] getCellBytes();
void putString(String string);
}