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index.mjs
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index.mjs
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import {promisify} from 'util'
import bindings from 'bindings'
import stream from 'stream'
import util from 'util'
var compressor = bindings('compressor.node');
var decompressor = bindings('decompressor.node');
var Transform = stream.Transform;
export const compress = promisify(function(input, params, cb) {
if (arguments.length === 2) {
cb = params;
params = {};
}
if (!Buffer.isBuffer(input)) {
process.nextTick(cb, new Error('Input is not a buffer.'));
return;
}
if (typeof cb !== 'function') {
process.nextTick(cb, new Error('Second argument is not a function.'));
return;
}
var stream = new TransformStreamCompressor(params);
var chunks = [];
var length = 0;
stream.on('error', cb);
stream.on('data', function(c) {
chunks.push(c);
length += c.length;
});
stream.on('end', function() {
cb(null, Buffer.concat(chunks, length));
});
stream.end(input);
});
export const decompress = promisify(function (input, params, cb) {
if (arguments.length === 2) {
cb = params;
params = {};
}
if (!Buffer.isBuffer(input)) {
process.nextTick(cb, new Error('Input is not a buffer.'));
return;
}
if (typeof cb !== 'function') {
process.nextTick(cb, new Error('Second argument is not a function.'));
return;
}
var stream = new TransformStreamDecompressor(params);
var chunks = [];
var length = 0;
stream.on('error', cb);
stream.on('data', function(c) {
chunks.push(c);
length += c.length;
});
stream.on('end', function() {
cb(null, Buffer.concat(chunks, length));
});
stream.end(input);
});
export function compressSync(input, params) {
if (!Buffer.isBuffer(input)) {
throw new Error('Input is not a buffer.');
}
var stream = new TransformStreamCompressor(params || {}, true);
var chunks = [];
var length = 0;
stream.on('error', function(e) {
throw e;
});
stream.on('data', function(c) {
chunks.push(c);
length += c.length;
});
stream.end(input);
return Buffer.concat(chunks, length);
}
export function decompressSync(input, params) {
if (!Buffer.isBuffer(input)) {
throw new Error('Input is not a buffer.');
}
var stream = new TransformStreamDecompressor(params || {}, true);
var chunks = [];
var length = 0;
stream.on('error', function(e) {
throw e;
});
stream.on('data', function(c) {
chunks.push(c);
length += c.length;
});
stream.end(input);
return Buffer.concat(chunks, length);
}
export function TransformStreamCompressor(params, sync) {
Transform.call(this, params);
this.compressor = new compressor.StreamCompressor(params || {});
this.sync = sync || false;
var blockSize = this.compressor.getBlockSize();
this.status = {
blockSize: blockSize,
remaining: blockSize
};
}
util.inherits(TransformStreamCompressor, Transform);
TransformStreamCompressor.prototype._transform = function(chunk, encoding, next) {
compressStreamChunk(this, chunk, this.compressor, this.status, this.sync, next);
};
TransformStreamCompressor.prototype._flush = function(done) {
var that = this;
this.compressor.compress(true, function(err, output) {
if (err) {
return done(err);
}
if (output) {
for (var i = 0; i < output.length; i++) {
that.push(output[i]);
}
}
return done();
}, !this.sync);
};
// We need to fill the blockSize for better compression results
export function compressStreamChunk(stream, chunk, compressor, status, sync, done) {
var length = chunk.length;
if (length > status.remaining) {
var slicedChunk = chunk.slice(0, status.remaining);
chunk = chunk.slice(status.remaining);
status.remaining = status.blockSize;
compressor.copy(slicedChunk);
compressor.compress(false, function(err, output) {
if (err) {
return done(err);
}
if (output) {
for (var i = 0; i < output.length; i++) {
stream.push(output[i]);
}
}
return compressStreamChunk(stream, chunk, compressor, status, sync, done);
}, !sync);
} else if (length <= status.remaining) {
status.remaining -= length;
compressor.copy(chunk);
return done();
}
}
export function compressStream(params) {
return new TransformStreamCompressor(params);
}
export function TransformStreamDecompressor(params, sync) {
Transform.call(this, params);
this.decompressor = new decompressor.StreamDecompressor(params || {});
this.sync = sync || false;
var blockSize = this.decompressor.getBlockSize();
this.status = {
blockSize: blockSize,
remaining: blockSize
};
}
util.inherits(TransformStreamDecompressor, Transform);
TransformStreamDecompressor.prototype._transform = function(chunk, encoding, next) {
decompressStreamChunk(this, chunk, this.decompressor, this.status, this.sync, next);
};
TransformStreamDecompressor.prototype._flush = function(done) {
var that = this;
this.decompressor.decompress(function(err, output) {
if (err) {
return done(err);
}
if (output) {
for (var i = 0; i < output.length; i++) {
that.push(output[i]);
}
}
return done();
}, !this.sync);
};
// We need to fill the blockSize for better compression results
export function decompressStreamChunk(stream, chunk, decompressor, status, sync, done) {
var length = chunk.length;
if (length > status.remaining) {
var slicedChunk = chunk.slice(0, status.remaining);
chunk = chunk.slice(status.remaining);
status.remaining = status.blockSize;
decompressor.copy(slicedChunk);
decompressor.decompress(function(err, output) {
if (err) {
return done(err);
}
if (output) {
for (var i = 0; i < output.length; i++) {
stream.push(output[i]);
}
}
return decompressStreamChunk(stream, chunk, decompressor, status, sync, done);
}, !sync);
} else if (length <= status.remaining) {
status.remaining -= length;
decompressor.copy(chunk);
return done();
}
}
export function decompressStream(params) {
return new TransformStreamDecompressor(params);
};