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moby--moby/pkg/jsonmessage/jsonmessage.go
Daniel Nephin a0ab33124a Extract stream output handling to a new type.
Signed-off-by: Daniel Nephin <dnephin@docker.com>
2016-09-08 12:33:41 -04:00

232 lines
6.7 KiB
Go

package jsonmessage
import (
"encoding/json"
"fmt"
"io"
"strings"
"time"
"github.com/docker/docker/pkg/jsonlog"
"github.com/docker/docker/pkg/term"
"github.com/docker/go-units"
)
// JSONError wraps a concrete Code and Message, `Code` is
// is an integer error code, `Message` is the error message.
type JSONError struct {
Code int `json:"code,omitempty"`
Message string `json:"message,omitempty"`
}
func (e *JSONError) Error() string {
return e.Message
}
// JSONProgress describes a Progress. terminalFd is the fd of the current terminal,
// Start is the initial value for the operation. Current is the current status and
// value of the progress made towards Total. Total is the end value describing when
// we made 100% progress for an operation.
type JSONProgress struct {
terminalFd uintptr
Current int64 `json:"current,omitempty"`
Total int64 `json:"total,omitempty"`
Start int64 `json:"start,omitempty"`
}
func (p *JSONProgress) String() string {
var (
width = 200
pbBox string
numbersBox string
timeLeftBox string
)
ws, err := term.GetWinsize(p.terminalFd)
if err == nil {
width = int(ws.Width)
}
if p.Current <= 0 && p.Total <= 0 {
return ""
}
current := units.HumanSize(float64(p.Current))
if p.Total <= 0 {
return fmt.Sprintf("%8v", current)
}
total := units.HumanSize(float64(p.Total))
percentage := int(float64(p.Current)/float64(p.Total)*100) / 2
if percentage > 50 {
percentage = 50
}
if width > 110 {
// this number can't be negative gh#7136
numSpaces := 0
if 50-percentage > 0 {
numSpaces = 50 - percentage
}
pbBox = fmt.Sprintf("[%s>%s] ", strings.Repeat("=", percentage), strings.Repeat(" ", numSpaces))
}
numbersBox = fmt.Sprintf("%8v/%v", current, total)
if p.Current > p.Total {
// remove total display if the reported current is wonky.
numbersBox = fmt.Sprintf("%8v", current)
}
if p.Current > 0 && p.Start > 0 && percentage < 50 {
fromStart := time.Now().UTC().Sub(time.Unix(p.Start, 0))
perEntry := fromStart / time.Duration(p.Current)
left := time.Duration(p.Total-p.Current) * perEntry
left = (left / time.Second) * time.Second
if width > 50 {
timeLeftBox = " " + left.String()
}
}
return pbBox + numbersBox + timeLeftBox
}
// JSONMessage defines a message struct. It describes
// the created time, where it from, status, ID of the
// message. It's used for docker events.
type JSONMessage struct {
Stream string `json:"stream,omitempty"`
Status string `json:"status,omitempty"`
Progress *JSONProgress `json:"progressDetail,omitempty"`
ProgressMessage string `json:"progress,omitempty"` //deprecated
ID string `json:"id,omitempty"`
From string `json:"from,omitempty"`
Time int64 `json:"time,omitempty"`
TimeNano int64 `json:"timeNano,omitempty"`
Error *JSONError `json:"errorDetail,omitempty"`
ErrorMessage string `json:"error,omitempty"` //deprecated
// Aux contains out-of-band data, such as digests for push signing.
Aux *json.RawMessage `json:"aux,omitempty"`
}
// Display displays the JSONMessage to `out`. `isTerminal` describes if `out`
// is a terminal. If this is the case, it will erase the entire current line
// when displaying the progressbar.
func (jm *JSONMessage) Display(out io.Writer, isTerminal bool) error {
if jm.Error != nil {
if jm.Error.Code == 401 {
return fmt.Errorf("Authentication is required.")
}
return jm.Error
}
var endl string
if isTerminal && jm.Stream == "" && jm.Progress != nil {
// <ESC>[2K = erase entire current line
fmt.Fprintf(out, "%c[2K\r", 27)
endl = "\r"
} else if jm.Progress != nil && jm.Progress.String() != "" { //disable progressbar in non-terminal
return nil
}
if jm.TimeNano != 0 {
fmt.Fprintf(out, "%s ", time.Unix(0, jm.TimeNano).Format(jsonlog.RFC3339NanoFixed))
} else if jm.Time != 0 {
fmt.Fprintf(out, "%s ", time.Unix(jm.Time, 0).Format(jsonlog.RFC3339NanoFixed))
}
if jm.ID != "" {
fmt.Fprintf(out, "%s: ", jm.ID)
}
if jm.From != "" {
fmt.Fprintf(out, "(from %s) ", jm.From)
}
if jm.Progress != nil && isTerminal {
fmt.Fprintf(out, "%s %s%s", jm.Status, jm.Progress.String(), endl)
} else if jm.ProgressMessage != "" { //deprecated
fmt.Fprintf(out, "%s %s%s", jm.Status, jm.ProgressMessage, endl)
} else if jm.Stream != "" {
fmt.Fprintf(out, "%s%s", jm.Stream, endl)
} else {
fmt.Fprintf(out, "%s%s\n", jm.Status, endl)
}
return nil
}
// DisplayJSONMessagesStream displays a json message stream from `in` to `out`, `isTerminal`
// describes if `out` is a terminal. If this is the case, it will print `\n` at the end of
// each line and move the cursor while displaying.
func DisplayJSONMessagesStream(in io.Reader, out io.Writer, terminalFd uintptr, isTerminal bool, auxCallback func(*json.RawMessage)) error {
var (
dec = json.NewDecoder(in)
ids = make(map[string]int)
)
for {
diff := 0
var jm JSONMessage
if err := dec.Decode(&jm); err != nil {
if err == io.EOF {
break
}
return err
}
if jm.Aux != nil {
if auxCallback != nil {
auxCallback(jm.Aux)
}
continue
}
if jm.Progress != nil {
jm.Progress.terminalFd = terminalFd
}
if jm.ID != "" && (jm.Progress != nil || jm.ProgressMessage != "") {
line, ok := ids[jm.ID]
if !ok {
// NOTE: This approach of using len(id) to
// figure out the number of lines of history
// only works as long as we clear the history
// when we output something that's not
// accounted for in the map, such as a line
// with no ID.
line = len(ids)
ids[jm.ID] = line
if isTerminal {
fmt.Fprintf(out, "\n")
}
} else {
diff = len(ids) - line
}
if isTerminal {
// NOTE: this appears to be necessary even if
// diff == 0.
// <ESC>[{diff}A = move cursor up diff rows
fmt.Fprintf(out, "%c[%dA", 27, diff)
}
} else {
// When outputting something that isn't progress
// output, clear the history of previous lines. We
// don't want progress entries from some previous
// operation to be updated (for example, pull -a
// with multiple tags).
ids = make(map[string]int)
}
err := jm.Display(out, isTerminal)
if jm.ID != "" && isTerminal {
// NOTE: this appears to be necessary even if
// diff == 0.
// <ESC>[{diff}B = move cursor down diff rows
fmt.Fprintf(out, "%c[%dB", 27, diff)
}
if err != nil {
return err
}
}
return nil
}
type stream interface {
io.Writer
FD() uintptr
IsTerminal() bool
}
// DisplayJSONMessagesToStream prints json messages to the output stream
func DisplayJSONMessagesToStream(in io.Reader, stream stream, auxCallback func(*json.RawMessage)) error {
return DisplayJSONMessagesStream(in, stream, stream.FD(), stream.IsTerminal(), auxCallback)
}