Use RefCounted as math.mp.Integer internal storage

This commit is contained in:
Eugen Wissner 2016-12-04 22:51:21 +01:00
parent 1c5796eb96
commit 86c08e7af6

View File

@ -11,17 +11,36 @@
module tanya.math.mp;
import std.algorithm.comparison;
import std.algorithm.mutation;
import std.algorithm.searching;
import std.algorithm.mutation;
import std.experimental.allocator;
import tanya.memory.allocator;
import tanya.memory.types;
struct Integer
{
private ubyte[] rep;
private RefCounted!(ubyte[]) rep;
private bool sign;
this(in uint value)
/**
* Creates a multiple precision integer.
*
* Params:
* value = Initial value.
* allocator = Allocator.
*/
this(in uint value, IAllocator allocator = theAllocator)
in
{
opAssign(value);
assert(allocator !is null);
}
body
{
this(allocator);
immutable size = calculateSizeFromInt(value);
rep = allocator.makeArray!ubyte(size);
assignInt(size, value);
}
///
@ -32,24 +51,37 @@ struct Integer
assert(h.rep[0] == 79);
}
this(in Integer value)
/// Ditto.
this(in Integer value, IAllocator allocator = theAllocator)
in
{
opAssign(value);
assert(allocator !is null);
}
body
{
this(allocator);
rep = allocator.makeArray!ubyte(value.length);
value.rep.get.copy(rep.get);
}
~this()
/// Ditto.
this(IAllocator allocator)
{
destroy(rep);
this.allocator = allocator;
rep = RefCounted!(ubyte[])(allocator);
}
Integer opAssign(in uint value)
/*
* Figure out the minimum amount of space this value will take
* up in bytes (leave at least one byte, though, if the value is 0).
*/
pragma(inline, true)
private ushort calculateSizeFromInt(in ref uint value)
const pure nothrow @safe @nogc
{
uint mask, shift;
ushort size = 4;
// Figure out the minimum amount of space this value will take
// up in bytes (leave at least one byte, though, if the value is 0).
for (mask = 0xff000000; mask > 0x000000ff; mask >>= 8)
for (uint mask = 0xff000000; mask > 0x000000ff; mask >>= 8)
{
if (value & mask)
{
@ -57,26 +89,44 @@ struct Integer
}
--size;
}
rep.length = size;
// Work backward through the int, masking off each byte
// (up to the first 0 byte) and copy it into the internal
// representation in big-endian format.
mask = 0x00000000ff;
shift = 0;
for (auto i = size; i; --i)
return size;
}
/*
* Work backward through the int, masking off each byte
* (up to the first 0 byte) and copy it into the internal
* representation in big-endian format.
*/
pragma(inline, true)
private void assignInt(in ref ushort size, in ref uint value)
pure nothrow @safe @nogc
{
uint mask = 0x00000000ff, shift;
for (ushort i = size; i; --i)
{
rep[i - 1] = cast(ubyte) ((value & mask) >> shift);
mask <<= 8;
shift += 8;
}
}
ref Integer opAssign(in uint value)
{
ushort size = calculateSizeFromInt(value);
checkAllocator();
allocator.resizeArray(rep.get, size);
assignInt(size, value);
return this;
}
Integer opAssign(in Integer value)
ref Integer opAssign(in Integer value)
{
rep.length = value.length;
value.rep.copy(rep);
checkAllocator();
allocator.resizeArray(rep, value.length);
value.rep.get.copy(rep.get);
return this;
}
@ -101,22 +151,42 @@ struct Integer
assert(h.rep[0] == 0);
}
/**
* Returns: Integer size.
*/
@property size_t length() const pure nothrow @safe @nogc
{
return rep.length;
return rep.get.length;
}
bool opEquals(in Integer h)
/**
* Params:
* h = The second integer.
*
* Returns: Whether the two integers are equal.
*/
bool opEquals(in Integer h) const
{
return rep == h.rep;
}
///
unittest
{
auto h1 = Integer(1019);
assert(h1 == Integer(1019));
assert(h1 != Integer(109));
}
/**
* Compare h1 to h2. Return:
* a positive number if h1 > h2
* a negative number if h1 < h2
* Params:
* h = The second integer.
*
* Returns: A positive number if $(D_INLINECODE this > h), a negative
* number if $(D_INLINECODE this > h), `0` otherwise.
*/
int opCmp(in Integer h)
int opCmp(in Integer h) const
{
if (length > h.length)
{
@ -165,21 +235,27 @@ struct Integer
}
/**
* Add two huges - overwrite h1 with the result.
* Assignment operators with another $(D_PSYMBOL Integer).
*
* Params:
* h = The second integer.
*
* Returns: $(D_KEYWORD this).
*/
Integer opOpAssign(string op)(Integer h)
ref Integer opOpAssign(string op)(in Integer h)
if (op == "+")
{
uint sum;
uint carry = 0;
checkAllocator();
// Adding h2 to h1. If h2 is > h1 to begin with, resize h1
if (h.length > length)
{
auto tmp = new ubyte[h.length];
tmp[h.length - length ..$] = rep[0..length];
destroy(rep);
auto tmp = allocator.makeArray!ubyte(h.length);
tmp[h.length - length .. $] = rep[0 .. length];
rep = tmp;
}
@ -206,10 +282,9 @@ struct Integer
if (carry)
{
// Still overflowed; allocate more space
ubyte[] tmp = new ubyte[length + 1];
auto tmp = allocator.makeArray!ubyte(length + 1);
tmp[1..$] = rep[0..length];
tmp[0] = 0x01;
destroy(rep);
rep = tmp;
}
return this;
@ -232,13 +307,16 @@ struct Integer
assert(h1.rep == [0x01, 0x00, 0x00, 0x11, 0x02]);
}
Integer opOpAssign(string op)(Integer h)
/// Ditto.
ref Integer opOpAssign(string op)(in Integer h)
if (op == "-")
{
auto i = rep.length;
auto j = h.rep.length;
uint borrow = 0;
checkAllocator();
do
{
int difference;
@ -271,10 +349,10 @@ struct Integer
immutable offset = rep.countUntil!(a => a != 0);
if (offset > 0)
{
ubyte[] tmp = rep;
rep = new ubyte[rep.length - offset];
tmp[offset..$].copy(rep);
destroy(tmp);
ubyte[] tmp;
allocator.resizeArray(tmp, rep.length - offset);
rep[offset .. $].copy(tmp);
rep = tmp;
}
return this;
}
@ -293,10 +371,10 @@ struct Integer
h2 = 4294967294;
h1 -= h2;
assert(h1.rep == [0x80, 0x00, 0x00, 0x01]);
}
Integer opOpAssign(string op)(in size_t n)
/// Ditto.
ref Integer opOpAssign(string op)(in size_t n)
if (op == "<<")
{
ubyte carry;
@ -305,14 +383,15 @@ struct Integer
immutable bit = n % 8;
immutable delta = 8 - bit;
checkAllocator();
if (cast(ubyte) (rep[0] >> delta))
{
rep.length = rep.length + n / 8 + 1;
allocator.resizeArray(rep, i + n / 8 + 1);
j = i + 1;
}
else
{
rep.length = rep.length + n / 8;
allocator.resizeArray(rep, i + n / 8);
j = i;
}
do
@ -339,13 +418,16 @@ struct Integer
assert(h1.rep == [0x01, 0xff, 0xff, 0xff, 0xfe]);
}
Integer opOpAssign(string op)(in size_t n)
/// Ditto.
ref Integer opOpAssign(string op)(in size_t n)
if (op == ">>")
{
immutable step = n / 8;
checkAllocator();
if (step >= rep.length)
{
rep.length = 1;
allocator.resizeArray(rep, 1);
rep[0] = 0;
return this;
}
@ -405,10 +487,8 @@ struct Integer
assert(h1.rep == [0x00]);
}
/**
* Multiply h1 by h2, overwriting the value of h1.
*/
Integer opOpAssign(string op)(in Integer h)
/// Ditto.
ref Integer opOpAssign(string op)(in Integer h)
if (op == "*")
{
ubyte mask;
@ -416,7 +496,6 @@ struct Integer
auto temp = Integer(this);
opAssign(0);
do
{
--i;
@ -443,16 +522,8 @@ struct Integer
assert(h1.rep == [0xdb, 0x18]); // 56088
}
/**
* divident = numerator, divisor = denominator
*
* Note that this process destroys divisor (and, of couse,
* overwrites quotient). The divident is the remainder of the
* division (if that's important to the caller). The divisor will
* be modified by this routine, but it will end up back where it
* "started".
*/
Integer opOpAssign(string op)(in Integer h)
/// Ditto.
ref Integer opOpAssign(string op)(in Integer h)
if ((op == "/") || (op == "%"))
{
auto divisor = Integer(h);
@ -460,6 +531,8 @@ struct Integer
// is being set or cleared on the current operation.
size_t bit_size;
checkAllocator();
// First, left-shift divisor until it's >= than the divident
while (opCmp(divisor) > 0)
{
@ -468,7 +541,7 @@ struct Integer
}
static if (op == "/")
{
auto quotient = new ubyte[bit_size / 8 + 1];
auto quotient = allocator.makeArray!ubyte(bit_size / 8 + 1);
}
auto bit_position = 8 - (bit_size % 8) - 1;
@ -494,7 +567,6 @@ struct Integer
static if (op == "/")
{
destroy(rep);
rep = quotient;
}
return this;
@ -522,7 +594,8 @@ struct Integer
assert(h1.rep == [0x7b]); // 123
}
Integer opOpAssign(string op)(in Integer exp)
/// Ditto.
ref Integer opOpAssign(string op)(in Integer exp)
if (op == "^^")
{
auto i = exp.rep.length;
@ -563,4 +636,6 @@ struct Integer
h1 ^^= h2;
assert(h1.rep == [0x1b, 0x5c, 0xab, 0x9c, 0x31, 0x10]);
}
mixin StructAllocator;
}