macaron/tree.go
2019-08-21 20:23:02 +00:00

391 lines
10 KiB
Go

// Copyright 2015 The Macaron Authors
//
// 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 macaron
import (
"regexp"
"strings"
"github.com/unknwon/com"
)
type patternType int8
const (
_PATTERN_STATIC patternType = iota // /home
_PATTERN_REGEXP // /:id([0-9]+)
_PATTERN_PATH_EXT // /*.*
_PATTERN_HOLDER // /:user
_PATTERN_MATCH_ALL // /*
)
// Leaf represents a leaf route information.
type Leaf struct {
parent *Tree
typ patternType
pattern string
rawPattern string // Contains wildcard instead of regexp
wildcards []string
reg *regexp.Regexp
optional bool
handle Handle
}
var wildcardPattern = regexp.MustCompile(`:[a-zA-Z0-9]+`)
func isSpecialRegexp(pattern, regStr string, pos []int) bool {
return len(pattern) >= pos[1]+len(regStr) && pattern[pos[1]:pos[1]+len(regStr)] == regStr
}
// getNextWildcard tries to find next wildcard and update pattern with corresponding regexp.
func getNextWildcard(pattern string) (wildcard, _ string) {
pos := wildcardPattern.FindStringIndex(pattern)
if pos == nil {
return "", pattern
}
wildcard = pattern[pos[0]:pos[1]]
// Reach last character or no regexp is given.
if len(pattern) == pos[1] {
return wildcard, strings.Replace(pattern, wildcard, `(.+)`, 1)
} else if pattern[pos[1]] != '(' {
switch {
case isSpecialRegexp(pattern, ":int", pos):
pattern = strings.Replace(pattern, ":int", "([0-9]+)", 1)
case isSpecialRegexp(pattern, ":string", pos):
pattern = strings.Replace(pattern, ":string", "([\\w]+)", 1)
default:
return wildcard, strings.Replace(pattern, wildcard, `(.+)`, 1)
}
}
// Cut out placeholder directly.
return wildcard, pattern[:pos[0]] + pattern[pos[1]:]
}
func getWildcards(pattern string) (string, []string) {
wildcards := make([]string, 0, 2)
// Keep getting next wildcard until nothing is left.
var wildcard string
for {
wildcard, pattern = getNextWildcard(pattern)
if len(wildcard) > 0 {
wildcards = append(wildcards, wildcard)
} else {
break
}
}
return pattern, wildcards
}
// getRawPattern removes all regexp but keeps wildcards for building URL path.
func getRawPattern(rawPattern string) string {
rawPattern = strings.Replace(rawPattern, ":int", "", -1)
rawPattern = strings.Replace(rawPattern, ":string", "", -1)
for {
startIdx := strings.Index(rawPattern, "(")
if startIdx == -1 {
break
}
closeIdx := strings.Index(rawPattern, ")")
if closeIdx > -1 {
rawPattern = rawPattern[:startIdx] + rawPattern[closeIdx+1:]
}
}
return rawPattern
}
func checkPattern(pattern string) (typ patternType, rawPattern string, wildcards []string, reg *regexp.Regexp) {
pattern = strings.TrimLeft(pattern, "?")
rawPattern = getRawPattern(pattern)
if pattern == "*" {
typ = _PATTERN_MATCH_ALL
} else if pattern == "*.*" {
typ = _PATTERN_PATH_EXT
} else if strings.Contains(pattern, ":") {
typ = _PATTERN_REGEXP
pattern, wildcards = getWildcards(pattern)
if pattern == "(.+)" {
typ = _PATTERN_HOLDER
} else {
reg = regexp.MustCompile(pattern)
}
}
return typ, rawPattern, wildcards, reg
}
func NewLeaf(parent *Tree, pattern string, handle Handle) *Leaf {
typ, rawPattern, wildcards, reg := checkPattern(pattern)
optional := false
if len(pattern) > 0 && pattern[0] == '?' {
optional = true
}
return &Leaf{parent, typ, pattern, rawPattern, wildcards, reg, optional, handle}
}
// URLPath build path part of URL by given pair values.
func (l *Leaf) URLPath(pairs ...string) string {
if len(pairs)%2 != 0 {
panic("number of pairs does not match")
}
urlPath := l.rawPattern
parent := l.parent
for parent != nil {
urlPath = parent.rawPattern + "/" + urlPath
parent = parent.parent
}
for i := 0; i < len(pairs); i += 2 {
if len(pairs[i]) == 0 {
panic("pair value cannot be empty: " + com.ToStr(i))
} else if pairs[i][0] != ':' && pairs[i] != "*" && pairs[i] != "*.*" {
pairs[i] = ":" + pairs[i]
}
urlPath = strings.Replace(urlPath, pairs[i], pairs[i+1], 1)
}
return urlPath
}
// Tree represents a router tree in Macaron.
type Tree struct {
parent *Tree
typ patternType
pattern string
rawPattern string
wildcards []string
reg *regexp.Regexp
subtrees []*Tree
leaves []*Leaf
}
func NewSubtree(parent *Tree, pattern string) *Tree {
typ, rawPattern, wildcards, reg := checkPattern(pattern)
return &Tree{parent, typ, pattern, rawPattern, wildcards, reg, make([]*Tree, 0, 5), make([]*Leaf, 0, 5)}
}
func NewTree() *Tree {
return NewSubtree(nil, "")
}
func (t *Tree) addLeaf(pattern string, handle Handle) *Leaf {
for i := 0; i < len(t.leaves); i++ {
if t.leaves[i].pattern == pattern {
return t.leaves[i]
}
}
leaf := NewLeaf(t, pattern, handle)
// Add exact same leaf to grandparent/parent level without optional.
if leaf.optional {
parent := leaf.parent
if parent.parent != nil {
parent.parent.addLeaf(parent.pattern, handle)
} else {
parent.addLeaf("", handle) // Root tree can add as empty pattern.
}
}
i := 0
for ; i < len(t.leaves); i++ {
if leaf.typ < t.leaves[i].typ {
break
}
}
if i == len(t.leaves) {
t.leaves = append(t.leaves, leaf)
} else {
t.leaves = append(t.leaves[:i], append([]*Leaf{leaf}, t.leaves[i:]...)...)
}
return leaf
}
func (t *Tree) addSubtree(segment, pattern string, handle Handle) *Leaf {
for i := 0; i < len(t.subtrees); i++ {
if t.subtrees[i].pattern == segment {
return t.subtrees[i].addNextSegment(pattern, handle)
}
}
subtree := NewSubtree(t, segment)
i := 0
for ; i < len(t.subtrees); i++ {
if subtree.typ < t.subtrees[i].typ {
break
}
}
if i == len(t.subtrees) {
t.subtrees = append(t.subtrees, subtree)
} else {
t.subtrees = append(t.subtrees[:i], append([]*Tree{subtree}, t.subtrees[i:]...)...)
}
return subtree.addNextSegment(pattern, handle)
}
func (t *Tree) addNextSegment(pattern string, handle Handle) *Leaf {
pattern = strings.TrimPrefix(pattern, "/")
i := strings.Index(pattern, "/")
if i == -1 {
return t.addLeaf(pattern, handle)
}
return t.addSubtree(pattern[:i], pattern[i+1:], handle)
}
func (t *Tree) Add(pattern string, handle Handle) *Leaf {
pattern = strings.TrimSuffix(pattern, "/")
return t.addNextSegment(pattern, handle)
}
func (t *Tree) matchLeaf(globLevel int, url string, params Params) (Handle, bool) {
url, err := PathUnescape(url)
if err != nil {
return nil, false
}
for i := 0; i < len(t.leaves); i++ {
switch t.leaves[i].typ {
case _PATTERN_STATIC:
if t.leaves[i].pattern == url {
return t.leaves[i].handle, true
}
case _PATTERN_REGEXP:
results := t.leaves[i].reg.FindStringSubmatch(url)
// Number of results and wildcasrd should be exact same.
if len(results)-1 != len(t.leaves[i].wildcards) {
break
}
for j := 0; j < len(t.leaves[i].wildcards); j++ {
params[t.leaves[i].wildcards[j]] = results[j+1]
}
return t.leaves[i].handle, true
case _PATTERN_PATH_EXT:
j := strings.LastIndex(url, ".")
if j > -1 {
params[":path"] = url[:j]
params[":ext"] = url[j+1:]
} else {
params[":path"] = url
}
return t.leaves[i].handle, true
case _PATTERN_HOLDER:
params[t.leaves[i].wildcards[0]] = url
return t.leaves[i].handle, true
case _PATTERN_MATCH_ALL:
params["*"] = url
params["*"+com.ToStr(globLevel)] = url
return t.leaves[i].handle, true
}
}
return nil, false
}
func (t *Tree) matchSubtree(globLevel int, segment, url string, params Params) (Handle, bool) {
unescapedSegment, err := PathUnescape(segment)
if err != nil {
return nil, false
}
for i := 0; i < len(t.subtrees); i++ {
switch t.subtrees[i].typ {
case _PATTERN_STATIC:
if t.subtrees[i].pattern == unescapedSegment {
if handle, ok := t.subtrees[i].matchNextSegment(globLevel, url, params); ok {
return handle, true
}
}
case _PATTERN_REGEXP:
results := t.subtrees[i].reg.FindStringSubmatch(unescapedSegment)
if len(results)-1 != len(t.subtrees[i].wildcards) {
break
}
for j := 0; j < len(t.subtrees[i].wildcards); j++ {
params[t.subtrees[i].wildcards[j]] = results[j+1]
}
if handle, ok := t.subtrees[i].matchNextSegment(globLevel, url, params); ok {
return handle, true
}
case _PATTERN_HOLDER:
if handle, ok := t.subtrees[i].matchNextSegment(globLevel+1, url, params); ok {
params[t.subtrees[i].wildcards[0]] = unescapedSegment
return handle, true
}
case _PATTERN_MATCH_ALL:
if handle, ok := t.subtrees[i].matchNextSegment(globLevel+1, url, params); ok {
params["*"+com.ToStr(globLevel)] = unescapedSegment
return handle, true
}
}
}
if len(t.leaves) > 0 {
leaf := t.leaves[len(t.leaves)-1]
unescapedURL, err := PathUnescape(segment + "/" + url)
if err != nil {
return nil, false
}
if leaf.typ == _PATTERN_PATH_EXT {
j := strings.LastIndex(unescapedURL, ".")
if j > -1 {
params[":path"] = unescapedURL[:j]
params[":ext"] = unescapedURL[j+1:]
} else {
params[":path"] = unescapedURL
}
return leaf.handle, true
} else if leaf.typ == _PATTERN_MATCH_ALL {
params["*"] = unescapedURL
params["*"+com.ToStr(globLevel)] = unescapedURL
return leaf.handle, true
}
}
return nil, false
}
func (t *Tree) matchNextSegment(globLevel int, url string, params Params) (Handle, bool) {
i := strings.Index(url, "/")
if i == -1 {
return t.matchLeaf(globLevel, url, params)
}
return t.matchSubtree(globLevel, url[:i], url[i+1:], params)
}
func (t *Tree) Match(url string) (Handle, Params, bool) {
url = strings.TrimPrefix(url, "/")
url = strings.TrimSuffix(url, "/")
params := make(Params)
handle, ok := t.matchNextSegment(0, url, params)
return handle, params, ok
}
// MatchTest returns true if given URL is matched by given pattern.
func MatchTest(pattern, url string) bool {
t := NewTree()
t.Add(pattern, nil)
_, _, ok := t.Match(url)
return ok
}