@loaders.gl/shapefile
Version:
Loader for the Shapefile Format
55 lines (54 loc) • 1.27 kB
JavaScript
// loaders.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
export class BinaryReader {
offset;
arrayBuffer;
constructor(arrayBuffer) {
/** current global (stream) offset */
this.offset = 0;
/** current buffer from iterator */
this.arrayBuffer = arrayBuffer;
}
/**
* Checks if there are available bytes in data
*
* @param bytes
* @returns boolean
*/
hasAvailableBytes(bytes) {
return this.arrayBuffer.byteLength - this.offset >= bytes;
}
/**
* Get the required number of bytes from the iterator
*
* @param bytes
* @returns Dataview
*/
getDataView(bytes) {
if (bytes && !this.hasAvailableBytes(bytes)) {
throw new Error('binary data exhausted');
}
const dataView = bytes
? new DataView(this.arrayBuffer, this.offset, bytes)
: new DataView(this.arrayBuffer, this.offset);
this.offset += bytes;
return dataView;
}
/**
* Skipping
*
* @param bytes
*/
skip(bytes) {
this.offset += bytes;
}
/**
* Rewinding
*
* @param bytes
*/
rewind(bytes) {
this.offset -= bytes;
}
}