diff options
Diffstat (limited to 'vendor/go.opencensus.io/internal/tagencoding')
-rw-r--r-- | vendor/go.opencensus.io/internal/tagencoding/tagencoding.go | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/vendor/go.opencensus.io/internal/tagencoding/tagencoding.go b/vendor/go.opencensus.io/internal/tagencoding/tagencoding.go new file mode 100644 index 000000000..3b1af8b4b --- /dev/null +++ b/vendor/go.opencensus.io/internal/tagencoding/tagencoding.go @@ -0,0 +1,72 @@ +// Copyright 2017, OpenCensus 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 tagencoding contains the tag encoding +// used interally by the stats collector. +package tagencoding // import "go.opencensus.io/internal/tagencoding" + +type Values struct { + Buffer []byte + WriteIndex int + ReadIndex int +} + +func (vb *Values) growIfRequired(expected int) { + if len(vb.Buffer)-vb.WriteIndex < expected { + tmp := make([]byte, 2*(len(vb.Buffer)+1)+expected) + copy(tmp, vb.Buffer) + vb.Buffer = tmp + } +} + +func (vb *Values) WriteValue(v []byte) { + length := len(v) & 0xff + vb.growIfRequired(1 + length) + + // writing length of v + vb.Buffer[vb.WriteIndex] = byte(length) + vb.WriteIndex++ + + if length == 0 { + // No value was encoded for this key + return + } + + // writing v + copy(vb.Buffer[vb.WriteIndex:], v[:length]) + vb.WriteIndex += length +} + +// ReadValue is the helper method to read the values when decoding valuesBytes to a map[Key][]byte. +func (vb *Values) ReadValue() []byte { + // read length of v + length := int(vb.Buffer[vb.ReadIndex]) + vb.ReadIndex++ + if length == 0 { + // No value was encoded for this key + return nil + } + + // read value of v + v := make([]byte, length) + endIdx := vb.ReadIndex + length + copy(v, vb.Buffer[vb.ReadIndex:endIdx]) + vb.ReadIndex = endIdx + return v +} + +func (vb *Values) Bytes() []byte { + return vb.Buffer[:vb.WriteIndex] +} |