tools/lz4-compress.js

// Copyright 2015 The Emscripten Authors.  All rights reserved.
// Emscripten is available under two separate licenses, the MIT license and the
// University of Illinois/NCSA Open Source License.  Both these licenses can be
// found in the LICENSE file.

// *** Environment setup code ***
var arguments_ = [];
var debug = false;

var ENVIRONMENT_IS_NODE = typeof process === 'object';
var ENVIRONMENT_IS_WEB = typeof window === 'object';
var ENVIRONMENT_IS_WORKER = typeof importScripts === 'function';
var ENVIRONMENT_IS_SHELL = !ENVIRONMENT_IS_WEB && !ENVIRONMENT_IS_NODE && !ENVIRONMENT_IS_WORKER;

if (ENVIRONMENT_IS_NODE) {
  // Expose functionality in the same simple way that the shells work
  // Note that we pollute the global namespace here, otherwise we break in node
  print = function(x) {
    process['stdout'].write(x + '\n');
  };
  printErr = function(x) {
    process['stderr'].write(x + '\n');
  };

  var nodeFS = require('fs');
  var nodePath = require('path');

  if (!nodeFS.existsSync) {
    nodeFS.existsSync = function(path) {
      try {
        return !!nodeFS.readFileSync(path);
      } catch(e) {
        return false;
      }
    }
  }

  function find(filename) {
    var prefixes = [nodePath.join(__dirname, '..', 'src'), process.cwd()];
    for (var i = 0; i < prefixes.length; ++i) {
      var combined = nodePath.join(prefixes[i], filename);
      if (nodeFS.existsSync(combined)) {
        return combined;
      }
    }
    return filename;
  }

  read = function(filename, binary) {
    filename = nodePath['normalize'](filename);
    var ret = nodeFS['readFileSync'](filename);
    // The path is absolute if the normalized version is the same as the resolved.
    if (!ret && filename != nodePath['resolve'](filename)) {
      filename = path.join(__dirname, '..', 'src', filename);
      ret = nodeFS['readFileSync'](filename);
    }
    if (ret && !binary) ret = ret.toString();
    return ret;
  };

  readBinary = function(filename) { return read(filename, true) };

  load = function(f) {
    globalEval(read(f));
  };

  arguments_ = process['argv'].slice(2);

} else if (ENVIRONMENT_IS_SHELL) {
  // Polyfill over SpiderMonkey/V8 differences
  if (!this['read']) {
    this['read'] = function(f) { snarf(f) };
  }

  if (typeof scriptArgs != 'undefined') {
    arguments_ = scriptArgs;
  } else if (typeof arguments != 'undefined') {
    arguments_ = arguments;
  }

} else if (ENVIRONMENT_IS_WEB) {
  this['print'] = printErr = function(x) {
    console.log(x);
  };

  this['read'] = function(url) {
    var xhr = new XMLHttpRequest();
    xhr.open('GET', url, false);
    xhr.send(null);
    return xhr.responseText;
  };

  if (this['arguments']) {
    arguments_ = arguments;
  }
} else if (ENVIRONMENT_IS_WORKER) {
  // We can do very little here...

  this['load'] = importScripts;

} else {
  throw 'Unknown runtime environment. Where are we?';
}

function globalEval(x) {
  eval.call(null, x);
}

if (typeof load === 'undefined' && typeof read != 'undefined') {
  this['load'] = function(f) {
    globalEval(read(f));
  };
}

if (typeof printErr === 'undefined') {
  this['printErr'] = function(){};
}

if (typeof print === 'undefined') {
  this['print'] = printErr;
}

assert = function(x, message) {
  if (!x) throw 'assertion failed: ' + message + ' : ' + new Error().stack;
}

if (!Math['imul'] || Math['imul'](0xffffffff, 5) !== -5) Math['imul'] = function imul(a, b) {
  var ah  = a >>> 16;
  var al = a & 0xffff;
  var bh  = b >>> 16;
  var bl = b & 0xffff;
  return (al*bl + ((ah*bl + al*bh) << 16))|0;
};

console.log = printErr;

// *** Environment setup code ***

var lz4 = arguments_[0];
var input = arguments_[1];
var output = arguments_[2];

load(lz4);

var data = readBinary(input);
if (!(data instanceof ArrayBuffer)) {
  printErr('converting to ArrayBuffer');
  data = new Uint8Array(data).buffer;
}

var start = Date.now();
var compressedData = MiniLZ4.compressPackage(data);
nodeFS['writeFileSync'](output, Buffer.from(compressedData['data']));
compressedData['data'] = null;
printErr('compressed in ' + (Date.now() - start) + ' ms');
print(JSON.stringify(compressedData));