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/*
* Copyright 2008 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// package com.google.zxing.common;
// import java.io.ByteArrayOutputStream;
use std::io::Write;
/**
* Class that lets one easily build an array of bytes by appending bits at a time.
*
* @author Sean Owen
*/
pub struct BitSourceBuilder {
output: Vec<u8>,
nextByte: u32,
bitsLeftInNextByte: u32,
}
impl BitSourceBuilder {
pub const fn new() -> Self {
Self {
output: Vec::new(),
nextByte: 0,
bitsLeftInNextByte: 8,
}
}
pub fn write(&mut self, value: u32, numBits: u32) {
if numBits <= self.bitsLeftInNextByte {
self.nextByte <<= numBits;
self.nextByte |= value;
self.bitsLeftInNextByte -= numBits;
if self.bitsLeftInNextByte == 0 {
self.output.push(self.nextByte as u8);
self.nextByte = 0;
self.bitsLeftInNextByte = 8;
}
} else {
let bitsToWriteNow = self.bitsLeftInNextByte;
let numRestOfBits = numBits - bitsToWriteNow;
let mask = 0xFF >> (8 - bitsToWriteNow);
let valueToWriteNow = (value >> numRestOfBits) & mask;
self.write(valueToWriteNow, bitsToWriteNow);
self.write(value, numRestOfBits);
}
}
pub fn asByteArray(&mut self) -> &Vec<u8> {
if self.bitsLeftInNextByte < 8 {
self.write(0, self.bitsLeftInNextByte);
}
&self.output
}
pub fn toByteArray(mut self) -> Vec<u8> {
if self.bitsLeftInNextByte < 8 {
self.write(0, self.bitsLeftInNextByte);
}
self.output
}
}
impl Default for BitSourceBuilder {
fn default() -> Self {
Self::new()
}
}
impl Write for BitSourceBuilder {
fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
let mut written = 0;
for byte in buf.iter() {
self.write(*byte as u32, 8);
written += 1;
}
Ok(written)
}
fn flush(&mut self) -> std::io::Result<()> {
Ok(())
}
}