mirror of
https://github.com/letic/terraform-provider-google.git
synced 2024-09-06 17:16:44 +00:00
148 lines
4.6 KiB
Go
148 lines
4.6 KiB
Go
![]() |
// Copyright 2018, 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 tracestate implements support for the Tracestate header of the
|
||
|
// W3C TraceContext propagation format.
|
||
|
package tracestate
|
||
|
|
||
|
import (
|
||
|
"fmt"
|
||
|
"regexp"
|
||
|
)
|
||
|
|
||
|
const (
|
||
|
keyMaxSize = 256
|
||
|
valueMaxSize = 256
|
||
|
maxKeyValuePairs = 32
|
||
|
)
|
||
|
|
||
|
const (
|
||
|
keyWithoutVendorFormat = `[a-z][_0-9a-z\-\*\/]{0,255}`
|
||
|
keyWithVendorFormat = `[a-z][_0-9a-z\-\*\/]{0,240}@[a-z][_0-9a-z\-\*\/]{0,13}`
|
||
|
keyFormat = `(` + keyWithoutVendorFormat + `)|(` + keyWithVendorFormat + `)`
|
||
|
valueFormat = `[\x20-\x2b\x2d-\x3c\x3e-\x7e]{0,255}[\x21-\x2b\x2d-\x3c\x3e-\x7e]`
|
||
|
)
|
||
|
|
||
|
var keyValidationRegExp = regexp.MustCompile(`^(` + keyFormat + `)$`)
|
||
|
var valueValidationRegExp = regexp.MustCompile(`^(` + valueFormat + `)$`)
|
||
|
|
||
|
// Tracestate represents tracing-system specific context in a list of key-value pairs. Tracestate allows different
|
||
|
// vendors propagate additional information and inter-operate with their legacy Id formats.
|
||
|
type Tracestate struct {
|
||
|
entries []Entry
|
||
|
}
|
||
|
|
||
|
// Entry represents one key-value pair in a list of key-value pair of Tracestate.
|
||
|
type Entry struct {
|
||
|
// Key is an opaque string up to 256 characters printable. It MUST begin with a lowercase letter,
|
||
|
// and can only contain lowercase letters a-z, digits 0-9, underscores _, dashes -, asterisks *, and
|
||
|
// forward slashes /.
|
||
|
Key string
|
||
|
|
||
|
// Value is an opaque string up to 256 characters printable ASCII RFC0020 characters (i.e., the
|
||
|
// range 0x20 to 0x7E) except comma , and =.
|
||
|
Value string
|
||
|
}
|
||
|
|
||
|
// Entries returns a slice of Entry.
|
||
|
func (ts *Tracestate) Entries() []Entry {
|
||
|
if ts == nil {
|
||
|
return nil
|
||
|
}
|
||
|
return ts.entries
|
||
|
}
|
||
|
|
||
|
func (ts *Tracestate) remove(key string) *Entry {
|
||
|
for index, entry := range ts.entries {
|
||
|
if entry.Key == key {
|
||
|
ts.entries = append(ts.entries[:index], ts.entries[index+1:]...)
|
||
|
return &entry
|
||
|
}
|
||
|
}
|
||
|
return nil
|
||
|
}
|
||
|
|
||
|
func (ts *Tracestate) add(entries []Entry) error {
|
||
|
for _, entry := range entries {
|
||
|
ts.remove(entry.Key)
|
||
|
}
|
||
|
if len(ts.entries)+len(entries) > maxKeyValuePairs {
|
||
|
return fmt.Errorf("adding %d key-value pairs to current %d pairs exceeds the limit of %d",
|
||
|
len(entries), len(ts.entries), maxKeyValuePairs)
|
||
|
}
|
||
|
ts.entries = append(entries, ts.entries...)
|
||
|
return nil
|
||
|
}
|
||
|
|
||
|
func isValid(entry Entry) bool {
|
||
|
return keyValidationRegExp.MatchString(entry.Key) &&
|
||
|
valueValidationRegExp.MatchString(entry.Value)
|
||
|
}
|
||
|
|
||
|
func containsDuplicateKey(entries ...Entry) (string, bool) {
|
||
|
keyMap := make(map[string]int)
|
||
|
for _, entry := range entries {
|
||
|
if _, ok := keyMap[entry.Key]; ok {
|
||
|
return entry.Key, true
|
||
|
}
|
||
|
keyMap[entry.Key] = 1
|
||
|
}
|
||
|
return "", false
|
||
|
}
|
||
|
|
||
|
func areEntriesValid(entries ...Entry) (*Entry, bool) {
|
||
|
for _, entry := range entries {
|
||
|
if !isValid(entry) {
|
||
|
return &entry, false
|
||
|
}
|
||
|
}
|
||
|
return nil, true
|
||
|
}
|
||
|
|
||
|
// New creates a Tracestate object from a parent and/or entries (key-value pair).
|
||
|
// Entries from the parent are copied if present. The entries passed to this function
|
||
|
// are inserted in front of those copied from the parent. If an entry copied from the
|
||
|
// parent contains the same key as one of the entry in entries then the entry copied
|
||
|
// from the parent is removed. See add func.
|
||
|
//
|
||
|
// An error is returned with nil Tracestate if
|
||
|
// 1. one or more entry in entries is invalid.
|
||
|
// 2. two or more entries in the input entries have the same key.
|
||
|
// 3. the number of entries combined from the parent and the input entries exceeds maxKeyValuePairs.
|
||
|
// (duplicate entry is counted only once).
|
||
|
func New(parent *Tracestate, entries ...Entry) (*Tracestate, error) {
|
||
|
if parent == nil && len(entries) == 0 {
|
||
|
return nil, nil
|
||
|
}
|
||
|
if entry, ok := areEntriesValid(entries...); !ok {
|
||
|
return nil, fmt.Errorf("key-value pair {%s, %s} is invalid", entry.Key, entry.Value)
|
||
|
}
|
||
|
|
||
|
if key, duplicate := containsDuplicateKey(entries...); duplicate {
|
||
|
return nil, fmt.Errorf("contains duplicate keys (%s)", key)
|
||
|
}
|
||
|
|
||
|
tracestate := Tracestate{}
|
||
|
|
||
|
if parent != nil && len(parent.entries) > 0 {
|
||
|
tracestate.entries = append([]Entry{}, parent.entries...)
|
||
|
}
|
||
|
|
||
|
err := tracestate.add(entries)
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
return &tracestate, nil
|
||
|
}
|