NAME
    Net::FCP - http://freenet.sf.net client protocol

SYNOPSIS
     use Net::FCP;

     my $fcp = new Net::FCP;

     my $ni = $fcp->txn_node_info->result;
     my $ni = $fcp->node_info;

DESCRIPTION
    See <http://freenet.sourceforge.net/index.php?page=fcp> for a
    description of what the messages do. I am too lazy to document all this
    here.

WARNING
    This module is alpha. While it probably won't destroy (much :) of your
    data, it currently falls short of what it should provide (intelligent
    uri following, splitfile downloads, healing...)

  IMPORT TAGS
    Nothing much can be "imported" from this module right now. There are,
    however, certain "import tags" that can be used to select the event
    model to be used.

    Event models are implemented as modules under the "Net::FCP::Event::xyz"
    class, where "xyz" is the event model to use. The default is "Event" (or
    later "Auto").

    The import tag to use is named "event=xyz", e.g. "event=Event",
    "event=Glib" etc.

    You should specify the event module to use only in the main program.

    If no event model has been specified, FCP tries to autodetect it on
    first use (e.g. first transaction), in this order: Coro, Event, Glib,
    Tk.

  FREENET BASICS
    Ok, this section will not explain any freenet basics to you, just some
    problems I found that you might want to avoid:

    freenet URIs are _NOT_ URIs
        Whenever a "uri" is required by the protocol, freenet expects a kind
        of URI prefixed with the "freenet:" scheme, e.g. "freenet:CHK...".
        However, these are not URIs, as freeent fails to parse them
        correctly, that is, you must unescape an escaped characters ("%2c"
        => ",") yourself. Maybe in the future this library will do it for
        you, so watch out for this incompatible change.

    Numbers are in HEX
        Virtually every number in the FCP protocol is in hex. Be sure to use
        "hex()" on all such numbers, as the module (currently) does nothing
        to convert these for you.

  THE Net::FCP CLASS
    $meta = Net::FCP::parse_metadata $string
        Parse a metadata string and return it.

        The metadata will be a hashref with key "version" (containing the
        mandatory version header entries) and key "raw" containing the
        original metadata string.

        All other headers are represented by arrayrefs (they can be
        repeated).

        Since this description is confusing, here is a rather verbose
        example of a parsed manifest:

           (
              raw => "Version...",
              version => { revision => 1 },
              document => [
                            {
                              info => { format" => "image/jpeg" },
                              name => "background.jpg",
                              redirect => { target => "freenet:CHK\@ZcagI,ra726bSw" },
                            },
                            {
                              info => { format" => "text/html" },
                              name => ".next",
                              redirect => { target => "freenet:SSK\@ilUPAgM/TFEE/3" },
                            },
                            {
                              info => { format" => "text/html" },
                              redirect => { target => "freenet:CHK\@8M8Po8ucwI,8xA" },
                            }
                          ]
           )

    $fcp = new Net::FCP [host => $host][, port => $port]
        Create a new virtual FCP connection to the given host and port
        (default 127.0.0.1:8481, or the environment variables "FREDHOST" and
        "FREDPORT").

        Connections are virtual because no persistent physical connection is
        established.

    $txn = $fcp->txn(type => attr => val,...)
        The low-level interface to transactions. Don't use it.

        Here are some examples of using transactions:

        The blocking case, no (visible) transactions involved:

           my $nodehello = $fcp->client_hello;

        A transaction used in a blocking fashion:

           my $txn = $fcp->txn_client_hello;
           ...
           my $nodehello = $txn->result;

        Or shorter:

           my $nodehello = $fcp->txn_client_hello->result;

        Setting callbacks:

           $fcp->txn_client_hello->cb(
              sub { my $nodehello => $_[0]->result }
           );

    $txn = $fcp->txn_client_hello
    $nodehello = $fcp->client_hello
        Executes a ClientHello request and returns it's results.

           {
             max_file_size => "5f5e100",
             node => "Fred,0.6,1.46,7050"
             protocol => "1.2",
           }

    $txn = $fcp->txn_client_info
    $nodeinfo = $fcp->client_info
        Executes a ClientInfo request and returns it's results.

           {
             active_jobs => "1f",
             allocated_memory => "bde0000",
             architecture => "i386",
             available_threads => 17,
             datastore_free => "5ce03400",
             datastore_max => "2540be400",
             datastore_used => "1f72bb000",
             estimated_load => 52,
             free_memory => "5cc0148",
             is_transient => "false",
             java_name => "Java HotSpot(_T_M) Server VM",
             java_vendor => "http://www.blackdown.org/",
             java_version => "Blackdown-1.4.1-01",
             least_recent_timestamp => "f41538b878",
             max_file_size => "5f5e100",
             most_recent_timestamp => "f77e2cc520"
             node_address => "1.2.3.4",
             node_port => 369,
             operating_system => "Linux",
             operating_system_version => "2.4.20",
             routing_time => "a5",
           }

    $txn = $fcp->txn_generate_chk ($metadata, $data[, $cipher])
    $uri = $fcp->generate_chk ($metadata, $data[, $cipher])
        Calculcates a CHK, given the metadata and data. $cipher is either
        "Rijndael" or "Twofish", with the latter being the default.

    $txn = $fcp->txn_generate_svk_pair
    ($public, $private) = @{ $fcp->generate_svk_pair }
        Creates a new SVK pair. Returns an arrayref.

           [
             "hKs0-WDQA4pVZyMPKNFsK1zapWY",
             "ZnmvMITaTXBMFGl4~jrjuyWxOWg"
           ]

    $txn = $fcp->txn_insert_private_key ($private)
    $public = $fcp->insert_private_key ($private)
        Inserts a private key. $private can be either an insert URI (must
        start with "freenet:SSK@") or a raw private key (i.e. the private
        value you get back from "generate_svk_pair").

        Returns the public key.

        UNTESTED.

    $txn = $fcp->txn_get_size ($uri)
    $length = $fcp->get_size ($uri)
        Finds and returns the size (rounded up to the nearest power of two)
        of the given document.

        UNTESTED.

    $txn = $fcp->txn_client_get ($uri [, $htl = 15 [, $removelocal = 0]])
    ($metadata, $data) = @{ $fcp->client_get ($uri, $htl, $removelocal)
        Fetches a (small, as it should fit into memory) file from freenet.
        $meta is the metadata (as returned by "parse_metadata" or "undef").

        Due to the overhead, a better method to download big files should be
        used.

          my ($meta, $data) = @{
             $fcp->client_get (
                "freenet:CHK@hdXaxkwZ9rA8-SidT0AN-bniQlgPAwI,XdCDmBuGsd-ulqbLnZ8v~w"
             )
          };

    $txn = $fcp->txn_client_put ($uri, $metadata, $data, $htl, $removelocal)
    my $uri = $fcp->client_put ($uri, $metadata, $data, $htl, $removelocal);
        Insert a new key. If the client is inserting a CHK, the URI may be
        abbreviated as just CHK@. In this case, the node will calculate the
        CHK.

        $meta can be a reference or a string (ONLY THE STRING CASE IS
        IMPLEMENTED!).

        THIS INTERFACE IS UNTESTED AND SUBJECT TO CHANGE.

    MISSING: (ClientPut), InsertKey

  THE Net::FCP::Txn CLASS
    All requests (or transactions) are executed in a asynchronous way. For
    each request, a "Net::FCP::Txn" object is created (worse: a tcp
    connection is created, too).

    For each request there is actually a different subclass (and it's
    possible to subclass these, although of course not documented).

    The most interesting method is "result".

    new arg => val,...
        Creates a new "Net::FCP::Txn" object. Not normally used.

    $txn = $txn->cb ($coderef)
        Sets a callback to be called when the request is finished. The
        coderef will be called with the txn as it's sole argument, so it has
        to call "result" itself.

        Returns the txn object, useful for chaining.

        Example:

           $fcp->txn_client_get ("freenet:CHK....")
              ->userdata ("ehrm")
              ->cb(sub {
                 my $data = shift->result;
              });

    $txn = $txn->userdata ([$userdata])
        Set user-specific data. This is useful in progress callbacks. The
        data can be accessed using "$txn->{userdata}".

        Returns the txn object, useful for chaining.

    $txn->cancel (%attr)
        Cancels the operation with a "cancel" exception anf the given
        attributes (consider at least giving the attribute "reason").

        UNTESTED.

    $result = $txn->result
        Waits until a result is available and then returns it.

        This waiting is (depending on your event model) not very efficient,
        as it is done outside the "mainloop". The biggest problem, however,
        is that it's blocking one thread of execution. Try to use the
        callback mechanism, if possible, and call result from within the
        callback (or after is has been run), as then no waiting is
        necessary.

  The Net::FCP::Exception CLASS
    Any unexpected (non-standard) responses that make it impossible to
    return the advertised result will result in an exception being thrown
    when the "result" method is called.

    These exceptions are represented by objects of this class.

    $exc = new Net::FCP::Exception $type, \%attr
        Create a new exception object of the given type (a string like
        "route_not_found"), and a hashref containing additional attributes
        (usually the attributes of the message causing the exception).

    $exc->type([$type])
        With no arguments, returns the exception type. Otherwise a boolean
        indicating wether the exception is of the given type is returned.

    $exc->attr([$attr])
        With no arguments, returns the attributes. Otherwise the named
        attribute value is returned.

SEE ALSO
    <http://freenet.sf.net>.

BUGS
AUTHOR
     Marc Lehmann <pcg@goof.com>
     http://www.goof.com/pcg/marc/