diff --git a/.chloggen/xpdata-mapbuilder.yaml b/.chloggen/xpdata-mapbuilder.yaml new file mode 100644 index 00000000000..75b923c3472 --- /dev/null +++ b/.chloggen/xpdata-mapbuilder.yaml @@ -0,0 +1,25 @@ +# Use this changelog template to create an entry for release notes. + +# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix' +change_type: 'enhancement' + +# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver) +component: xpdata + +# A brief description of the change. Surround your text with quotes ("") if it needs to start with a backtick (`). +note: Add experimental MapBuilder struct to optimize pcommon.Map construction + +# One or more tracking issues or pull requests related to the change +issues: [13617] + +# (Optional) One or more lines of additional information to render under the primary note. +# These lines will be padded with 2 spaces and then inserted directly into the document. +# Use pipe (|) for multiline entries. +subtext: + +# Optional: The change log or logs in which this entry should be included. +# e.g. '[user]' or '[user, api]' +# Include 'user' if the change is relevant to end users. +# Include 'api' if there is a change to a library API. +# Default: '[user]' +change_logs: [api] diff --git a/pdata/xpdata/map_builder.go b/pdata/xpdata/map_builder.go new file mode 100644 index 00000000000..0a217237043 --- /dev/null +++ b/pdata/xpdata/map_builder.go @@ -0,0 +1,51 @@ +// Copyright The OpenTelemetry Authors +// SPDX-License-Identifier: Apache-2.0 + +package xpdata // import "go.opentelemetry.io/collector/pdata/xpdata" + +import ( + "go.opentelemetry.io/collector/pdata/internal" + otlpcommon "go.opentelemetry.io/collector/pdata/internal/data/protogen/common/v1" + "go.opentelemetry.io/collector/pdata/pcommon" +) + +// MapBuilder is an experimental struct which can be used to create a pcommon.Map more efficiently +// than by repeated use of the Put family of methods, which check for duplicate keys on every call +// (a linear time operation). +// A zero-initialized MapBuilder is ready for use. +type MapBuilder struct { + state internal.State + pairs []otlpcommon.KeyValue +} + +// EnsureCapacity increases the capacity of this MapBuilder instance, if necessary, +// to ensure that it can hold at least the number of elements specified by the capacity argument. +func (mb *MapBuilder) EnsureCapacity(capacity int) { + oldValues := mb.pairs + if capacity <= cap(oldValues) { + return + } + mb.pairs = make([]otlpcommon.KeyValue, len(oldValues), capacity) + copy(mb.pairs, oldValues) +} + +func (mb *MapBuilder) getValue(i int) pcommon.Value { + return pcommon.Value(internal.NewValue(&mb.pairs[i].Value, &mb.state)) +} + +// AppendEmpty appends a key/value pair to the MapBuilder and return the inserted value. +// This method does not check for duplicate keys and has an amortized constant time complexity. +func (mb *MapBuilder) AppendEmpty(k string) pcommon.Value { + mb.pairs = append(mb.pairs, otlpcommon.KeyValue{Key: k}) + return mb.getValue(len(mb.pairs) - 1) +} + +// UnsafeIntoMap transfers the contents of a MapBuilder into a Map, without checking for duplicate keys. +// If the MapBuilder contains duplicate keys, the behavior of the resulting Map is unspecified. +// This operation has constant time complexity and makes no allocations. +// After this operation, the MapBuilder is reset to an empty state. +func (mb *MapBuilder) UnsafeIntoMap(m pcommon.Map) { + internal.GetMapState(internal.Map(m)).AssertMutable() + *internal.GetOrigMap(internal.Map(m)) = mb.pairs + mb.pairs = nil +} diff --git a/pdata/xpdata/map_builder_test.go b/pdata/xpdata/map_builder_test.go new file mode 100644 index 00000000000..ef3fec798f4 --- /dev/null +++ b/pdata/xpdata/map_builder_test.go @@ -0,0 +1,29 @@ +// Copyright The OpenTelemetry Authors +// SPDX-License-Identifier: Apache-2.0 + +package xpdata_test + +import ( + "testing" + + "github.com/stretchr/testify/assert" + + "go.opentelemetry.io/collector/pdata/pcommon" + "go.opentelemetry.io/collector/pdata/xpdata" +) + +func TestMapBuilder(t *testing.T) { + var mb xpdata.MapBuilder + mb.EnsureCapacity(3) + mb.AppendEmpty("key1").SetStr("val") + mb.AppendEmpty("key2").SetInt(42) + + m := pcommon.NewMap() + mb.UnsafeIntoMap(m) + + assert.Equal(t, 2, m.Len()) + val, ok := m.Get("key1") + assert.True(t, ok && val.Type() == pcommon.ValueTypeStr && val.Str() == "val") + val, ok = m.Get("key2") + assert.True(t, ok && val.Type() == pcommon.ValueTypeInt && val.Int() == 42) +}