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wanderer🌟 / js-dfinity-radix-tree



Commit fb6c040c6945375f945c7613513fc1a550c557fc

Browse Files

readded single array nodes

wanderer committed on 8/4/2017, 8:06:42 PM
Parent: f9516195f8ab298aa8892fc99db3029a7a3d7742

Files changed

index.jschanged
tests/index.jschanged
index.jsView
@@ -3,22 +3,38 @@
33 … const TextEncoder = require('text-encoding').TextEncoder
44 …
55 … const encoder = new TextEncoder('utf-8')
66 …
7-const EXTENSION = 0
8-const BRANCH = 1
9-const VALUE = 2
7 …+const LBRANCH = 0
8 …+const RBRANCH = 1
9 …+const EXTENSION = 2
10 …+const VALUE = 3
1011 …
1112 … const RadixTree = module.exports = class RadixTree {
13 …+ /**
14 …+ * @param opts
15 …+ * @param opts.root {object} a merkle root to a radix tree. If none, RadixTree will create an new root.
16 …+ * @param opts.graph {object} an instance of [ipld-graph-builder](https://github.com/ipld/js-ipld-graph-builder) alternitvly `opts.dag` can be used
17 …+ * @param opts.dag {object} an instance if [ipfs.dag](https://github.com/ipfs/js-ipfs#dag). If there is no `opts.graph` this will be used to create a new graph instance.
18 …+ */
1219 … constructor (opts) {
1320 … this.root = opts.root || {'/': undefined}
1421 … this.graph = opts.graph || new Graph(opts.dag)
1522 … }
1623 …
24 …+ /**
25 …+ * returns an Uint1Array constructir which is used to repersent keys
26 …+ * @returns {object}
27 …+ */
1728 … static get ArrayConstructor () {
1829 … return Uint1Array
1930 … }
2031 …
32 …+ /**
33 …+ * converts a TypedArray or Buffer to an Uint1Array
34 …+ * @param {TypedArray} array - the array to convert
35 …+ * @returns {TypedArray}
36 …+ */
2137 … static toTypedArray (array) {
2238 … return new RadixTree.ArrayConstructor(new Uint8Array(array).buffer)
2339 … }
2440 …
@@ -27,10 +43,10 @@
2743 … let root = this.root
2844 … let parent
2945 … while (1) {
3046 … // load the root
31- await this.graph.get(root, 0, true)
32- if (hasExtension(root)) {
47 …+ const exNode = await this.graph.get(root, EXTENSION, true)
48 …+ if (exNode) {
3349 … let extensionIndex = 0
3450 … const extensionLen = getExLength(root)
3551 … const extension = getExtension(root)
3652 … let subKey
@@ -86,14 +102,24 @@
86102 … index: index
87103 … }
88104 … }
89105 …
106 …+ /**
107 …+ * gets a value given a key
108 …+ * @param {*} key
109 …+ * @return {Promise}
110 …+ */
90111 … async get (key) {
91112 … key = RadixTree.formatKey(key)
92113 … const result = await this._get(key)
93114 … return result.value
94115 … }
95116 …
117 …+ /**
118 …+ * stores a value at a given key
119 …+ * @param {*} key
120 …+ * @return {Promise}
121 …+ */
96122 … async set (key, value) {
97123 … key = RadixTree.formatKey(key)
98124 …
99125 … if (value.length > 32) {
@@ -129,25 +155,32 @@
129155 … const extension = key.subarray(result.index + 1, key.length)
130156 … const newNode = createNode(extension, [], value)
131157 … const rootBranch = getBranch(root)
132158 … rootBranch[keySegment] = newNode
159 …+ setBranch(root, rootBranch)
133160 … } else {
134161 … setValue(root, value)
135162 … }
136163 … }
137164 … }
138165 … }
139166 …
167 …+ /**
168 …+ * deletes a value at a given key
169 …+ * @param {*} key
170 …+ * @return {Promise}
171 …+ */
140172 … async delete (key) {
141173 … key = RadixTree.formatKey(key)
142174 … const results = await this._get(key)
143- if (results.value) {
175 …+ if (results.value !== undefined) {
144176 … const root = results.root
145177 … const parent = results.parent
146178 …
147179 … deleteValue(root)
148180 …
149- if (getBranch(root).length) {
181 …+ const branch = getBranch(root)
182 …+ if (branch.some(el => el !== undefined)) {
150183 … joinNodes(root)
151184 … } else {
152185 … if (!parent) {
153186 … root['/'] = undefined
@@ -188,26 +221,49 @@
188221 … }
189222 … }
190223 … }
191224 …
225 …+ /**
226 …+ * creates a merkle root for the current tree
227 …+ * @returns {Promise}
228 …+ */
192229 … createMerkleRoot () {
193230 … return this.graph.flush(this.root)
194231 … }
195232 …
196233 … static formatKey (key) {
197234 … if (typeof key === 'string') {
198235 … key = encoder.encode(key)
199236 … }
200- return new RadixTree.ArrayConstructor(key.buffer)
237 …+
238 …+ if (key.constructor !== RadixTree.ArrayConstructor) {
239 …+ return new RadixTree.ArrayConstructor(key.buffer)
240 …+ } else {
241 …+ return key
242 …+ }
201243 … }
202244 … }
203245 …
246 …+function createNode (ex, branch, value) {
247 …+ const node = {
248 …+ '/': []
249 …+ }
250 …+
251 …+ setValue(node, value)
252 …+ setExtension(node, ex)
253 …+ setBranch(node, branch)
254 …+
255 …+ return node
256 …+}
257 …+
258 …+// helper functions for nodes
204259 … function setBranch (node, branch) {
205- node['/'][BRANCH] = branch
260 …+ node['/'][LBRANCH] = branch[0]
261 …+ node['/'][RBRANCH] = branch[1]
206262 … }
207263 …
208264 … function getBranch (node) {
209- return node['/'][BRANCH]
265 …+ return node['/'].slice(LBRANCH, 2)
210266 … }
211267 …
212268 … function getValue (node) {
213269 … return node['/'][VALUE]
@@ -216,14 +272,14 @@
216272 … function deleteValue (node) {
217273 … node['/'].pop()
218274 … }
219275 …
220-function hasExtension (node) {
221- return node['/'][EXTENSION].length === 2
222-}
223-
224276 … function getExtension (node) {
225- return RadixTree.toTypedArray(node['/'][EXTENSION][1]).subarray(0, getExLength(node))
277 …+ if (node['/'][EXTENSION]) {
278 …+ return RadixTree.toTypedArray(node['/'][EXTENSION][1]).subarray(0, getExLength(node))
279 …+ } else {
280 …+ return []
281 …+ }
226282 … }
227283 …
228284 … function getExLength (node) {
229285 … return node['/'][EXTENSION][0]
@@ -232,28 +288,17 @@
232288 … function setExtension (node, ex) {
233289 … if (ex && ex.length) {
234290 … node['/'][EXTENSION] = [ex.length, new Buffer(ex.buffer)]
235291 … } else {
236- node['/'][EXTENSION] = []
292 …+ if (getValue(node) === undefined && node['/'][EXTENSION] !== undefined) {
293 …+ node['/'].pop()
294 …+ } else if (node['/'][EXTENSION] !== undefined) {
295 …+ node['/'][EXTENSION] = undefined
296 …+ }
237297 … }
238298 … }
239299 …
240300 … function setValue (node, val) {
241- node['/'][VALUE] = val
242-}
243-
244-function createNode (ex, branch, value) {
245- if (ex && ex.length) {
246- ex = [ex.length, new Buffer(ex.buffer)]
247- } else {
248- ex = []
301 …+ if (val !== undefined) {
302 …+ node['/'][VALUE] = val
249303 … }
250-
251- const node = {
252- '/': [ex, branch]
253- }
254-
255- if (value !== undefined) {
256- node['/'].push(value)
257- }
258- return node
259304 … }
tests/index.jsView
@@ -58,38 +58,19 @@
5858 … const tree = new RadixTree({
5959 … dag: node.dag
6060 … })
6161 …
62- let key0 = new RadixTree.ArrayConstructor([1, 1, 0, 0])
62 …+ let key0 = new RadixTree.ArrayConstructor([1, 1])
6363 … await tree.set(key0, 'cat')
64- let key1 = new RadixTree.ArrayConstructor([0, 1, 0, 1])
64 …+ let key1 = new RadixTree.ArrayConstructor([0, 1])
6565 … await tree.set(key1, 'cat2')
66- let val = await tree.get(key0)
67- t.equals(val, 'cat')
6866 …
69- val = await tree.get(key1)
70- t.equals(val, 'cat2')
67 …+ let key2 = new RadixTree.ArrayConstructor([1, 0])
68 …+ await tree.set(key2, 'cat')
69 …+ let key3 = new RadixTree.ArrayConstructor([0, 0])
70 …+ await tree.set(key3, 'cat3')
71 …+ // console.log(JSON.stringify(tree.root, null, 2))
7172 …
72- let key3 = new RadixTree.ArrayConstructor([0, 1, 0, 1, 1])
73- await tree.set(key3, 'test')
74- val = await tree.get(key3)
75-
76- t.equals(val, 'test')
77-
78- let key4 = new RadixTree.ArrayConstructor([0, 1, 0, 0, 0])
79- await tree.set(key4, 'dog')
80- val = await tree.get(key4)
81-
82- let key5 = new RadixTree.ArrayConstructor([0, 1, 1, 0, 0])
83- await tree.set(key5, 'dog2')
84- val = await tree.get(key5)
85- t.equals(val, 'dog2')
86-
87- await tree.delete(key0)
88-
89- console.log(JSON.stringify(tree.root, null, 2))
90- val = await tree.get(key5)
91- t.equals(val, 'dog2')
9273 … t.end()
9374 … })
9475 …
9576 … tape('delete', async t => {
@@ -134,16 +115,30 @@
134115 … t.equals(value.toString(), saved.toString())
135116 … t.end()
136117 … })
137118 …
138- tape('falures', async t => {
119 …+ tape('random', async t => {
139120 … const tree = new RadixTree({
140121 … dag: node.dag
141122 … })
142- const key = crypto.createHash('sha256').update((0).toString()).digest().slice(0, 20)
143- await tree.set(key, 0)
144- const value = await tree.get(key)
145- t.equals(value, 0)
123 …+ const entries = 100
124 …+ for (let i = 0; i < entries; i++) {
125 …+ const key = crypto.createHash('sha256').update(i.toString()).digest().slice(0, 20)
126 …+ await tree.set(key, i)
127 …+ }
146128 …
129 …+ for (let i = 0; i < entries; i++) {
130 …+ const key = crypto.createHash('sha256').update(i.toString()).digest().slice(0, 20)
131 …+ const value = await tree.get(key)
132 …+ t.equals(value, i)
133 …+ }
134 …+
135 …+ for (let i = 0; i < entries; i++) {
136 …+ const key = crypto.createHash('sha256').update(i.toString()).digest().slice(0, 20)
137 …+ await tree.delete(key)
138 …+ }
139 …+
140 …+ t.equals(tree.root['/'], undefined)
141 …+
147142 … t.end()
148143 … })
149144 … })

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