syncthing/vendor/github.com/a8m/mark/mark.go
Jakob Borg 916ec63af6 cmd/stdiscosrv: New discovery server (fixes #4618)
This is a new revision of the discovery server. Relevant changes and
non-changes:

- Protocol towards clients is unchanged.

- Recommended large scale design is still to be deployed nehind nginx (I
  tested, and it's still a lot faster at terminating TLS).

- Database backend is leveldb again, only. It scales enough, is easy to
  setup, and we don't need any backend to take care of.

- Server supports replication. This is a simple TCP channel - protect it
  with a firewall when deploying over the internet. (We deploy this within
  the same datacenter, and with firewall.) Any incoming client announces
  are sent over the replication channel(s) to other peer discosrvs.
  Incoming replication changes are applied to the database as if they came
  from clients, but without the TLS/certificate overhead.

- Metrics are exposed using the prometheus library, when enabled.

- The database values and replication protocol is protobuf, because JSON
  was quite CPU intensive when I tried that and benchmarked it.

- The "Retry-After" value for failed lookups gets slowly increased from
  a default of 120 seconds, by 5 seconds for each failed lookup,
  independently by each discosrv. This lowers the query load over time for
  clients that are never seen. The Retry-After maxes out at 3600 after a
  couple of weeks of this increase. The number of failed lookups is
  stored in the database, now and then (avoiding making each lookup a
  database put).

All in all this means clients can be pointed towards a cluster using
just multiple A / AAAA records to gain both load sharing and redundancy
(if one is down, clients will talk to the remaining ones).

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4648
2018-01-14 08:52:31 +00:00

61 lines
1.2 KiB
Go

package mark
import "strings"
// Mark
type Mark struct {
*parse
Input string
}
// Mark options used to configure your Mark object
// set `Smartypants` and `Fractions` to true to enable
// smartypants and smartfractions rendering.
type Options struct {
Gfm bool
Tables bool
Smartypants bool
Fractions bool
}
// DefaultOptions return an options struct with default configuration
// it's means that only Gfm, and Tables set to true.
func DefaultOptions() *Options {
return &Options{
Gfm: true,
Tables: true,
}
}
// New return a new Mark
func New(input string, opts *Options) *Mark {
// Preprocessing
input = strings.Replace(input, "\t", " ", -1)
if opts == nil {
opts = DefaultOptions()
}
return &Mark{
Input: input,
parse: newParse(input, opts),
}
}
// parse and render input
func (m *Mark) Render() string {
m.parse.parse()
m.render()
return m.output
}
// AddRenderFn let you pass NodeType, and RenderFn function
// and override the default Node rendering
func (m *Mark) AddRenderFn(typ NodeType, fn RenderFn) {
m.renderFn[typ] = fn
}
// Staic render function
func Render(input string) string {
m := New(input, nil)
return m.Render()
}