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Diffstat (limited to 'vendor/k8s.io/apimachinery/pkg/api/resource/quantity.go')
-rw-r--r-- | vendor/k8s.io/apimachinery/pkg/api/resource/quantity.go | 792 |
1 files changed, 792 insertions, 0 deletions
diff --git a/vendor/k8s.io/apimachinery/pkg/api/resource/quantity.go b/vendor/k8s.io/apimachinery/pkg/api/resource/quantity.go new file mode 100644 index 000000000..3a9560882 --- /dev/null +++ b/vendor/k8s.io/apimachinery/pkg/api/resource/quantity.go @@ -0,0 +1,792 @@ +/* +Copyright 2014 The Kubernetes Authors. + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +package resource + +import ( + "bytes" + "errors" + "fmt" + "math/big" + "regexp" + "strconv" + "strings" + + flag "github.com/spf13/pflag" + + "github.com/go-openapi/spec" + inf "gopkg.in/inf.v0" + "k8s.io/apimachinery/pkg/openapi" +) + +// Quantity is a fixed-point representation of a number. +// It provides convenient marshaling/unmarshaling in JSON and YAML, +// in addition to String() and Int64() accessors. +// +// The serialization format is: +// +// <quantity> ::= <signedNumber><suffix> +// (Note that <suffix> may be empty, from the "" case in <decimalSI>.) +// <digit> ::= 0 | 1 | ... | 9 +// <digits> ::= <digit> | <digit><digits> +// <number> ::= <digits> | <digits>.<digits> | <digits>. | .<digits> +// <sign> ::= "+" | "-" +// <signedNumber> ::= <number> | <sign><number> +// <suffix> ::= <binarySI> | <decimalExponent> | <decimalSI> +// <binarySI> ::= Ki | Mi | Gi | Ti | Pi | Ei +// (International System of units; See: http://physics.nist.gov/cuu/Units/binary.html) +// <decimalSI> ::= m | "" | k | M | G | T | P | E +// (Note that 1024 = 1Ki but 1000 = 1k; I didn't choose the capitalization.) +// <decimalExponent> ::= "e" <signedNumber> | "E" <signedNumber> +// +// No matter which of the three exponent forms is used, no quantity may represent +// a number greater than 2^63-1 in magnitude, nor may it have more than 3 decimal +// places. Numbers larger or more precise will be capped or rounded up. +// (E.g.: 0.1m will rounded up to 1m.) +// This may be extended in the future if we require larger or smaller quantities. +// +// When a Quantity is parsed from a string, it will remember the type of suffix +// it had, and will use the same type again when it is serialized. +// +// Before serializing, Quantity will be put in "canonical form". +// This means that Exponent/suffix will be adjusted up or down (with a +// corresponding increase or decrease in Mantissa) such that: +// a. No precision is lost +// b. No fractional digits will be emitted +// c. The exponent (or suffix) is as large as possible. +// The sign will be omitted unless the number is negative. +// +// Examples: +// 1.5 will be serialized as "1500m" +// 1.5Gi will be serialized as "1536Mi" +// +// NOTE: We reserve the right to amend this canonical format, perhaps to +// allow 1.5 to be canonical. +// TODO: Remove above disclaimer after all bikeshedding about format is over, +// or after March 2015. +// +// Note that the quantity will NEVER be internally represented by a +// floating point number. That is the whole point of this exercise. +// +// Non-canonical values will still parse as long as they are well formed, +// but will be re-emitted in their canonical form. (So always use canonical +// form, or don't diff.) +// +// This format is intended to make it difficult to use these numbers without +// writing some sort of special handling code in the hopes that that will +// cause implementors to also use a fixed point implementation. +// +// +protobuf=true +// +protobuf.embed=string +// +protobuf.options.marshal=false +// +protobuf.options.(gogoproto.goproto_stringer)=false +// +k8s:openapi-gen=true +type Quantity struct { + // i is the quantity in int64 scaled form, if d.Dec == nil + i int64Amount + // d is the quantity in inf.Dec form if d.Dec != nil + d infDecAmount + // s is the generated value of this quantity to avoid recalculation + s string + + // Change Format at will. See the comment for Canonicalize for + // more details. + Format +} + +// CanonicalValue allows a quantity amount to be converted to a string. +type CanonicalValue interface { + // AsCanonicalBytes returns a byte array representing the string representation + // of the value mantissa and an int32 representing its exponent in base-10. Callers may + // pass a byte slice to the method to avoid allocations. + AsCanonicalBytes(out []byte) ([]byte, int32) + // AsCanonicalBase1024Bytes returns a byte array representing the string representation + // of the value mantissa and an int32 representing its exponent in base-1024. Callers + // may pass a byte slice to the method to avoid allocations. + AsCanonicalBase1024Bytes(out []byte) ([]byte, int32) +} + +// Format lists the three possible formattings of a quantity. +type Format string + +const ( + DecimalExponent = Format("DecimalExponent") // e.g., 12e6 + BinarySI = Format("BinarySI") // e.g., 12Mi (12 * 2^20) + DecimalSI = Format("DecimalSI") // e.g., 12M (12 * 10^6) +) + +// MustParse turns the given string into a quantity or panics; for tests +// or others cases where you know the string is valid. +func MustParse(str string) Quantity { + q, err := ParseQuantity(str) + if err != nil { + panic(fmt.Errorf("cannot parse '%v': %v", str, err)) + } + return q +} + +const ( + // splitREString is used to separate a number from its suffix; as such, + // this is overly permissive, but that's OK-- it will be checked later. + splitREString = "^([+-]?[0-9.]+)([eEinumkKMGTP]*[-+]?[0-9]*)$" +) + +var ( + // splitRE is used to get the various parts of a number. + splitRE = regexp.MustCompile(splitREString) + + // Errors that could happen while parsing a string. + ErrFormatWrong = errors.New("quantities must match the regular expression '" + splitREString + "'") + ErrNumeric = errors.New("unable to parse numeric part of quantity") + ErrSuffix = errors.New("unable to parse quantity's suffix") +) + +// parseQuantityString is a fast scanner for quantity values. +func parseQuantityString(str string) (positive bool, value, num, denom, suffix string, err error) { + positive = true + pos := 0 + end := len(str) + + // handle leading sign + if pos < end { + switch str[0] { + case '-': + positive = false + pos++ + case '+': + pos++ + } + } + + // strip leading zeros +Zeroes: + for i := pos; ; i++ { + if i >= end { + num = "0" + value = num + return + } + switch str[i] { + case '0': + pos++ + default: + break Zeroes + } + } + + // extract the numerator +Num: + for i := pos; ; i++ { + if i >= end { + num = str[pos:end] + value = str[0:end] + return + } + switch str[i] { + case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': + default: + num = str[pos:i] + pos = i + break Num + } + } + + // if we stripped all numerator positions, always return 0 + if len(num) == 0 { + num = "0" + } + + // handle a denominator + if pos < end && str[pos] == '.' { + pos++ + Denom: + for i := pos; ; i++ { + if i >= end { + denom = str[pos:end] + value = str[0:end] + return + } + switch str[i] { + case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': + default: + denom = str[pos:i] + pos = i + break Denom + } + } + // TODO: we currently allow 1.G, but we may not want to in the future. + // if len(denom) == 0 { + // err = ErrFormatWrong + // return + // } + } + value = str[0:pos] + + // grab the elements of the suffix + suffixStart := pos + for i := pos; ; i++ { + if i >= end { + suffix = str[suffixStart:end] + return + } + if !strings.ContainsAny(str[i:i+1], "eEinumkKMGTP") { + pos = i + break + } + } + if pos < end { + switch str[pos] { + case '-', '+': + pos++ + } + } +Suffix: + for i := pos; ; i++ { + if i >= end { + suffix = str[suffixStart:end] + return + } + switch str[i] { + case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': + default: + break Suffix + } + } + // we encountered a non decimal in the Suffix loop, but the last character + // was not a valid exponent + err = ErrFormatWrong + return +} + +// ParseQuantity turns str into a Quantity, or returns an error. +func ParseQuantity(str string) (Quantity, error) { + if len(str) == 0 { + return Quantity{}, ErrFormatWrong + } + if str == "0" { + return Quantity{Format: DecimalSI, s: str}, nil + } + + positive, value, num, denom, suf, err := parseQuantityString(str) + if err != nil { + return Quantity{}, err + } + + base, exponent, format, ok := quantitySuffixer.interpret(suffix(suf)) + if !ok { + return Quantity{}, ErrSuffix + } + + precision := int32(0) + scale := int32(0) + mantissa := int64(1) + switch format { + case DecimalExponent, DecimalSI: + scale = exponent + precision = maxInt64Factors - int32(len(num)+len(denom)) + case BinarySI: + scale = 0 + switch { + case exponent >= 0 && len(denom) == 0: + // only handle positive binary numbers with the fast path + mantissa = int64(int64(mantissa) << uint64(exponent)) + // 1Mi (2^20) has ~6 digits of decimal precision, so exponent*3/10 -1 is roughly the precision + precision = 15 - int32(len(num)) - int32(float32(exponent)*3/10) - 1 + default: + precision = -1 + } + } + + if precision >= 0 { + // if we have a denominator, shift the entire value to the left by the number of places in the + // denominator + scale -= int32(len(denom)) + if scale >= int32(Nano) { + shifted := num + denom + + var value int64 + value, err := strconv.ParseInt(shifted, 10, 64) + if err != nil { + return Quantity{}, ErrNumeric + } + if result, ok := int64Multiply(value, int64(mantissa)); ok { + if !positive { + result = -result + } + // if the number is in canonical form, reuse the string + switch format { + case BinarySI: + if exponent%10 == 0 && (value&0x07 != 0) { + return Quantity{i: int64Amount{value: result, scale: Scale(scale)}, Format: format, s: str}, nil + } + default: + if scale%3 == 0 && !strings.HasSuffix(shifted, "000") && shifted[0] != '0' { + return Quantity{i: int64Amount{value: result, scale: Scale(scale)}, Format: format, s: str}, nil + } + } + return Quantity{i: int64Amount{value: result, scale: Scale(scale)}, Format: format}, nil + } + } + } + + amount := new(inf.Dec) + if _, ok := amount.SetString(value); !ok { + return Quantity{}, ErrNumeric + } + + // So that no one but us has to think about suffixes, remove it. + if base == 10 { + amount.SetScale(amount.Scale() + Scale(exponent).infScale()) + } else if base == 2 { + // numericSuffix = 2 ** exponent + numericSuffix := big.NewInt(1).Lsh(bigOne, uint(exponent)) + ub := amount.UnscaledBig() + amount.SetUnscaledBig(ub.Mul(ub, numericSuffix)) + } + + // Cap at min/max bounds. + sign := amount.Sign() + if sign == -1 { + amount.Neg(amount) + } + + // This rounds non-zero values up to the minimum representable value, under the theory that + // if you want some resources, you should get some resources, even if you asked for way too small + // of an amount. Arguably, this should be inf.RoundHalfUp (normal rounding), but that would have + // the side effect of rounding values < .5n to zero. + if v, ok := amount.Unscaled(); v != int64(0) || !ok { + amount.Round(amount, Nano.infScale(), inf.RoundUp) + } + + // The max is just a simple cap. + // TODO: this prevents accumulating quantities greater than int64, for instance quota across a cluster + if format == BinarySI && amount.Cmp(maxAllowed.Dec) > 0 { + amount.Set(maxAllowed.Dec) + } + + if format == BinarySI && amount.Cmp(decOne) < 0 && amount.Cmp(decZero) > 0 { + // This avoids rounding and hopefully confusion, too. + format = DecimalSI + } + if sign == -1 { + amount.Neg(amount) + } + + return Quantity{d: infDecAmount{amount}, Format: format}, nil +} + +// DeepCopy returns a deep-copy of the Quantity value. Note that the method +// receiver is a value, so we can mutate it in-place and return it. +func (q Quantity) DeepCopy() Quantity { + if q.d.Dec != nil { + tmp := &inf.Dec{} + q.d.Dec = tmp.Set(q.d.Dec) + } + return q +} + +// OpenAPIDefinition returns openAPI definition for this type. +func (_ Quantity) OpenAPIDefinition() openapi.OpenAPIDefinition { + return openapi.OpenAPIDefinition{ + Schema: spec.Schema{ + SchemaProps: spec.SchemaProps{ + Type: []string{"string"}, + Format: "", + }, + }, + } +} + +// CanonicalizeBytes returns the canonical form of q and its suffix (see comment on Quantity). +// +// Note about BinarySI: +// * If q.Format is set to BinarySI and q.Amount represents a non-zero value between +// -1 and +1, it will be emitted as if q.Format were DecimalSI. +// * Otherwise, if q.Format is set to BinarySI, frational parts of q.Amount will be +// rounded up. (1.1i becomes 2i.) +func (q *Quantity) CanonicalizeBytes(out []byte) (result, suffix []byte) { + if q.IsZero() { + return zeroBytes, nil + } + + var rounded CanonicalValue + format := q.Format + switch format { + case DecimalExponent, DecimalSI: + case BinarySI: + if q.CmpInt64(-1024) > 0 && q.CmpInt64(1024) < 0 { + // This avoids rounding and hopefully confusion, too. + format = DecimalSI + } else { + var exact bool + if rounded, exact = q.AsScale(0); !exact { + // Don't lose precision-- show as DecimalSI + format = DecimalSI + } + } + default: + format = DecimalExponent + } + + // TODO: If BinarySI formatting is requested but would cause rounding, upgrade to + // one of the other formats. + switch format { + case DecimalExponent, DecimalSI: + number, exponent := q.AsCanonicalBytes(out) + suffix, _ := quantitySuffixer.constructBytes(10, exponent, format) + return number, suffix + default: + // format must be BinarySI + number, exponent := rounded.AsCanonicalBase1024Bytes(out) + suffix, _ := quantitySuffixer.constructBytes(2, exponent*10, format) + return number, suffix + } +} + +// AsInt64 returns a representation of the current value as an int64 if a fast conversion +// is possible. If false is returned, callers must use the inf.Dec form of this quantity. +func (q *Quantity) AsInt64() (int64, bool) { + if q.d.Dec != nil { + return 0, false + } + return q.i.AsInt64() +} + +// ToDec promotes the quantity in place to use an inf.Dec representation and returns itself. +func (q *Quantity) ToDec() *Quantity { + if q.d.Dec == nil { + q.d.Dec = q.i.AsDec() + q.i = int64Amount{} + } + return q +} + +// AsDec returns the quantity as represented by a scaled inf.Dec. +func (q *Quantity) AsDec() *inf.Dec { + if q.d.Dec != nil { + return q.d.Dec + } + q.d.Dec = q.i.AsDec() + q.i = int64Amount{} + return q.d.Dec +} + +// AsCanonicalBytes returns the canonical byte representation of this quantity as a mantissa +// and base 10 exponent. The out byte slice may be passed to the method to avoid an extra +// allocation. +func (q *Quantity) AsCanonicalBytes(out []byte) (result []byte, exponent int32) { + if q.d.Dec != nil { + return q.d.AsCanonicalBytes(out) + } + return q.i.AsCanonicalBytes(out) +} + +// IsZero returns true if the quantity is equal to zero. +func (q *Quantity) IsZero() bool { + if q.d.Dec != nil { + return q.d.Dec.Sign() == 0 + } + return q.i.value == 0 +} + +// Sign returns 0 if the quantity is zero, -1 if the quantity is less than zero, or 1 if the +// quantity is greater than zero. +func (q *Quantity) Sign() int { + if q.d.Dec != nil { + return q.d.Dec.Sign() + } + return q.i.Sign() +} + +// AsScaled returns the current value, rounded up to the provided scale, and returns +// false if the scale resulted in a loss of precision. +func (q *Quantity) AsScale(scale Scale) (CanonicalValue, bool) { + if q.d.Dec != nil { + return q.d.AsScale(scale) + } + return q.i.AsScale(scale) +} + +// RoundUp updates the quantity to the provided scale, ensuring that the value is at +// least 1. False is returned if the rounding operation resulted in a loss of precision. +// Negative numbers are rounded away from zero (-9 scale 1 rounds to -10). +func (q *Quantity) RoundUp(scale Scale) bool { + if q.d.Dec != nil { + q.s = "" + d, exact := q.d.AsScale(scale) + q.d = d + return exact + } + // avoid clearing the string value if we have already calculated it + if q.i.scale >= scale { + return true + } + q.s = "" + i, exact := q.i.AsScale(scale) + q.i = i + return exact +} + +// Add adds the provide y quantity to the current value. If the current value is zero, +// the format of the quantity will be updated to the format of y. +func (q *Quantity) Add(y Quantity) { + q.s = "" + if q.d.Dec == nil && y.d.Dec == nil { + if q.i.value == 0 { + q.Format = y.Format + } + if q.i.Add(y.i) { + return + } + } else if q.IsZero() { + q.Format = y.Format + } + q.ToDec().d.Dec.Add(q.d.Dec, y.AsDec()) +} + +// Sub subtracts the provided quantity from the current value in place. If the current +// value is zero, the format of the quantity will be updated to the format of y. +func (q *Quantity) Sub(y Quantity) { + q.s = "" + if q.IsZero() { + q.Format = y.Format + } + if q.d.Dec == nil && y.d.Dec == nil && q.i.Sub(y.i) { + return + } + q.ToDec().d.Dec.Sub(q.d.Dec, y.AsDec()) +} + +// Cmp returns 0 if the quantity is equal to y, -1 if the quantity is less than y, or 1 if the +// quantity is greater than y. +func (q *Quantity) Cmp(y Quantity) int { + if q.d.Dec == nil && y.d.Dec == nil { + return q.i.Cmp(y.i) + } + return q.AsDec().Cmp(y.AsDec()) +} + +// CmpInt64 returns 0 if the quantity is equal to y, -1 if the quantity is less than y, or 1 if the +// quantity is greater than y. +func (q *Quantity) CmpInt64(y int64) int { + if q.d.Dec != nil { + return q.d.Dec.Cmp(inf.NewDec(y, inf.Scale(0))) + } + return q.i.Cmp(int64Amount{value: y}) +} + +// Neg sets quantity to be the negative value of itself. +func (q *Quantity) Neg() { + q.s = "" + if q.d.Dec == nil { + q.i.value = -q.i.value + return + } + q.d.Dec.Neg(q.d.Dec) +} + +// int64QuantityExpectedBytes is the expected width in bytes of the canonical string representation +// of most Quantity values. +const int64QuantityExpectedBytes = 18 + +// String formats the Quantity as a string, caching the result if not calculated. +// String is an expensive operation and caching this result significantly reduces the cost of +// normal parse / marshal operations on Quantity. +func (q *Quantity) String() string { + if len(q.s) == 0 { + result := make([]byte, 0, int64QuantityExpectedBytes) + number, suffix := q.CanonicalizeBytes(result) + number = append(number, suffix...) + q.s = string(number) + } + return q.s +} + +// MarshalJSON implements the json.Marshaller interface. +func (q Quantity) MarshalJSON() ([]byte, error) { + if len(q.s) > 0 { + out := make([]byte, len(q.s)+2) + out[0], out[len(out)-1] = '"', '"' + copy(out[1:], q.s) + return out, nil + } + result := make([]byte, int64QuantityExpectedBytes, int64QuantityExpectedBytes) + result[0] = '"' + number, suffix := q.CanonicalizeBytes(result[1:1]) + // if the same slice was returned to us that we passed in, avoid another allocation by copying number into + // the source slice and returning that + if len(number) > 0 && &number[0] == &result[1] && (len(number)+len(suffix)+2) <= int64QuantityExpectedBytes { + number = append(number, suffix...) + number = append(number, '"') + return result[:1+len(number)], nil + } + // if CanonicalizeBytes needed more space than our slice provided, we may need to allocate again so use + // append + result = result[:1] + result = append(result, number...) + result = append(result, suffix...) + result = append(result, '"') + return result, nil +} + +// UnmarshalJSON implements the json.Unmarshaller interface. +// TODO: Remove support for leading/trailing whitespace +func (q *Quantity) UnmarshalJSON(value []byte) error { + l := len(value) + if l == 4 && bytes.Equal(value, []byte("null")) { + q.d.Dec = nil + q.i = int64Amount{} + return nil + } + if l >= 2 && value[0] == '"' && value[l-1] == '"' { + value = value[1 : l-1] + } + + parsed, err := ParseQuantity(strings.TrimSpace(string(value))) + if err != nil { + return err + } + + // This copy is safe because parsed will not be referred to again. + *q = parsed + return nil +} + +// NewQuantity returns a new Quantity representing the given +// value in the given format. +func NewQuantity(value int64, format Format) *Quantity { + return &Quantity{ + i: int64Amount{value: value}, + Format: format, + } +} + +// NewMilliQuantity returns a new Quantity representing the given +// value * 1/1000 in the given format. Note that BinarySI formatting +// will round fractional values, and will be changed to DecimalSI for +// values x where (-1 < x < 1) && (x != 0). +func NewMilliQuantity(value int64, format Format) *Quantity { + return &Quantity{ + i: int64Amount{value: value, scale: -3}, + Format: format, + } +} + +// NewScaledQuantity returns a new Quantity representing the given +// value * 10^scale in DecimalSI format. +func NewScaledQuantity(value int64, scale Scale) *Quantity { + return &Quantity{ + i: int64Amount{value: value, scale: scale}, + Format: DecimalSI, + } +} + +// Value returns the value of q; any fractional part will be lost. +func (q *Quantity) Value() int64 { + return q.ScaledValue(0) +} + +// MilliValue returns the value of ceil(q * 1000); this could overflow an int64; +// if that's a concern, call Value() first to verify the number is small enough. +func (q *Quantity) MilliValue() int64 { + return q.ScaledValue(Milli) +} + +// ScaledValue returns the value of ceil(q * 10^scale); this could overflow an int64. +// To detect overflow, call Value() first and verify the expected magnitude. +func (q *Quantity) ScaledValue(scale Scale) int64 { + if q.d.Dec == nil { + i, _ := q.i.AsScaledInt64(scale) + return i + } + dec := q.d.Dec + return scaledValue(dec.UnscaledBig(), int(dec.Scale()), int(scale.infScale())) +} + +// Set sets q's value to be value. +func (q *Quantity) Set(value int64) { + q.SetScaled(value, 0) +} + +// SetMilli sets q's value to be value * 1/1000. +func (q *Quantity) SetMilli(value int64) { + q.SetScaled(value, Milli) +} + +// SetScaled sets q's value to be value * 10^scale +func (q *Quantity) SetScaled(value int64, scale Scale) { + q.s = "" + q.d.Dec = nil + q.i = int64Amount{value: value, scale: scale} +} + +// Copy is a convenience function that makes a deep copy for you. Non-deep +// copies of quantities share pointers and you will regret that. +func (q *Quantity) Copy() *Quantity { + if q.d.Dec == nil { + return &Quantity{ + s: q.s, + i: q.i, + Format: q.Format, + } + } + tmp := &inf.Dec{} + return &Quantity{ + s: q.s, + d: infDecAmount{tmp.Set(q.d.Dec)}, + Format: q.Format, + } +} + +// qFlag is a helper type for the Flag function +type qFlag struct { + dest *Quantity +} + +// Sets the value of the internal Quantity. (used by flag & pflag) +func (qf qFlag) Set(val string) error { + q, err := ParseQuantity(val) + if err != nil { + return err + } + // This copy is OK because q will not be referenced again. + *qf.dest = q + return nil +} + +// Converts the value of the internal Quantity to a string. (used by flag & pflag) +func (qf qFlag) String() string { + return qf.dest.String() +} + +// States the type of flag this is (Quantity). (used by pflag) +func (qf qFlag) Type() string { + return "quantity" +} + +// QuantityFlag is a helper that makes a quantity flag (using standard flag package). +// Will panic if defaultValue is not a valid quantity. +func QuantityFlag(flagName, defaultValue, description string) *Quantity { + q := MustParse(defaultValue) + flag.Var(NewQuantityFlagValue(&q), flagName, description) + return &q +} + +// NewQuantityFlagValue returns an object that can be used to back a flag, +// pointing at the given Quantity variable. +func NewQuantityFlagValue(q *Quantity) flag.Value { + return qFlag{q} +} |