/**
* Data writer.
*/
export class DataWriter {
/**
* Is the endianness Little Endian.
*
* @type {boolean}
*/
#isLittleEndian = true;
/**
* The main data view.
*
* @type {DataView}
*/
#view;
/**
* @param {ArrayBuffer} buffer The input array buffer.
* @param {boolean} [isLittleEndian] Flag to tell if the data is
* little or big endian.
*/
constructor(buffer, isLittleEndian) {
// Set endian flag if not defined.
if (typeof isLittleEndian !== 'undefined') {
this.#isLittleEndian = isLittleEndian;
}
this.#view = new DataView(buffer);
}
/**
* Write Uint8 data.
*
* @param {number} byteOffset The offset to start writing from.
* @param {number} value The data to write.
* @returns {number} The new offset position.
*/
writeUint8(byteOffset, value) {
this.#view.setUint8(byteOffset, value);
return byteOffset + Uint8Array.BYTES_PER_ELEMENT;
}
/**
* Write Int8 data.
*
* @param {number} byteOffset The offset to start writing from.
* @param {number} value The data to write.
* @returns {number} The new offset position.
*/
writeInt8(byteOffset, value) {
this.#view.setInt8(byteOffset, value);
return byteOffset + Int8Array.BYTES_PER_ELEMENT;
}
/**
* Write Uint16 data.
*
* @param {number} byteOffset The offset to start writing from.
* @param {number} value The data to write.
* @returns {number} The new offset position.
*/
writeUint16(byteOffset, value) {
this.#view.setUint16(byteOffset, value, this.#isLittleEndian);
return byteOffset + Uint16Array.BYTES_PER_ELEMENT;
}
/**
* Write Int16 data.
*
* @param {number} byteOffset The offset to start writing from.
* @param {number} value The data to write.
* @returns {number} The new offset position.
*/
writeInt16(byteOffset, value) {
this.#view.setInt16(byteOffset, value, this.#isLittleEndian);
return byteOffset + Int16Array.BYTES_PER_ELEMENT;
}
/**
* Write Uint32 data.
*
* @param {number} byteOffset The offset to start writing from.
* @param {number} value The data to write.
* @returns {number} The new offset position.
*/
writeUint32(byteOffset, value) {
this.#view.setUint32(byteOffset, value, this.#isLittleEndian);
return byteOffset + Uint32Array.BYTES_PER_ELEMENT;
}
/**
* Write Uint64 data.
*
* @param {number} byteOffset The offset to start writing from.
* @param {bigint} value The data to write.
* @returns {number} The new offset position.
*/
writeUint64(byteOffset, value) {
this.#view.setBigUint64(byteOffset, value, this.#isLittleEndian);
return byteOffset + BigUint64Array.BYTES_PER_ELEMENT;
}
/**
* Write Int32 data.
*
* @param {number} byteOffset The offset to start writing from.
* @param {number} value The data to write.
* @returns {number} The new offset position.
*/
writeInt32(byteOffset, value) {
this.#view.setInt32(byteOffset, value, this.#isLittleEndian);
return byteOffset + Int32Array.BYTES_PER_ELEMENT;
}
/**
* Write Int64 data.
*
* @param {number} byteOffset The offset to start writing from.
* @param {bigint} value The data to write.
* @returns {number} The new offset position.
*/
writeInt64(byteOffset, value) {
this.#view.setBigInt64(byteOffset, value, this.#isLittleEndian);
return byteOffset + BigInt64Array.BYTES_PER_ELEMENT;
}
/**
* Write Float32 data.
*
* @param {number} byteOffset The offset to start writing from.
* @param {number} value The data to write.
* @returns {number} The new offset position.
*/
writeFloat32(byteOffset, value) {
this.#view.setFloat32(byteOffset, value, this.#isLittleEndian);
return byteOffset + Float32Array.BYTES_PER_ELEMENT;
}
/**
* Write Float64 data.
*
* @param {number} byteOffset The offset to start writing from.
* @param {number} value The data to write.
* @returns {number} The new offset position.
*/
writeFloat64(byteOffset, value) {
this.#view.setFloat64(byteOffset, value, this.#isLittleEndian);
return byteOffset + Float64Array.BYTES_PER_ELEMENT;
}
/**
* Write string data of length 4 as hexadecimal (no '0x' prefix).
*
* @param {number} byteOffset The offset to start writing from.
* @param {string} str The hexadecimal string to write ('####').
* @returns {number} The new offset position.
*/
writeHex(byteOffset, str) {
// remove first two chars and parse
const value = parseInt(str, 16);
this.#view.setUint16(byteOffset, value, this.#isLittleEndian);
return byteOffset + Uint16Array.BYTES_PER_ELEMENT;
}
/**
* Write a boolean array as binary.
*
* @param {number} byteOffset The offset to start writing from.
* @param {Array} array The array to write.
* @returns {number} The new offset position.
*/
writeBinaryArray(byteOffset, array) {
if (array.length % 8 !== 0) {
throw new Error('Cannot write boolean array as binary.');
}
let byte = null;
let val = null;
for (let i = 0, len = array.length; i < len; i += 8) {
byte = 0;
for (let j = 0; j < 8; ++j) {
val = array[i + j] === 0 ? 0 : 1;
byte += val << j;
}
byteOffset = this.writeUint8(byteOffset, byte);
}
return byteOffset;
}
/**
* Write Uint8 array.
*
* @param {number} byteOffset The offset to start writing from.
* @param {Array|Uint8Array} array The array to write.
* @returns {number} The new offset position.
*/
writeUint8Array(byteOffset, array) {
for (let i = 0, len = array.length; i < len; ++i) {
byteOffset = this.writeUint8(byteOffset, array[i]);
}
return byteOffset;
}
/**
* Write Int8 array.
*
* @param {number} byteOffset The offset to start writing from.
* @param {Array} array The array to write.
* @returns {number} The new offset position.
*/
writeInt8Array(byteOffset, array) {
for (let i = 0, len = array.length; i < len; ++i) {
byteOffset = this.writeInt8(byteOffset, array[i]);
}
return byteOffset;
}
/**
* Write Uint16 array.
*
* @param {number} byteOffset The offset to start writing from.
* @param {Array} array The array to write.
* @returns {number} The new offset position.
*/
writeUint16Array(byteOffset, array) {
for (let i = 0, len = array.length; i < len; ++i) {
byteOffset = this.writeUint16(byteOffset, array[i]);
}
return byteOffset;
}
/**
* Write Int16 array.
*
* @param {number} byteOffset The offset to start writing from.
* @param {Array} array The array to write.
* @returns {number} The new offset position.
*/
writeInt16Array(byteOffset, array) {
for (let i = 0, len = array.length; i < len; ++i) {
byteOffset = this.writeInt16(byteOffset, array[i]);
}
return byteOffset;
}
/**
* Write Uint32 array.
*
* @param {number} byteOffset The offset to start writing from.
* @param {Array} array The array to write.
* @returns {number} The new offset position.
*/
writeUint32Array(byteOffset, array) {
for (let i = 0, len = array.length; i < len; ++i) {
byteOffset = this.writeUint32(byteOffset, array[i]);
}
return byteOffset;
}
/**
* Write Uint64 array.
*
* @param {number} byteOffset The offset to start writing from.
* @param {Array} array The array to write.
* @returns {number} The new offset position.
*/
writeUint64Array(byteOffset, array) {
for (let i = 0, len = array.length; i < len; ++i) {
byteOffset = this.writeUint64(byteOffset, array[i]);
}
return byteOffset;
}
/**
* Write Int32 array.
*
* @param {number} byteOffset The offset to start writing from.
* @param {Array} array The array to write.
* @returns {number} The new offset position.
*/
writeInt32Array(byteOffset, array) {
for (let i = 0, len = array.length; i < len; ++i) {
byteOffset = this.writeInt32(byteOffset, array[i]);
}
return byteOffset;
}
/**
* Write Int64 array.
*
* @param {number} byteOffset The offset to start writing from.
* @param {Array} array The array to write.
* @returns {number} The new offset position.
*/
writeInt64Array(byteOffset, array) {
for (let i = 0, len = array.length; i < len; ++i) {
byteOffset = this.writeInt64(byteOffset, array[i]);
}
return byteOffset;
}
/**
* Write Float32 array.
*
* @param {number} byteOffset The offset to start writing from.
* @param {Array} array The array to write.
* @returns {number} The new offset position.
*/
writeFloat32Array(byteOffset, array) {
for (let i = 0, len = array.length; i < len; ++i) {
byteOffset = this.writeFloat32(byteOffset, array[i]);
}
return byteOffset;
}
/**
* Write Float64 array.
*
* @param {number} byteOffset The offset to start writing from.
* @param {Array} array The array to write.
* @returns {number} The new offset position.
*/
writeFloat64Array(byteOffset, array) {
for (let i = 0, len = array.length; i < len; ++i) {
byteOffset = this.writeFloat64(byteOffset, array[i]);
}
return byteOffset;
}
} // class DataWriter