During the extraction from a ZIP archive the decompression for each file can be done independently from each other.

fpZip creates an asynchronous task for each file to be decompressed as soon as the compressed data is read into memory. The pseudo code in an asynchronous programming language is as follows:

ExtractArchive(archive)
{
  Memory inMemory;
  ReadFile(archive, inMemory);

  Memory outMemory[archive.fileCount];
  for (i = 0; i < archive.fileCount; ++i)
    Decompress(archive.file[i], inMemory, outMemory[i]);
}

Decompress(file, inMemory, outMemory)
{
  Inflate(inMemory, outMemory);
  crc = CRC32(outMemory);
  WriteFile(file, outMemory);
  FileCheck(crc);
}

Thus we get the following dependency diagram: