flatbuffers
Version:
Memory Efficient Serialization Library
190 lines (189 loc) • 9.94 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Reference = exports.toReference = void 0;
const bit_width_util_js_1 = require("./bit-width-util.js");
const value_type_js_1 = require("./value-type.js");
const value_type_util_js_1 = require("./value-type-util.js");
const reference_util_js_1 = require("./reference-util.js");
const flexbuffers_util_js_1 = require("./flexbuffers-util.js");
const bit_width_js_1 = require("./bit-width.js");
function toReference(buffer) {
const len = buffer.byteLength;
if (len < 3) {
throw "Buffer needs to be bigger than 3";
}
const dataView = new DataView(buffer);
const byteWidth = dataView.getUint8(len - 1);
const packedType = dataView.getUint8(len - 2);
const parentWidth = (0, bit_width_util_js_1.fromByteWidth)(byteWidth);
const offset = len - byteWidth - 2;
return new Reference(dataView, offset, parentWidth, packedType, "/");
}
exports.toReference = toReference;
function valueForIndexWithKey(index, key, dataView, offset, parentWidth, byteWidth, length, path) {
const _indirect = (0, reference_util_js_1.indirect)(dataView, offset, parentWidth);
const elementOffset = _indirect + index * byteWidth;
const packedType = dataView.getUint8(_indirect + length * byteWidth + index);
return new Reference(dataView, elementOffset, (0, bit_width_util_js_1.fromByteWidth)(byteWidth), packedType, `${path}/${key}`);
}
class Reference {
constructor(dataView, offset, parentWidth, packedType, path) {
this.dataView = dataView;
this.offset = offset;
this.parentWidth = parentWidth;
this.packedType = packedType;
this.path = path;
this._length = -1;
this.byteWidth = 1 << (packedType & 3);
this.valueType = packedType >> 2;
}
isNull() { return this.valueType === value_type_js_1.ValueType.NULL; }
isNumber() { return (0, value_type_util_js_1.isNumber)(this.valueType) || (0, value_type_util_js_1.isIndirectNumber)(this.valueType); }
isFloat() { return value_type_js_1.ValueType.FLOAT === this.valueType || value_type_js_1.ValueType.INDIRECT_FLOAT === this.valueType; }
isInt() { return this.isNumber() && !this.isFloat(); }
isString() { return value_type_js_1.ValueType.STRING === this.valueType || value_type_js_1.ValueType.KEY === this.valueType; }
isBool() { return value_type_js_1.ValueType.BOOL === this.valueType; }
isBlob() { return value_type_js_1.ValueType.BLOB === this.valueType; }
isVector() { return (0, value_type_util_js_1.isAVector)(this.valueType); }
isMap() { return value_type_js_1.ValueType.MAP === this.valueType; }
boolValue() {
if (this.isBool()) {
return (0, reference_util_js_1.readInt)(this.dataView, this.offset, this.parentWidth) > 0;
}
return null;
}
intValue() {
if (this.valueType === value_type_js_1.ValueType.INT) {
return (0, reference_util_js_1.readInt)(this.dataView, this.offset, this.parentWidth);
}
if (this.valueType === value_type_js_1.ValueType.UINT) {
return (0, reference_util_js_1.readUInt)(this.dataView, this.offset, this.parentWidth);
}
if (this.valueType === value_type_js_1.ValueType.INDIRECT_INT) {
return (0, reference_util_js_1.readInt)(this.dataView, (0, reference_util_js_1.indirect)(this.dataView, this.offset, this.parentWidth), (0, bit_width_util_js_1.fromByteWidth)(this.byteWidth));
}
if (this.valueType === value_type_js_1.ValueType.INDIRECT_UINT) {
return (0, reference_util_js_1.readUInt)(this.dataView, (0, reference_util_js_1.indirect)(this.dataView, this.offset, this.parentWidth), (0, bit_width_util_js_1.fromByteWidth)(this.byteWidth));
}
return null;
}
floatValue() {
if (this.valueType === value_type_js_1.ValueType.FLOAT) {
return (0, reference_util_js_1.readFloat)(this.dataView, this.offset, this.parentWidth);
}
if (this.valueType === value_type_js_1.ValueType.INDIRECT_FLOAT) {
return (0, reference_util_js_1.readFloat)(this.dataView, (0, reference_util_js_1.indirect)(this.dataView, this.offset, this.parentWidth), (0, bit_width_util_js_1.fromByteWidth)(this.byteWidth));
}
return null;
}
numericValue() { return this.floatValue() || this.intValue(); }
stringValue() {
if (this.valueType === value_type_js_1.ValueType.STRING || this.valueType === value_type_js_1.ValueType.KEY) {
const begin = (0, reference_util_js_1.indirect)(this.dataView, this.offset, this.parentWidth);
return (0, flexbuffers_util_js_1.fromUTF8Array)(new Uint8Array(this.dataView.buffer, begin, this.length()));
}
return null;
}
blobValue() {
if (this.isBlob()) {
const begin = (0, reference_util_js_1.indirect)(this.dataView, this.offset, this.parentWidth);
return new Uint8Array(this.dataView.buffer, begin, this.length());
}
return null;
}
get(key) {
const length = this.length();
if (Number.isInteger(key) && (0, value_type_util_js_1.isAVector)(this.valueType)) {
if (key >= length || key < 0) {
throw `Key: [${key}] is not applicable on ${this.path} of ${this.valueType} length: ${length}`;
}
const _indirect = (0, reference_util_js_1.indirect)(this.dataView, this.offset, this.parentWidth);
const elementOffset = _indirect + key * this.byteWidth;
let _packedType = this.dataView.getUint8(_indirect + length * this.byteWidth + key);
if ((0, value_type_util_js_1.isTypedVector)(this.valueType)) {
const _valueType = (0, value_type_util_js_1.typedVectorElementType)(this.valueType);
_packedType = (0, value_type_util_js_1.packedType)(_valueType, bit_width_js_1.BitWidth.WIDTH8);
}
else if ((0, value_type_util_js_1.isFixedTypedVector)(this.valueType)) {
const _valueType = (0, value_type_util_js_1.fixedTypedVectorElementType)(this.valueType);
_packedType = (0, value_type_util_js_1.packedType)(_valueType, bit_width_js_1.BitWidth.WIDTH8);
}
return new Reference(this.dataView, elementOffset, (0, bit_width_util_js_1.fromByteWidth)(this.byteWidth), _packedType, `${this.path}[${key}]`);
}
if (typeof key === 'string') {
const index = (0, reference_util_js_1.keyIndex)(key, this.dataView, this.offset, this.parentWidth, this.byteWidth, length);
if (index !== null) {
return valueForIndexWithKey(index, key, this.dataView, this.offset, this.parentWidth, this.byteWidth, length, this.path);
}
}
throw `Key [${key}] is not applicable on ${this.path} of ${this.valueType}`;
}
length() {
let size;
if (this._length > -1) {
return this._length;
}
if ((0, value_type_util_js_1.isFixedTypedVector)(this.valueType)) {
this._length = (0, value_type_util_js_1.fixedTypedVectorElementSize)(this.valueType);
}
else if (this.valueType === value_type_js_1.ValueType.BLOB
|| this.valueType === value_type_js_1.ValueType.MAP
|| (0, value_type_util_js_1.isAVector)(this.valueType)) {
this._length = (0, reference_util_js_1.readUInt)(this.dataView, (0, reference_util_js_1.indirect)(this.dataView, this.offset, this.parentWidth) - this.byteWidth, (0, bit_width_util_js_1.fromByteWidth)(this.byteWidth));
}
else if (this.valueType === value_type_js_1.ValueType.NULL) {
this._length = 0;
}
else if (this.valueType === value_type_js_1.ValueType.STRING) {
const _indirect = (0, reference_util_js_1.indirect)(this.dataView, this.offset, this.parentWidth);
let sizeByteWidth = this.byteWidth;
size = (0, reference_util_js_1.readUInt)(this.dataView, _indirect - sizeByteWidth, (0, bit_width_util_js_1.fromByteWidth)(this.byteWidth));
while (this.dataView.getInt8(_indirect + size) !== 0) {
sizeByteWidth <<= 1;
size = (0, reference_util_js_1.readUInt)(this.dataView, _indirect - sizeByteWidth, (0, bit_width_util_js_1.fromByteWidth)(this.byteWidth));
}
this._length = size;
}
else if (this.valueType === value_type_js_1.ValueType.KEY) {
const _indirect = (0, reference_util_js_1.indirect)(this.dataView, this.offset, this.parentWidth);
size = 1;
while (this.dataView.getInt8(_indirect + size) !== 0) {
size++;
}
this._length = size;
}
else {
this._length = 1;
}
return Number(this._length);
}
toObject() {
const length = this.length();
if (this.isVector()) {
const result = [];
for (let i = 0; i < length; i++) {
result.push(this.get(i).toObject());
}
return result;
}
if (this.isMap()) {
const result = {};
for (let i = 0; i < length; i++) {
const key = (0, reference_util_js_1.keyForIndex)(i, this.dataView, this.offset, this.parentWidth, this.byteWidth);
result[key] = valueForIndexWithKey(i, key, this.dataView, this.offset, this.parentWidth, this.byteWidth, length, this.path).toObject();
}
return result;
}
if (this.isNull()) {
return null;
}
if (this.isBool()) {
return this.boolValue();
}
if (this.isNumber()) {
return this.numericValue();
}
return this.blobValue() || this.stringValue();
}
}
exports.Reference = Reference;