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// Copyright (c) 2020 Cisco and/or its affiliates.
//
// 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 statsclient
import (
"fmt"
"git.fd.io/govpp.git/adapter"
"sync/atomic"
"time"
"unsafe"
)
var (
// ErrStatDataLenIncorrect is returned when stat data does not match vector
// length of a respective data directory
ErrStatDataLenIncorrect = fmt.Errorf("stat data length incorrect")
)
var (
MaxWaitInProgress = time.Millisecond * 100
CheckDelayInProgress = time.Microsecond * 10
)
const (
minVersion = 1
maxVersion = 2
)
const (
statDirIllegal = 0
statDirScalarIndex = 1
statDirCounterVectorSimple = 2
statDirCounterVectorCombined = 3
statDirErrorIndex = 4
statDirNameVector = 5
statDirEmpty = 6
statDirSymlink = 7
)
type (
dirVector unsafe.Pointer
dirSegment unsafe.Pointer
dirName []byte
dirType int32
)
// statSegment represents common API for every stats API version
type statSegment interface {
// GetDirectoryVector returns pointer to memory where the beginning
// of the data directory is located.
GetDirectoryVector() dirVector
// GetStatDirOnIndex accepts directory vector and particular index.
// Returns pointer to the beginning of the segment. Also the directory
// name as [128]byte and the directory type is returned for easy use
// without needing to know the exact segment version.
//
// Note that if the index is equal to 0, the result pointer points to
// the same memory address as the argument.
GetStatDirOnIndex(v dirVector, index uint32) (dirSegment, dirName, dirType)
// GetEpoch re-loads stats header and returns current epoch
//and 'inProgress' value
GetEpoch() (int64, bool)
// CopyEntryData accepts pointer to a directory segment and returns adapter.Stat
// based on directory type populated with data. The index is an optional parameter
// (used by symlinks) returning stats for item on the given index only.
// Use ^uint32(0) as an empty index (since 0 is a valid value).
CopyEntryData(segment dirSegment, index uint32) adapter.Stat
// UpdateEntryData accepts pointer to a directory segment with data, and stat
// segment to update
UpdateEntryData(segment dirSegment, s *adapter.Stat) error
}
// vecHeader represents a vector header
type vecHeader struct {
length uint64
vectorData [0]uint8
}
func (t dirType) String() string {
return adapter.StatType(t).String()
}
func getVersion(data []byte) uint64 {
type apiVersion struct {
value uint64
}
header := (*apiVersion)(unsafe.Pointer(&data[0]))
version := &apiVersion{
value: atomic.LoadUint64(&header.value),
}
debugf("stats API version loaded: %d", version.value)
return version.value
}
func vectorLen(v dirVector) dirVector {
vec := *(*vecHeader)(unsafe.Pointer(uintptr(v) - unsafe.Sizeof(uint64(0))))
return dirVector(&vec.length)
}
//go:nosplit
func statSegPointer(v dirVector, offset uintptr) dirVector {
return dirVector(uintptr(v) + offset)
}
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