Compress all instructions (closes #19 github issue)

ChangeLog

@@ -1,3 +1,9 @@
+2012-02-26 Keith Winstein <mosh-devel@mit.edu>
+
+	* Version 0.96 released.
+
+	* Compress all instructions with zlib
+
 2012-02-25 Keith Winstein <mosh-devel@mit.edu>
 
 	* Version 0.95 released.

configure.ac

@@ -2,7 +2,7 @@
 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ([2.65])
-AC_INIT([mosh], [0.95], [mosh-devel@mit.edu])
+AC_INIT([mosh], [0.96], [mosh-devel@mit.edu])
 AM_INIT_AUTOMAKE([-Wall -Werror])
 AC_CONFIG_SRCDIR([src/frontend/mosh-client.cc])
 AC_CONFIG_MACRO_DIR([m4])
@@ -41,6 +41,7 @@ AC_CHECK_FUNCS([clock_gettime gettimeofday inet_ntoa iswprint memchr memset nl_l
 
 # Checks for protobuf
 PKG_CHECK_MODULES([protobuf], [protobuf])
+PKG_CHECK_MODULES([zlib], [zlib])
 
 AC_CONFIG_FILES([Makefile src/Makefile src/crypto/Makefile src/frontend/Makefile src/network/Makefile src/protobufs/Makefile src/statesync/Makefile src/terminal/Makefile src/util/Makefile scripts/Makefile src/examples/Makefile man/Makefile])
 AC_OUTPUT

debian/changelog

@@ -1,3 +1,11 @@
+mosh (0.96-1) unstable; urgency=low
+
+  * Version 0.96 released.
+
+  * Compress all instructions with zlib
+
+ -- Keith Winstein <keithw@mit.edu>  Sun, 26 Feb 2012 04:40:46 -0500
+
 mosh (0.95-1) unstable; urgency=low
 
   * Version 0.95 released.

src/network/Makefile.am

@@ -3,4 +3,4 @@ AM_CXXFLAGS = -pedantic -Wno-long-long -Werror -Wall -Wextra -Weffc++ -fno-defau
 
 noinst_LIBRARIES = libmoshnetwork.a
 
-libmoshnetwork_a_SOURCES = network.cc network.h networktransport.cc networktransport.h transportfragment.cc transportfragment.h transportsender.cc transportsender.h transportstate.h
+libmoshnetwork_a_SOURCES = network.cc network.h networktransport.cc networktransport.h transportfragment.cc transportfragment.h transportsender.cc transportsender.h transportstate.h compressor.cc compressor.h

src/network/compressor.cc

@@ -0,0 +1,32 @@
+#include <zlib.h>
+#include <assert.h>
+
+#include "compressor.h"
+
+using namespace Network;
+using namespace std;
+
+string Compressor::compress_str( const string input )
+{
+  size_t len = BUFFER_SIZE;
+  assert( Z_OK == compress( buffer, &len,
+			    reinterpret_cast<const unsigned char *>( input.data() ),
+			    input.size() ) );
+  return string( reinterpret_cast<char *>( buffer ), len );
+}
+
+string Compressor::uncompress_str( const string input )
+{
+  size_t len = BUFFER_SIZE;
+  assert( Z_OK == uncompress( buffer, &len,
+			      reinterpret_cast<const unsigned char *>( input.data() ),
+			      input.size() ) );
+  return string( reinterpret_cast<char *>( buffer ), len );
+}
+
+/* construct on first use */
+Compressor & Network::get_compressor( void )
+{
+  static Compressor the_compressor;
+  return the_compressor;
+}

src/network/compressor.h

@@ -0,0 +1,28 @@
+#ifndef COMPRESSOR_H
+#define COMPRESSOR_H
+
+#include <string>
+
+namespace Network {
+  class Compressor {
+  private:
+    static const int BUFFER_SIZE = 2048 * 2048; /* effective limit on terminal size */
+
+    unsigned char *buffer;
+
+  public:
+    Compressor() : buffer( NULL ) { buffer = new unsigned char[ BUFFER_SIZE ]; }
+    ~Compressor() { if ( buffer ) { delete[] buffer; } }
+
+    std::string compress_str( const std::string input );
+    std::string uncompress_str( const std::string input );
+
+    /* unused */
+    Compressor( const Compressor & );
+    Compressor & operator=( const Compressor & );
+  };
+
+  Compressor & get_compressor( void );
+}
+
+#endif

src/network/transportfragment.cc

@@ -21,6 +21,7 @@
 
 #include "transportfragment.h"
 #include "transportinstruction.pb.h"
+#include "compressor.h"
 
 using namespace Network;
 using namespace TransportBuffers;
@@ -121,7 +122,7 @@ Instruction FragmentAssembly::get_assembly( void )
   }
 
   Instruction ret;
-  assert( ret.ParseFromString( encoded ) );
+  assert( ret.ParseFromString( get_compressor().uncompress_str( encoded ) ) );
 
   fragments.clear();
   fragments_arrived = 0;
@@ -155,7 +156,7 @@ vector<Fragment> Fragmenter::make_fragments( const Instruction &inst, int MTU )
   last_instruction = inst;
   last_MTU = MTU;
 
-  string payload = inst.SerializeAsString();
+  string payload = get_compressor().compress_str( inst.SerializeAsString() );
   uint16_t fragment_num = 0;
   vector<Fragment> ret;