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// addRoute adds a node with the given handle to the path.
// 非并发安全
func (n *node) addRoute(path string, handlers HandlersChain) {
fullPath := path
n.priority++
numParams := countParams(path)
// Empty tree
if len(n.path) == 0 && len(n.children) == 0 {
n.insertChild(numParams, path, fullPath, handlers)
n.nType = root
return
}
parentFullPathIndex := 0
walk:
for {
// Update maxParams of the current node
if numParams > n.maxParams {
n.maxParams = numParams
}
// 查找最长公共前缀
// This also implies that the common prefix contains no ':' or '*'
// since the existing key can't contain those chars.
i := longestCommonPrefix(path, n.path)
// 分裂节点
if i < len(n.path) {
child := node{
path: n.path[i:],
wildChild: n.wildChild,
indices: n.indices,
children: n.children,
handlers: n.handlers,
priority: n.priority - 1,
fullPath: n.fullPath,
}
// Update maxParams (max of all children)
for i := range child.children {
if child.children[i].maxParams > child.maxParams {
child.maxParams = child.children[i].maxParams
}
}
n.children = []*node{&child}
// []byte for proper unicode char conversion, see #65
n.indices = string([]byte{n.path[i]})
n.path = path[:i]
n.handlers = nil
n.wildChild = false
n.fullPath = fullPath[:parentFullPathIndex+i]
}
// Make new node a child of this node
if i < len(path) {
path = path[i:]
if n.wildChild {
parentFullPathIndex += len(n.path)
n = n.children[0]
n.priority++
// Update maxParams of the child node
if numParams > n.maxParams {
n.maxParams = numParams
}
numParams--
// Check if the wildcard matches
if len(path) >= len(n.path) && n.path == path[:len(n.path)] {
// check for longer wildcard, e.g. :name and :names
if len(n.path) >= len(path) || path[len(n.path)] == '/' {
continue walk
}
}
pathSeg := path
if n.nType != catchAll {
pathSeg = strings.SplitN(path, "/", 2)[0]
}
prefix := fullPath[:strings.Index(fullPath, pathSeg)] + n.path
panic("'" + pathSeg +
"' in new path '" + fullPath +
"' conflicts with existing wildcard '" + n.path +
"' in existing prefix '" + prefix +
"'")
}
c := path[0]
// slash after param
if n.nType == param && c == '/' && len(n.children) == 1 {
parentFullPathIndex += len(n.path)
n = n.children[0]
n.priority++
continue walk
}
// 找到子节点path值首字符与当前URL首字母相等的子节点并进入到此子节点并从循环最开始执行
for i, max := 0, len(n.indices); i < max; i++ {
if c == n.indices[i] {
parentFullPathIndex += len(n.path)
i = n.incrementChildPrio(i)
n = n.children[i]
continue walk
}
}
// Otherwise insert it
if c != ':' && c != '*' {
// []byte for proper unicode char conversion, see #65
n.indices += string([]byte{c})
child := &node{
maxParams: numParams,
fullPath: fullPath,
}
n.children = append(n.children, child)
n.incrementChildPrio(len(n.indices) - 1)
n = child
}
n.insertChild(numParams, path, fullPath, handlers)
return
}
// Otherwise and handle to current node
if n.handlers != nil {
panic("handlers are already registered for path '" + fullPath + "'")
}
n.handlers = handlers
return
}
}
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