forked from labstack/echo
/
router.go
298 lines (266 loc) · 5.23 KB
/
router.go
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package echo
import "net/http"
type (
router struct {
trees map[string]*node
echo *Echo
}
node struct {
typ ntype
label byte
prefix string
parent *node
children children
handler HandlerFunc
pnames []string
echo *Echo
}
ntype uint8
children []*node
)
const (
stype ntype = iota
ptype
mtype
)
func NewRouter(e *Echo) (r *router) {
r = &router{
trees: make(map[string]*node),
echo: e,
}
for _, m := range methods {
r.trees[m] = &node{
prefix: "",
children: children{},
}
}
return
}
func (r *router) Add(method, path string, h HandlerFunc, echo *Echo) {
var pnames []string // Param names
for i, l := 0, len(path); i < l; i++ {
if path[i] == ':' {
j := i + 1
r.insert(method, path[:i], nil, stype, nil, echo)
for ; i < l && path[i] != '/'; i++ {
}
pnames = append(pnames, path[j:i])
path = path[:j] + path[i:]
i, l = j, len(path)
if i == l {
r.insert(method, path[:i], h, ptype, pnames, echo)
return
}
r.insert(method, path[:i], nil, ptype, pnames, echo)
} else if path[i] == '*' {
r.insert(method, path[:i], nil, stype, nil, echo)
pnames = append(pnames, "_name")
r.insert(method, path[:i+1], h, mtype, pnames, echo)
return
}
}
r.insert(method, path, h, stype, pnames, echo)
}
func (r *router) insert(method, path string, h HandlerFunc, t ntype, pnames []string, echo *Echo) {
cn := r.trees[method] // Current node as root
search := path
for {
sl := len(search)
pl := len(cn.prefix)
l := lcp(search, cn.prefix)
if l == 0 {
// At root node
cn.label = search[0]
cn.prefix = search
if h != nil {
cn.typ = t
cn.handler = h
cn.pnames = pnames
cn.echo = echo
}
} else if l < pl {
// Split node
n := newNode(cn.typ, cn.prefix[l:], cn, cn.children, cn.handler, cn.pnames, cn.echo)
cn.children = children{n} // Add to parent
// Reset parent node
cn.typ = stype
cn.label = cn.prefix[0]
cn.prefix = cn.prefix[:l]
cn.handler = nil
cn.pnames = nil
cn.echo = nil
if l == sl {
// At parent node
cn.typ = t
cn.handler = h
cn.pnames = pnames
cn.echo = echo
} else {
// Create child node
n = newNode(t, search[l:], cn, nil, h, pnames, echo)
cn.children = append(cn.children, n)
}
} else if l < sl {
search = search[l:]
c := cn.findChild(search[0])
if c != nil {
// Go deeper
cn = c
continue
}
// Create child node
n := newNode(t, search, cn, nil, h, pnames, echo)
cn.children = append(cn.children, n)
} else {
// Node already exists
if h != nil {
cn.handler = h
cn.pnames = pnames
cn.echo = echo
}
}
return
}
}
func newNode(t ntype, pfx string, p *node, c children, h HandlerFunc, pnames []string, echo *Echo) *node {
return &node{
typ: t,
label: pfx[0],
prefix: pfx,
parent: p,
children: c,
handler: h,
pnames: pnames,
echo: echo,
}
}
func (n *node) addChild(c *node) {
}
func (n *node) findChild(l byte) *node {
for _, c := range n.children {
if c.label == l {
return c
}
}
return nil
}
func (n *node) findSchild(l byte) *node {
for _, c := range n.children {
if c.label == l && c.typ == stype {
return c
}
}
return nil
}
func (n *node) findPchild() *node {
for _, c := range n.children {
if c.typ == ptype {
return c
}
}
return nil
}
func (n *node) findMchild() *node {
for _, c := range n.children {
if c.typ == mtype {
return c
}
}
return nil
}
// Length of longest common prefix
func lcp(a, b string) (i int) {
max := len(a)
l := len(b)
if l < max {
max = l
}
for ; i < max && a[i] == b[i]; i++ {
}
return
}
func (r *router) Find(method, path string, ctx *Context) (h HandlerFunc, echo *Echo) {
cn := r.trees[method] // Current node as root
search := path
c := new(node) // Child node
n := 0 // Param counter
// TODO: Check empty path???
// Search order static > param > match-any
for {
if search == "" {
// Found
ctx.pnames = cn.pnames
h = cn.handler
echo = cn.echo
return
}
pl := len(cn.prefix)
l := lcp(search, cn.prefix)
if l == pl {
// Continue search
search = search[l:]
} else if l < pl && cn.label != ':' {
goto Up
}
if search == "" {
// TODO: Needs improvement
if cn.findMchild() == nil {
continue
}
// Empty value
goto MatchAny
}
// Static node
c = cn.findSchild(search[0])
if c != nil {
cn = c
continue
}
// Param node
Param:
c = cn.findPchild()
if c != nil {
cn = c
i, l := 0, len(search)
for ; i < l && search[i] != '/'; i++ {
}
ctx.pvalues[n] = search[:i]
n++
search = search[i:]
continue
}
// Match-any node
MatchAny:
c = cn.findMchild()
if c != nil {
cn = c
ctx.pvalues[n] = search
search = "" // End search
continue
}
Up:
tn := cn // Save current node
cn = cn.parent
if cn == nil {
// Not found
return
}
// Search upwards
if l == pl {
// Reset search
search = tn.prefix + search
}
goto Param
}
}
func (r *router) ServeHTTP(w http.ResponseWriter, req *http.Request) {
c := r.echo.pool.Get().(*Context)
h, _ := r.Find(req.Method, req.URL.Path, c)
c.reset(w, req, nil)
if h != nil {
h(c)
} else {
r.echo.notFoundHandler(c)
}
r.echo.pool.Put(c)
}