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Add bitseq package

- Initial version
- It allows handling reservation/release of a finite set
  of resources through large bitmask.
- It represents the bitmask as a list of equal
  consecutive 32 bits long bitmask symbols.
  It basically operates on a run-length encoding
  of the bitmask without encode/decode processing.

Signed-off-by: Alessandro Boch <aboch@docker.com>
This commit is contained in:
Alessandro Boch 2015-06-12 12:03:33 -07:00
parent 678d50f5b5
commit 5034c9bb11
2 changed files with 594 additions and 0 deletions

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// Package bitseq provides a structure and utilities for representing long bitmask
// as sequence of run-lenght encoded blocks. It operates direclty on the encoded
// representation, it does not decode/encode.
package bitseq
import (
"fmt"
)
// Block Sequence constants
// If needed we can think of making these configurable
const (
blockLen = 32
blockBytes = blockLen / 8
blockMAX = 1<<blockLen - 1
blockFirstBit = 1 << (blockLen - 1)
)
// Sequence reresents a recurring sequence of 32 bits long bitmasks
type Sequence struct {
Block uint32 // block representing 4 byte long allocation bitmask
Count uint32 // number of consecutive blocks
Next *Sequence // next sequence
}
// New returns a sequence initialized to represent a bitmaks of numElements bits
func New(numElements uint32) *Sequence {
return &Sequence{Block: 0x0, Count: getNumBlocks(numElements), Next: nil}
}
// String returns a string representation of the block sequence starting from this block
func (s *Sequence) String() string {
var nextBlock string
if s.Next == nil {
nextBlock = "end"
} else {
nextBlock = s.Next.String()
}
return fmt.Sprintf("(0x%x, %d)->%s", s.Block, s.Count, nextBlock)
}
// GetAvailableBit returns the position of the first unset bit in the bitmask represented by this sequence
func (s *Sequence) GetAvailableBit() (bytePos, bitPos int) {
if s.Block == blockMAX || s.Count == 0 {
return -1, -1
}
bits := 0
bitSel := uint32(blockFirstBit)
for bitSel > 0 && s.Block&bitSel != 0 {
bitSel >>= 1
bits++
}
return bits / 8, bits % 8
}
// Equal checks if this sequence is equal to the passed one
func (s *Sequence) Equal(o *Sequence) bool {
this := s
other := o
for this != nil {
if other == nil {
return false
}
if this.Block != other.Block || this.Count != other.Count {
return false
}
this = this.Next
other = other.Next
}
// Check if other is longer than this
if other != nil {
return false
}
return true
}
// GetFirstAvailable looks for the first unset bit in passed mask
func GetFirstAvailable(head *Sequence) (int, int) {
byteIndex := 0
current := head
for current != nil {
if current.Block != blockMAX {
bytePos, bitPos := current.GetAvailableBit()
return byteIndex + bytePos, bitPos
}
byteIndex += int(current.Count * blockBytes)
current = current.Next
}
return -1, -1
}
// CheckIfAvailable checks if the bit correspondent to the specified ordinal is unset
// If the ordinal is beyond the Sequence limits, a negative response is returned
func CheckIfAvailable(head *Sequence, ordinal int) (int, int) {
bytePos := ordinal / 8
bitPos := ordinal % 8
// Find the Sequence containing this byte
current, _, _, inBlockBytePos := findSequence(head, bytePos)
if current != nil {
// Check whether the bit corresponding to the ordinal address is unset
bitSel := uint32(blockFirstBit >> uint(inBlockBytePos*8+bitPos))
if current.Block&bitSel == 0 {
return bytePos, bitPos
}
}
return -1, -1
}
// Given the byte position and the sequences list head, return the pointer to the
// sequence containing the byte (current), the pointer to the previous sequence,
// the number of blocks preceding the block containing the byte inside the current sequence.
// If bytePos is outside of the list, function will return (nil, nil, 0, -1)
func findSequence(head *Sequence, bytePos int) (*Sequence, *Sequence, uint32, int) {
// Find the Sequence containing this byte
previous := head
current := head
n := bytePos
for current.Next != nil && n >= int(current.Count*blockBytes) { // Nil check for less than 32 addresses masks
n -= int(current.Count * blockBytes)
previous = current
current = current.Next
}
// If byte is outside of the list, let caller know
if n >= int(current.Count*blockBytes) {
return nil, nil, 0, -1
}
// Find the byte position inside the block and the number of blocks
// preceding the block containing the byte inside this sequence
precBlocks := uint32(n / blockBytes)
inBlockBytePos := bytePos % blockBytes
return current, previous, precBlocks, inBlockBytePos
}
// PushReservation pushes the bit reservation inside the bitmask.
// Given byte and bit positions, identify the sequence (current) which holds the block containing the affected bit.
// Create a new block with the modified bit according to the operation (allocate/release).
// Create a new Sequence containing the new Block and insert it in the proper position.
// Remove current sequence if empty.
// Check if new Sequence can be merged with neighbour (previous/Next) sequences.
//
//
// Identify "current" Sequence containing block:
// [prev seq] [current seq] [Next seq]
//
// Based on block position, resulting list of sequences can be any of three forms:
//
// Block position Resulting list of sequences
// A) Block is first in current: [prev seq] [new] [modified current seq] [Next seq]
// B) Block is last in current: [prev seq] [modified current seq] [new] [Next seq]
// C) Block is in the middle of current: [prev seq] [curr pre] [new] [curr post] [Next seq]
func PushReservation(bytePos, bitPos int, head *Sequence, release bool) *Sequence {
// Store list's head
newHead := head
// Find the Sequence containing this byte
current, previous, precBlocks, inBlockBytePos := findSequence(head, bytePos)
if current == nil {
return newHead
}
// Construct updated block
bitSel := uint32(blockFirstBit >> uint(inBlockBytePos*8+bitPos))
newBlock := current.Block
if release {
newBlock &^= bitSel
} else {
newBlock |= bitSel
}
// Quit if it was a redundant request
if current.Block == newBlock {
return newHead
}
// Current Sequence inevitably looses one block, upadate Count
current.Count--
// Create new sequence
newSequence := &Sequence{Block: newBlock, Count: 1}
// Insert the new sequence in the list based on block position
if precBlocks == 0 { // First in sequence (A)
newSequence.Next = current
if current == head {
newHead = newSequence
previous = newHead
} else {
previous.Next = newSequence
}
removeCurrentIfEmpty(&newHead, newSequence, current)
mergeSequences(previous)
} else if precBlocks == current.Count-2 { // Last in sequence (B)
newSequence.Next = current.Next
current.Next = newSequence
mergeSequences(current)
} else { // In between the sequence (C)
currPre := &Sequence{Block: current.Block, Count: precBlocks, Next: newSequence}
currPost := current
currPost.Count -= precBlocks
newSequence.Next = currPost
if currPost == head {
newHead = currPre
} else {
previous.Next = currPre
}
// No merging or empty current possible here
}
return newHead
}
// Removes the current sequence from the list if empty, adjusting the head pointer if needed
func removeCurrentIfEmpty(head **Sequence, previous, current *Sequence) {
if current.Count == 0 {
if current == *head {
*head = current.Next
} else {
previous.Next = current.Next
current = current.Next
}
}
}
// Given a pointer to a Sequence, it checks if it can be merged with any following sequences
// It stops when no more merging is possible.
// TODO: Optimization: only attempt merge from start to end sequence, no need to scan till the end of the list
func mergeSequences(seq *Sequence) {
if seq != nil {
// Merge all what possible from seq
for seq.Next != nil && seq.Block == seq.Next.Block {
seq.Count += seq.Next.Count
seq.Next = seq.Next.Next
}
// Move to Next
mergeSequences(seq.Next)
}
}
// Serialize converts the sequence into a byte array
func Serialize(head *Sequence) ([]byte, error) {
return nil, nil
}
// Deserialize decodes the byte array into a sequence
func Deserialize(data []byte) (*Sequence, error) {
return nil, nil
}
func getNumBlocks(numBits uint32) uint32 {
numBlocks := numBits / blockLen
if numBits%blockLen != 0 {
numBlocks++
}
return numBlocks
}

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package bitseq
import (
"testing"
)
func TestSequenceGetAvailableBit(t *testing.T) {
input := []struct {
head *Sequence
bytePos int
bitPos int
}{
{&Sequence{Block: 0x0, Count: 0}, -1, -1},
{&Sequence{Block: 0x0, Count: 1}, 0, 0},
{&Sequence{Block: 0x0, Count: 100}, 0, 0},
{&Sequence{Block: 0x80000000, Count: 0}, -1, -1},
{&Sequence{Block: 0x80000000, Count: 1}, 0, 1},
{&Sequence{Block: 0x80000000, Count: 100}, 0, 1},
{&Sequence{Block: 0xFF000000, Count: 0}, -1, -1},
{&Sequence{Block: 0xFF000000, Count: 1}, 1, 0},
{&Sequence{Block: 0xFF000000, Count: 100}, 1, 0},
{&Sequence{Block: 0xFF800000, Count: 0}, -1, -1},
{&Sequence{Block: 0xFF800000, Count: 1}, 1, 1},
{&Sequence{Block: 0xFF800000, Count: 100}, 1, 1},
{&Sequence{Block: 0xFFC0FF00, Count: 0}, -1, -1},
{&Sequence{Block: 0xFFC0FF00, Count: 1}, 1, 2},
{&Sequence{Block: 0xFFC0FF00, Count: 100}, 1, 2},
{&Sequence{Block: 0xFFE0FF00, Count: 0}, -1, -1},
{&Sequence{Block: 0xFFE0FF00, Count: 1}, 1, 3},
{&Sequence{Block: 0xFFE0FF00, Count: 100}, 1, 3},
{&Sequence{Block: 0xFFFEFF00, Count: 0}, -1, -1},
{&Sequence{Block: 0xFFFEFF00, Count: 1}, 1, 7},
{&Sequence{Block: 0xFFFEFF00, Count: 100}, 1, 7},
{&Sequence{Block: 0xFFFFC0FF, Count: 0}, -1, -1},
{&Sequence{Block: 0xFFFFC0FF, Count: 1}, 2, 2},
{&Sequence{Block: 0xFFFFC0FF, Count: 100}, 2, 2},
{&Sequence{Block: 0xFFFFFF00, Count: 0}, -1, -1},
{&Sequence{Block: 0xFFFFFF00, Count: 1}, 3, 0},
{&Sequence{Block: 0xFFFFFF00, Count: 100}, 3, 0},
{&Sequence{Block: 0xFFFFFFFE, Count: 0}, -1, -1},
{&Sequence{Block: 0xFFFFFFFE, Count: 1}, 3, 7},
{&Sequence{Block: 0xFFFFFFFE, Count: 100}, 3, 7},
{&Sequence{Block: 0xFFFFFFFF, Count: 0}, -1, -1},
{&Sequence{Block: 0xFFFFFFFF, Count: 1}, -1, -1},
{&Sequence{Block: 0xFFFFFFFF, Count: 100}, -1, -1},
}
for n, i := range input {
b, bb := i.head.GetAvailableBit()
if b != i.bytePos || bb != i.bitPos {
t.Fatalf("Error in Sequence.getAvailableBit() (%d).\nExp: (%d, %d)\nGot: (%d, %d),", n, i.bytePos, i.bitPos, b, bb)
}
}
}
func TestSequenceEqual(t *testing.T) {
input := []struct {
first *Sequence
second *Sequence
areEqual bool
}{
{&Sequence{Block: 0x0, Count: 8, Next: nil}, &Sequence{Block: 0x0, Count: 8}, true},
{&Sequence{Block: 0x0, Count: 0, Next: nil}, &Sequence{Block: 0x0, Count: 0}, true},
{&Sequence{Block: 0x0, Count: 2, Next: nil}, &Sequence{Block: 0x0, Count: 1, Next: &Sequence{Block: 0x0, Count: 1}}, false},
{&Sequence{Block: 0x0, Count: 2, Next: &Sequence{Block: 0x1, Count: 1}}, &Sequence{Block: 0x0, Count: 2}, false},
{&Sequence{Block: 0x12345678, Count: 8, Next: nil}, &Sequence{Block: 0x12345678, Count: 8}, true},
{&Sequence{Block: 0x12345678, Count: 8, Next: nil}, &Sequence{Block: 0x12345678, Count: 9}, false},
{&Sequence{Block: 0x12345678, Count: 1, Next: &Sequence{Block: 0XFFFFFFFF, Count: 1}}, &Sequence{Block: 0x12345678, Count: 1}, false},
{&Sequence{Block: 0x12345678, Count: 1}, &Sequence{Block: 0x12345678, Count: 1, Next: &Sequence{Block: 0XFFFFFFFF, Count: 1}}, false},
}
for n, i := range input {
if i.areEqual != i.first.Equal(i.second) {
t.Fatalf("Error in Sequence.Equal() (%d).\nExp: %t\nGot: %t,", n, i.areEqual, !i.areEqual)
}
}
}
func TestGetFirstAvailable(t *testing.T) {
input := []struct {
mask *Sequence
bytePos int
bitPos int
}{
{&Sequence{Block: 0xffffffff, Count: 2048}, -1, -1},
{&Sequence{Block: 0x0, Count: 8}, 0, 0},
{&Sequence{Block: 0x80000000, Count: 8}, 0, 1},
{&Sequence{Block: 0xC0000000, Count: 8}, 0, 2},
{&Sequence{Block: 0xE0000000, Count: 8}, 0, 3},
{&Sequence{Block: 0xF0000000, Count: 8}, 0, 4},
{&Sequence{Block: 0xF8000000, Count: 8}, 0, 5},
{&Sequence{Block: 0xFC000000, Count: 8}, 0, 6},
{&Sequence{Block: 0xFE000000, Count: 8}, 0, 7},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0x00000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 0},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0x80000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 1},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xC0000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 2},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xE0000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 3},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xF0000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 4},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xF8000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 5},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFC000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 6},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFE000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 7},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFF000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 0},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFF800000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 1},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFC00000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 2},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFE00000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 3},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFF00000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 4},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFF80000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 5},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFFC0000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 6},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFFE0000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 7},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xfffffffe, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 7, 7},
{&Sequence{Block: 0xffffffff, Count: 2, Next: &Sequence{Block: 0x0, Count: 6}}, 8, 0},
}
for n, i := range input {
bytePos, bitPos := GetFirstAvailable(i.mask)
if bytePos != i.bytePos || bitPos != i.bitPos {
t.Fatalf("Error in (%d) getFirstAvailable(). Expected (%d, %d). Got (%d, %d)", n, i.bytePos, i.bitPos, bytePos, bitPos)
}
}
}
func TestFindSequence(t *testing.T) {
input := []struct {
head *Sequence
bytePos int
precBlocks uint32
inBlockBytePos int
}{
{&Sequence{Block: 0xffffffff, Count: 0}, 0, 0, -1},
{&Sequence{Block: 0xffffffff, Count: 0}, 31, 0, -1},
{&Sequence{Block: 0xffffffff, Count: 0}, 100, 0, -1},
{&Sequence{Block: 0x0, Count: 1}, 0, 0, 0},
{&Sequence{Block: 0x0, Count: 1}, 1, 0, 1},
{&Sequence{Block: 0x0, Count: 1}, 31, 0, -1},
{&Sequence{Block: 0x0, Count: 1}, 60, 0, -1},
{&Sequence{Block: 0xffffffff, Count: 10}, 0, 0, 0},
{&Sequence{Block: 0xffffffff, Count: 10}, 3, 0, 3},
{&Sequence{Block: 0xffffffff, Count: 10}, 4, 1, 0},
{&Sequence{Block: 0xffffffff, Count: 10}, 7, 1, 3},
{&Sequence{Block: 0xffffffff, Count: 10}, 8, 2, 0},
{&Sequence{Block: 0xffffffff, Count: 10}, 39, 9, 3},
{&Sequence{Block: 0xffffffff, Count: 10, Next: &Sequence{Block: 0xcc000000, Count: 10}}, 79, 9, 3},
{&Sequence{Block: 0xffffffff, Count: 10, Next: &Sequence{Block: 0xcc000000, Count: 10}}, 80, 0, -1},
}
for n, i := range input {
_, _, precBlocks, inBlockBytePos := findSequence(i.head, i.bytePos)
if precBlocks != i.precBlocks || inBlockBytePos != i.inBlockBytePos {
t.Fatalf("Error in (%d) findSequence(). Expected (%d, %d). Got (%d, %d)", n, i.precBlocks, i.inBlockBytePos, precBlocks, inBlockBytePos)
}
}
}
func TestCheckIfAvailable(t *testing.T) {
input := []struct {
head *Sequence
ordinal int
bytePos int
bitPos int
}{
{&Sequence{Block: 0xffffffff, Count: 0}, 0, -1, -1},
{&Sequence{Block: 0xffffffff, Count: 0}, 31, -1, -1},
{&Sequence{Block: 0xffffffff, Count: 0}, 100, -1, -1},
{&Sequence{Block: 0x0, Count: 1}, 0, 0, 0},
{&Sequence{Block: 0x0, Count: 1}, 1, 0, 1},
{&Sequence{Block: 0x0, Count: 1}, 31, 3, 7},
{&Sequence{Block: 0x0, Count: 1}, 60, -1, -1},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0x800000ff, Count: 1}}, 31, -1, -1},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0x800000ff, Count: 1}}, 32, -1, -1},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0x800000ff, Count: 1}}, 33, 4, 1},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xC00000ff, Count: 1}}, 33, -1, -1},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xC00000ff, Count: 1}}, 34, 4, 2},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xC00000ff, Count: 1, Next: &Sequence{Block: 0x0, Count: 1}}}, 55, 6, 7},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xC00000ff, Count: 1, Next: &Sequence{Block: 0x0, Count: 1}}}, 56, -1, -1},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xC00000ff, Count: 1, Next: &Sequence{Block: 0x0, Count: 1}}}, 63, -1, -1},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xC00000ff, Count: 1, Next: &Sequence{Block: 0x0, Count: 1}}}, 64, 8, 0},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xC00000ff, Count: 1, Next: &Sequence{Block: 0x0, Count: 1}}}, 95, 11, 7},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xC00000ff, Count: 1, Next: &Sequence{Block: 0x0, Count: 1}}}, 96, -1, -1},
}
for n, i := range input {
bytePos, bitPos := CheckIfAvailable(i.head, i.ordinal)
if bytePos != i.bytePos || bitPos != i.bitPos {
t.Fatalf("Error in (%d) checkIfAvailable(ord:%d). Expected (%d, %d). Got (%d, %d)", n, i.ordinal, i.bytePos, i.bitPos, bytePos, bitPos)
}
}
}
func TestMergeSequences(t *testing.T) {
input := []struct {
original *Sequence
merged *Sequence
}{
{&Sequence{Block: 0xFE000000, Count: 8, Next: &Sequence{Block: 0xFE000000, Count: 2}}, &Sequence{Block: 0xFE000000, Count: 10}},
{&Sequence{Block: 0xFFFFFFFF, Count: 8, Next: &Sequence{Block: 0xFFFFFFFF, Count: 1}}, &Sequence{Block: 0xFFFFFFFF, Count: 9}},
{&Sequence{Block: 0xFFFFFFFF, Count: 1, Next: &Sequence{Block: 0xFFFFFFFF, Count: 8}}, &Sequence{Block: 0xFFFFFFFF, Count: 9}},
{&Sequence{Block: 0xFFFFFFF0, Count: 8, Next: &Sequence{Block: 0xFFFFFFF0, Count: 1}}, &Sequence{Block: 0xFFFFFFF0, Count: 9}},
{&Sequence{Block: 0xFFFFFFF0, Count: 1, Next: &Sequence{Block: 0xFFFFFFF0, Count: 8}}, &Sequence{Block: 0xFFFFFFF0, Count: 9}},
{&Sequence{Block: 0xFE, Count: 8, Next: &Sequence{Block: 0xFE, Count: 1, Next: &Sequence{Block: 0xFE, Count: 5}}}, &Sequence{Block: 0xFE, Count: 14}},
{&Sequence{Block: 0xFE, Count: 8, Next: &Sequence{Block: 0xFE, Count: 1, Next: &Sequence{Block: 0xFE, Count: 5, Next: &Sequence{Block: 0xFF, Count: 1}}}},
&Sequence{Block: 0xFE, Count: 14, Next: &Sequence{Block: 0xFF, Count: 1}}},
// No merge
{&Sequence{Block: 0xFE, Count: 8, Next: &Sequence{Block: 0xF8, Count: 1, Next: &Sequence{Block: 0xFE, Count: 5}}},
&Sequence{Block: 0xFE, Count: 8, Next: &Sequence{Block: 0xF8, Count: 1, Next: &Sequence{Block: 0xFE, Count: 5}}}},
// No merge from head: // Merge function tries to merge from passed head. If it can't merge with Next, it does not reattempt with Next as head
{&Sequence{Block: 0xFE, Count: 8, Next: &Sequence{Block: 0xFF, Count: 1, Next: &Sequence{Block: 0xFF, Count: 5}}},
&Sequence{Block: 0xFE, Count: 8, Next: &Sequence{Block: 0xFF, Count: 6}}},
}
for n, i := range input {
mergeSequences(i.original)
for !i.merged.Equal(i.original) {
t.Fatalf("Error in (%d) mergeSequences().\nExp: %s\nGot: %s,", n, i.merged, i.original)
}
}
}
func TestPushReservation(t *testing.T) {
input := []struct {
mask *Sequence
bytePos int
bitPos int
newMask *Sequence
}{
// Create first Sequence and fill in 8 addresses starting from address 0
{&Sequence{Block: 0x0, Count: 8, Next: nil}, 0, 0, &Sequence{Block: 0x80000000, Count: 1, Next: &Sequence{Block: 0x0, Count: 7, Next: nil}}},
{&Sequence{Block: 0x80000000, Count: 8}, 0, 1, &Sequence{Block: 0xC0000000, Count: 1, Next: &Sequence{Block: 0x80000000, Count: 7, Next: nil}}},
{&Sequence{Block: 0xC0000000, Count: 8}, 0, 2, &Sequence{Block: 0xE0000000, Count: 1, Next: &Sequence{Block: 0xC0000000, Count: 7, Next: nil}}},
{&Sequence{Block: 0xE0000000, Count: 8}, 0, 3, &Sequence{Block: 0xF0000000, Count: 1, Next: &Sequence{Block: 0xE0000000, Count: 7, Next: nil}}},
{&Sequence{Block: 0xF0000000, Count: 8}, 0, 4, &Sequence{Block: 0xF8000000, Count: 1, Next: &Sequence{Block: 0xF0000000, Count: 7, Next: nil}}},
{&Sequence{Block: 0xF8000000, Count: 8}, 0, 5, &Sequence{Block: 0xFC000000, Count: 1, Next: &Sequence{Block: 0xF8000000, Count: 7, Next: nil}}},
{&Sequence{Block: 0xFC000000, Count: 8}, 0, 6, &Sequence{Block: 0xFE000000, Count: 1, Next: &Sequence{Block: 0xFC000000, Count: 7, Next: nil}}},
{&Sequence{Block: 0xFE000000, Count: 8}, 0, 7, &Sequence{Block: 0xFF000000, Count: 1, Next: &Sequence{Block: 0xFE000000, Count: 7, Next: nil}}},
{&Sequence{Block: 0x80000000, Count: 1, Next: &Sequence{Block: 0x0, Count: 7}}, 0, 1, &Sequence{Block: 0xC0000000, Count: 1, Next: &Sequence{Block: 0x0, Count: 7, Next: nil}}},
// Create second Sequence and fill in 8 addresses starting from address 32
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0x00000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6, Next: nil}}}, 4, 0,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0x80000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0x80000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 1,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xC0000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xC0000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 2,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xE0000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xE0000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 3,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xF0000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xF0000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 4,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xF8000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xF8000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 5,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFC000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFC000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 6,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFE000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFE000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 4, 7,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFF000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
// fill in 8 addresses starting from address 40
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFF000000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 0,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFF800000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFF800000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 1,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFC00000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFC00000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 2,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFE00000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFE00000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 3,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFF00000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFF00000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 4,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFF80000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFF80000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 5,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFFC0000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFFC0000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 6,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFFE0000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFFE0000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}, 5, 7,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xFFFF0000, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 6}}}},
// Insert new Sequence
{&Sequence{Block: 0xffffffff, Count: 2, Next: &Sequence{Block: 0x0, Count: 6}}, 8, 0,
&Sequence{Block: 0xffffffff, Count: 2, Next: &Sequence{Block: 0x80000000, Count: 1, Next: &Sequence{Block: 0x0, Count: 5}}}},
{&Sequence{Block: 0xffffffff, Count: 2, Next: &Sequence{Block: 0x80000000, Count: 1, Next: &Sequence{Block: 0x0, Count: 5}}}, 8, 1,
&Sequence{Block: 0xffffffff, Count: 2, Next: &Sequence{Block: 0xC0000000, Count: 1, Next: &Sequence{Block: 0x0, Count: 5}}}},
// Merge affected with Next
{&Sequence{Block: 0xffffffff, Count: 7, Next: &Sequence{Block: 0xfffffffe, Count: 2, Next: &Sequence{Block: 0xffffffff, Count: 1}}}, 31, 7,
&Sequence{Block: 0xffffffff, Count: 8, Next: &Sequence{Block: 0xfffffffe, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 1}}}},
{&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xfffffffc, Count: 1, Next: &Sequence{Block: 0xfffffffe, Count: 6}}}, 7, 6,
&Sequence{Block: 0xffffffff, Count: 1, Next: &Sequence{Block: 0xfffffffe, Count: 7}}},
// Merge affected with Next and Next.Next
{&Sequence{Block: 0xffffffff, Count: 7, Next: &Sequence{Block: 0xfffffffe, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 1}}}, 31, 7,
&Sequence{Block: 0xffffffff, Count: 9}},
{&Sequence{Block: 0xffffffff, Count: 7, Next: &Sequence{Block: 0xfffffffe, Count: 1}}, 31, 7,
&Sequence{Block: 0xffffffff, Count: 8}},
// Merge affected with previous and Next
{&Sequence{Block: 0xffffffff, Count: 7, Next: &Sequence{Block: 0xfffffffe, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 1}}}, 31, 7,
&Sequence{Block: 0xffffffff, Count: 9}},
// Redundant push: No change
{&Sequence{Block: 0xffff0000, Count: 1}, 0, 0, &Sequence{Block: 0xffff0000, Count: 1}},
{&Sequence{Block: 0xffff0000, Count: 7}, 25, 7, &Sequence{Block: 0xffff0000, Count: 7}},
{&Sequence{Block: 0xffffffff, Count: 7, Next: &Sequence{Block: 0xfffffffe, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 1}}}, 7, 7,
&Sequence{Block: 0xffffffff, Count: 7, Next: &Sequence{Block: 0xfffffffe, Count: 1, Next: &Sequence{Block: 0xffffffff, Count: 1}}}},
}
for n, i := range input {
mask := PushReservation(i.bytePos, i.bitPos, i.mask, false)
if !mask.Equal(i.newMask) {
t.Fatalf("Error in (%d) pushReservation():\n%s + (%d,%d):\nExp: %s\nGot: %s,", n, i.mask, i.bytePos, i.bitPos, i.newMask, mask)
}
}
}