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NAME |
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Net::FCP - http://freenet.sf.net client protocol |
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|
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SYNOPSIS |
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use Net::FCP; |
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|
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my $fcp = new Net::FCP; |
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|
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my $ni = $fcp->txn_node_info->result; |
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my $ni = $fcp->node_info; |
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|
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DESCRIPTION |
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See <http://freenet.sourceforge.net/index.php?page=fcp> for a |
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description of what the messages do. I am too lazy to document all this |
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here. |
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|
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WARNING |
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This module is alpha. While it probably won't destroy (much :) of your |
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data, it currently falls short of what it should provide (intelligent |
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uri following, splitfile downloads, healing...) |
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|
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IMPORT TAGS |
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Nothing much can be "imported" from this module right now. There are, |
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however, certain "import tags" that can be used to select the event |
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model to be used. |
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|
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Event models are implemented as modules under the "Net::FCP::Event::xyz" |
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class, where "xyz" is the event model to use. The default is "Event" (or |
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later "Auto"). |
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|
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The import tag to use is named "event=xyz", e.g. "event=Event", |
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"event=Glib" etc. |
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|
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You should specify the event module to use only in the main program. |
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|
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If no event model has been specified, FCP tries to autodetect it on |
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first use (e.g. first transaction), in this order: Coro, Event, Glib, |
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Tk. |
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|
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FREENET BASICS |
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Ok, this section will not explain any freenet basics to you, just some |
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problems I found that you might want to avoid: |
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|
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freenet URIs are _NOT_ URIs |
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Whenever a "uri" is required by the protocol, freenet expects a kind |
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of URI prefixed with the "freenet:" scheme, e.g. "freenet:CHK...". |
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However, these are not URIs, as freeent fails to parse them |
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correctly, that is, you must unescape an escaped characters ("%2c" |
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=> ",") yourself. Maybe in the future this library will do it for |
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you, so watch out for this incompatible change. |
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|
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Numbers are in HEX |
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Virtually every number in the FCP protocol is in hex. Be sure to use |
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"hex()" on all such numbers, as the module (currently) does nothing |
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to convert these for you. |
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|
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THE Net::FCP CLASS |
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$meta = Net::FCP::parse_metadata $string |
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Parse a metadata string and return it. |
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|
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The metadata will be a hashref with key "version" (containing the |
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mandatory version header entries) and key "raw" containing the |
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original metadata string. |
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|
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All other headers are represented by arrayrefs (they can be |
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repeated). |
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|
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Since this description is confusing, here is a rather verbose |
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example of a parsed manifest: |
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|
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( |
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raw => "Version...", |
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version => { revision => 1 }, |
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document => [ |
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{ |
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info => { format" => "image/jpeg" }, |
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name => "background.jpg", |
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redirect => { target => "freenet:CHK\@ZcagI,ra726bSw" }, |
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}, |
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{ |
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info => { format" => "text/html" }, |
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name => ".next", |
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redirect => { target => "freenet:SSK\@ilUPAgM/TFEE/3" }, |
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}, |
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{ |
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info => { format" => "text/html" }, |
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redirect => { target => "freenet:CHK\@8M8Po8ucwI,8xA" }, |
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} |
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] |
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) |
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|
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$string = Net::FCP::build_metadata $meta |
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Takes a hash reference as returned by "Net::FCP::parse_metadata" and |
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returns the corresponding string form. If a string is given, it's |
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returned as is. |
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|
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$fcp = new Net::FCP [host => $host][, port => $port][, progress => \&cb] |
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Create a new virtual FCP connection to the given host and port |
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(default 127.0.0.1:8481, or the environment variables "FREDHOST" and |
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"FREDPORT"). |
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|
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Connections are virtual because no persistent physical connection is |
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established. |
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|
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You can install a progress callback that is being called with the |
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Net::FCP object, a txn object, the type of the transaction and the |
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attributes. Use it like this: |
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|
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sub progress_cb { |
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my ($self, $txn, $type, $attr) = @_; |
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|
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warn "progress<$txn,$type," . (join ":", %$attr) . ">\n"; |
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} |
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|
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$txn = $fcp->txn(type => attr => val,...) |
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The low-level interface to transactions. Don't use it. |
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|
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Here are some examples of using transactions: |
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|
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The blocking case, no (visible) transactions involved: |
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|
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my $nodehello = $fcp->client_hello; |
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|
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A transaction used in a blocking fashion: |
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|
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my $txn = $fcp->txn_client_hello; |
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... |
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my $nodehello = $txn->result; |
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|
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Or shorter: |
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|
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my $nodehello = $fcp->txn_client_hello->result; |
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|
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Setting callbacks: |
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|
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$fcp->txn_client_hello->cb( |
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sub { my $nodehello => $_[0]->result } |
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); |
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|
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$txn = $fcp->txn_client_hello |
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$nodehello = $fcp->client_hello |
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Executes a ClientHello request and returns it's results. |
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|
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{ |
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max_file_size => "5f5e100", |
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node => "Fred,0.6,1.46,7050" |
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protocol => "1.2", |
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} |
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|
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$txn = $fcp->txn_client_info |
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$nodeinfo = $fcp->client_info |
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Executes a ClientInfo request and returns it's results. |
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|
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{ |
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active_jobs => "1f", |
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allocated_memory => "bde0000", |
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architecture => "i386", |
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available_threads => 17, |
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datastore_free => "5ce03400", |
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datastore_max => "2540be400", |
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datastore_used => "1f72bb000", |
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estimated_load => 52, |
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free_memory => "5cc0148", |
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is_transient => "false", |
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java_name => "Java HotSpot(_T_M) Server VM", |
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java_vendor => "http://www.blackdown.org/", |
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java_version => "Blackdown-1.4.1-01", |
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least_recent_timestamp => "f41538b878", |
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max_file_size => "5f5e100", |
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most_recent_timestamp => "f77e2cc520" |
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node_address => "1.2.3.4", |
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node_port => 369, |
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operating_system => "Linux", |
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operating_system_version => "2.4.20", |
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routing_time => "a5", |
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} |
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|
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$txn = $fcp->txn_generate_chk ($metadata, $data[, $cipher]) |
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$uri = $fcp->generate_chk ($metadata, $data[, $cipher]) |
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Calculates a CHK, given the metadata and data. $cipher is either |
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"Rijndael" or "Twofish", with the latter being the default. |
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|
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$txn = $fcp->txn_generate_svk_pair |
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($public, $private) = @{ $fcp->generate_svk_pair } |
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Creates a new SVK pair. Returns an arrayref with the public key, the |
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private key and a crypto key, which is just additional entropy. |
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|
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[ |
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"acLx4dux9fvvABH15Gk6~d3I-yw", |
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"cPoDkDMXDGSMM32plaPZDhJDxSs", |
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"BH7LXCov0w51-y9i~BoB3g", |
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] |
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|
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A private key (for inserting) can be constructed like this: |
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|
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SSK@<private_key>,<crypto_key>/<name> |
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|
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It can be used to insert data. The corresponding public key looks |
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like this: |
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|
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SSK@<public_key>PAgM,<crypto_key>/<name> |
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|
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Watch out for the "PAgM"-part! |
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|
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$txn = $fcp->txn_invert_private_key ($private) |
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$public = $fcp->invert_private_key ($private) |
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Inverts a private key (returns the public key). $private can be |
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either an insert URI (must start with "freenet:SSK@") or a raw |
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private key (i.e. the private value you get back from |
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"generate_svk_pair"). |
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|
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Returns the public key. |
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|
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$txn = $fcp->txn_get_size ($uri) |
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$length = $fcp->get_size ($uri) |
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Finds and returns the size (rounded up to the nearest power of two) |
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of the given document. |
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|
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$txn = $fcp->txn_client_get ($uri [, $htl = 15 [, $removelocal = 0]]) |
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($metadata, $data) = @{ $fcp->client_get ($uri, $htl, $removelocal) |
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Fetches a (small, as it should fit into memory) file from freenet. |
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$meta is the metadata (as returned by "parse_metadata" or "undef"). |
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|
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The $uri should begin with "freenet:", but the scheme is currently |
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added, if missing. |
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|
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Due to the overhead, a better method to download big files should be |
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used. |
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|
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my ($meta, $data) = @{ |
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$fcp->client_get ( |
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"freenet:CHK@hdXaxkwZ9rA8-SidT0AN-bniQlgPAwI,XdCDmBuGsd-ulqbLnZ8v~w" |
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) |
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}; |
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|
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$txn = $fcp->txn_client_put ($uri, $metadata, $data, $htl, $removelocal) |
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my $uri = $fcp->client_put ($uri, $metadata, $data, $htl, $removelocal); |
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Insert a new key. If the client is inserting a CHK, the URI may be |
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abbreviated as just CHK@. In this case, the node will calculate the |
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CHK. If the key is a private SSK key, the node will calculcate the |
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public key and the resulting public URI. |
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|
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$meta can be a hash reference (same format as returned by |
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"Net::FCP::parse_metadata") or a string. |
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|
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The result is an arrayref with the keys "uri", "public_key" and |
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"private_key". |
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|
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THE Net::FCP::Txn CLASS |
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All requests (or transactions) are executed in a asynchronous way. For |
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each request, a "Net::FCP::Txn" object is created (worse: a tcp |
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connection is created, too). |
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|
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For each request there is actually a different subclass (and it's |
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possible to subclass these, although of course not documented). |
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|
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The most interesting method is "result". |
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|
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new arg => val,... |
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Creates a new "Net::FCP::Txn" object. Not normally used. |
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|
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$txn = $txn->cb ($coderef) |
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Sets a callback to be called when the request is finished. The |
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coderef will be called with the txn as it's sole argument, so it has |
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to call "result" itself. |
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|
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Returns the txn object, useful for chaining. |
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|
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Example: |
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|
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$fcp->txn_client_get ("freenet:CHK....") |
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->userdata ("ehrm") |
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->cb(sub { |
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my $data = shift->result; |
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}); |
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|
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$txn = $txn->userdata ([$userdata]) |
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Set user-specific data. This is useful in progress callbacks. The |
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data can be accessed using "$txn->{userdata}". |
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|
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Returns the txn object, useful for chaining. |
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|
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$txn->cancel (%attr) |
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Cancels the operation with a "cancel" exception anf the given |
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attributes (consider at least giving the attribute "reason"). |
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|
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UNTESTED. |
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|
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$result = $txn->result |
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Waits until a result is available and then returns it. |
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|
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This waiting is (depending on your event model) not very efficient, |
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as it is done outside the "mainloop". The biggest problem, however, |
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is that it's blocking one thread of execution. Try to use the |
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callback mechanism, if possible, and call result from within the |
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callback (or after is has been run), as then no waiting is |
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necessary. |
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|
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The Net::FCP::Exception CLASS |
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Any unexpected (non-standard) responses that make it impossible to |
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return the advertised result will result in an exception being thrown |
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when the "result" method is called. |
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|
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These exceptions are represented by objects of this class. |
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|
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$exc = new Net::FCP::Exception $type, \%attr |
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Create a new exception object of the given type (a string like |
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"route_not_found"), and a hashref containing additional attributes |
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(usually the attributes of the message causing the exception). |
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|
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$exc->type([$type]) |
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With no arguments, returns the exception type. Otherwise a boolean |
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indicating wether the exception is of the given type is returned. |
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|
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$exc->attr([$attr]) |
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With no arguments, returns the attributes. Otherwise the named |
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attribute value is returned. |
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|
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SEE ALSO |
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<http://freenet.sf.net>. |
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|
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BUGS |
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AUTHOR |
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Marc Lehmann <pcg@goof.com> |
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http://www.goof.com/pcg/marc/ |
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|
