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superkartoffelsuperkartoffel
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very basic implementation of protobuf decoding
1 parent 9cdfa2d commit c9c4dac

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5 files changed

+190
-6
lines changed

5 files changed

+190
-6
lines changed

‎app/src/components/Sidebar/ValueRenderer/Protobuf.tsx‎

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@@ -0,0 +1,162 @@
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interface Field {
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key: number,
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value: any
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}
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class Protobuf {
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TYPE: number;
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NUMBER: number;
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MSB: number;
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VALUE: number;
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offset: number;
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LENGTH: number;
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data: (Int8Array | Uint8Array);
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constructor(data: (Int8Array | Uint8Array)) {
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this.data = data;
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// Set up masks
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this.TYPE = 0x07;
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this.NUMBER = 0x78;
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this.MSB = 0x80;
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this.VALUE = 0x7f;
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// Declare offset and length
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this.offset = 0;
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this.LENGTH = data.length;
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}
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static decode(input: (Int8Array | Uint8Array)) {
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const pb = new Protobuf(input);
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return pb._parse();
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}
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_parse() {
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let object = {};
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// Continue reading whilst we still have data
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while (this.offset < this.LENGTH) {
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const field = this._parseField();
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object = this._addField(field, object);
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}
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// Throw an error if we have gone beyond the end of the data
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if (this.offset > this.LENGTH) {
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throw new Error("Exhausted Buffer");
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}
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return object;
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}
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_addField(field: Field, object: any) {
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// Get the field key/values
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const key = field.key;
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const value = field.value;
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object[key] = Object.prototype.hasOwnProperty.call(object, key) ?
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object[key] instanceof Array ?
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object[key].concat([value]) :
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[object[key], value] :
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value;
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return object;
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}
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_parseField() {
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// Get the field headers
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const header = this._fieldHeader();
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const type = header.type;
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const key = header.key;
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switch (type) {
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// varint
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case 0:
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return { "key": key, "value": this._varInt() };
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// fixed 64
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case 1:
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return { "key": key, "value": this._uint64() };
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// length delimited
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case 2:
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return { "key": key, "value": this._lenDelim() };
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// fixed 32
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case 5:
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return { "key": key, "value": this._uint32() };
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// unknown type
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default:
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throw new Error("Unknown type 0x" + type.toString(16));
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}
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}
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_fieldHeader() {
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// Make sure we call type then number to preserve offset
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return { "type": this._fieldType(), "key": this._fieldNumber() };
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}
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_fieldType() {
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// Field type stored in lower 3 bits of tag byte
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return this.data[this.offset] & this.TYPE;
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}
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_fieldNumber() {
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let shift = -3;
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let fieldNumber = 0;
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do {
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fieldNumber += shift < 28 ?
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shift === -3 ?
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(this.data[this.offset] & this.NUMBER) >> -shift :
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(this.data[this.offset] & this.VALUE) << shift :
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(this.data[this.offset] & this.VALUE) * Math.pow(2, shift);
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shift += 7;
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} while ((this.data[this.offset++] & this.MSB) === this.MSB);
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return fieldNumber;
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}
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_varInt() {
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let value = 0;
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let shift = 0;
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// Keep reading while upper bit set
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do {
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value += shift < 28 ?
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(this.data[this.offset] & this.VALUE) << shift :
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(this.data[this.offset] & this.VALUE) * Math.pow(2, shift);
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shift += 7;
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} while ((this.data[this.offset++] & this.MSB) === this.MSB);
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return value;
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}
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_uint64() {
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// Read off a Uint64
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let num = this.data[this.offset++] * 0x1000000 + (this.data[this.offset++] << 16) + (this.data[this.offset++] << 8) + this.data[this.offset++];
124+
num = num * 0x100000000 + this.data[this.offset++] * 0x1000000 + (this.data[this.offset++] << 16) + (this.data[this.offset++] << 8) + this.data[this.offset++];
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return num;
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}
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_lenDelim() {
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// Read off the field length
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const length = this._varInt();
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const fieldBytes = this.data.slice(this.offset, this.offset + length);
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let field;
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try {
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// Attempt to parse as a new Protobuf Object
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const pbObject = new Protobuf(fieldBytes);
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field = pbObject._parse();
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} catch (err) {
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// Otherwise treat as bytes
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field = this._byteArrayToChars(fieldBytes);
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}
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// Move the offset and return the field
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this.offset += length;
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return field;
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}
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_uint32() {
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// Use a dataview to read off the integer
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const dataview = new DataView(new Uint8Array(this.data.slice(this.offset, this.offset + 4)).buffer);
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const value = dataview.getUint32(0);
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this.offset += 4;
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return value;
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}
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_byteArrayToChars(byteArray: (Int8Array | Uint8Array)) {
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if (!byteArray) return "";
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let str = "";
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// String concatenation appears to be faster than an array join
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for (let i = 0; i < byteArray.length;) {
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str += String.fromCharCode(byteArray[i++]);
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}
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return str;
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}
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}
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export default Protobuf;

‎app/src/components/Sidebar/ValueRenderer/ValueRenderer.tsx‎

Lines changed: 14 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -7,6 +7,7 @@ import { connect } from 'react-redux'
77
import { default as ReactResizeDetector } from 'react-resize-detector'
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import { ValueRendererDisplayMode } from '../../../reducers/Settings'
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import { Typography, Fade, Grow } from '@material-ui/core'
10+
import Protobuf from './Protobuf';
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interface Props {
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message: q.Message
@@ -43,6 +44,19 @@ class ValueRenderer extends React.Component<Props, State> {
4344
return [undefined, undefined]
4445
}
4546

47+
let obj = {}
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try {
49+
const byteArray = Base64Message.ToByteArray(msg);
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obj = Protobuf.decode(byteArray);
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}
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catch (e) {
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console.log("Caught exception while decoding protobuf: ", e);
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}
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if (obj) {
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return [JSON.stringify(obj, undefined, ' '), 'json'];
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}
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4660
const str = Base64Message.toUnicodeString(msg)
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try {
4862
JSON.parse(str)

‎backend/src/Model/Base64Message.ts‎

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Original file line numberDiff line numberDiff line change
@@ -12,10 +12,18 @@ export class Base64Message {
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this.length = base64Str.length
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}
1414

15+
public static toBase64(message: Base64Message) {
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return message.base64Message || ''
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}
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1519
public static toUnicodeString(message: Base64Message) {
1620
return message.unicodeValue || ''
1721
}
1822

23+
public static ToByteArray(message: Base64Message): Uint8Array {
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return Base64.toUint8Array(message.base64Message)
25+
}
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1927
public static fromBuffer(buffer: Buffer) {
2028
return new Base64Message(buffer.toString('base64'))
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}

‎package.json‎

Lines changed: 2 additions & 2 deletions
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@@ -110,7 +110,7 @@
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"electron-telemetry": "git+https://github.com/thomasnordquist/electron-telemetry.git#dist",
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"electron-updater": "^4.0.6",
112112
"fs-extra": "9",
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"js-base64": "^2.5.1",
113+
"js-base64": "^2.6.3",
114114
"json-to-ast": "^2.1.0",
115115
"lowdb": "^1.0.0",
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"mime": "^2.4.4",
@@ -119,4 +119,4 @@
119119
"yarn-run-all": "^3.1.1"
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},
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"optionalDependencies": {}
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}
122+
}

‎yarn.lock‎

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@@ -3026,10 +3026,10 @@ jake@^10.6.1:
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filelist "^1.0.1"
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minimatch "^3.0.4"
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js-base64@^2.5.1:
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version "2.5.2"
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resolved "https://registry.yarnpkg.com/js-base64/-/js-base64-2.5.2.tgz#313b6274dda718f714d00b3330bbae6e38e90209"
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integrity sha512-Vg8czh0Q7sFBSUMWWArX/miJeBWYBPpdU/3M/DKSaekLMqrqVPaedp+5mZhie/r0lgrcaYBfwXatEew6gwgiQQ==
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js-base64@^2.6.3:
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version "2.6.4"
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resolved "https://registry.yarnpkg.com/js-base64/-/js-base64-2.6.4.tgz#f4e686c5de1ea1f867dbcad3d46d969428df98c4"
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integrity sha512-pZe//GGmwJndub7ZghVHz7vjb2LgC1m8B07Au3eYqeqv9emhESByMXxaEgkUkEqJe87oBbSniGYoQNIBklc7IQ==
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js-tokens@^4.0.0:
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version "4.0.0"

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