First commit

node_modules/find-my-way/lib/node.js

@@ -0,0 +1,228 @@
+'use strict'
+
+const HandlerStorage = require('./handler-storage')
+
+const NODE_TYPES = {
+  STATIC: 0,
+  PARAMETRIC: 1,
+  WILDCARD: 2
+}
+
+class Node {
+  constructor () {
+    this.isLeafNode = false
+    this.routes = null
+    this.handlerStorage = null
+  }
+
+  addRoute (route, constrainer) {
+    if (this.routes === null) {
+      this.routes = []
+    }
+    if (this.handlerStorage === null) {
+      this.handlerStorage = new HandlerStorage()
+    }
+    this.isLeafNode = true
+    this.routes.push(route)
+    this.handlerStorage.addHandler(constrainer, route)
+  }
+}
+
+class ParentNode extends Node {
+  constructor () {
+    super()
+    this.staticChildren = {}
+  }
+
+  findStaticMatchingChild (path, pathIndex) {
+    const staticChild = this.staticChildren[path.charAt(pathIndex)]
+    if (staticChild === undefined || !staticChild.matchPrefix(path, pathIndex)) {
+      return null
+    }
+    return staticChild
+  }
+
+  getStaticChild (path, pathIndex = 0) {
+    if (path.length === pathIndex) {
+      return this
+    }
+
+    const staticChild = this.findStaticMatchingChild(path, pathIndex)
+    if (staticChild) {
+      return staticChild.getStaticChild(path, pathIndex + staticChild.prefix.length)
+    }
+
+    return null
+  }
+
+  createStaticChild (path) {
+    if (path.length === 0) {
+      return this
+    }
+
+    let staticChild = this.staticChildren[path.charAt(0)]
+    if (staticChild) {
+      let i = 1
+      for (; i < staticChild.prefix.length; i++) {
+        if (path.charCodeAt(i) !== staticChild.prefix.charCodeAt(i)) {
+          staticChild = staticChild.split(this, i)
+          break
+        }
+      }
+      return staticChild.createStaticChild(path.slice(i))
+    }
+
+    const label = path.charAt(0)
+    this.staticChildren[label] = new StaticNode(path)
+    return this.staticChildren[label]
+  }
+}
+
+class StaticNode extends ParentNode {
+  constructor (prefix) {
+    super()
+    this.prefix = prefix
+    this.wildcardChild = null
+    this.parametricChildren = []
+    this.kind = NODE_TYPES.STATIC
+    this._compilePrefixMatch()
+  }
+
+  getParametricChild (regex) {
+    const regexpSource = regex && regex.source
+
+    const parametricChild = this.parametricChildren.find(child => {
+      const childRegexSource = child.regex && child.regex.source
+      return childRegexSource === regexpSource
+    })
+
+    if (parametricChild) {
+      return parametricChild
+    }
+
+    return null
+  }
+
+  createParametricChild (regex, staticSuffix, nodePath) {
+    let parametricChild = this.getParametricChild(regex)
+    if (parametricChild) {
+      parametricChild.nodePaths.add(nodePath)
+      return parametricChild
+    }
+
+    parametricChild = new ParametricNode(regex, staticSuffix, nodePath)
+    this.parametricChildren.push(parametricChild)
+    this.parametricChildren.sort((child1, child2) => {
+      if (!child1.isRegex) return 1
+      if (!child2.isRegex) return -1
+
+      if (child1.staticSuffix === null) return 1
+      if (child2.staticSuffix === null) return -1
+
+      if (child2.staticSuffix.endsWith(child1.staticSuffix)) return 1
+      if (child1.staticSuffix.endsWith(child2.staticSuffix)) return -1
+
+      return 0
+    })
+
+    return parametricChild
+  }
+
+  getWildcardChild () {
+    return this.wildcardChild
+  }
+
+  createWildcardChild () {
+    this.wildcardChild = this.getWildcardChild() || new WildcardNode()
+    return this.wildcardChild
+  }
+
+  split (parentNode, length) {
+    const parentPrefix = this.prefix.slice(0, length)
+    const childPrefix = this.prefix.slice(length)
+
+    this.prefix = childPrefix
+    this._compilePrefixMatch()
+
+    const staticNode = new StaticNode(parentPrefix)
+    staticNode.staticChildren[childPrefix.charAt(0)] = this
+    parentNode.staticChildren[parentPrefix.charAt(0)] = staticNode
+
+    return staticNode
+  }
+
+  getNextNode (path, pathIndex, nodeStack, paramsCount) {
+    let node = this.findStaticMatchingChild(path, pathIndex)
+    let parametricBrotherNodeIndex = 0
+
+    if (node === null) {
+      if (this.parametricChildren.length === 0) {
+        return this.wildcardChild
+      }
+
+      node = this.parametricChildren[0]
+      parametricBrotherNodeIndex = 1
+    }
+
+    if (this.wildcardChild !== null) {
+      nodeStack.push({
+        paramsCount,
+        brotherPathIndex: pathIndex,
+        brotherNode: this.wildcardChild
+      })
+    }
+
+    for (let i = this.parametricChildren.length - 1; i >= parametricBrotherNodeIndex; i--) {
+      nodeStack.push({
+        paramsCount,
+        brotherPathIndex: pathIndex,
+        brotherNode: this.parametricChildren[i]
+      })
+    }
+
+    return node
+  }
+
+  _compilePrefixMatch () {
+    if (this.prefix.length === 1) {
+      this.matchPrefix = () => true
+      return
+    }
+
+    const lines = []
+    for (let i = 1; i < this.prefix.length; i++) {
+      const charCode = this.prefix.charCodeAt(i)
+      lines.push(`path.charCodeAt(i + ${i}) === ${charCode}`)
+    }
+    this.matchPrefix = new Function('path', 'i', `return ${lines.join(' && ')}`) // eslint-disable-line
+  }
+}
+
+class ParametricNode extends ParentNode {
+  constructor (regex, staticSuffix, nodePath) {
+    super()
+    this.isRegex = !!regex
+    this.regex = regex || null
+    this.staticSuffix = staticSuffix || null
+    this.kind = NODE_TYPES.PARAMETRIC
+
+    this.nodePaths = new Set([nodePath])
+  }
+
+  getNextNode (path, pathIndex) {
+    return this.findStaticMatchingChild(path, pathIndex)
+  }
+}
+
+class WildcardNode extends Node {
+  constructor () {
+    super()
+    this.kind = NODE_TYPES.WILDCARD
+  }
+
+  getNextNode () {
+    return null
+  }
+}
+
+module.exports = { StaticNode, ParametricNode, WildcardNode, NODE_TYPES }