Improving routing performance and benchmark suite

Before this commit, all the node types were added to the same list of
children nodes. Taking in consideration that only one Param and Any type
of node could exist per node, two new node struct field were added to hold
the references to those kind of nodes.
This avoid the need to iterate through all the Static type nodes just to
find one Param or Any type node. Those iterations could be performed
multiple times in the same iteration of Router#Find.
Removing the route comments of the Router benchmark tests.
Updating the Router benchmarks tests to find the routes defined to each
particular benchmark. Before, all the benchmarks tried to find only the
GitHub API.
Adding new router benchmarks to measure when the Router try to find
routes that are not registered.

Author: pafuent

router.go

@@ -14,14 +14,16 @@ type (
 		echo   *Echo
 	}
 	node struct {
-		kind          kind
-		label         byte
-		prefix        string
-		parent        *node
-		children      children
-		ppath         string
-		pnames        []string
-		methodHandler *methodHandler
+		kind            kind
+		label           byte
+		prefix          string
+		parent          *node
+		staticChildrens children
+		ppath           string
+		pnames          []string
+		methodHandler   *methodHandler
+		paramChildren   *node
+		anyChildren     *node
 	}
 	kind          uint8
 	children      []*node
@@ -44,6 +46,9 @@ const (
 	skind kind = iota
 	pkind
 	akind
+
+	paramLabel = byte(':')
+	anyLabel   = byte('*')
 )
 
 // NewRouter returns a new Router instance.
@@ -134,23 +139,32 @@ func (r *Router) insert(method, path string, h HandlerFunc, t kind, ppath string
 			}
 		} else if l < pl {
 			// Split node
-			n := newNode(cn.kind, cn.prefix[l:], cn, cn.children, cn.methodHandler, cn.ppath, cn.pnames)
+			n := newNode(cn.kind, cn.prefix[l:], cn, cn.staticChildrens, cn.methodHandler, cn.ppath, cn.pnames, cn.paramChildren, cn.anyChildren)
 
 			// Update parent path for all children to new node
-			for _, child := range cn.children {
+			for _, child := range cn.staticChildrens {
 				child.parent = n
 			}
+			if cn.paramChildren != nil {
+				cn.paramChildren.parent = n
+			}
+			if cn.anyChildren != nil {
+				cn.anyChildren.parent = n
+			}
 
 			// Reset parent node
 			cn.kind = skind
 			cn.label = cn.prefix[0]
 			cn.prefix = cn.prefix[:l]
-			cn.children = nil
+			cn.staticChildrens = nil
 			cn.methodHandler = new(methodHandler)
 			cn.ppath = ""
 			cn.pnames = nil
+			cn.paramChildren = nil
+			cn.anyChildren = nil
 
-			cn.addChild(n)
+			// Only Static children could reach here
+			cn.addStaticChild(n)
 
 			if l == sl {
 				// At parent node
@@ -160,9 +174,10 @@ func (r *Router) insert(method, path string, h HandlerFunc, t kind, ppath string
 				cn.pnames = pnames
 			} else {
 				// Create child node
-				n = newNode(t, search[l:], cn, nil, new(methodHandler), ppath, pnames)
+				n = newNode(t, search[l:], cn, nil, new(methodHandler), ppath, pnames, nil, nil)
 				n.addHandler(method, h)
-				cn.addChild(n)
+				// Only Static children could reach here
+				cn.addStaticChild(n)
 			}
 		} else if l < sl {
 			search = search[l:]
@@ -173,9 +188,16 @@ func (r *Router) insert(method, path string, h HandlerFunc, t kind, ppath string
 				continue
 			}
 			// Create child node
-			n := newNode(t, search, cn, nil, new(methodHandler), ppath, pnames)
+			n := newNode(t, search, cn, nil, new(methodHandler), ppath, pnames, nil, nil)
 			n.addHandler(method, h)
-			cn.addChild(n)
+			switch t {
+			case skind:
+				cn.addStaticChild(n)
+			case pkind:
+				cn.paramChildren = n
+			case akind:
+				cn.anyChildren = n
+			}
 		} else {
 			// Node already exists
 			if h != nil {
@@ -190,46 +212,45 @@ func (r *Router) insert(method, path string, h HandlerFunc, t kind, ppath string
 	}
 }
 
-func newNode(t kind, pre string, p *node, c children, mh *methodHandler, ppath string, pnames []string) *node {
+func newNode(t kind, pre string, p *node, sc children, mh *methodHandler, ppath string, pnames []string, paramChildren, anyChildren *node) *node {
 	return &node{
-		kind:          t,
-		label:         pre[0],
-		prefix:        pre,
-		parent:        p,
-		children:      c,
-		ppath:         ppath,
-		pnames:        pnames,
-		methodHandler: mh,
+		kind:            t,
+		label:           pre[0],
+		prefix:          pre,
+		parent:          p,
+		staticChildrens: sc,
+		ppath:           ppath,
+		pnames:          pnames,
+		methodHandler:   mh,
+		paramChildren:   paramChildren,
+		anyChildren:     anyChildren,
 	}
 }
 
-func (n *node) addChild(c *node) {
-	n.children = append(n.children, c)
+func (n *node) addStaticChild(c *node) {
+	n.staticChildrens = append(n.staticChildrens, c)
 }
 
-func (n *node) findChild(l byte, t kind) *node {
-	for _, c := range n.children {
-		if c.label == l && c.kind == t {
+func (n *node) findStaticChild(l byte) *node {
+	for _, c := range n.staticChildrens {
+		if c.label == l {
 			return c
 		}
 	}
 	return nil
 }
 
 func (n *node) findChildWithLabel(l byte) *node {
-	for _, c := range n.children {
+	for _, c := range n.staticChildrens {
 		if c.label == l {
 			return c
 		}
 	}
-	return nil
-}
-
-func (n *node) findChildByKind(t kind) *node {
-	for _, c := range n.children {
-		if c.kind == t {
-			return c
-		}
+	if l == paramLabel {
+		return n.paramChildren
+	}
+	if l == anyLabel {
+		return n.anyChildren
 	}
 	return nil
 }
@@ -356,7 +377,7 @@ func (r *Router) Find(method, path string, c Context) {
 		// Attempt to go back up the tree on no matching prefix or no remaining search
 		if l != pl || search == "" {
 			// Handle special case of trailing slash route with existing any route (see #1526)
-			if path[len(path)-1] == '/' && cn.findChildByKind(akind) != nil {
+			if path[len(path)-1] == '/' && cn.anyChildren != nil {
 				goto Any
 			}
 			if nn == nil { // Issue #1348
@@ -372,7 +393,7 @@ func (r *Router) Find(method, path string, c Context) {
 		}
 
 		// Static node
-		if child = cn.findChild(search[0], skind); child != nil {
+		if child = cn.findStaticChild(search[0]); child != nil {
 			// Save next
 			if cn.prefix[len(cn.prefix)-1] == '/' { // Issue #623
 				nk = pkind
@@ -385,7 +406,7 @@ func (r *Router) Find(method, path string, c Context) {
 
 	Param:
 		// Param node
-		if child = cn.findChildByKind(pkind); child != nil {
+		if child = cn.paramChildren; child != nil {
 			// Issue #378
 			if len(pvalues) == n {
 				continue
@@ -410,7 +431,7 @@ func (r *Router) Find(method, path string, c Context) {
 
 	Any:
 		// Any node
-		if cn = cn.findChildByKind(akind); cn != nil {
+		if cn = cn.anyChildren; cn != nil {
 			// If any node is found, use remaining path for pvalues
 			pvalues[len(cn.pnames)-1] = search
 			break
@@ -424,7 +445,7 @@ func (r *Router) Find(method, path string, c Context) {
 			search = ns
 			np := nn.parent
 			// Consider param route one level up only
-			if cn = nn.findChildByKind(pkind); cn != nil {
+			if cn = nn.paramChildren; cn != nil {
 				pos := strings.IndexByte(ns, '/')
 				if pos == -1 {
 					// If no slash is remaining in search string set param value
@@ -441,7 +462,7 @@ func (r *Router) Find(method, path string, c Context) {
 			// No param route found, try to resolve nearest any route
 			for {
 				np = nn.parent
-				if cn = nn.findChildByKind(akind); cn != nil {
+				if cn = nn.anyChildren; cn != nil {
 					break
 				}
 				if np == nil {
@@ -472,7 +493,7 @@ func (r *Router) Find(method, path string, c Context) {
 
 		// Dig further for any, might have an empty value for *, e.g.
 		// serving a directory. Issue #207.
-		if cn = cn.findChildByKind(akind); cn == nil {
+		if cn = cn.anyChildren; cn == nil {
 			return
 		}
 		if h := cn.findHandler(method); h != nil {