It doesn't look like it has an existing interface for setting zlib options. Reading through the source[1], it looks like it chooses Z_BEST_COMPRESSION (-9 to the gzip command line program) whereas gzip defaults to -6. I'll work up a patch to pass the compression value through as another option to the constructor.
--Pete On Jul 15, 4:09 pm, Kenton Varda <ken...@google.com> wrote: > Hmm, probably GzipOutputStream is not setting the same compression > parameters as gzip itself uses by default. I'm happy to accept a patch > fixing this. Does the interface (to GzipOutputStream) currently have a way > to control compression parameters? If not, it probably should. > > > > On Wed, Jul 15, 2009 at 3:50 PM, Peter Keen <peter.k...@gmail.com> wrote: > > > Hi guys, > > > I'm playing around with protocol buffers for a project at work and I'm > > coming across a possibly weird problem. I have the following setup in > > my main(): > > > std::cerr << "creating file" << std::endl; > > int fd = open("blah.repo", O_WRONLY, O_CREAT); > > if ( fd == -1 ) { > > std::cerr << "ERROR: " << errno << " " << strerror(errno) << > > std::endl; > > return 1; > > } > > > ZeroCopyOutputStream* raw_output = new FileOutputStream(fd); > > GzipOutputStream* gzip_output = new GzipOutputStream(raw_output, > > GzipOutputStream::ZLIB); > > CodedOutputStream* coded_output = new CodedOutputStream > > (gzip_output); > > // CodedOutputStream* coded_output = new CodedOutputStream > > (raw_output); > > > This version takes, say, 8 seconds to create and serialize 100k simple > > messages. If I flip it to not use the GzipOutputStream, it takes > > roughly 1 second. Using gzip(1) to compress the resulting file takes > > less than half a second. > > > Is there an option I need to be setting to bring it up to parity with > > the command-line program or could there be a bug in GzipOutputStream? > > For what it's worth, GzipInputStream is roughly on parity with a raw > > CodedOutputStream. > > > Thanks, > > Pete --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Protocol Buffers" group. To post to this group, send email to protobuf@googlegroups.com To unsubscribe from this group, send email to protobuf+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/protobuf?hl=en -~----------~----~----~----~------~----~------~--~---