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'use strict';
const fs = require('fs');
const stream = require('stream');
const zlib = require('zlib');
const {promisify} = require('util');
const duplexer = require('duplexer');
const getOptions = options => ({level: 9, ...options});
const gzip = promisify(zlib.gzip);
module.exports = async (input, options) => {
if (!input) {
return 0;
}
const data = await gzip(input, getOptions(options));
return data.length;
};
module.exports.sync = (input, options) => zlib.gzipSync(input, getOptions(options)).length;
module.exports.stream = options => {
const input = new stream.PassThrough();
const output = new stream.PassThrough();
const wrapper = duplexer(input, output);
let gzipSize = 0;
const gzip = zlib.createGzip(getOptions(options))
.on('data', buf => {
gzipSize += buf.length;
})
.on('error', () => {
wrapper.gzipSize = 0;
})
.on('end', () => {
wrapper.gzipSize = gzipSize;
wrapper.emit('gzip-size', gzipSize);
output.end();
});
input.pipe(gzip);
input.pipe(output, {end: false});
return wrapper;
};
module.exports.file = (path, options) => {
return new Promise((resolve, reject) => {
const stream = fs.createReadStream(path);
stream.on('error', reject);
const gzipStream = stream.pipe(module.exports.stream(options));
gzipStream.on('error', reject);
gzipStream.on('gzip-size', resolve);
});
};
module.exports.fileSync = (path, options) => module.exports.sync(fs.readFileSync(path), options);
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