diff options
Diffstat (limited to 'vendor/go.opentelemetry.io/otel/attribute/set.go')
| -rw-r--r-- | vendor/go.opentelemetry.io/otel/attribute/set.go | 139 |
1 files changed, 59 insertions, 80 deletions
diff --git a/vendor/go.opentelemetry.io/otel/attribute/set.go b/vendor/go.opentelemetry.io/otel/attribute/set.go index fb6da5145..bff9c7fdb 100644 --- a/vendor/go.opentelemetry.io/otel/attribute/set.go +++ b/vendor/go.opentelemetry.io/otel/attribute/set.go @@ -1,24 +1,14 @@ // Copyright The OpenTelemetry 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. +// SPDX-License-Identifier: Apache-2.0 package attribute // import "go.opentelemetry.io/otel/attribute" import ( + "cmp" "encoding/json" "reflect" + "slices" "sort" - "sync" ) type ( @@ -26,23 +16,33 @@ type ( // immutable set of attributes, with an internal cache for storing // attribute encodings. // - // This type supports the Equivalent method of comparison using values of - // type Distinct. + // This type will remain comparable for backwards compatibility. The + // equivalence of Sets across versions is not guaranteed to be stable. + // Prior versions may find two Sets to be equal or not when compared + // directly (i.e. ==), but subsequent versions may not. Users should use + // the Equals method to ensure stable equivalence checking. + // + // Users should also use the Distinct returned from Equivalent as a map key + // instead of a Set directly. In addition to that type providing guarantees + // on stable equivalence, it may also provide performance improvements. Set struct { equivalent Distinct } - // Distinct wraps a variable-size array of KeyValue, constructed with keys - // in sorted order. This can be used as a map key or for equality checking - // between Sets. + // Distinct is a unique identifier of a Set. + // + // Distinct is designed to be ensures equivalence stability: comparisons + // will return the save value across versions. For this reason, Distinct + // should always be used as a map key instead of a Set. Distinct struct { iface interface{} } - // Sortable implements sort.Interface, used for sorting KeyValue. This is - // an exported type to support a memory optimization. A pointer to one of - // these is needed for the call to sort.Stable(), which the caller may - // provide in order to avoid an allocation. See NewSetWithSortable(). + // Sortable implements sort.Interface, used for sorting KeyValue. + // + // Deprecated: This type is no longer used. It was added as a performance + // optimization for Go < 1.21 that is no longer needed (Go < 1.21 is no + // longer supported by the module). Sortable []KeyValue ) @@ -56,12 +56,6 @@ var ( iface: [0]KeyValue{}, }, } - - // sortables is a pool of Sortables used to create Sets with a user does - // not provide one. - sortables = sync.Pool{ - New: func() interface{} { return new(Sortable) }, - } ) // EmptySet returns a reference to a Set with no elements. @@ -187,13 +181,7 @@ func empty() Set { // Except for empty sets, this method adds an additional allocation compared // with calls that include a Sortable. func NewSet(kvs ...KeyValue) Set { - // Check for empty set. - if len(kvs) == 0 { - return empty() - } - srt := sortables.Get().(*Sortable) - s, _ := NewSetWithSortableFiltered(kvs, srt, nil) - sortables.Put(srt) + s, _ := NewSetWithFiltered(kvs, nil) return s } @@ -201,12 +189,10 @@ func NewSet(kvs ...KeyValue) Set { // NewSetWithSortableFiltered for more details. // // This call includes a Sortable option as a memory optimization. -func NewSetWithSortable(kvs []KeyValue, tmp *Sortable) Set { - // Check for empty set. - if len(kvs) == 0 { - return empty() - } - s, _ := NewSetWithSortableFiltered(kvs, tmp, nil) +// +// Deprecated: Use [NewSet] instead. +func NewSetWithSortable(kvs []KeyValue, _ *Sortable) Set { + s, _ := NewSetWithFiltered(kvs, nil) return s } @@ -220,48 +206,12 @@ func NewSetWithFiltered(kvs []KeyValue, filter Filter) (Set, []KeyValue) { if len(kvs) == 0 { return empty(), nil } - srt := sortables.Get().(*Sortable) - s, filtered := NewSetWithSortableFiltered(kvs, srt, filter) - sortables.Put(srt) - return s, filtered -} - -// NewSetWithSortableFiltered returns a new Set. -// -// Duplicate keys are eliminated by taking the last value. This -// re-orders the input slice so that unique last-values are contiguous -// at the end of the slice. -// -// This ensures the following: -// -// - Last-value-wins semantics -// - Caller sees the reordering, but doesn't lose values -// - Repeated call preserve last-value wins. -// -// Note that methods are defined on Set, although this returns Set. Callers -// can avoid memory allocations by: -// -// - allocating a Sortable for use as a temporary in this method -// - allocating a Set for storing the return value of this constructor. -// -// The result maintains a cache of encoded attributes, by attribute.EncoderID. -// This value should not be copied after its first use. -// -// The second []KeyValue return value is a list of attributes that were -// excluded by the Filter (if non-nil). -func NewSetWithSortableFiltered(kvs []KeyValue, tmp *Sortable, filter Filter) (Set, []KeyValue) { - // Check for empty set. - if len(kvs) == 0 { - return empty(), nil - } - - *tmp = kvs // Stable sort so the following de-duplication can implement // last-value-wins semantics. - sort.Stable(tmp) - - *tmp = nil + slices.SortStableFunc(kvs, func(a, b KeyValue) int { + return cmp.Compare(a.Key, b.Key) + }) position := len(kvs) - 1 offset := position - 1 @@ -289,6 +239,35 @@ func NewSetWithSortableFiltered(kvs []KeyValue, tmp *Sortable, filter Filter) (S return Set{equivalent: computeDistinct(kvs)}, nil } +// NewSetWithSortableFiltered returns a new Set. +// +// Duplicate keys are eliminated by taking the last value. This +// re-orders the input slice so that unique last-values are contiguous +// at the end of the slice. +// +// This ensures the following: +// +// - Last-value-wins semantics +// - Caller sees the reordering, but doesn't lose values +// - Repeated call preserve last-value wins. +// +// Note that methods are defined on Set, although this returns Set. Callers +// can avoid memory allocations by: +// +// - allocating a Sortable for use as a temporary in this method +// - allocating a Set for storing the return value of this constructor. +// +// The result maintains a cache of encoded attributes, by attribute.EncoderID. +// This value should not be copied after its first use. +// +// The second []KeyValue return value is a list of attributes that were +// excluded by the Filter (if non-nil). +// +// Deprecated: Use [NewSetWithFiltered] instead. +func NewSetWithSortableFiltered(kvs []KeyValue, _ *Sortable, filter Filter) (Set, []KeyValue) { + return NewSetWithFiltered(kvs, filter) +} + // filteredToFront filters slice in-place using keep function. All KeyValues that need to // be removed are moved to the front. All KeyValues that need to be kept are // moved (in-order) to the back. The index for the first KeyValue to be kept is |