mirror of
https://github.com/vlang/v.git
synced 2023-08-10 21:13:21 +03:00
bitfield: update module
This commit is contained in:
Alexey
GitHub
parent
8f06d60084
commit
bb587c27a8
@ -25,56 +25,6 @@ const (
|
||||
SLOT_SIZE = 32
|
||||
)
|
||||
|
||||
fn bitmask(bitnr int) u32 {
|
||||
return u32(u32(1) << u32(bitnr % SLOT_SIZE))
|
||||
}
|
||||
|
||||
fn bitslot(size int) int {
|
||||
return size / SLOT_SIZE
|
||||
}
|
||||
|
||||
fn bitget(instance BitField, bitnr int) int {
|
||||
return (instance.field[bitslot(bitnr)] >> (bitnr % SLOT_SIZE)) & u32(1)
|
||||
}
|
||||
|
||||
fn bitset(instance mut BitField, bitnr int) {
|
||||
instance.field[bitslot(bitnr)] = instance.field[bitslot(bitnr)] | bitmask(bitnr)
|
||||
}
|
||||
|
||||
fn bitclear(instance mut BitField, bitnr int) {
|
||||
instance.field[bitslot(bitnr)] = instance.field[bitslot(bitnr)] & ~bitmask(bitnr)
|
||||
}
|
||||
|
||||
fn bittoggle(instance mut BitField, bitnr int) {
|
||||
instance.field[bitslot(bitnr)] = instance.field[bitslot(bitnr)] ^ bitmask(bitnr)
|
||||
}
|
||||
/*
|
||||
#define BITTEST(a, b) ((a)->field[BITSLOT(b)] & BITMASK(b))
|
||||
*/
|
||||
|
||||
fn min(input1 int, input2 int) int {
|
||||
if input1 < input2 {
|
||||
return input1
|
||||
}
|
||||
else {
|
||||
return input2
|
||||
}
|
||||
}
|
||||
|
||||
fn bitnslots(length int) int {
|
||||
return (length - 1) / SLOT_SIZE + 1
|
||||
}
|
||||
|
||||
fn cleartail(instance mut BitField) {
|
||||
tail := instance.size % SLOT_SIZE
|
||||
if tail != 0 {
|
||||
// create a mask for the tail
|
||||
mask := u32((1 << tail) - 1)
|
||||
// clear the extra bits
|
||||
instance.field[bitnslots(instance.size) - 1] = instance.field[bitnslots(instance.size) - 1] & mask
|
||||
}
|
||||
}
|
||||
|
||||
// public functions
|
||||
|
||||
// from_bytes() converts a byte array into a bitfield.
|
||||
@ -86,10 +36,9 @@ pub fn from_bytes(input []byte) BitField {
|
||||
return output
|
||||
}
|
||||
|
||||
// from_string() converts a string of characters ('0' and '1') to a bit
|
||||
// from_str converts a string of characters ('0' and '1') to a bit
|
||||
// array. Any character different from '0' is treated as '1'.
|
||||
|
||||
pub fn from_string(input string) BitField {
|
||||
pub fn from_str(input string) BitField {
|
||||
mut output := new(input.len)
|
||||
for i in 0..input.len {
|
||||
if input[i] != `0` {
|
||||
@ -99,9 +48,8 @@ pub fn from_string(input string) BitField {
|
||||
return output
|
||||
}
|
||||
|
||||
// str() converts the bit array to a string of characters ('0' and '1') and
|
||||
// str converts the bit array to a string of characters ('0' and '1') and
|
||||
// return the string
|
||||
|
||||
pub fn (input BitField) str() string {
|
||||
mut output := ''
|
||||
for i in 0..input.size {
|
||||
@ -115,8 +63,7 @@ pub fn (input BitField) str() string {
|
||||
return output
|
||||
}
|
||||
|
||||
//new() creates an empty bit array of capable of storing 'size' bits.
|
||||
|
||||
// new creates an empty bit array of capable of storing 'size' bits.
|
||||
pub fn new(size int) BitField {
|
||||
output := BitField{
|
||||
size: size
|
||||
@ -132,121 +79,113 @@ pub fn del(instance *BitField) {
|
||||
}
|
||||
*/
|
||||
|
||||
// getbit() returns the value (0 or 1) of bit number 'bit_nr' (count from
|
||||
// 0)
|
||||
|
||||
// getbit returns the value (0 or 1) of bit number 'bit_nr' (count from 0).
|
||||
pub fn (instance BitField) getbit(bitnr int) int {
|
||||
if bitnr >= instance.size {return 0}
|
||||
return bitget(instance, bitnr)
|
||||
if bitnr >= instance.size {
|
||||
return 0
|
||||
}
|
||||
return (instance.field[bitslot(bitnr)] >> (bitnr % SLOT_SIZE)) & u32(1)
|
||||
}
|
||||
|
||||
// setbit() set bit number 'bit_nr' to 1 (count from 0)
|
||||
|
||||
// setbit sets bit number 'bit_nr' to 1 (count from 0).
|
||||
pub fn (instance mut BitField) setbit(bitnr int) {
|
||||
if bitnr >= instance.size {return}
|
||||
bitset(mut instance, bitnr)
|
||||
if bitnr >= instance.size {
|
||||
return
|
||||
}
|
||||
instance.field[bitslot(bitnr)] |= bitmask(bitnr)
|
||||
}
|
||||
|
||||
// clearbit() clears (sets to zero) bit number 'bit_nr' (count from 0)
|
||||
|
||||
// clearbit clears (sets to zero) bit number 'bit_nr' (count from 0).
|
||||
pub fn (instance mut BitField) clearbit(bitnr int) {
|
||||
if bitnr >= instance.size {return}
|
||||
bitclear(mut instance, bitnr)
|
||||
if bitnr >= instance.size {
|
||||
return
|
||||
}
|
||||
instance.field[bitslot(bitnr)] &= ~bitmask(bitnr)
|
||||
}
|
||||
|
||||
// setall() sets all bits in the array to 1
|
||||
|
||||
// setall sets all bits in the array to 1.
|
||||
pub fn (instance mut BitField) setall() {
|
||||
for i in 0..bitnslots(instance.size) {
|
||||
instance.field[i] = u32(-1)
|
||||
}
|
||||
cleartail(mut instance)
|
||||
instance.cleartail()
|
||||
}
|
||||
|
||||
// clearall() clears (sets to zero) all bits in the array
|
||||
|
||||
// clearall clears (sets to zero) all bits in the array.
|
||||
pub fn (instance mut BitField) clearall() {
|
||||
for i in 0..bitnslots(instance.size) {
|
||||
instance.field[i] = u32(0)
|
||||
}
|
||||
}
|
||||
|
||||
// togglebit() change the value (from 0 to 1 or from 1 to 0) of bit
|
||||
// number 'bit_nr'
|
||||
|
||||
// togglebit changes the value (from 0 to 1 or from 1 to 0) of bit
|
||||
// number 'bit_nr'.
|
||||
pub fn (instance mut BitField) togglebit(bitnr int) {
|
||||
if bitnr >= instance.size {return}
|
||||
bittoggle(mut instance, bitnr)
|
||||
if bitnr >= instance.size {
|
||||
return
|
||||
}
|
||||
instance.field[bitslot(bitnr)] ^= bitmask(bitnr)
|
||||
}
|
||||
|
||||
// bfand() perform logical AND operation on every pair of bits from 'input1'
|
||||
// and 'input2' and return the result as a new array. If inputs differ in size,
|
||||
// bfand performs logical AND operation on every pair of bits from 'input1' and
|
||||
// 'input2' and returns the result as a new array. If inputs differ in size,
|
||||
// the tail of the longer one is ignored.
|
||||
|
||||
pub fn bfand(input1 BitField, input2 BitField) BitField {
|
||||
size := min(input1.size, input2.size)
|
||||
bitnslots := bitnslots(size)
|
||||
mut output := new(size)
|
||||
mut i := 0
|
||||
for i < bitnslots {
|
||||
for i in 0..bitnslots {
|
||||
output.field[i] = input1.field[i] & input2.field[i]
|
||||
i++
|
||||
}
|
||||
cleartail(mut output)
|
||||
output.cleartail()
|
||||
return output
|
||||
}
|
||||
|
||||
// bfnot() toggle all bits in a bit array and return the result as a new array
|
||||
|
||||
// bfnot toggles all bits in a bit array and returns the result as a new array.
|
||||
pub fn bfnot(input BitField) BitField {
|
||||
size := input.size
|
||||
bitnslots := bitnslots(size)
|
||||
mut output := new(size)
|
||||
mut i := 0
|
||||
for i < bitnslots {
|
||||
for i in 0..bitnslots {
|
||||
output.field[i] = ~input.field[i]
|
||||
i++
|
||||
}
|
||||
cleartail(mut output)
|
||||
output.cleartail()
|
||||
return output
|
||||
}
|
||||
|
||||
// bfor() perform logical OR operation on every pair of bits from 'input1' and
|
||||
// 'input2' and return the result as a new array. If inputs differ in size, the
|
||||
// tail of the longer one is ignored.
|
||||
|
||||
// bfor performs logical OR operation on every pair of bits from 'input1' and
|
||||
// 'input2' and returns the result as a new array. If inputs differ in size,
|
||||
// the tail of the longer one is ignored.
|
||||
pub fn bfor(input1 BitField, input2 BitField) BitField {
|
||||
size := min(input1.size, input2.size)
|
||||
bitnslots := bitnslots(size)
|
||||
mut output := new(size)
|
||||
mut i := 0
|
||||
for i < bitnslots {
|
||||
for i in 0..bitnslots {
|
||||
output.field[i] = input1.field[i] | input2.field[i]
|
||||
i++
|
||||
}
|
||||
cleartail(mut output)
|
||||
output.cleartail()
|
||||
return output
|
||||
}
|
||||
|
||||
// bfxor(input1 BitField, input2 BitField) perform logical XOR operation on
|
||||
// every pair of bits from 'input1' and 'input2' and return the result as a new
|
||||
// array. If inputs differ in size, the tail of the longer one is ignored.
|
||||
|
||||
// bfxor perform logical XOR operation on every pair of bits from 'input1' and
|
||||
// 'input2' and returns the result as a new array. If inputs differ in size,
|
||||
// the tail of the longer one is ignored.
|
||||
pub fn bfxor(input1 BitField, input2 BitField) BitField {
|
||||
size := min(input1.size, input2.size)
|
||||
bitnslots := bitnslots(size)
|
||||
mut output := new(size)
|
||||
mut i := 0
|
||||
for i < bitnslots {
|
||||
for i in 0..bitnslots {
|
||||
output.field[i] = input1.field[i] ^ input2.field[i]
|
||||
i++
|
||||
}
|
||||
cleartail(mut output)
|
||||
output.cleartail()
|
||||
return output
|
||||
}
|
||||
|
||||
// join() concatenates two bit arrays and return the result as a new array.
|
||||
|
||||
// join concatenates two bit arrays and return the result as a new array.
|
||||
pub fn join(input1 BitField, input2 BitField) BitField {
|
||||
output_size := input1.size + input2.size
|
||||
mut output := new(output_size)
|
||||
@ -291,38 +230,33 @@ pub fn join(input1 BitField, input2 BitField) BitField {
|
||||
return output
|
||||
}
|
||||
|
||||
// getsize() returns the number of bits the array can hold
|
||||
|
||||
// getsize returns the number of bits the array can hold.
|
||||
pub fn (instance BitField) getsize() int {
|
||||
return instance.size
|
||||
}
|
||||
|
||||
// clone() create a copy of a bit array
|
||||
|
||||
pub fn clone(input BitField) BitField {
|
||||
bitnslots := bitnslots(input.size)
|
||||
mut output := new(input.size)
|
||||
mut i := 0
|
||||
for i < bitnslots {
|
||||
output.field[i] = input.field[i]
|
||||
// clone creates a copy of a bit array.
|
||||
pub fn (instance BitField) clone() BitField {
|
||||
bitnslots := bitnslots(instance.size)
|
||||
mut output := new(instance.size)
|
||||
for i in 0..bitnslots {
|
||||
output.field[i] = instance.field[i]
|
||||
i++
|
||||
}
|
||||
return output
|
||||
}
|
||||
|
||||
// cmp() compare two bit arrays bit by bit and return 'true' if they are
|
||||
// cmp compares two bit arrays bit by bit and returns 'true' if they are
|
||||
// identical by length and contents and 'false' otherwise.
|
||||
|
||||
pub fn cmp(input1 BitField, input2 BitField) bool {
|
||||
if input1.size != input2.size {return false}
|
||||
for i in 0..bitnslots(input1.size) {
|
||||
if input1.field[i] != input2.field[i] {return false}
|
||||
pub fn (instance BitField) cmp(input BitField) bool {
|
||||
if instance.size != input.size {return false}
|
||||
for i in 0..bitnslots(instance.size) {
|
||||
if instance.field[i] != input.field[i] {return false}
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
// popcount() returns the number of set bits (ones) in the array
|
||||
|
||||
// popcount returns the number of set bits (ones) in the array.
|
||||
pub fn (instance BitField) popcount() int {
|
||||
size := instance.size
|
||||
bitnslots := bitnslots(size)
|
||||
@ -343,16 +277,14 @@ pub fn (instance BitField) popcount() int {
|
||||
return count
|
||||
}
|
||||
|
||||
// hamming () compute the Hamming distance between two bit arrays.
|
||||
|
||||
// hamming computes the Hamming distance between two bit arrays.
|
||||
pub fn hamming (input1 BitField, input2 BitField) int {
|
||||
input_xored := bfxor(input1, input2)
|
||||
return input_xored.popcount()
|
||||
}
|
||||
|
||||
// pos() checks if the array contains a sub-array 'needle' and returns its
|
||||
// pos checks if the array contains a sub-array 'needle' and returns its
|
||||
// position if it does, -1 if it does not, and -2 on error.
|
||||
|
||||
pub fn (haystack BitField) pos(needle BitField) int {
|
||||
heystack_size := haystack.size
|
||||
needle_size := needle.size
|
||||
@ -364,7 +296,7 @@ pub fn (haystack BitField) pos(needle BitField) int {
|
||||
}
|
||||
for i := 0; i <= diff; i++ {
|
||||
needle_candidate := haystack.slice(i, needle_size + i)
|
||||
if cmp(needle_candidate, needle) {
|
||||
if needle_candidate.cmp(needle) {
|
||||
// needle matches a sub-array of haystack; return starting position of the sub-array
|
||||
return i
|
||||
}
|
||||
@ -373,9 +305,8 @@ pub fn (haystack BitField) pos(needle BitField) int {
|
||||
return -1
|
||||
}
|
||||
|
||||
// slice() return a sub-array of bits between 'start_bit_nr' (included) and
|
||||
// 'end_bit_nr' (excluded)
|
||||
|
||||
// slice returns a sub-array of bits between 'start_bit_nr' (included) and
|
||||
// 'end_bit_nr' (excluded).
|
||||
pub fn (input BitField) slice(_start int, _end int) BitField {
|
||||
// boundary checks
|
||||
mut start := _start
|
||||
@ -441,9 +372,8 @@ pub fn (input BitField) slice(_start int, _end int) BitField {
|
||||
return output
|
||||
}
|
||||
|
||||
// reverse() reverses the order of bits in the array (swap the first with the
|
||||
// last, the second with the last but one and so on)
|
||||
|
||||
// reverse reverses the order of bits in the array (swap the first with the
|
||||
// last, the second with the last but one and so on).
|
||||
pub fn (instance BitField) reverse() BitField {
|
||||
size := instance.size
|
||||
bitnslots := bitnslots(size)
|
||||
@ -451,20 +381,20 @@ pub fn (instance BitField) reverse() BitField {
|
||||
for i:= 0; i < (bitnslots - 1); i++ {
|
||||
for j in 0..SLOT_SIZE {
|
||||
if u32(instance.field[i] >> u32(j)) & u32(1) == u32(1) {
|
||||
bitset(mut output, size - i * SLOT_SIZE - j - 1)
|
||||
output.setbit(size - i * SLOT_SIZE - j - 1)
|
||||
}
|
||||
}
|
||||
}
|
||||
bits_in_last_input_slot := (size - 1) % SLOT_SIZE + 1
|
||||
for j in 0..bits_in_last_input_slot {
|
||||
if u32(instance.field[bitnslots - 1] >> u32(j)) & u32(1) == u32(1) {
|
||||
bitset(mut output, bits_in_last_input_slot - j - 1)
|
||||
output.setbit(bits_in_last_input_slot - j - 1)
|
||||
}
|
||||
}
|
||||
return output
|
||||
}
|
||||
|
||||
// resize changes the size of the bit array to 'new_size'
|
||||
// resize changes the size of the bit array to 'new_size'.
|
||||
pub fn (instance mut BitField) resize(new_size int) {
|
||||
new_bitnslots := bitnslots(new_size)
|
||||
old_size := instance.size
|
||||
@ -476,13 +406,12 @@ pub fn (instance mut BitField) resize(new_size int) {
|
||||
instance.field = field.clone()
|
||||
instance.size = new_size
|
||||
if new_size < old_size && new_size % SLOT_SIZE != 0 {
|
||||
cleartail(mut instance)
|
||||
instance.cleartail()
|
||||
}
|
||||
}
|
||||
|
||||
// rotate(offset int) circular-shift the bits by 'offset' positions (move
|
||||
// 'offset' bit to 0, 'offset+1' bit to 1, and so on)
|
||||
|
||||
// rotate circular-shifts the bits by 'offset' positions (move
|
||||
// 'offset' bit to 0, 'offset+1' bit to 1, and so on).
|
||||
pub fn (instance BitField) rotate(offset int) BitField {
|
||||
/**
|
||||
* This function "cuts" the bitfield into two and swaps them.
|
||||
@ -506,3 +435,36 @@ pub fn (instance BitField) rotate(offset int) BitField {
|
||||
output := join(second_chunk, first_chunk)
|
||||
return output
|
||||
}
|
||||
|
||||
// Internal functions
|
||||
|
||||
fn (instance mut BitField) cleartail() {
|
||||
tail := instance.size % SLOT_SIZE
|
||||
if tail != 0 {
|
||||
// create a mask for the tail
|
||||
mask := u32((1 << tail) - 1)
|
||||
// clear the extra bits
|
||||
instance.field[bitnslots(instance.size) - 1] = instance.field[bitnslots(instance.size) - 1] & mask
|
||||
}
|
||||
}
|
||||
|
||||
fn bitmask(bitnr int) u32 {
|
||||
return u32(u32(1) << u32(bitnr % SLOT_SIZE))
|
||||
}
|
||||
|
||||
fn bitslot(size int) int {
|
||||
return size / SLOT_SIZE
|
||||
}
|
||||
|
||||
fn min(input1 int, input2 int) int {
|
||||
if input1 < input2 {
|
||||
return input1
|
||||
}
|
||||
else {
|
||||
return input2
|
||||
}
|
||||
}
|
||||
|
||||
fn bitnslots(length int) int {
|
||||
return (length - 1) / SLOT_SIZE + 1
|
||||
}
|
||||
|
||||
@ -54,9 +54,9 @@ fn test_clone_cmp() {
|
||||
input.setbit(i)
|
||||
}
|
||||
}
|
||||
output := bitfield.clone(input)
|
||||
output := input.clone()
|
||||
assert output.getsize() == len
|
||||
assert bitfield.cmp(input, output) == true
|
||||
assert input.cmp(output) == true
|
||||
}
|
||||
|
||||
fn test_slice_join() {
|
||||
@ -75,7 +75,7 @@ fn test_slice_join() {
|
||||
chunk2 := input.slice(point, input.getsize())
|
||||
// concatenate them back into one and compare to the original
|
||||
output := bitfield.join(chunk1, chunk2)
|
||||
if !bitfield.cmp(input, output) {
|
||||
if !input.cmp(output) {
|
||||
result = 0
|
||||
}
|
||||
}
|
||||
@ -137,7 +137,7 @@ fn test_bf_from_bytes() {
|
||||
assert result == 1
|
||||
}
|
||||
|
||||
fn test_bf_from_string() {
|
||||
fn test_bf_from_str() {
|
||||
rand.seed(time.now().unix)
|
||||
len := 80
|
||||
mut input := ''
|
||||
@ -149,7 +149,7 @@ fn test_bf_from_string() {
|
||||
input = input + '0'
|
||||
}
|
||||
}
|
||||
output := bitfield.from_string(input)
|
||||
output := bitfield.from_str(input)
|
||||
mut result := 1
|
||||
for i in 0..len {
|
||||
if input[i] != output.getbit(i) + 48 {
|
||||
@ -229,7 +229,7 @@ fn test_bf_reverse() {
|
||||
input.setbit(i)
|
||||
}
|
||||
}
|
||||
check := bitfield.clone(input)
|
||||
check := input.clone()
|
||||
output := input.reverse()
|
||||
mut result := 1
|
||||
for i in 0..len {
|
||||
@ -279,7 +279,7 @@ fn test_bf_pos() {
|
||||
needle.setbit(r)
|
||||
|
||||
// create the haystack, make sure it contains the needle
|
||||
mut haystack := bitfield.clone(needle)
|
||||
mut haystack := needle.clone()
|
||||
|
||||
// if there is space between the start of the haystack and the sought needle, fill it with zeroes
|
||||
if j > 0 {
|
||||
|
||||
Loading…
Reference in New Issue
Block a user