Pike 7.6 release notes

This document outlines the changes since Pike 7.4.

New/improved functionality

• fewer magical hacks

  Several Pike modules have been cleaned up from old hacks and workarounds for problems which now have proper solutions. This should reduce size, and improve performance, dumpability and readability of the affected code. In addition lots of internal types in Pike have been tightened up and several more files now use the pragma strict_types, which has helped locating and fixing some previously undiscovered bugs.

• garbage collection strategy is now configurable

  The garbage collector can now be configured to take both the amount of garbage and the cpu time spent in the gc into account. Automatic garbage collections can also be disabled in critical regions. (Use the function Pike.gc_parameters for this.)

• hash() modified

  The string hash functions are now byte-order independent. The old hash function is available as hash_7_4 or as hash when running in 7.4 compatibility mode or lower.

• --help

  The Pike --help message has been improved, and it is possible to retrieve further information about options and environment variables. In addition, most of the tools and build scripts now accept --help and describes what they do and what options they take.

• INT64

  On 64 bit architechtures Pike will now use full 64 bits integer before resorting to Gmp.mpz objects for large numbers.

• IPv6

  Networking code in Pike has been updated to work with IPv6. This includes both low-level fixes in the socket handling as well as high-level changes such as IP parsing and protocol additions such as AAAA records in Protocol.DNS.

• module system improved

  Both dynamic and static modules now appears as objects, and they both support having an identifier _module_value, which will then be what is presented by the resolver as the module. _module_value can be a constant, which will prevent the program from being automatically cloned.

• mysqls

  The Mysql glue can operate over SSL, providing additional data security. Use the "mysqls://" protocol in the Sql.Sql module to access this feature.

• reworked codec

  The codec for serialization of Pike data types has been updated and has a significally improved success rate at encoding modules. (See the encode_value and decode_value functions.)

• sort() is portable

  Sort is now locale and platform independent. In other words, strings are now compared only according to the unicode value of every character.

• sort() is stable

  Unlike previous releases, sort() will keep the original order of elements that are equal. At first, we considered keeping the old sort function in parallel with the new one, as a "faster but unstable" alternative, but it turned out that there was no noticable different in speed between the new and the old function.

• trace() can trace all threads

  The configure option --without-thread-trace has been removed, but instead the trace() function has been extended to make it possible to set the trace level in all threads simultaneously.

• unbug

  The Pike debugger unbug has been significtly optimized.

• Unicode

  Pike 7.6 uses the Unicode 4.0.1 tables for case info and normalization.

• upper_case() and lower_case() extended

  The built-in functions upper_case and lower_case now also works on single characters represented as integers.

• #warning

  A new The Pike preprocessor directive #warning has been added. It simply writes the rest of the line to stderr.

The Pike master object

• The new option --dumpversion prints out the Pike version in a more easily parsed way than --version.
• The master now supplies argv to the started application, so it can use the create() method for execution. Some people find it a more elegant solution than having a main function.
• The "-e" flag to Pike has been improved with a number of convenience wrappers. When compiling code with "pike -e", the macro NOT(X) will expand to !(X) and CHAR(X) to 'X', making it easier to solve quote problems from a shell. If the return from a pike -e statement is a positive integer it will be used as pikes exit code. If the return value is a string it will be output (with a "\n" added, if the string didn't already end in "\n"). Finally there is a predefined variable env that contains the environment variables as a string:string mapping.

Building and installing pike

• To simplify the process of building Pike source distributions it is now possible to bundle less common libraries such as Nettle with Pike. The bundles, found in the "bundles" directory, will be compiled and statically linked if no matching library is found on the system.
• The Pike build process no longer builds a bootstrap pike, used to run various small programs to generate source files. This means that in order to build Pike from CVS you need the latest major version of Pike installed on your system. Pike source distributions contain these generated files, and are not affected.
• By default, pike want to build a documentation source file, i.e. "make && make doc && make install". This makes it possible for third party modules to integrate its documentation into the system Pike documentation. If you do not want to build a documentation source file, use "make install_nodoc" instead of "make install".

Changes and additions to -x utilities

• benchmark

  A set of benchmarks is available in the benchmark tool. They are based on the Great Computer Language Shootout, but have been modified to make more sense in the context of Pike, and to test various aspects of Pike we suspect (or at least at one time suspected) to have bad performance.

• cgrep

  Context sensitive grep is very helpful when you are looking for substrings that are common. The implemented search modes are:

  • Complete token
  • Part of a token
  • Complete string literal
  • Part of a string literal
  • Part of a comment
  
  Example:

      $ cd Pike/7.6/src
      $ grep or * | wc -l
      18907
      $ pike -x cgrep -T or * | wc -l
      14

• dump

  Dumps Pike .pike and .pmod module files to precompiled .o files for shorter load times. Previously available as src/dumpmodule.pike in the Pike source tree, but moved into the Pike builtin tools to facilitate dumping of external modules.

• extract_locale

  Locale extractor utility used to extract localizable strings from an application into an xml format, to later be used by the Locale module.

• monger

  A new utility to download, install and otherwise manage external modules from the Fresh Pike project (modules.gotpike.com).

• rsif

  rsif can now work recursively in a file structure if given the flag -r or --recursive. Example:

      pike -x rsif -r 7.4 7.6

New modules, classes and methods added

• ADT.BitBuffer

  When operating on data formats that are defined on bit level, the ADT.BitBuffer presents a convenient interface. It operates as a FIFO buffer on bit level, which allows you to read and write bits and bytes.

      > ADT.BitBuffer b=ADT.BitBuffer();
      > b->put1(2);
      (1) Result: ADT.BitBuffer(11)
      > b->put0(15);
      (2) Result: ADT.BitBuffer("À\0"0)
      > b->drain();
      (3) Result: "À\0"
      > sizeof(b);
      (4) Result: 1

• ADT.CircularList

  This is an circular list implemented as a C wrapper around an array. It has a constant time complexity for pop and push. It has a limited max size but it can be increased manually by calling the allocate() method. It supports pushing, popping and peeking at both ends of the list, as well as removing and insering elements at any position in the list.

• ADT.Sequence

  The sequence work similar to an array but has the ability to insert and remove elements at any position. It also has functions to retrieve iterators for forward and backward iteration over the elements in the sequence.

• ADT.Struct

  This module makes it possible to work with binary formats of the "packed struct" type. Simply create a class inheriting ADT.Struct, specify its members in order, create an object with a file object as argument, and then read the decoded values from the object as ordinary variables. An example, reading ID3 metadata headers from an MP3 file:

      class ID3 {
        inherit ADT.Struct;
        Item head = Chars(3);
        Item title = Chars(30);
        Item artist = Chars(30);
        Item album = Chars(30);
        Item year = Chars(4);
        Item comment = Chars(30);
        Item genre = Byte();
      }
  
      Stdio.File f = Stdio.File("foo.mp3");
      f->seek(-128);
      ADT.Struct tag = ID3(f);
      if(tag->head=="TAG") {
        write("Title: %s\n", tag->title);
        tag->title = "A new title" + "\0"*19;
        f->seek(-128);
        f->write( (string)tag );
      }

• Array

  The Array module has been extended with Array.all and Array.any which determine if all or any of the elements in an array meet a given condition. The function Array.partition has also been added, which divides the elements of an array into two arrays, selected according to a given condition.

• Bz2

  Support for the compression format used by the bzip2 program. The module interface is almost identical to that of the Gz module.

• Calendar module

  The %S format was added to Calendar.parse() to parse seconds since the Epoch. The TimeRange class is extended with a format method format_commonlog(), a tzname_utc_offset (+HHMM) and tzname_location(), which, when available, returns zone names like "Europe/Stockholm". The database has been updated with Swedish pre-1901 namedays and Finnish namedays.

• Crypto/Nettle

  The crypto module has been almost completely rewritten, and now uses libnettle as backend instead of the built-in crypto algorithms that Pike had before. This way Pike will benefit from the more active development and optimization work in the Nettle project. The most common hash and cipher methods are already written in assembler for several platforms. As an example SHA1 is about 40% faster than before on Intel platforms.

  With the new nettle support comes support for two new cipher algorithms, Blowfish and Serpent, and the new NIST hash algorithm SHA256. Note that the new Crypto module has renamed its identifiers to be consistent with the rest of Pike, and in some cases to clarify or correct bad names. The old names still work, but produce a warning unless Pike is run in compatibility mode. Compatibility outside compatibility mode will be removed in the future.

  The interfaces for the hash and cipher algorithms have been improved, and no longer only conform to predefined interfaces, but actually inherits Hash/HashState and Cipher/CipherState. Every algorithm is in itself a module in the Crypto module, and inherits the Hash/Cipher class. This module contains instance non-specific methods such as digest_size or key_size. By calling the `() method in the module a HashState/CipherState object is returned, which is a hash/cipher instance which can be used for streaming operations.

  Examples:

      Crypto.MD5.hash("Hash this string");
  
      Crypto.MD5()->update("Hash this ")->update("string")->digest();
      

  The confusing and hard-to-use Crypto.randomness has been obsoleted by the Nettle implementation of the Yarrow random generator. The Nettle implementation of Yarrow uses AES and SHA256. The Crypto.Random module acts as a frontend before system crypto sources, and ensure that almost no matter how bad your OS is, you will still get cryptographically strong random data.

• Crypto.PGP

  The start of a PGP/GPG toolkit. It still cannot handle all types of signatures nor generate any, but it is useful to verify selfsigned code and data.

• Debug.Wrapper

  A simple litte wrapper that can be placed around another object to get printouts about what is happening to it. Only a few LFUNs are currently supported.

      > object x=Debug.Wrapper(Crypto.MD5());
      Debug.Wrapper is proxying ___Nettle.MD5_State()
      > x->name();
      ___Nettle.MD5_State()->name
      (1) Result: "md5"
      > !x;
      !___Nettle.MD5_State()
      (2) Result: 0

• Error

  The root of the Pike exception hiearchy. Even though it is work in progress, it is already usable.

      > mixed err = catch( 1/0 );
      > err;
      (1) Result: Error.Math("Division by zero.\n")
      > object_program(err)==Error.Math;
      (2) Result: 1

• EXIF

  The EXIF module is now much more robust than before, and can handle some of the erroneous EXIF tags some cameras procduce. Extended support for Nikon cameras.

• Filesystem.Traversion

  The Filesystem.Traversion iterator is a handy way to descend into a directory structure (depth first) and perform actions on all or some of the files.

  Example:

      foreach(Filesystem.Traversion("."); string dir; string file)
        if(file[-1]=='~' || file=="core") rm(dir+file);

• Float

  Here constants and functions that deal specifically with the float data type is stored. Currently, it only contains various constants that describe the precision and limitations of the float type with which Pike was compiled.

• Function

  The Function module has been extended with the fixpoint combinator "Y", useful when writing recursive lambdas, a curry function, to partially evaluate a function call, and a callback caller function that protects the caller from exceptions in the callback function.

• Geography

  The Geography.Position object can now also convert to and from the Swedish RT38 (Rikets Triangulering 1938) position format.

• GLUE

  The GL Universal Environment is a GL toolkit that makes implementing GL applications in Pike really simple. GLUE has several orthogonal components like object oriented encapsulation of GL, drawing primitives, texture handling and text generation. The most fundamental part is however an abstract interface to a GL area driver, like GTK or SDL.

      int main() {
        GLUE.init();
        draw_frame();
        return -1;
      }
  
      void draw_frame() {
        call_out(draw_frame, 0.02); // 1/(50 fps)
        do_gl_code();
        GLUE.swap_buffers();
      }

• Image.NEO

  Support for one of the major image formats on Atari ST/STE, including decoding of color cycling. The C bitmap and palette handler can be used to implement other atari image formats.

• Int

  The Int module contains a few functions and constants that deal specifically with the integer data type. Currently it contains parity and byte swapping functions, and constants for the system maxint and minint.

• Pike.Security

  Functions and classes that deal with the Pike security system (requires Pike to be compiled with --with-security to be present) are stored in this module. Beware that the Pike security system is still very experimental.

• Process.Process

  The Process.Process class is extended to handle a time-out callback and a read callback, to make it easier to manage processes in an asynchronous way.

• Protocols.Bittorrent

  This is a Pike implementation of the client side of the popular Bittorrent protocol. Both creating torrent files and seeding as well as downloading and verifying files are supported. There are also several functions to retreive auxillary information such as identifying the other peer clients.

• Protocols.HTTP.Session

  Handles an HTTP connection as a session, with cookies, redirects, HTTP keep-alive, etc.

• Protocols.LMTP/Protocols.SMTP

  Protocols.LMTP implements a server for the Local Mail Transfer Protocol, LMTP, as specified in RFC2033. This module has been well tested against Postfix clients. Protocols.LMTP is based on a new server implementation in Protocols.SMTP.

• Protocols.OBEX

  An implementation of the IrDA(R) Object Exchange Protocol. OBEX is a protocol for sending and receiving binary objects to mobile devices using transports such as IR and Bluetooth.

• Regexp.PCRE added to give libpcre support

  Are you a closet perler? For those who missed the richer flora of regexp syntax that Perl supports, the Perl Compatible Regular Expression module is the answer. If you compile libpcre with UTF-8 support you will also get transparent wide string support. Several convenience functions are also added to the Regexp module to enable easier access to regular expressions.

• SSL

  Large parts of the SSL module have been rewritten, either as part of the rewrite of the Crypto module or in an attempt to fix various issues regarding blocking/nonblocking files, threads, etc.

• Standards.IDNA

  Internet Engineering Task Force (IETF), RFC 3490. Your most likely application of this will be the encoding and decoding of punycode. Example:

      Standards.IDNA.zone_to_unicode("www.xn--rksmrgs-5wao1o.org");

• Thread

  Thread.Fifo and Thread.Queue have been extended with try_* varieties of all functions that can block, and with functions that make them both implement the same interface. Both also have fallbacks for running in nonthreaded mode.

• Web.RDF/RDFS/OWL/RSS

  Pike now has support for the W3C semantic web formats OWL, RDF and RDFS, which are used for expressing structure and metadata information. There is also some support for the syndication format RSS (which happens to be a simple application of RDF).

  This sample program reads an OWL file, parses the dataset contained in it, and then lists the data classes in that dataset:

      int main(int argc, array argv)
      {
        object owlset = Web.OWL();
        string input = Stdio.read_file(argv[1]);
        owlset->parse_owl(input);
  
        write("Classes:\n");
  
        foreach(owlset->find_statements(0,
                                        owlset->rdf_type,
                                        owlset->owl_Class);
                               array statement)
          write("- %O\n", statement[0]);
  
        return 0;
      }

Optimizations

• Instantiation and destruction of pike classes is now significantly faster.
• Handling of bignums has been optimized, especially conversion to/from normal integers.
• String case conversion is now five times faster than before on average.

Compatibility changes

• Incompatible changes have been in ADT.Heap, Array.diff3_old, Crypto, Locale.Charset, Protocols.SMTP, SSL, Sql.sql, Standards.ASN1, Standards.PKCS, Stdio.File, Thread.Mutex and rusage(). Please refer to the 7.4 namespace in the compatibility section of the documentation for a complete description of these changes. Using #pike 7.4 or starting Pike with -V7.4 activates the compatibility layer, which should make it possible to run old code with newer pikes.

Compatibility changes without backward compatibility

• Module ABI changed

  The pike_frame struct has a new member, which makes modules compiled with Pike 7.4, and earlier versions of Pike, incompatible with Pike 7.6.

C level/development changes

• The security.h include file is renamed to pike_security.h
• The testsuite has three new, handy macros: cond_resolv, test_program_eq and test_program_equal, all defined in mktestsuite. A testsuite test that produces a warning, unless it is a test_warning test, will now be considered an error. The test program can now run testsuites in forked processes. By default every testsuite file will now be run in a forked process. If a directory named extra_tests exists on the top level of the Pike source directory, that directory will also be recursed for testsuite.in files.
• The cmod API has been extended in many details, making it easier to work with. Variable declarations may now use the object(programname) syntax. Void in parameters may be 0. Varargs and optional arguments are now typechecked properly. It is possible to INHERIT a program into a PIKECLASS. It is possible to set attributes on a PIKEVAR. A program may be flagged as a prototype, which will make the function bodies to be ignored. It is also possible to set program flags, such as PROGRAM_DESTRUCT_IMMEDIATE. See bin/precompile.pike for documentation.
• The make file has a few new targets that should be self explanatory: gdb_hilfe, valgrind_hilfe and valgrind_verify.
• The header file module_magic.h is deprecated. Use the PIKE_MODULE_INIT and PIKE_MODULE_EXIT macros in your modules instead.
• The backend has a new interface to handle references from backend objects to callbacks in files.