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Diffstat (limited to 'dcc.h')
| -rw-r--r-- | dcc.h | 125 |
1 files changed, 125 insertions, 0 deletions
@@ -0,0 +1,125 @@ +/********************************************************************\ +* BitlBee -- An IRC to other IM-networks gateway * +* * +* Copyright 2006 Marijn Kruisselbrink and others * +* Copyright 2007 Uli Meis <a.sporto+bee@gmail.com> * +\********************************************************************/ + +/* + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License with + the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL; + if not, write to the Free Software Foundation, Inc., 59 Temple Place, + Suite 330, Boston, MA 02111-1307 USA +*/ + +/* + * DCC SEND + * + * Historically, DCC means send 1024 Bytes and wait for a 4 byte reply + * acknowledging all transferred data. This is ridiculous for two reasons. The + * first being that TCP is a stream oriented protocol that doesn't care much + * about your idea of a packet. The second reason being that TCP is a reliable + * transfer protocol with its own sophisticated ACK mechanism, making DCCs ACK + * mechanism look like a joke. For these reasons, DCCs requirements have + * (hopefully) been relaxed in most implementations and this implementation + * depends upon at least the following: The 1024 bytes need not be transferred + * at once, i.e. packets can be smaller. A second relaxation has apparently + * gotten the name "DCC SEND ahead" which basically means to not give a damn + * about those DCC ACKs and just send data as you please. This behaviour is + * enabled by default. Note that this also means that packets may be as large + * as the maximum segment size. + */ + +#ifndef _DCC_H +#define _DCC_H + +/* don't wait for acknowledgments */ +#define DCC_SEND_AHEAD + +/* This multiplier specifies how many bytes we + * can go ahead within one event loop cycle. Notice that all in all, + * we can easily be more ahead if the event loop shoots often enough. + * (or the receiver processes slow enough) + * + * Setting this value too high will cause send buffer overflows. + */ +#define DCC_SEND_AHEAD_MUL 10 + +/* + * queue thresholds for the out of data and overflow conditions + */ +#define DCC_QUEUE_THRESHOLD_LOW 2048 +#define DCC_QUEUE_THRESHOLD_HIGH 65536 + +/* only used in non-ahead mode */ +#define DCC_PACKET_SIZE 1024 + +/* stores buffers handed over by IM protocols */ +struct dcc_buffer { + char *b; + int len; +}; + +typedef struct dcc_file_transfer { + + struct im_connection *ic; + + /* + * Depending in the status of the file transfer, this is either the socket that is + * being listened on for connections, or the socket over which the file transfer is + * taking place. + */ + int fd; + + /* + * IDs returned by b_input_add for watch_ing over the above socket. + */ + gint watch_in; /* readable */ + gint watch_out; /* writable */ + + /* + * The total number of queued bytes. The following equality should always hold: + * + * queued_bytes = sum(queued_buffers.len) - buffer_pos + */ + unsigned int queued_bytes; + + /* + * A list of dcc_buffer structures. + * These are provided by the protocols directly so that no copying is neccessary. + */ + GSList *queued_buffers; + + /* + * current position within the first buffer. + * Is non-null if the whole buffer couldn't be sent at once. + */ + int buffer_pos; + + /* + * The total amount of bytes that have been sent to the irc client. + */ + size_t bytes_sent; + + /* imcb's handle */ + file_transfer_t *ft; + +} dcc_file_transfer_t; + +file_transfer_t *dccs_send_start( struct im_connection *ic, char *user_nick, char *file_name, size_t file_size ); + +void dcc_canceled( file_transfer_t *file, char *reason ); + +gboolean dccs_send_write( file_transfer_t *file, gpointer data, unsigned int data_size ); + +#endif |