#include <I3Identifier.h>

Public Member Functions
	I3Identifier ()
	Constructor.
	I3Identifier (unsigned char b)
	Constructs an identifier filled with a byte.
	I3Identifier (int prefixL, int keyL)
	Constructor for variable prefix length, key length.
	I3Identifier (const I3Identifier &id)
	Copy constructor.
	I3Identifier (std::string s)
	Constructs an identifier from the hash of a string.
int	getKeyLength () const
	Returns the key length (total length) in bits.
int	getPrefixLength () const
	Returns the prefix length in bits.
void	clear ()
	Sets all bits to 0.
int	compareTo (const I3Identifier &) const
	Comparation function.
bool	operator< (const I3Identifier &) const
	"Less than" comparation function
bool	operator> (const I3Identifier &) const
	"Greater than" comparation function
bool	operator== (const I3Identifier &) const
	"Equals" comparation function
I3Identifier &	operator= (const I3Identifier &)
	Copy operator.
bool	isClear ()
	Checks if this identifier has been cleared.
bool	isMatch (const I3Identifier &id) const
	Checks if this identifier's first prefixLength bits equal those of id.
int	distanceTo (const I3Identifier &id) const
	Returns the "distance to" a identifier.
void	createFromHash (const std::string &s, const std::string &o="")
	Creates an identifier from the hash of a string.
void	createRandomKey ()
void	createRandomPrefix ()
void	createRandomSuffix ()
int	length () const
OverlayKey	asOverlayKey () const
	Creates an OverlayKey from an identifier, to be used in the overlay underneath.
void	setName (std::string s)
std::string	getName ()
	~I3Identifier ()
	Destructor.

Protected Member Functions
void	initKey (int prefixL, int keyL)
	Inits the key with a given prefix length and key length.

Protected Attributes
unsigned char *	key
	Identifier bits.
unsigned short	prefixLength
	Size of prefix in bits.
unsigned short	keyLength
	Size of identifier in bits.
std::string	name

Friends
std::ostream &	operator<< (std::ostream &os, const I3Identifier &id)
	String stream output operator.

Detailed Description

Definition at line 40 of file I3Identifier.h.

Constructor & Destructor Documentation

I3Identifier::I3Identifier ( )

Constructor.

Definition at line 36 of file I3Identifier.cc.

{
    initKey(DEFAULT_PREFIX_LENGTH, DEFAULT_KEY_LENGTH);
}

I3Identifier::I3Identifier ( unsigned char b )

Constructs an identifier filled with a byte.

Parameters

b	Byte to fill with

I3Identifier::I3Identifier	(	int	prefixL,
		int	keyL
	)

Constructor for variable prefix length, key length.

Parameters

prefixL	Prefix length
keyL	Key length

Definition at line 41 of file I3Identifier.cc.

{
    initKey(prefixL, keyL);
}

I3Identifier::I3Identifier ( const I3Identifier & id )

Copy constructor.

Parameters

id	Identifier to copy

Definition at line 46 of file I3Identifier.cc.

{
    initKey(DEFAULT_PREFIX_LENGTH, DEFAULT_KEY_LENGTH);
    *this = id;
}

I3Identifier::I3Identifier ( std::string s )

Constructs an identifier from the hash of a string.

Parameters

s	String to be hashed

Definition at line 52 of file I3Identifier.cc.

{
    initKey(DEFAULT_PREFIX_LENGTH, DEFAULT_KEY_LENGTH);
    createFromHash(s);
}

I3Identifier::~I3Identifier ( )

Destructor.

Definition at line 230 of file I3Identifier.cc.

{
    if (key == 0) {
        cout << "Warning: key already deleted." << endl;
    }
    delete[] key;
    key = 0;
}

Member Function Documentation

OverlayKey I3Identifier::asOverlayKey ( ) const

Creates an OverlayKey from an identifier, to be used in the overlay underneath.

No hashing is done, the first min(OverlayKey::keySize, keyLength) bits are copied directly.

Returns: An overlay key

Definition at line 124 of file I3Identifier.cc.

Referenced by I3::handleUDPMessage(), and I3::sendPacket().

{
    return OverlayKey(key, prefixLength / 8);
}

void I3Identifier::clear ( )

Sets all bits to 0.

Definition at line 58 of file I3Identifier.cc.

Referenced by I3Trigger::clear(), and I3SubIdentifier::setIPAddress().

{
    memset(key, 0, keyLength / 8);
}

int I3Identifier::compareTo ( const I3Identifier & id ) const

Comparation function.

Definition at line 81 of file I3Identifier.cc.

Referenced by I3Trigger::compareTo(), and I3SubIdentifier::compareTo().

{
    return memcmp(key, id.key, keyLength / 8);
}

void I3Identifier::createFromHash	(	const std::string &	s,
		const std::string &	o = `""`
	)

Creates an identifier from the hash of a string.

Parameters

s	String to be hashed to form the prefix
o	String to be hashed to form the remaining bits

Definition at line 129 of file I3Identifier.cc.

Referenced by I3HostMobility::discoverPartners(), I3LatencyStretch::handleTimerEvent(), and I3SessionClient::handleTimerEvent().

{
    uint8_t temp[20];
    CSHA1 sha1;
    int size1, size2;
    sha1.Reset();
    sha1.Update((uint8_t*)p.c_str(), p.size());
    sha1.Final();
    sha1.GetHash(temp);
    clear();
    size1 = prefixLength / 8;
    if (size1 > 20) size1 = 20;
    memcpy(key, temp, size1);
    name = p + ":0";
    if (o.size() == 0) return;
    name = p + ":" + o;
    sha1.Reset();
    sha1.Update((uint8_t*)o.c_str(), o.size());
    sha1.Final();
    sha1.GetHash(temp);
    clear();
    size2 = (keyLength - prefixLength) / 8;
    if (size2 > 20) size2 = 20;
    memcpy(key + size1, temp, size2);
}

void I3Identifier::createRandomKey ( )

Definition at line 162 of file I3Identifier.cc.

Referenced by I3BaseApp::bootstrapI3(), I3Triggers::deliver(), and I3BaseApp::retrieveClosestIdentifier().

{
    createRandomPrefix();
    createRandomSuffix();
}

void I3Identifier::createRandomPrefix ( )

Definition at line 168 of file I3Identifier.cc.

{
    for (int i = 0; i < prefixLength / 8; i++) {
        key[i] = intrand(256);
    }
}

void I3Identifier::createRandomSuffix ( )

Definition at line 175 of file I3Identifier.cc.

Referenced by I3HostMobility::discoverPartners(), I3LatencyStretch::handleTimerEvent(), I3SessionClient::handleTimerEvent(), and I3Anycast::initializeI3().

{
    for (int i = prefixLength / 8; i < keyLength / 8; i++) {
        key[i] = intrand(256);
    }
}

int I3Identifier::distanceTo ( const I3Identifier & id ) const

Returns the "distance to" a identifier.

This is used when many triggers match an identifier, to check which is the biggest prefix match. The distance is defined as the index of the byte (counting from the end) which is the first that is not equal, multiplied by 256, then added the XOR'ing of the differing byte. That way an earlier differing bits are considered "further" from later differing ones (notice that this distance is not a real metric!)

Parameters

id	Identifier to be compared to

Definition at line 113 of file I3Identifier.cc.

Referenced by I3::findClosestMatch().

{
    int index;
    for (index = 0; index < keyLength; index++) {
        if (key[index] != id.key[index]) break;
    }
    return (keyLength - index) * 256 + (key[index] ^ id.key[index]);
}

int I3Identifier::getKeyLength ( ) const

Returns the key length (total length) in bits.

Definition at line 76 of file I3Identifier.cc.

{
    return keyLength;
}

std::string I3Identifier::getName ( )

Definition at line 190 of file I3Identifier.cc.

                                {
    return name;
}

int I3Identifier::getPrefixLength ( ) const

Returns the prefix length in bits.

Definition at line 71 of file I3Identifier.cc.

{
    return prefixLength;
}

void I3Identifier::initKey	(	int	prefixL,
		int	keyL
	)

protected

Inits the key with a given prefix length and key length.

Parameters

prefixL	Prefix length
keyL	Key (identifier) length

Definition at line 29 of file I3Identifier.cc.

{
    prefixLength = prefixL;
    keyLength = keyL;
    key = new unsigned char[keyLength / 8];
}

bool I3Identifier::isClear ( )

Checks if this identifier has been cleared.

Definition at line 63 of file I3Identifier.cc.

{
    for (int i = 0; i < keyLength / 8; i++) {
        if (key[i] != 0) return true;
    }
    return false;
}

bool I3Identifier::isMatch ( const I3Identifier & id ) const

Checks if this identifier's first prefixLength bits equal those of id.

Parameters

id	Identifier to be matched against

Definition at line 108 of file I3Identifier.cc.

{
    return memcmp(key, id.key, prefixLength / 8) == 0;
}

int I3Identifier::length ( ) const

Definition at line 182 of file I3Identifier.cc.

Referenced by I3SubIdentifier::length(), and I3Trigger::length().

                               {
    return 16 + keyLength;
}

bool I3Identifier::operator< ( const I3Identifier & id ) const

"Less than" comparation function

Definition at line 86 of file I3Identifier.cc.

{
    return compareTo(id) < 0;
}

I3Identifier & I3Identifier::operator= ( const I3Identifier & id )

Copy operator.

Definition at line 101 of file I3Identifier.cc.

{
    memcpy(key, id.key, keyLength / 8);
    name = id.name;
    return *this;
}

bool I3Identifier::operator== ( const I3Identifier & id ) const

"Equals" comparation function

Definition at line 96 of file I3Identifier.cc.

{
    return compareTo(id) == 0;
}

bool I3Identifier::operator> ( const I3Identifier & id ) const

"Greater than" comparation function

Definition at line 91 of file I3Identifier.cc.

{
    return compareTo(id) > 0;
}

void I3Identifier::setName ( std::string s )

Definition at line 186 of file I3Identifier.cc.

Referenced by I3BaseApp::retrieveClosestIdentifier().

                                      {
    name = s;
}

Friends And Related Function Documentation

std::ostream& operator<<	(	std::ostream &	os,
		const I3Identifier &	id
	)

friend

String stream output operator.

Parameters

os	String stream
id	I3Identifier to be output

Returns: os parameter

Definition at line 195 of file I3Identifier.cc.

{
    bool allzeros;
    const char hex[] = "0123456789abcdef";
    string s0, s1;
    if (id.name.length() != 0) {
        os << "(" << id.name << ") ";
    }
    for (int i = 0; i < id.prefixLength / 8; i++) {
        os << hex[id.key[i] >> 4];
        os << hex[id.key[i] & 0xf];
    }
    os << ':';
    allzeros = true;
    for (int i = id.prefixLength / 8; i < id.keyLength / 8; i++) {
        if (id.key[i] != 0) {
            allzeros = false;
            break;
        }
    }
    if (allzeros) {
        os << "0...";
    } else {
        for (int i = id.prefixLength / 8; i < id.keyLength / 8; i++) {
            os << hex[id.key[i] >> 4];
            os << hex[id.key[i] & 0xf];
        }
    }
    return os;
}

Member Data Documentation

unsigned char* I3Identifier::key

protected

Identifier bits.

Definition at line 142 of file I3Identifier.h.

unsigned short I3Identifier::keyLength

protected

Size of identifier in bits.

Definition at line 148 of file I3Identifier.h.

std::string I3Identifier::name

protected

Definition at line 150 of file I3Identifier.h.

unsigned short I3Identifier::prefixLength

protected

Size of prefix in bits.

Definition at line 145 of file I3Identifier.h.

The documentation for this class was generated from the following files:

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation