mv tmlibs files to libs dir

2026-09-19 14:34:17 +00:00 · 2018-07-01 22:36:03 -04:00
parent 2d7ffdd72b
commit ae3bf81833
174 changed files with 0 additions and 0 deletions
@@ -0,0 +1,378 @@
+package common
+
+import (
+	"encoding/binary"
+	"fmt"
+	"regexp"
+	"strings"
+	"sync"
+)
+
+type BitArray struct {
+	mtx   sync.Mutex
+	Bits  int      `json:"bits"`  // NOTE: persisted via reflect, must be exported
+	Elems []uint64 `json:"elems"` // NOTE: persisted via reflect, must be exported
+}
+
+// There is no BitArray whose Size is 0.  Use nil instead.
+func NewBitArray(bits int) *BitArray {
+	if bits <= 0 {
+		return nil
+	}
+	return &BitArray{
+		Bits:  bits,
+		Elems: make([]uint64, (bits+63)/64),
+	}
+}
+
+func (bA *BitArray) Size() int {
+	if bA == nil {
+		return 0
+	}
+	return bA.Bits
+}
+
+// NOTE: behavior is undefined if i >= bA.Bits
+func (bA *BitArray) GetIndex(i int) bool {
+	if bA == nil {
+		return false
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+	return bA.getIndex(i)
+}
+
+func (bA *BitArray) getIndex(i int) bool {
+	if i >= bA.Bits {
+		return false
+	}
+	return bA.Elems[i/64]&(uint64(1)<<uint(i%64)) > 0
+}
+
+// NOTE: behavior is undefined if i >= bA.Bits
+func (bA *BitArray) SetIndex(i int, v bool) bool {
+	if bA == nil {
+		return false
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+	return bA.setIndex(i, v)
+}
+
+func (bA *BitArray) setIndex(i int, v bool) bool {
+	if i >= bA.Bits {
+		return false
+	}
+	if v {
+		bA.Elems[i/64] |= (uint64(1) << uint(i%64))
+	} else {
+		bA.Elems[i/64] &= ^(uint64(1) << uint(i%64))
+	}
+	return true
+}
+
+func (bA *BitArray) Copy() *BitArray {
+	if bA == nil {
+		return nil
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+	return bA.copy()
+}
+
+func (bA *BitArray) copy() *BitArray {
+	c := make([]uint64, len(bA.Elems))
+	copy(c, bA.Elems)
+	return &BitArray{
+		Bits:  bA.Bits,
+		Elems: c,
+	}
+}
+
+func (bA *BitArray) copyBits(bits int) *BitArray {
+	c := make([]uint64, (bits+63)/64)
+	copy(c, bA.Elems)
+	return &BitArray{
+		Bits:  bits,
+		Elems: c,
+	}
+}
+
+// Returns a BitArray of larger bits size.
+func (bA *BitArray) Or(o *BitArray) *BitArray {
+	if bA == nil && o == nil {
+		return nil
+	}
+	if bA == nil && o != nil {
+		return o.Copy()
+	}
+	if o == nil {
+		return bA.Copy()
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+	c := bA.copyBits(MaxInt(bA.Bits, o.Bits))
+	for i := 0; i < len(c.Elems); i++ {
+		c.Elems[i] |= o.Elems[i]
+	}
+	return c
+}
+
+// Returns a BitArray of smaller bit size.
+func (bA *BitArray) And(o *BitArray) *BitArray {
+	if bA == nil || o == nil {
+		return nil
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+	return bA.and(o)
+}
+
+func (bA *BitArray) and(o *BitArray) *BitArray {
+	c := bA.copyBits(MinInt(bA.Bits, o.Bits))
+	for i := 0; i < len(c.Elems); i++ {
+		c.Elems[i] &= o.Elems[i]
+	}
+	return c
+}
+
+func (bA *BitArray) Not() *BitArray {
+	if bA == nil {
+		return nil // Degenerate
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+	c := bA.copy()
+	for i := 0; i < len(c.Elems); i++ {
+		c.Elems[i] = ^c.Elems[i]
+	}
+	return c
+}
+
+func (bA *BitArray) Sub(o *BitArray) *BitArray {
+	if bA == nil || o == nil {
+		// TODO: Decide if we should do 1's complement here?
+		return nil
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+	if bA.Bits > o.Bits {
+		c := bA.copy()
+		for i := 0; i < len(o.Elems)-1; i++ {
+			c.Elems[i] &= ^c.Elems[i]
+		}
+		i := len(o.Elems) - 1
+		if i >= 0 {
+			for idx := i * 64; idx < o.Bits; idx++ {
+				// NOTE: each individual GetIndex() call to o is safe.
+				c.setIndex(idx, c.getIndex(idx) && !o.GetIndex(idx))
+			}
+		}
+		return c
+	}
+	return bA.and(o.Not()) // Note degenerate case where o == nil
+}
+
+func (bA *BitArray) IsEmpty() bool {
+	if bA == nil {
+		return true // should this be opposite?
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+	for _, e := range bA.Elems {
+		if e > 0 {
+			return false
+		}
+	}
+	return true
+}
+
+func (bA *BitArray) IsFull() bool {
+	if bA == nil {
+		return true
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+
+	// Check all elements except the last
+	for _, elem := range bA.Elems[:len(bA.Elems)-1] {
+		if (^elem) != 0 {
+			return false
+		}
+	}
+
+	// Check that the last element has (lastElemBits) 1's
+	lastElemBits := (bA.Bits+63)%64 + 1
+	lastElem := bA.Elems[len(bA.Elems)-1]
+	return (lastElem+1)&((uint64(1)<<uint(lastElemBits))-1) == 0
+}
+
+func (bA *BitArray) PickRandom() (int, bool) {
+	if bA == nil {
+		return 0, false
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+
+	length := len(bA.Elems)
+	if length == 0 {
+		return 0, false
+	}
+	randElemStart := RandIntn(length)
+	for i := 0; i < length; i++ {
+		elemIdx := ((i + randElemStart) % length)
+		if elemIdx < length-1 {
+			if bA.Elems[elemIdx] > 0 {
+				randBitStart := RandIntn(64)
+				for j := 0; j < 64; j++ {
+					bitIdx := ((j + randBitStart) % 64)
+					if (bA.Elems[elemIdx] & (uint64(1) << uint(bitIdx))) > 0 {
+						return 64*elemIdx + bitIdx, true
+					}
+				}
+				PanicSanity("should not happen")
+			}
+		} else {
+			// Special case for last elem, to ignore straggler bits
+			elemBits := bA.Bits % 64
+			if elemBits == 0 {
+				elemBits = 64
+			}
+			randBitStart := RandIntn(elemBits)
+			for j := 0; j < elemBits; j++ {
+				bitIdx := ((j + randBitStart) % elemBits)
+				if (bA.Elems[elemIdx] & (uint64(1) << uint(bitIdx))) > 0 {
+					return 64*elemIdx + bitIdx, true
+				}
+			}
+		}
+	}
+	return 0, false
+}
+
+// String returns a string representation of BitArray: BA{<bit-string>},
+// where <bit-string> is a sequence of 'x' (1) and '_' (0).
+// The <bit-string> includes spaces and newlines to help people.
+// For a simple sequence of 'x' and '_' characters with no spaces or newlines,
+// see the MarshalJSON() method.
+// Example: "BA{_x_}" or "nil-BitArray" for nil.
+func (bA *BitArray) String() string {
+	return bA.StringIndented("")
+}
+
+func (bA *BitArray) StringIndented(indent string) string {
+	if bA == nil {
+		return "nil-BitArray"
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+	return bA.stringIndented(indent)
+}
+
+func (bA *BitArray) stringIndented(indent string) string {
+	lines := []string{}
+	bits := ""
+	for i := 0; i < bA.Bits; i++ {
+		if bA.getIndex(i) {
+			bits += "x"
+		} else {
+			bits += "_"
+		}
+		if i%100 == 99 {
+			lines = append(lines, bits)
+			bits = ""
+		}
+		if i%10 == 9 {
+			bits += indent
+		}
+		if i%50 == 49 {
+			bits += indent
+		}
+	}
+	if len(bits) > 0 {
+		lines = append(lines, bits)
+	}
+	return fmt.Sprintf("BA{%v:%v}", bA.Bits, strings.Join(lines, indent))
+}
+
+func (bA *BitArray) Bytes() []byte {
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+
+	numBytes := (bA.Bits + 7) / 8
+	bytes := make([]byte, numBytes)
+	for i := 0; i < len(bA.Elems); i++ {
+		elemBytes := [8]byte{}
+		binary.LittleEndian.PutUint64(elemBytes[:], bA.Elems[i])
+		copy(bytes[i*8:], elemBytes[:])
+	}
+	return bytes
+}
+
+// NOTE: other bitarray o is not locked when reading,
+// so if necessary, caller must copy or lock o prior to calling Update.
+// If bA is nil, does nothing.
+func (bA *BitArray) Update(o *BitArray) {
+	if bA == nil || o == nil {
+		return
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+
+	copy(bA.Elems, o.Elems)
+}
+
+// MarshalJSON implements json.Marshaler interface by marshaling bit array
+// using a custom format: a string of '-' or 'x' where 'x' denotes the 1 bit.
+func (bA *BitArray) MarshalJSON() ([]byte, error) {
+	if bA == nil {
+		return []byte("null"), nil
+	}
+
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+
+	bits := `"`
+	for i := 0; i < bA.Bits; i++ {
+		if bA.getIndex(i) {
+			bits += `x`
+		} else {
+			bits += `_`
+		}
+	}
+	bits += `"`
+	return []byte(bits), nil
+}
+
+var bitArrayJSONRegexp = regexp.MustCompile(`\A"([_x]*)"\z`)
+
+// UnmarshalJSON implements json.Unmarshaler interface by unmarshaling a custom
+// JSON description.
+func (bA *BitArray) UnmarshalJSON(bz []byte) error {
+	b := string(bz)
+	if b == "null" {
+		// This is required e.g. for encoding/json when decoding
+		// into a pointer with pre-allocated BitArray.
+		bA.Bits = 0
+		bA.Elems = nil
+		return nil
+	}
+
+	// Validate 'b'.
+	match := bitArrayJSONRegexp.FindStringSubmatch(b)
+	if match == nil {
+		return fmt.Errorf("BitArray in JSON should be a string of format %q but got %s", bitArrayJSONRegexp.String(), b)
+	}
+	bits := match[1]
+
+	// Construct new BitArray and copy over.
+	numBits := len(bits)
+	bA2 := NewBitArray(numBits)
+	for i := 0; i < numBits; i++ {
+		if bits[i] == 'x' {
+			bA2.SetIndex(i, true)
+		}
+	}
+	*bA = *bA2
+	return nil
+}