99 lines
2.6 KiB
Go
99 lines
2.6 KiB
Go
package instana
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import (
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"bytes"
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"encoding/binary"
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"errors"
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"io/ioutil"
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"math/rand"
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"os"
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"strconv"
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"strings"
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"sync"
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"time"
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)
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var (
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seededIDGen = rand.New(rand.NewSource(time.Now().UnixNano()))
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seededIDLock sync.Mutex
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)
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func randomID() int64 {
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seededIDLock.Lock()
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defer seededIDLock.Unlock()
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return int64(seededIDGen.Int63())
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}
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// ID2Header converts an Instana ID to a value that can be used in
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// context propagation (such as HTTP headers). More specifically,
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// this converts a signed 64 bit integer into an unsigned hex string.
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func ID2Header(id int64) (string, error) {
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// FIXME: We're assuming LittleEndian here
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// Write out _signed_ 64bit integer to byte buffer
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buf := new(bytes.Buffer)
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if err := binary.Write(buf, binary.LittleEndian, id); err == nil {
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// Read bytes back into _unsigned_ 64 bit integer
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var unsigned uint64
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if err = binary.Read(buf, binary.LittleEndian, &unsigned); err == nil {
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// Convert uint64 to hex string equivalent and return that
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return strconv.FormatUint(unsigned, 16), nil
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}
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log.debug(err)
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} else {
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log.debug(err)
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}
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return "", errors.New("context corrupted; could not convert value")
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}
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// Header2ID converts an header context value into an Instana ID. More
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// specifically, this converts an unsigned 64 bit hex value into a signed
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// 64bit integer.
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func Header2ID(header string) (int64, error) {
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// FIXME: We're assuming LittleEndian here
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// Parse unsigned 64 bit hex string into unsigned 64 bit base 10 integer
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if unsignedID, err := strconv.ParseUint(header, 16, 64); err == nil {
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// Write out _unsigned_ 64bit integer to byte buffer
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buf := new(bytes.Buffer)
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if err = binary.Write(buf, binary.LittleEndian, unsignedID); err == nil {
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// Read bytes back into _signed_ 64 bit integer
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var signedID int64
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if err = binary.Read(buf, binary.LittleEndian, &signedID); err == nil {
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// The success case
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return signedID, nil
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}
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log.debug(err)
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} else {
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log.debug(err)
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}
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} else {
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log.debug(err)
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}
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return int64(0), errors.New("context corrupted; could not convert value")
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}
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func getCommandLine() (string, []string) {
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var cmdlinePath string = "/proc/" + strconv.Itoa(os.Getpid()) + "/cmdline"
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cmdline, err := ioutil.ReadFile(cmdlinePath)
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if err != nil {
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log.debug("No /proc. Returning OS reported cmdline")
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return os.Args[0], os.Args[1:]
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}
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parts := strings.FieldsFunc(string(cmdline), func(c rune) bool {
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if c == '\u0000' {
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return true
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}
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return false
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})
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log.debug("cmdline says:", parts[0], parts[1:])
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return parts[0], parts[1:]
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}
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func abs(x int64) int64 {
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y := x >> 63
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return (x + y) ^ y
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}
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