107 lines
1.8 KiB
Go
107 lines
1.8 KiB
Go
package router
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import (
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"fmt"
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)
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type Router struct {
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selectors []string
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symbols map[string]string
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navigable bool
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}
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func NewRouter() Router {
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return Router{
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symbols: make(map[string]string),
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navigable: true,
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}
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}
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func NewStaticRouter(symbol string) Router {
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return Router{
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symbols: map[string]string{"_": symbol},
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navigable: false,
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}
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}
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func(r *Router) Add(selector string, symbol string) error {
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if r.symbols[selector] != "" {
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return fmt.Errorf("selector %v already set to symbol %v", selector, symbol)
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}
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l := len(selector)
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if (l > 255) {
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return fmt.Errorf("selector too long (is %v, max 255)", l)
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}
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l = len(symbol)
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if (l > 255) {
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return fmt.Errorf("symbol too long (is %v, max 255)", l)
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}
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r.selectors = append(r.selectors, selector)
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r.symbols[selector] = symbol
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return nil
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}
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func(r *Router) Get(selector string) string {
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return r.symbols[selector]
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}
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func(r *Router) Default() string {
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return r.symbols["_"]
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}
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func(r *Router) Next() []byte {
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if len(r.selectors) == 0 {
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return []byte{}
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}
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k := r.selectors[0]
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r.selectors = r.selectors[1:]
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v := r.symbols[k]
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if len(r.selectors) == 0 {
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r.symbols = nil
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} else {
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delete(r.symbols, k)
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}
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lk := len(k)
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lv := len(v)
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b := []byte{uint8(lk)}
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b = append(b, k...)
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b = append(b, uint8(lv))
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b = append(b, v...)
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return b
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}
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func(r *Router) ToBytes() []byte {
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b := []byte{}
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for true {
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v := r.Next()
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if len(v) == 0 {
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break
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}
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b = append(b, v...)
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}
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return b
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}
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func FromBytes(b []byte) Router {
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rb := NewRouter()
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navigable := true
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for len(b) > 0 {
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var k string
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l := b[0]
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if l == 0 {
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navigable = false
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} else {
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k = string(b[1:1+l])
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b = b[1+l:]
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}
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l = b[0]
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v := string(b[1:1+l])
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if !navigable {
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return NewStaticRouter(v)
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}
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b = b[1+l:]
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rb.Add(k, v)
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}
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return rb
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}
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