use go 1.12

Signed-off-by: hongming <talonwan@yunify.com>

vendor/github.com/mholt/caddy/caddyhttp/httpserver/vhosttrie.go

@@ -0,0 +1,180 @@
+// Copyright 2015 Light Code Labs, LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package httpserver
+
+import (
+	"net"
+	"strings"
+)
+
+// vhostTrie facilitates virtual hosting. It matches
+// requests first by hostname (with support for
+// wildcards as TLS certificates support them), then
+// by longest matching path.
+type vhostTrie struct {
+	fallbackHosts []string
+	edges         map[string]*vhostTrie
+	site          *SiteConfig // site to match on this node; also known as a virtual host
+	path          string      // the path portion of the key for the associated site
+}
+
+// newVHostTrie returns a new vhostTrie.
+func newVHostTrie() *vhostTrie {
+	// TODO: fallbackHosts doesn't discriminate between network interfaces;
+	// i.e. if there is a host "0.0.0.0", it could match a request coming
+	// in to "[::1]" (and vice-versa) even though the IP versions differ.
+	// This might be OK, or maybe it's not desirable. The 'bind' directive
+	// can be used to restrict what interface a listener binds to.
+	return &vhostTrie{edges: make(map[string]*vhostTrie), fallbackHosts: []string{"0.0.0.0", "[::]", ""}}
+}
+
+// Insert adds stack to t keyed by key. The key should be
+// a valid "host/path" combination (or just host).
+func (t *vhostTrie) Insert(key string, site *SiteConfig) {
+	host, path := t.splitHostPath(key)
+	if _, ok := t.edges[host]; !ok {
+		t.edges[host] = newVHostTrie()
+	}
+	t.edges[host].insertPath(path, path, site)
+}
+
+// insertPath expects t to be a host node (not a root node),
+// and inserts site into the t according to remainingPath.
+func (t *vhostTrie) insertPath(remainingPath, originalPath string, site *SiteConfig) {
+	if remainingPath == "" {
+		t.site = site
+		t.path = originalPath
+		return
+	}
+	ch := string(remainingPath[0])
+	if _, ok := t.edges[ch]; !ok {
+		t.edges[ch] = newVHostTrie()
+	}
+	t.edges[ch].insertPath(remainingPath[1:], originalPath, site)
+}
+
+// Match returns the virtual host (site) in v with
+// the closest match to key. If there was a match,
+// it returns the SiteConfig and the path portion of
+// the key used to make the match. The matched path
+// would be a prefix of the path portion of the
+// key, if not the whole path portion of the key.
+// If there is no match, nil and empty string will
+// be returned.
+//
+// A typical key will be in the form "host" or "host/path".
+func (t *vhostTrie) Match(key string) (*SiteConfig, string) {
+	host, path := t.splitHostPath(key)
+	// try the given host, then, if no match, try fallback hosts
+	branch := t.matchHost(host)
+	for _, h := range t.fallbackHosts {
+		if branch != nil {
+			break
+		}
+		branch = t.matchHost(h)
+	}
+	if branch == nil {
+		return nil, ""
+	}
+	node := branch.matchPath(path)
+	if node == nil {
+		return nil, ""
+	}
+	return node.site, node.path
+}
+
+// matchHost returns the vhostTrie matching host. The matching
+// algorithm is the same as used to match certificates to host
+// with SNI during TLS handshakes. In other words, it supports,
+// to some degree, the use of wildcard (*) characters.
+func (t *vhostTrie) matchHost(host string) *vhostTrie {
+	// try exact match
+	if subtree, ok := t.edges[host]; ok {
+		return subtree
+	}
+
+	// then try replacing labels in the host
+	// with wildcards until we get a match
+	labels := strings.Split(host, ".")
+	for i := range labels {
+		labels[i] = "*"
+		candidate := strings.Join(labels, ".")
+		if subtree, ok := t.edges[candidate]; ok {
+			return subtree
+		}
+	}
+
+	return nil
+}
+
+// matchPath traverses t until it finds the longest key matching
+// remainingPath, and returns its node.
+func (t *vhostTrie) matchPath(remainingPath string) *vhostTrie {
+	var longestMatch *vhostTrie
+	for len(remainingPath) > 0 {
+		ch := string(remainingPath[0])
+		next, ok := t.edges[ch]
+		if !ok {
+			break
+		}
+		if next.site != nil {
+			longestMatch = next
+		}
+		t = next
+		remainingPath = remainingPath[1:]
+	}
+	return longestMatch
+}
+
+// splitHostPath separates host from path in key.
+func (t *vhostTrie) splitHostPath(key string) (host, path string) {
+	parts := strings.SplitN(key, "/", 2)
+	host, path = strings.ToLower(parts[0]), "/"
+	if len(parts) > 1 {
+		path += parts[1]
+	}
+	// strip out the port (if present) from the host, since
+	// each port has its own socket, and each socket has its
+	// own listener, and each listener has its own server
+	// instance, and each server instance has its own vhosts.
+	// removing the port is a simple way to standardize so
+	// when requests come in, we can be sure to get a match.
+	hostname, _, err := net.SplitHostPort(host)
+	if err == nil {
+		host = hostname
+	}
+	return
+}
+
+// String returns a list of all the entries in t; assumes that
+// t is a root node.
+func (t *vhostTrie) String() string {
+	var s string
+	for host, edge := range t.edges {
+		s += edge.str(host)
+	}
+	return s
+}
+
+func (t *vhostTrie) str(prefix string) string {
+	var s string
+	for key, edge := range t.edges {
+		if edge.site != nil {
+			s += prefix + key + "\n"
+		}
+		s += edge.str(prefix + key)
+	}
+	return s
+}