gotosocial/vendor/github.com/gogo/protobuf/proto/extensions.go
Daniele Sluijters acc333c40b
[feature] Inherit resource limits from cgroups (#1336)
When GTS is running in a container runtime which has configured CPU or
memory limits or under an init system that uses cgroups to impose CPU
and memory limits the values the Go runtime sees for GOMAXPROCS and
GOMEMLIMIT are still based on the host resources, not the cgroup.

At least for the throttling middlewares which use GOMAXPROCS to
configure their queue size, this can result in GTS running with values
too big compared to the resources that will actuall be available to it.

This introduces 2 dependencies which can pick up resource contraints
from the current cgroup and tune the Go runtime accordingly. This should
result in the different queues being appropriately sized and in general
more predictable performance. These dependencies are a no-op on
non-Linux systems or if running in a cgroup that doesn't set a limit on
CPU or memory.

The automatic tuning of GOMEMLIMIT can be disabled by either explicitly
setting GOMEMLIMIT yourself or by setting AUTOMEMLIMIT=off. The
automatic tuning of GOMAXPROCS can similarly be counteracted by setting
GOMAXPROCS yourself.
2023-01-17 20:59:04 +00:00

606 lines
18 KiB
Go

// Go support for Protocol Buffers - Google's data interchange format
//
// Copyright 2010 The Go Authors. All rights reserved.
// https://github.com/golang/protobuf
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package proto
/*
* Types and routines for supporting protocol buffer extensions.
*/
import (
"errors"
"fmt"
"io"
"reflect"
"strconv"
"sync"
)
// ErrMissingExtension is the error returned by GetExtension if the named extension is not in the message.
var ErrMissingExtension = errors.New("proto: missing extension")
// ExtensionRange represents a range of message extensions for a protocol buffer.
// Used in code generated by the protocol compiler.
type ExtensionRange struct {
Start, End int32 // both inclusive
}
// extendableProto is an interface implemented by any protocol buffer generated by the current
// proto compiler that may be extended.
type extendableProto interface {
Message
ExtensionRangeArray() []ExtensionRange
extensionsWrite() map[int32]Extension
extensionsRead() (map[int32]Extension, sync.Locker)
}
// extendableProtoV1 is an interface implemented by a protocol buffer generated by the previous
// version of the proto compiler that may be extended.
type extendableProtoV1 interface {
Message
ExtensionRangeArray() []ExtensionRange
ExtensionMap() map[int32]Extension
}
// extensionAdapter is a wrapper around extendableProtoV1 that implements extendableProto.
type extensionAdapter struct {
extendableProtoV1
}
func (e extensionAdapter) extensionsWrite() map[int32]Extension {
return e.ExtensionMap()
}
func (e extensionAdapter) extensionsRead() (map[int32]Extension, sync.Locker) {
return e.ExtensionMap(), notLocker{}
}
// notLocker is a sync.Locker whose Lock and Unlock methods are nops.
type notLocker struct{}
func (n notLocker) Lock() {}
func (n notLocker) Unlock() {}
// extendable returns the extendableProto interface for the given generated proto message.
// If the proto message has the old extension format, it returns a wrapper that implements
// the extendableProto interface.
func extendable(p interface{}) (extendableProto, error) {
switch p := p.(type) {
case extendableProto:
if isNilPtr(p) {
return nil, fmt.Errorf("proto: nil %T is not extendable", p)
}
return p, nil
case extendableProtoV1:
if isNilPtr(p) {
return nil, fmt.Errorf("proto: nil %T is not extendable", p)
}
return extensionAdapter{p}, nil
case extensionsBytes:
return slowExtensionAdapter{p}, nil
}
// Don't allocate a specific error containing %T:
// this is the hot path for Clone and MarshalText.
return nil, errNotExtendable
}
var errNotExtendable = errors.New("proto: not an extendable proto.Message")
func isNilPtr(x interface{}) bool {
v := reflect.ValueOf(x)
return v.Kind() == reflect.Ptr && v.IsNil()
}
// XXX_InternalExtensions is an internal representation of proto extensions.
//
// Each generated message struct type embeds an anonymous XXX_InternalExtensions field,
// thus gaining the unexported 'extensions' method, which can be called only from the proto package.
//
// The methods of XXX_InternalExtensions are not concurrency safe in general,
// but calls to logically read-only methods such as has and get may be executed concurrently.
type XXX_InternalExtensions struct {
// The struct must be indirect so that if a user inadvertently copies a
// generated message and its embedded XXX_InternalExtensions, they
// avoid the mayhem of a copied mutex.
//
// The mutex serializes all logically read-only operations to p.extensionMap.
// It is up to the client to ensure that write operations to p.extensionMap are
// mutually exclusive with other accesses.
p *struct {
mu sync.Mutex
extensionMap map[int32]Extension
}
}
// extensionsWrite returns the extension map, creating it on first use.
func (e *XXX_InternalExtensions) extensionsWrite() map[int32]Extension {
if e.p == nil {
e.p = new(struct {
mu sync.Mutex
extensionMap map[int32]Extension
})
e.p.extensionMap = make(map[int32]Extension)
}
return e.p.extensionMap
}
// extensionsRead returns the extensions map for read-only use. It may be nil.
// The caller must hold the returned mutex's lock when accessing Elements within the map.
func (e *XXX_InternalExtensions) extensionsRead() (map[int32]Extension, sync.Locker) {
if e.p == nil {
return nil, nil
}
return e.p.extensionMap, &e.p.mu
}
// ExtensionDesc represents an extension specification.
// Used in generated code from the protocol compiler.
type ExtensionDesc struct {
ExtendedType Message // nil pointer to the type that is being extended
ExtensionType interface{} // nil pointer to the extension type
Field int32 // field number
Name string // fully-qualified name of extension, for text formatting
Tag string // protobuf tag style
Filename string // name of the file in which the extension is defined
}
func (ed *ExtensionDesc) repeated() bool {
t := reflect.TypeOf(ed.ExtensionType)
return t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8
}
// Extension represents an extension in a message.
type Extension struct {
// When an extension is stored in a message using SetExtension
// only desc and value are set. When the message is marshaled
// enc will be set to the encoded form of the message.
//
// When a message is unmarshaled and contains extensions, each
// extension will have only enc set. When such an extension is
// accessed using GetExtension (or GetExtensions) desc and value
// will be set.
desc *ExtensionDesc
value interface{}
enc []byte
}
// SetRawExtension is for testing only.
func SetRawExtension(base Message, id int32, b []byte) {
if ebase, ok := base.(extensionsBytes); ok {
clearExtension(base, id)
ext := ebase.GetExtensions()
*ext = append(*ext, b...)
return
}
epb, err := extendable(base)
if err != nil {
return
}
extmap := epb.extensionsWrite()
extmap[id] = Extension{enc: b}
}
// isExtensionField returns true iff the given field number is in an extension range.
func isExtensionField(pb extendableProto, field int32) bool {
for _, er := range pb.ExtensionRangeArray() {
if er.Start <= field && field <= er.End {
return true
}
}
return false
}
// checkExtensionTypes checks that the given extension is valid for pb.
func checkExtensionTypes(pb extendableProto, extension *ExtensionDesc) error {
var pbi interface{} = pb
// Check the extended type.
if ea, ok := pbi.(extensionAdapter); ok {
pbi = ea.extendableProtoV1
}
if ea, ok := pbi.(slowExtensionAdapter); ok {
pbi = ea.extensionsBytes
}
if a, b := reflect.TypeOf(pbi), reflect.TypeOf(extension.ExtendedType); a != b {
return fmt.Errorf("proto: bad extended type; %v does not extend %v", b, a)
}
// Check the range.
if !isExtensionField(pb, extension.Field) {
return errors.New("proto: bad extension number; not in declared ranges")
}
return nil
}
// extPropKey is sufficient to uniquely identify an extension.
type extPropKey struct {
base reflect.Type
field int32
}
var extProp = struct {
sync.RWMutex
m map[extPropKey]*Properties
}{
m: make(map[extPropKey]*Properties),
}
func extensionProperties(ed *ExtensionDesc) *Properties {
key := extPropKey{base: reflect.TypeOf(ed.ExtendedType), field: ed.Field}
extProp.RLock()
if prop, ok := extProp.m[key]; ok {
extProp.RUnlock()
return prop
}
extProp.RUnlock()
extProp.Lock()
defer extProp.Unlock()
// Check again.
if prop, ok := extProp.m[key]; ok {
return prop
}
prop := new(Properties)
prop.Init(reflect.TypeOf(ed.ExtensionType), "unknown_name", ed.Tag, nil)
extProp.m[key] = prop
return prop
}
// HasExtension returns whether the given extension is present in pb.
func HasExtension(pb Message, extension *ExtensionDesc) bool {
if epb, doki := pb.(extensionsBytes); doki {
ext := epb.GetExtensions()
buf := *ext
o := 0
for o < len(buf) {
tag, n := DecodeVarint(buf[o:])
fieldNum := int32(tag >> 3)
if int32(fieldNum) == extension.Field {
return true
}
wireType := int(tag & 0x7)
o += n
l, err := size(buf[o:], wireType)
if err != nil {
return false
}
o += l
}
return false
}
// TODO: Check types, field numbers, etc.?
epb, err := extendable(pb)
if err != nil {
return false
}
extmap, mu := epb.extensionsRead()
if extmap == nil {
return false
}
mu.Lock()
_, ok := extmap[extension.Field]
mu.Unlock()
return ok
}
// ClearExtension removes the given extension from pb.
func ClearExtension(pb Message, extension *ExtensionDesc) {
clearExtension(pb, extension.Field)
}
func clearExtension(pb Message, fieldNum int32) {
if epb, ok := pb.(extensionsBytes); ok {
offset := 0
for offset != -1 {
offset = deleteExtension(epb, fieldNum, offset)
}
return
}
epb, err := extendable(pb)
if err != nil {
return
}
// TODO: Check types, field numbers, etc.?
extmap := epb.extensionsWrite()
delete(extmap, fieldNum)
}
// GetExtension retrieves a proto2 extended field from pb.
//
// If the descriptor is type complete (i.e., ExtensionDesc.ExtensionType is non-nil),
// then GetExtension parses the encoded field and returns a Go value of the specified type.
// If the field is not present, then the default value is returned (if one is specified),
// otherwise ErrMissingExtension is reported.
//
// If the descriptor is not type complete (i.e., ExtensionDesc.ExtensionType is nil),
// then GetExtension returns the raw encoded bytes of the field extension.
func GetExtension(pb Message, extension *ExtensionDesc) (interface{}, error) {
if epb, doki := pb.(extensionsBytes); doki {
ext := epb.GetExtensions()
return decodeExtensionFromBytes(extension, *ext)
}
epb, err := extendable(pb)
if err != nil {
return nil, err
}
if extension.ExtendedType != nil {
// can only check type if this is a complete descriptor
if cerr := checkExtensionTypes(epb, extension); cerr != nil {
return nil, cerr
}
}
emap, mu := epb.extensionsRead()
if emap == nil {
return defaultExtensionValue(extension)
}
mu.Lock()
defer mu.Unlock()
e, ok := emap[extension.Field]
if !ok {
// defaultExtensionValue returns the default value or
// ErrMissingExtension if there is no default.
return defaultExtensionValue(extension)
}
if e.value != nil {
// Already decoded. Check the descriptor, though.
if e.desc != extension {
// This shouldn't happen. If it does, it means that
// GetExtension was called twice with two different
// descriptors with the same field number.
return nil, errors.New("proto: descriptor conflict")
}
return e.value, nil
}
if extension.ExtensionType == nil {
// incomplete descriptor
return e.enc, nil
}
v, err := decodeExtension(e.enc, extension)
if err != nil {
return nil, err
}
// Remember the decoded version and drop the encoded version.
// That way it is safe to mutate what we return.
e.value = v
e.desc = extension
e.enc = nil
emap[extension.Field] = e
return e.value, nil
}
// defaultExtensionValue returns the default value for extension.
// If no default for an extension is defined ErrMissingExtension is returned.
func defaultExtensionValue(extension *ExtensionDesc) (interface{}, error) {
if extension.ExtensionType == nil {
// incomplete descriptor, so no default
return nil, ErrMissingExtension
}
t := reflect.TypeOf(extension.ExtensionType)
props := extensionProperties(extension)
sf, _, err := fieldDefault(t, props)
if err != nil {
return nil, err
}
if sf == nil || sf.value == nil {
// There is no default value.
return nil, ErrMissingExtension
}
if t.Kind() != reflect.Ptr {
// We do not need to return a Ptr, we can directly return sf.value.
return sf.value, nil
}
// We need to return an interface{} that is a pointer to sf.value.
value := reflect.New(t).Elem()
value.Set(reflect.New(value.Type().Elem()))
if sf.kind == reflect.Int32 {
// We may have an int32 or an enum, but the underlying data is int32.
// Since we can't set an int32 into a non int32 reflect.value directly
// set it as a int32.
value.Elem().SetInt(int64(sf.value.(int32)))
} else {
value.Elem().Set(reflect.ValueOf(sf.value))
}
return value.Interface(), nil
}
// decodeExtension decodes an extension encoded in b.
func decodeExtension(b []byte, extension *ExtensionDesc) (interface{}, error) {
t := reflect.TypeOf(extension.ExtensionType)
unmarshal := typeUnmarshaler(t, extension.Tag)
// t is a pointer to a struct, pointer to basic type or a slice.
// Allocate space to store the pointer/slice.
value := reflect.New(t).Elem()
var err error
for {
x, n := decodeVarint(b)
if n == 0 {
return nil, io.ErrUnexpectedEOF
}
b = b[n:]
wire := int(x) & 7
b, err = unmarshal(b, valToPointer(value.Addr()), wire)
if err != nil {
return nil, err
}
if len(b) == 0 {
break
}
}
return value.Interface(), nil
}
// GetExtensions returns a slice of the extensions present in pb that are also listed in es.
// The returned slice has the same length as es; missing extensions will appear as nil elements.
func GetExtensions(pb Message, es []*ExtensionDesc) (extensions []interface{}, err error) {
epb, err := extendable(pb)
if err != nil {
return nil, err
}
extensions = make([]interface{}, len(es))
for i, e := range es {
extensions[i], err = GetExtension(epb, e)
if err == ErrMissingExtension {
err = nil
}
if err != nil {
return
}
}
return
}
// ExtensionDescs returns a new slice containing pb's extension descriptors, in undefined order.
// For non-registered extensions, ExtensionDescs returns an incomplete descriptor containing
// just the Field field, which defines the extension's field number.
func ExtensionDescs(pb Message) ([]*ExtensionDesc, error) {
epb, err := extendable(pb)
if err != nil {
return nil, err
}
registeredExtensions := RegisteredExtensions(pb)
emap, mu := epb.extensionsRead()
if emap == nil {
return nil, nil
}
mu.Lock()
defer mu.Unlock()
extensions := make([]*ExtensionDesc, 0, len(emap))
for extid, e := range emap {
desc := e.desc
if desc == nil {
desc = registeredExtensions[extid]
if desc == nil {
desc = &ExtensionDesc{Field: extid}
}
}
extensions = append(extensions, desc)
}
return extensions, nil
}
// SetExtension sets the specified extension of pb to the specified value.
func SetExtension(pb Message, extension *ExtensionDesc, value interface{}) error {
if epb, ok := pb.(extensionsBytes); ok {
ClearExtension(pb, extension)
newb, err := encodeExtension(extension, value)
if err != nil {
return err
}
bb := epb.GetExtensions()
*bb = append(*bb, newb...)
return nil
}
epb, err := extendable(pb)
if err != nil {
return err
}
if err := checkExtensionTypes(epb, extension); err != nil {
return err
}
typ := reflect.TypeOf(extension.ExtensionType)
if typ != reflect.TypeOf(value) {
return fmt.Errorf("proto: bad extension value type. got: %T, want: %T", value, extension.ExtensionType)
}
// nil extension values need to be caught early, because the
// encoder can't distinguish an ErrNil due to a nil extension
// from an ErrNil due to a missing field. Extensions are
// always optional, so the encoder would just swallow the error
// and drop all the extensions from the encoded message.
if reflect.ValueOf(value).IsNil() {
return fmt.Errorf("proto: SetExtension called with nil value of type %T", value)
}
extmap := epb.extensionsWrite()
extmap[extension.Field] = Extension{desc: extension, value: value}
return nil
}
// ClearAllExtensions clears all extensions from pb.
func ClearAllExtensions(pb Message) {
if epb, doki := pb.(extensionsBytes); doki {
ext := epb.GetExtensions()
*ext = []byte{}
return
}
epb, err := extendable(pb)
if err != nil {
return
}
m := epb.extensionsWrite()
for k := range m {
delete(m, k)
}
}
// A global registry of extensions.
// The generated code will register the generated descriptors by calling RegisterExtension.
var extensionMaps = make(map[reflect.Type]map[int32]*ExtensionDesc)
// RegisterExtension is called from the generated code.
func RegisterExtension(desc *ExtensionDesc) {
st := reflect.TypeOf(desc.ExtendedType).Elem()
m := extensionMaps[st]
if m == nil {
m = make(map[int32]*ExtensionDesc)
extensionMaps[st] = m
}
if _, ok := m[desc.Field]; ok {
panic("proto: duplicate extension registered: " + st.String() + " " + strconv.Itoa(int(desc.Field)))
}
m[desc.Field] = desc
}
// RegisteredExtensions returns a map of the registered extensions of a
// protocol buffer struct, indexed by the extension number.
// The argument pb should be a nil pointer to the struct type.
func RegisteredExtensions(pb Message) map[int32]*ExtensionDesc {
return extensionMaps[reflect.TypeOf(pb).Elem()]
}