From 3abc96e3cdc4e74daf52fff5fe7eb36b9674904b Mon Sep 17 00:00:00 2001 From: thinkerou Date: Sun, 1 Dec 2019 19:53:03 +0800 Subject: [PATCH] tree: sync part httprouter codes and reduce if/else (#2163) --- tree.go | 370 ++++++++++++++++++++++++++++---------------------------- 1 file changed, 188 insertions(+), 182 deletions(-) diff --git a/tree.go b/tree.go index 41947570..1187f3f6 100644 --- a/tree.go +++ b/tree.go @@ -62,6 +62,15 @@ func min(a, b int) int { return b } +func longestCommonPrefix(a, b string) int { + i := 0 + max := min(len(a), len(b)) + for i < max && a[i] == b[i] { + i++ + } + return i +} + func countParams(path string) uint8 { var n uint for i := 0; i < len(path); i++ { @@ -127,135 +136,132 @@ func (n *node) addRoute(path string, handlers HandlersChain) { 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 - // non-empty tree - if len(n.path) > 0 || len(n.children) > 0 { - walk: - for { - // Update maxParams of the current node - if numParams > n.maxParams { - n.maxParams = numParams +walk: + for { + // Update maxParams of the current node + if numParams > n.maxParams { + n.maxParams = numParams + } + + // Find the longest common prefix. + // This also implies that the common prefix contains no ':' or '*' + // since the existing key can't contain those chars. + i := longestCommonPrefix(path, n.path) + + // Split edge + 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, } - // Find the longest common prefix. - // This also implies that the common prefix contains no ':' or '*' - // since the existing key can't contain those chars. - i := 0 - max := min(len(path), len(n.path)) - for i < max && path[i] == n.path[i] { - i++ + // Update maxParams (max of all children) + for i := range child.children { + if child.children[i].maxParams > child.maxParams { + child.maxParams = child.children[i].maxParams + } } - // Split edge - 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, + 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-- - // 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 - } - - // Check if a child with the next path byte exists - for i := 0; i < len(n.indices); i++ { - if c == n.indices[i] { - parentFullPathIndex += len(n.path) - i = n.incrementChildPrio(i) - n = n.children[i] + // 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 } } - // 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 + pathSeg := path + if n.nType != catchAll { + pathSeg = strings.SplitN(path, "/", 2)[0] } - n.insertChild(numParams, path, fullPath, handlers) - return - - } else if i == len(path) { // Make node a (in-path) leaf - if n.handlers != nil { - panic("handlers are already registered for path '" + fullPath + "'") - } - n.handlers = handlers + 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 + } + + // Check if a child with the next path byte exists + for i := 0; i < len(n.indices); 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 + + } else if i == len(path) { // Make node a (in-path) leaf + if n.handlers != nil { + panic("handlers are already registered for path '" + fullPath + "'") + } + n.handlers = handlers } - } else { // Empty tree - n.insertChild(numParams, path, fullPath, handlers) - n.nType = root + return } } @@ -542,75 +548,7 @@ func (n *node) findCaseInsensitivePath(path string, fixTrailingSlash bool) (ciPa path = path[len(n.path):] ciPath = append(ciPath, n.path...) - if len(path) > 0 { - // If this node does not have a wildcard (param or catchAll) child, - // we can just look up the next child node and continue to walk down - // the tree - if !n.wildChild { - r := unicode.ToLower(rune(path[0])) - for i, index := range n.indices { - // must use recursive approach since both index and - // ToLower(index) could exist. We must check both. - if r == unicode.ToLower(index) { - out, found := n.children[i].findCaseInsensitivePath(path, fixTrailingSlash) - if found { - return append(ciPath, out...), true - } - } - } - - // Nothing found. We can recommend to redirect to the same URL - // without a trailing slash if a leaf exists for that path - found = fixTrailingSlash && path == "/" && n.handlers != nil - return - } - - n = n.children[0] - switch n.nType { - case param: - // find param end (either '/' or path end) - k := 0 - for k < len(path) && path[k] != '/' { - k++ - } - - // add param value to case insensitive path - ciPath = append(ciPath, path[:k]...) - - // we need to go deeper! - if k < len(path) { - if len(n.children) > 0 { - path = path[k:] - n = n.children[0] - continue - } - - // ... but we can't - if fixTrailingSlash && len(path) == k+1 { - return ciPath, true - } - return - } - - if n.handlers != nil { - return ciPath, true - } else if fixTrailingSlash && len(n.children) == 1 { - // No handle found. Check if a handle for this path + a - // trailing slash exists - n = n.children[0] - if n.path == "/" && n.handlers != nil { - return append(ciPath, '/'), true - } - } - return - - case catchAll: - return append(ciPath, path...), true - - default: - panic("invalid node type") - } - } else { + if len(path) == 0 { // We should have reached the node containing the handle. // Check if this node has a handle registered. if n.handlers != nil { @@ -633,6 +571,74 @@ func (n *node) findCaseInsensitivePath(path string, fixTrailingSlash bool) (ciPa } return } + + // If this node does not have a wildcard (param or catchAll) child, + // we can just look up the next child node and continue to walk down + // the tree + if !n.wildChild { + r := unicode.ToLower(rune(path[0])) + for i, index := range n.indices { + // must use recursive approach since both index and + // ToLower(index) could exist. We must check both. + if r == unicode.ToLower(index) { + out, found := n.children[i].findCaseInsensitivePath(path, fixTrailingSlash) + if found { + return append(ciPath, out...), true + } + } + } + + // Nothing found. We can recommend to redirect to the same URL + // without a trailing slash if a leaf exists for that path + found = fixTrailingSlash && path == "/" && n.handlers != nil + return + } + + n = n.children[0] + switch n.nType { + case param: + // find param end (either '/' or path end) + k := 0 + for k < len(path) && path[k] != '/' { + k++ + } + + // add param value to case insensitive path + ciPath = append(ciPath, path[:k]...) + + // we need to go deeper! + if k < len(path) { + if len(n.children) > 0 { + path = path[k:] + n = n.children[0] + continue + } + + // ... but we can't + if fixTrailingSlash && len(path) == k+1 { + return ciPath, true + } + return + } + + if n.handlers != nil { + return ciPath, true + } else if fixTrailingSlash && len(n.children) == 1 { + // No handle found. Check if a handle for this path + a + // trailing slash exists + n = n.children[0] + if n.path == "/" && n.handlers != nil { + return append(ciPath, '/'), true + } + } + return + + case catchAll: + return append(ciPath, path...), true + + default: + panic("invalid node type") + } } // Nothing found.