Handling 64-bit Integers
64-bit Integers
Lua numbers are floating points (doubles) internally, not integers; thus while they can represent incredibly large numbers, above 2^53 they lose integral precision - they can't represent every whole integer value. For example if you set a lua variable to the number 9007199254740992 and tried to increment it by 1, you'd get the same number because it can't represent 9007199254740993 (only the even number 9007199254740994).
Therefore, in order to count higher than 2^53 in integers, we need a true integer type. The way this is done is with an explicit 'Int64' or 'UInt64' object (i.e., Lua userdata). This object has metamethods for all of the math and comparison operators, so you can handle it like any number variable. For the math operators, it can even be mixed with plain Lua numbers.
For example 'my64num = my64num + 1' will work even if 'my64num' is a Int64 or UInt64 object. Note that comparison operators ('==','<=','>',etc.) will not work with plain numbers - only other Int64/UInt64 objects. This is a limitation of Lua itself, in terms of how it handles operator overloading.
Previous to Wireshark release 1.11, Int64 and UInt64 could only be created by tvbrange:int64() or tvbrange:le_int64(), or tvbrange:uint64() or tvbrange:le_uint64() or tvbrange:bitfield(), and had only a couple functions (the metamethods tostring() and concat()). All of the functions on this page are only available starting in Wireshark 1.11 and higher.
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Many of the UInt64/Int64 functions accept a Lua number as an argument. You should be very careful to never use Lua numbers bigger than 32-bits (i.e., the number value 4,294,967,295 or the literal 0xFFFFFFFF) for such arguments, because Lua itself does not handle bigger numbers consistently across platforms (32-bit vs. 64-bit systems), and because a Lua number is a C-code double which cannot have more than 53 bits of precision. Instead, use a Int64 or UInt64 for the argument.
For example, do this:
1 local mynum = UInt64(0x2b89dd1e, 0x3f91df0b)
...instead of this:
And do this:
1 local masked = mynum:band(UInt64(0, 0xFFFFFFFF))
...instead of this:
Int64
An Int64 represents a signed 64-bit integer.
function |
description |
Creates an Int64 object |
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Creates an Int64 of the max value |
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Creates an Int64 of the min value |
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Decodes an 8-byte Lua string to an Int64 |
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Encodes the Int64 into an 8-byte Lua string |
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Creates an Int64 from a hex string |
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Gets a hex string from a Int64 |
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Gets a Lua number of the Int64 value |
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Gets the high 32-bit number of the Int64 value |
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Gets the lower 32-bit number of the Int64 value |
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Gets the bitwise 'not' of the Int64 value |
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Gets the bitwise 'and' of the Int64 values |
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Gets the bitwise 'or' of the Int64 values |
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Gets the bitwise 'xor' of the Int64 values |
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Gets the bitwise logical left-shift the Int64 value |
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Gets the bitwise logical right-shift the Int64 value |
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Gets the bitwise arithmetic right-shift the Int64 value |
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Gets the bitwise left rotation of the Int64 value |
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Gets the bitwise right rotation of the Int64 value |
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Gets the byte swap of the Int64 value |
metamethod |
calling function |
description |
tostring() |
Gets a digit string of the Int64 value |
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- |
Gets the negative of the Int64 value |
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+ |
Gets the addition of the Int64 with another Int64/UInt64/number |
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- |
Gets the subtraction of the Int64 with another Int64/UInt64/number |
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* |
Gets the multiplication of the Int64 with another Int64/UInt64/number |
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/ |
Gets the integer division of the Int64 with another Int64/UInt64/number |
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% |
Gets the remainder of division of the Int64 with another Int64/UInt64/number |
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^ |
Gets the power of the Int64 to another Int64/UInt64/number |
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== |
Returns true if the Int64 equals another Int64/UInt64/number |
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< |
Returns true if the Int64 is less than another Int64/UInt64/number |
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<= |
Returns true if the Int64 is less than or equal to another Int64/UInt64/number |
Int64.new([num [,high_num]])
Description
Creates a new Int64 object.
Parameters
num (optional) : number|Int64|UInt64|string
A number, UInt64, Int64, or string of ascii digits to assign the value of the new Int64. Defaults to 0. If high_num is given, then this must be a number type, and will only be the lower 32-bits of the integer.
high_num (optional) : number
- The number to set the high-order 32 bits of the 64-bit integer.
Returns
Int64 : The created Int64
Int64.max()
Description
Creates an Int64 of the max possible (positive) value. In other words, this should return an Int64 object of the number 9,223,372,036,854,775,807.
Returns
Int64 : The created Int64
Int64.min()
Description
Creates an Int64 of the min possible (negative) value. In other words, this should return an Int64 object of the number -9,223,372,036,854,775,808.
Returns
Int64 : The created Int64
Int64.decode(string [,endian])
Description
- Decodes an 8-byte Lua string, using given endianess, into a new Int64 object. The default endianess is host-order, which is not portable across platforms.
Parameters
string : string
- The Lua string containing a binary 64-bit integer
endian (optional) : boolean
- If set to true then little-endian is used, if false then big-endian; if missing/nil (default), native host endian.
Returns
Int64 : The created Int64, or nil on failure.
int64:encode([endian])
Description
- Encodes the Int64 number into an 8-byte Lua string, using given endianess. The default endianess is host-order, which is not portable across platforms.
Parameters
endian (optional) : boolean
- If set to true then little-endian is used, if false then big-endian; if missing/nil (default), native host endian.
Returns
string : The created Lua 8-byte string.
Int64.fromhex(hex)
Description
- Creates an Int64 object from the given hex string. The hex letter may be either upper or lower-case, but without a leading '0x' nor separators between hex characters.
Parameters
hex : string
- The hex-ascii string to create an Int64 from.
Returns
Int64 : The created Int64
int64:tohex([numbytes])
Description
- Returns a hex string of the Int64 value. The hex letters will be lower-case, without a leading '0x' nor separators between hex characters.
Parameters
numbytes (optional) : number
- The number of hex-chars/nibbles to generate, negative means uppercase (default=16).
Returns
string : The hex string.
int64:tonumber()
Description
- Returns a Lua number of the Int64 value - this may lose precision, if the number is greater than 2^53.
Returns
number : The Lua number value.
int64:higher()
Description
- Returns a Lua number of the higher 32-bits of the Int64 value. A negative Int64 will return a negative Lua number.
Returns
number : The Lua number value.
int64:lower()
Description
- Returns a Lua number of the lower 32-bits of the Int64 value. (always positive)
Returns
number : The Lua number value.
int64:bnot()
Description
- Returns a Int64 of the bitwise 'not' operation.
Returns
Int64 : The created Int64.
int64:band(arg1 [, arg2 [, ...]])
Description
- Returns a Int64 of the bitwise 'and' operation, with the given number/Int64/UInt64. Note that multiple arguments are allowed.
Parameters
arg1 : number|Int64|UInt64|string
- The number/Int64/UInt64/hex-string to bitwise 'and' the Int64 with.
Returns
Int64 : The created Int64.
int64:bor(arg1 [, arg2 [, ...]])
Description
- Returns a Int64 of the bitwise 'or' operation, with the given number/Int64/UInt64. Note that multiple arguments are allowed.
Parameters
arg1 : number|Int64|UInt64|string
- The number/Int64/UInt64/hex-string to bitwise 'or' the Int64 with.
Returns
Int64 : The created Int64.
int64:bxor(arg1 [, arg2 [, ...]])
Description
- Returns a Int64 of the bitwise 'xor' operation, with the given number/Int64/UInt64. Note that multiple arguments are allowed.
Parameters
arg1 : number|Int64|UInt64|string
- The number of bits to left-shift by (1-63).
Returns
Int64 : The created Int64.
int64:lshift(numbits)
Description
- Returns a Int64 of the bitwise logical left-shift operation, by the given number of bits.
Parameters
numbits : number
- The number of bits to left-shift by.
Returns
Int64 : The created Int64.
int64:rshift(numbits)
Description
- Returns a Int64 of the bitwise logical right-shift operation, by the given number of bits.
Parameters
numbits : number
- The number of bits to right-shift by.
Returns
Int64 : The created Int64.
int64:arshift(numbits)
Description
- Returns a Int64 of the bitwise arithmetic right-shift operation, by the given number of bits.
Parameters
numbits : number
- The number of bits to arithmetic right-shift by.
Returns
Int64 : The created Int64.
int64:rol(numbits)
Description
- Returns a Int64 of the bitwise left rotation operation, by the given number of bits (up to 63).
Parameters
numbits : number
- The number of bits to roll left by.
Returns
Int64 : The created Int64.
int64:ror(numbits)
Description
- Returns a Int64 of the bitwise right rotation operation, by the given number of bits (up to 63).
Parameters
numbits : number
- The number of bits to roll right by.
Returns
Int64 : The created Int64.
int64:bswap()
Description
- Returns a Int64 of the bytes swapped. This can be used to convert little-endian 64 bit numbers to big-endian 64 bit numbers or vice versa.
Returns
Int64 : The created Int64.
Int64 metamethods
Int64.__tostring()
Description
- Returns a string of decimal digits for the Int64's number. Called by the tostring() Lua function.
Returns
string : The string of digits.
Int64.__unm()
Description
- Returns the negative of the Int64, in a new Int64. Called by the '-' negative symbol.
Returns
Int64 : The negated Int64.
Int64.__add()
Description
- Returns an Int64 of two Int64/UInt64/numbers added. Called by the '+' operation.
Returns
Int64 : The resultant Int64.
Int64.__sub()
Description
- Returns an Int64 of two Int64/UInt64/numbers subtracted. Called by the '-' operation.
Returns
Int64 : The resultant Int64.
Int64.__mul()
Description
- Returns an Int64 of two Int64/UInt64/numbers multiplied. Called by the '*' operation.
Returns
Int64 : The resultant Int64.
Int64.__div()
Description
- Returns an Int64 of two Int64/UInt64/numbers divided, without remainder. Called by the '/' operation.
Returns
Int64 : The resultant Int64.
Int64.__mod()
Description
- Returns an Int64 of the remainder of two Int64/UInt64/numbers divided. Called by the '%' operation.
Returns
Int64 : The resultant Int64.
Int64.__pow()
Description
- Returns an Int64 of an Int64 taken to the power of an Int64/UInt64/number. Called by the '^' operation.
Returns
Int64 : The resultant Int64.
Int64.__eq()
Description
- Returns true if the Int64 equals another Int64 or UInt64. Called by the '==' operation.
Returns
boolean : True if equal, else false.
Int64.__lt()
Description
Returns true if the Int64 is less than another Int64 or UInt64. Called by the '<' operation.
Returns
boolean : True if the Int64 is less, else false.
Int64.__le()
Description
Returns true if the Int64 is less than or equal to another Int64 or UInt64. Called by the '<=' operation.
Returns
boolean : True if the Int64 is less than or equal, else false.
UInt64
A UInt64 represents a 64-bit unsigned integer.
function |
description |
Creates an UInt64 object |
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Creates an UInt64 of the max value |
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Creates an UInt64 of the min value |
|
Decodes an 8-byte Lua string to an UInt64 |
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Encodes the UInt64 into an 8-byte Lua string |
|
Creates an UInt64 from a hex string |
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Gets a hex string from a UInt64 |
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Gets a Lua number of the UInt64 value |
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Gets the high 32-bit number of the UInt64 value |
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Gets the lower 32-bit number of the UInt64 value |
|
Gets the bitwise 'not' of the UInt64 value |
|
Gets the bitwise 'and' of the UInt64 values |
|
Gets the bitwise 'or' of the UInt64 values |
|
Gets the bitwise 'xor' of the UInt64 values |
|
Gets the bitwise logical left-shift the UInt64 value |
|
Gets the bitwise logical right-shift the UInt64 value |
|
Gets the bitwise arithmetic right-shift the UInt64 value |
|
Gets the bitwise left rotation of the UInt64 value |
|
Gets the bitwise right rotation of the UInt64 value |
|
Gets the byte swap of the UInt64 value |
metamethod |
calling function |
description |
tostring() |
Gets a digit string of the UInt64 value |
|
- |
Gets the negative of the UInt64 value |
|
+ |
Gets the addition of the UInt64 with another Int64/UInt64/number |
|
- |
Gets the subtraction of the UInt64 with another Int64/UInt64/number |
|
* |
Gets the multiplication of the UInt64 with another Int64/UInt64/number |
|
/ |
Gets the integer division of the UInt64 with another Int64/UInt64/number |
|
% |
Gets the remainder of division of the UInt64 with another Int64/UInt64/number |
|
^ |
Gets the power of the UInt64 to another Int64/UInt64/number |
|
== |
Returns true if the UInt64 equals another Int64/UInt64/number |
|
< |
Returns true if the UInt64 is less than another Int64/UInt64/number |
|
<= |
Returns true if the UInt64 is less than or equal to another Int64/UInt64/number |
UInt64.new([num [,high_num]])
Description
Creates a new UInt64 object.
Parameters
num (optional) : number|UInt64|UUInt64|string
A number, UUInt64, UInt64, or string of ascii digits to assign the value of the new UInt64. Defaults to 0. If high_num is given, then this must be a number type, and will only be the lower 32-bits of the integer.
high_num (optional) : number
- The number to set the high-order 32 bits of the 64-bit integer.
Returns
UInt64 : The created UInt64
UInt64.max()
Description
Creates an UInt64 of the max possible value. In other words, this should return an UInt64 object of the number 18,446,744,073,709,551,615.
Returns
UInt64 : The created UInt64
UInt64.min()
Description
Creates an UInt64 of the min possible value. In other words, this should return an UInt64 object of the number 0.
Returns
UInt64 : The created UInt64
UInt64.decode(string [,endian])
Description
- Decodes an 8-byte Lua string, using given endianess, into a new UInt64 object. The default endianess is host-order, which is not portable across platforms.
Parameters
string : string
- The Lua string containing a binary 64-bit integer
endian (optional) : boolean
- If set to true then little-endian is used, if false then big-endian; if missing/nil (default), native host endian.
Returns
UInt64 : The created UInt64, or nil on failure.
uint64:encode([endian])
Description
- Encodes the UInt64 number into an 8-byte Lua string, using given endianess. The default endianess is host-order, which is not portable across platforms.
Parameters
endian (optional) : boolean
- If set to true then little-endian is used, if false then big-endian; if missing/nil (default), native host endian.
Returns
string : The created Lua 8-byte string.
UInt64.fromhex(hex)
Description
- Creates an UInt64 object from the given hex string. The hex letter may be either upper or lower-case, but without a leading '0x' nor separators between hex characters.
Parameters
hex : string
- The hex-ascii string to create an UInt64 from.
Returns
UInt64 : The created UInt64
uint64:tohex([numbytes])
Description
- Returns a hex string of the UInt64 value. The hex letters will be lower-case, without a leading '0x' nor separators between hex characters.
Parameters
numbytes (optional) : number
- The number of hex-chars/nibbles to generate, negative means uppercase (default=16).
Returns
string : The hex string.
uint64:tonumber()
Description
- Returns a Lua number of the UInt64 value - this may lose precision, if the number is greater than 2^53.
Returns
number : The Lua number value.
uint64:higher()
Description
- Returns a Lua number of the higher 32-bits of the UInt64 value.
Returns
number : The Lua number value.
uint64:lower()
Description
- Returns a Lua number of the lower 32-bits of the UInt64 value.
Returns
number : The Lua number value.
uint64:bnot()
Description
- Returns a UInt64 of the bitwise 'not' operation.
Returns
UInt64 : The created UInt64.
uint64:band(arg1 [, arg2 [, ...]])
Description
- Returns a UInt64 of the bitwise 'and' operation, with the given number/UInt64/UInt64. Note that multiple arguments are allowed.
Parameters
arg1 : number|UInt64|UUInt64|string
- The number/UInt64/UInt64/hex-string to bitwise 'and' the UInt64 with.
Returns
UInt64 : The created UInt64.
uint64:bor(arg1 [, arg2 [, ...]])
Description
- Returns a UInt64 of the bitwise 'or' operation, with the given number/UInt64/UInt64. Note that multiple arguments are allowed.
Parameters
arg1 : number|UInt64|UUInt64|string
- The number/UInt64/UInt64/hex-string to bitwise 'or' the UInt64 with.
Returns
UInt64 : The created UInt64.
uint64:bxor(arg1 [, arg2 [, ...]])
Description
- Returns a UInt64 of the bitwise 'xor' operation, with the given number/UInt64/UInt64. Note that multiple arguments are allowed.
Parameters
arg1 : number|UInt64|UUInt64|string
- The number of bits to left-shift by (1-63).
Returns
UInt64 : The created UInt64.
uint64:lshift(numbits)
Description
- Returns a UInt64 of the bitwise logical left-shift operation, by the given number of bits.
Parameters
numbits : number
- The number of bits to left-shift by.
Returns
UInt64 : The created UInt64.
uint64:rshift(numbits)
Description
- Returns a UInt64 of the bitwise logical right-shift operation, by the given number of bits.
Parameters
numbits : number
- The number of bits to right-shift by.
Returns
UInt64 : The created UInt64.
uint64:arshift(numbits)
Description
- Returns a UInt64 of the bitwise arithmetic right-shift operation, by the given number of bits.
Parameters
numbits : number
- The number of bits to arithmetic right-shift by.
Returns
UInt64 : The created UInt64.
uint64:rol(numbits)
Description
- Returns a UInt64 of the bitwise left rotation operation, by the given number of bits (up to 63).
Parameters
numbits : number
- The number of bits to roll left by.
Returns
UInt64 : The created UInt64.
uint64:ror(numbits)
Description
- Returns a UInt64 of the bitwise right rotation operation, by the given number of bits (up to 63).
Parameters
numbits : number
- The number of bits to roll right by.
Returns
UInt64 : The created UInt64.
uint64:bswap()
Description
- Returns a UInt64 of the bytes swapped. This can be used to convert little-endian 64 bit numbers to big-endian 64 bit numbers or vice versa.
Returns
UInt64 : The created UInt64.
UInt64 metamethods
UInt64.__tostring()
Description
- Returns a string of decimal digits for the UInt64's number. Called by the tostring() Lua function.
Returns
string : The string of digits.
UInt64.__unm()
Description
- Returns the the UInt64, in a new UInt64, since there cannot be a negative of a unsigned integer. Called by the '-' negative symbol.
Returns
UInt64 : The negated UInt64.
UInt64.__add()
Description
- Returns a UInt64 of two Int64/UInt64/numbers added. Called by the '+' operation.
Returns
UInt64 : The resultant UInt64.
UInt64.__sub()
Description
- Returns a UInt64 of two Int64/UInt64/numbers subtracted. Called by the '-' operation.
Returns
UInt64 : The resultant UInt64.
UInt64.__mul()
Description
- Returns a UInt64 of two Int64/UInt64/numbers multiplied. Called by the '*' operation.
Returns
UInt64 : The resultant UInt64.
UInt64.__div()
Description
- Returns a UInt64 of two Int64/UInt64/numbers divided, without remainder. Called by the '/' operation.
Returns
UInt64 : The resultant UInt64.
UInt64.__mod()
Description
- Returns a UInt64 of the remainder of two Int64/UInt64/numbers divided. Called by the '%' operation.
Returns
UInt64 : The resultant UInt64.
UInt64.__pow()
Description
- Returns a UInt64 of an Int64 taken to the power of an Int64/UInt64/number. Called by the '^' operation.
Returns
UInt64 : The resultant UInt64.
UInt64.__eq()
Description
- Returns true if the Int64 equals another Int64 or UInt64. Called by the '==' operation.
Returns
boolean : True if equal, else false.
UInt64.__lt()
Description
Returns true if the Int64 is less than another Int64 or UInt64. Called by the '<' operation.
Returns
boolean : True if the Int64 is less, else false.
UInt64.__le()
Description
Returns true if the Int64 is less than or equal to another Int64 or UInt64. Called by the '<=' operation.
Returns
boolean : True if the Int64 is less than or equal, else false.