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-rw-r--r--vendor/github.com/julienschmidt/httprouter/tree.go656
1 files changed, 656 insertions, 0 deletions
diff --git a/vendor/github.com/julienschmidt/httprouter/tree.go b/vendor/github.com/julienschmidt/httprouter/tree.go
new file mode 100644
index 000000000..a8fa98b04
--- /dev/null
+++ b/vendor/github.com/julienschmidt/httprouter/tree.go
@@ -0,0 +1,656 @@
+// Copyright 2013 Julien Schmidt. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be found
+// in the LICENSE file.
+
+package httprouter
+
+import (
+ "strings"
+ "unicode"
+ "unicode/utf8"
+)
+
+func min(a, b int) int {
+ if a <= b {
+ return a
+ }
+ return b
+}
+
+func countParams(path string) uint8 {
+ var n uint
+ for i := 0; i < len(path); i++ {
+ if path[i] != ':' && path[i] != '*' {
+ continue
+ }
+ n++
+ }
+ if n >= 255 {
+ return 255
+ }
+ return uint8(n)
+}
+
+type nodeType uint8
+
+const (
+ static nodeType = iota // default
+ root
+ param
+ catchAll
+)
+
+type node struct {
+ path string
+ wildChild bool
+ nType nodeType
+ maxParams uint8
+ indices string
+ children []*node
+ handle Handle
+ priority uint32
+}
+
+// increments priority of the given child and reorders if necessary
+func (n *node) incrementChildPrio(pos int) int {
+ n.children[pos].priority++
+ prio := n.children[pos].priority
+
+ // adjust position (move to front)
+ newPos := pos
+ for newPos > 0 && n.children[newPos-1].priority < prio {
+ // swap node positions
+ n.children[newPos-1], n.children[newPos] = n.children[newPos], n.children[newPos-1]
+
+ newPos--
+ }
+
+ // build new index char string
+ if newPos != pos {
+ n.indices = n.indices[:newPos] + // unchanged prefix, might be empty
+ n.indices[pos:pos+1] + // the index char we move
+ n.indices[newPos:pos] + n.indices[pos+1:] // rest without char at 'pos'
+ }
+
+ return newPos
+}
+
+// addRoute adds a node with the given handle to the path.
+// Not concurrency-safe!
+func (n *node) addRoute(path string, handle Handle) {
+ fullPath := path
+ n.priority++
+ numParams := countParams(path)
+
+ // 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
+ }
+
+ // 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++
+ }
+
+ // Split edge
+ if i < len(n.path) {
+ child := node{
+ path: n.path[i:],
+ wildChild: n.wildChild,
+ nType: static,
+ indices: n.indices,
+ children: n.children,
+ handle: n.handle,
+ priority: n.priority - 1,
+ }
+
+ // 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.handle = nil
+ n.wildChild = false
+ }
+
+ // Make new node a child of this node
+ if i < len(path) {
+ path = path[i:]
+
+ if n.wildChild {
+ 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
+ (len(n.path) >= len(path) || path[len(n.path)] == '/') {
+ continue walk
+ } else {
+ // Wildcard conflict
+ var pathSeg string
+ if n.nType == catchAll {
+ pathSeg = path
+ } else {
+ 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 {
+ 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] {
+ 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,
+ }
+ n.children = append(n.children, child)
+ n.incrementChildPrio(len(n.indices) - 1)
+ n = child
+ }
+ n.insertChild(numParams, path, fullPath, handle)
+ return
+
+ } else if i == len(path) { // Make node a (in-path) leaf
+ if n.handle != nil {
+ panic("a handle is already registered for path '" + fullPath + "'")
+ }
+ n.handle = handle
+ }
+ return
+ }
+ } else { // Empty tree
+ n.insertChild(numParams, path, fullPath, handle)
+ n.nType = root
+ }
+}
+
+func (n *node) insertChild(numParams uint8, path, fullPath string, handle Handle) {
+ var offset int // already handled bytes of the path
+
+ // find prefix until first wildcard (beginning with ':'' or '*'')
+ for i, max := 0, len(path); numParams > 0; i++ {
+ c := path[i]
+ if c != ':' && c != '*' {
+ continue
+ }
+
+ // find wildcard end (either '/' or path end)
+ end := i + 1
+ for end < max && path[end] != '/' {
+ switch path[end] {
+ // the wildcard name must not contain ':' and '*'
+ case ':', '*':
+ panic("only one wildcard per path segment is allowed, has: '" +
+ path[i:] + "' in path '" + fullPath + "'")
+ default:
+ end++
+ }
+ }
+
+ // check if this Node existing children which would be
+ // unreachable if we insert the wildcard here
+ if len(n.children) > 0 {
+ panic("wildcard route '" + path[i:end] +
+ "' conflicts with existing children in path '" + fullPath + "'")
+ }
+
+ // check if the wildcard has a name
+ if end-i < 2 {
+ panic("wildcards must be named with a non-empty name in path '" + fullPath + "'")
+ }
+
+ if c == ':' { // param
+ // split path at the beginning of the wildcard
+ if i > 0 {
+ n.path = path[offset:i]
+ offset = i
+ }
+
+ child := &node{
+ nType: param,
+ maxParams: numParams,
+ }
+ n.children = []*node{child}
+ n.wildChild = true
+ n = child
+ n.priority++
+ numParams--
+
+ // if the path doesn't end with the wildcard, then there
+ // will be another non-wildcard subpath starting with '/'
+ if end < max {
+ n.path = path[offset:end]
+ offset = end
+
+ child := &node{
+ maxParams: numParams,
+ priority: 1,
+ }
+ n.children = []*node{child}
+ n = child
+ }
+
+ } else { // catchAll
+ if end != max || numParams > 1 {
+ panic("catch-all routes are only allowed at the end of the path in path '" + fullPath + "'")
+ }
+
+ if len(n.path) > 0 && n.path[len(n.path)-1] == '/' {
+ panic("catch-all conflicts with existing handle for the path segment root in path '" + fullPath + "'")
+ }
+
+ // currently fixed width 1 for '/'
+ i--
+ if path[i] != '/' {
+ panic("no / before catch-all in path '" + fullPath + "'")
+ }
+
+ n.path = path[offset:i]
+
+ // first node: catchAll node with empty path
+ child := &node{
+ wildChild: true,
+ nType: catchAll,
+ maxParams: 1,
+ }
+ n.children = []*node{child}
+ n.indices = string(path[i])
+ n = child
+ n.priority++
+
+ // second node: node holding the variable
+ child = &node{
+ path: path[i:],
+ nType: catchAll,
+ maxParams: 1,
+ handle: handle,
+ priority: 1,
+ }
+ n.children = []*node{child}
+
+ return
+ }
+ }
+
+ // insert remaining path part and handle to the leaf
+ n.path = path[offset:]
+ n.handle = handle
+}
+
+// Returns the handle registered with the given path (key). The values of
+// wildcards are saved to a map.
+// If no handle can be found, a TSR (trailing slash redirect) recommendation is
+// made if a handle exists with an extra (without the) trailing slash for the
+// given path.
+func (n *node) getValue(path string) (handle Handle, p Params, tsr bool) {
+walk: // outer loop for walking the tree
+ for {
+ if len(path) > len(n.path) {
+ if path[:len(n.path)] == n.path {
+ path = path[len(n.path):]
+ // 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 {
+ c := path[0]
+ for i := 0; i < len(n.indices); i++ {
+ if c == n.indices[i] {
+ n = n.children[i]
+ continue walk
+ }
+ }
+
+ // Nothing found.
+ // We can recommend to redirect to the same URL without a
+ // trailing slash if a leaf exists for that path.
+ tsr = (path == "/" && n.handle != nil)
+ return
+
+ }
+
+ // handle wildcard child
+ n = n.children[0]
+ switch n.nType {
+ case param:
+ // find param end (either '/' or path end)
+ end := 0
+ for end < len(path) && path[end] != '/' {
+ end++
+ }
+
+ // save param value
+ if p == nil {
+ // lazy allocation
+ p = make(Params, 0, n.maxParams)
+ }
+ i := len(p)
+ p = p[:i+1] // expand slice within preallocated capacity
+ p[i].Key = n.path[1:]
+ p[i].Value = path[:end]
+
+ // we need to go deeper!
+ if end < len(path) {
+ if len(n.children) > 0 {
+ path = path[end:]
+ n = n.children[0]
+ continue walk
+ }
+
+ // ... but we can't
+ tsr = (len(path) == end+1)
+ return
+ }
+
+ if handle = n.handle; handle != nil {
+ return
+ } else if len(n.children) == 1 {
+ // No handle found. Check if a handle for this path + a
+ // trailing slash exists for TSR recommendation
+ n = n.children[0]
+ tsr = (n.path == "/" && n.handle != nil)
+ }
+
+ return
+
+ case catchAll:
+ // save param value
+ if p == nil {
+ // lazy allocation
+ p = make(Params, 0, n.maxParams)
+ }
+ i := len(p)
+ p = p[:i+1] // expand slice within preallocated capacity
+ p[i].Key = n.path[2:]
+ p[i].Value = path
+
+ handle = n.handle
+ return
+
+ default:
+ panic("invalid node type")
+ }
+ }
+ } else if path == n.path {
+ // We should have reached the node containing the handle.
+ // Check if this node has a handle registered.
+ if handle = n.handle; handle != nil {
+ return
+ }
+
+ if path == "/" && n.wildChild && n.nType != root {
+ tsr = true
+ return
+ }
+
+ // No handle found. Check if a handle for this path + a
+ // trailing slash exists for trailing slash recommendation
+ for i := 0; i < len(n.indices); i++ {
+ if n.indices[i] == '/' {
+ n = n.children[i]
+ tsr = (len(n.path) == 1 && n.handle != nil) ||
+ (n.nType == catchAll && n.children[0].handle != nil)
+ return
+ }
+ }
+
+ return
+ }
+
+ // Nothing found. We can recommend to redirect to the same URL with an
+ // extra trailing slash if a leaf exists for that path
+ tsr = (path == "/") ||
+ (len(n.path) == len(path)+1 && n.path[len(path)] == '/' &&
+ path == n.path[:len(n.path)-1] && n.handle != nil)
+ return
+ }
+}
+
+// Makes a case-insensitive lookup of the given path and tries to find a handler.
+// It can optionally also fix trailing slashes.
+// It returns the case-corrected path and a bool indicating whether the lookup
+// was successful.
+func (n *node) findCaseInsensitivePath(path string, fixTrailingSlash bool) (ciPath []byte, found bool) {
+ return n.findCaseInsensitivePathRec(
+ path,
+ strings.ToLower(path),
+ make([]byte, 0, len(path)+1), // preallocate enough memory for new path
+ [4]byte{}, // empty rune buffer
+ fixTrailingSlash,
+ )
+}
+
+// shift bytes in array by n bytes left
+func shiftNRuneBytes(rb [4]byte, n int) [4]byte {
+ switch n {
+ case 0:
+ return rb
+ case 1:
+ return [4]byte{rb[1], rb[2], rb[3], 0}
+ case 2:
+ return [4]byte{rb[2], rb[3]}
+ case 3:
+ return [4]byte{rb[3]}
+ default:
+ return [4]byte{}
+ }
+}
+
+// recursive case-insensitive lookup function used by n.findCaseInsensitivePath
+func (n *node) findCaseInsensitivePathRec(path, loPath string, ciPath []byte, rb [4]byte, fixTrailingSlash bool) ([]byte, bool) {
+ loNPath := strings.ToLower(n.path)
+
+walk: // outer loop for walking the tree
+ for len(loPath) >= len(loNPath) && (len(loNPath) == 0 || loPath[1:len(loNPath)] == loNPath[1:]) {
+ // add common path to result
+ ciPath = append(ciPath, n.path...)
+
+ if path = path[len(n.path):]; len(path) > 0 {
+ loOld := loPath
+ loPath = loPath[len(loNPath):]
+
+ // 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 {
+ // skip rune bytes already processed
+ rb = shiftNRuneBytes(rb, len(loNPath))
+
+ if rb[0] != 0 {
+ // old rune not finished
+ for i := 0; i < len(n.indices); i++ {
+ if n.indices[i] == rb[0] {
+ // continue with child node
+ n = n.children[i]
+ loNPath = strings.ToLower(n.path)
+ continue walk
+ }
+ }
+ } else {
+ // process a new rune
+ var rv rune
+
+ // find rune start
+ // runes are up to 4 byte long,
+ // -4 would definitely be another rune
+ var off int
+ for max := min(len(loNPath), 3); off < max; off++ {
+ if i := len(loNPath) - off; utf8.RuneStart(loOld[i]) {
+ // read rune from cached lowercase path
+ rv, _ = utf8.DecodeRuneInString(loOld[i:])
+ break
+ }
+ }
+
+ // calculate lowercase bytes of current rune
+ utf8.EncodeRune(rb[:], rv)
+ // skipp already processed bytes
+ rb = shiftNRuneBytes(rb, off)
+
+ for i := 0; i < len(n.indices); i++ {
+ // lowercase matches
+ if n.indices[i] == rb[0] {
+ // must use a recursive approach since both the
+ // uppercase byte and the lowercase byte might exist
+ // as an index
+ if out, found := n.children[i].findCaseInsensitivePathRec(
+ path, loPath, ciPath, rb, fixTrailingSlash,
+ ); found {
+ return out, true
+ }
+ break
+ }
+ }
+
+ // same for uppercase rune, if it differs
+ if up := unicode.ToUpper(rv); up != rv {
+ utf8.EncodeRune(rb[:], up)
+ rb = shiftNRuneBytes(rb, off)
+
+ for i := 0; i < len(n.indices); i++ {
+ // uppercase matches
+ if n.indices[i] == rb[0] {
+ // continue with child node
+ n = n.children[i]
+ loNPath = strings.ToLower(n.path)
+ continue walk
+ }
+ }
+ }
+ }
+
+ // Nothing found. We can recommend to redirect to the same URL
+ // without a trailing slash if a leaf exists for that path
+ return ciPath, (fixTrailingSlash && path == "/" && n.handle != nil)
+ }
+
+ 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 {
+ // continue with child node
+ n = n.children[0]
+ loNPath = strings.ToLower(n.path)
+ loPath = loPath[k:]
+ path = path[k:]
+ continue
+ }
+
+ // ... but we can't
+ if fixTrailingSlash && len(path) == k+1 {
+ return ciPath, true
+ }
+ return ciPath, false
+ }
+
+ if n.handle != 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.handle != nil {
+ return append(ciPath, '/'), true
+ }
+ }
+ return ciPath, false
+
+ case catchAll:
+ return append(ciPath, path...), true
+
+ default:
+ panic("invalid node type")
+ }
+ } else {
+ // We should have reached the node containing the handle.
+ // Check if this node has a handle registered.
+ if n.handle != nil {
+ return ciPath, true
+ }
+
+ // No handle found.
+ // Try to fix the path by adding a trailing slash
+ if fixTrailingSlash {
+ for i := 0; i < len(n.indices); i++ {
+ if n.indices[i] == '/' {
+ n = n.children[i]
+ if (len(n.path) == 1 && n.handle != nil) ||
+ (n.nType == catchAll && n.children[0].handle != nil) {
+ return append(ciPath, '/'), true
+ }
+ return ciPath, false
+ }
+ }
+ }
+ return ciPath, false
+ }
+ }
+
+ // Nothing found.
+ // Try to fix the path by adding / removing a trailing slash
+ if fixTrailingSlash {
+ if path == "/" {
+ return ciPath, true
+ }
+ if len(loPath)+1 == len(loNPath) && loNPath[len(loPath)] == '/' &&
+ loPath[1:] == loNPath[1:len(loPath)] && n.handle != nil {
+ return append(ciPath, n.path...), true
+ }
+ }
+ return ciPath, false
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-08-22 15:43:09 +0800