guacamole-spice-protocol/libguac/include/guacio.h

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2010-12-08 21:14:04 +00:00
/*
* Guacamole - Clientless Remote Desktop
* Copyright (C) 2010 Michael Jumper
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef _GUACIO_H
#define _GUACIO_H
#include <unistd.h>
/**
* Defines the GUACIO object and functionss for using and manipulating it.
*
* @file guacio.h
*/
/**
* The core I/O object of Guacamole. GUACIO provides buffered input and output
* as well as convenience methods for efficiently writing base64 data.
*/
typedef struct GUACIO {
/**
* The file descriptor to be read from / written to.
*/
int fd;
/**
* The number of bytes present in the base64 "ready" buffer.
*/
int ready;
/**
* The base64 "ready" buffer. Once this buffer is filled, base64 data is
* flushed to the main write buffer.
*/
int ready_buf[3];
/**
* The number of bytes currently in the main write buffer.
*/
int written;
/**
* The main write buffer. Bytes written go here before being flushed
* to the open file descriptor.
*/
char out_buf[8192];
/**
* The current size of the instruction buffer.
*/
int instructionbuf_size;
/**
* The number of bytes currently in the instruction buffer.
*/
int instructionbuf_used_length;
/**
* The instruction buffer. This is essentially the input buffer,
* provided as a convenience to be used to buffer instructions until
* those instructions are complete and ready to be parsed.
*/
char* instructionbuf;
} GUACIO;
/**
* Allocates and initializes a new GUACIO object with the given open
* file descriptor.
*
* @param fd An open file descriptor that this GUACIO object should manage.
* @return A newly allocated GUACIO object associated with the given
* file descriptor.
*/
GUACIO* guac_open(int fd);
/**
* Writes the given unsigned int to the given GUACIO object. The data
* written may be buffered until the buffer is flushed automatically or
* manually.
*
* @param io The GUACIO object to write to.
* @param i The unsigned int to write.
* @return Zero on success, or non-zero if an error occurs while writing.
*/
ssize_t guac_write_int(GUACIO* io, unsigned int i);
/**
* Writes the given string to the given GUACIO object. The data
* written may be buffered until the buffer is flushed automatically or
* manually. Note that if the string can contain characters used
* internally by the Guacamole protocol (commas, semicolons, or
* backslashes) it will need to be escaped.
*
* @param io The GUACIO object to write to.
* @param str The string to write.
* @return Zero on success, or non-zero if an error occurs while writing.
*/
ssize_t guac_write_string(GUACIO* io, const char* str);
/**
* Writes the given binary data to the given GUACIO object as base64-encoded
* data. The data written may be buffered until the buffer is flushed
* automatically or manually. Beware that because base64 data is buffered
* on top of the write buffer already used, a call to guac_flush_base64() must
* be made before non-base64 writes (or writes of an independent block of
* base64 data) can be made.
*
* @param io The GUACIO object to write to.
* @param buf A buffer containing the data to write.
* @param count The number of bytes to write.
* @return Zero on success, or non-zero if an error occurs while writing.
*/
ssize_t guac_write_base64(GUACIO* io, const void* buf, size_t count);
/**
* Flushes the base64 buffer, writing padding characters as necessary.
*
* @param io The GUACIO object to flush
* @return Zero on success, or non-zero if an error occurs during flush.
*/
ssize_t guac_flush_base64(GUACIO* io);
/**
* Flushes the write buffer.
*
* @param io The GUACIO object to flush
* @return Zero on success, or non-zero if an error occurs during flush.
*/
ssize_t guac_flush(GUACIO* io);
/**
* Waits for input to be available on the given GUACIO object until the
* specified timeout elapses.
*
* @param io The GUACIO object to wait for.
* @param usec_timeout The maximum number of microseconds to wait for data, or
* -1 to potentially wait forever.
* @return Positive on success, zero if the timeout elapsed and no data is
* available, negative on error.
*/
int guac_select(GUACIO* io, int usec_timeout);
/**
* Frees resources allocated to the given GUACIO object. Note that this
* implicitly flush all buffers, but will NOT close the associated file
* descriptor.
*
* @param io The GUACIO object to close.
*/
void guac_close(GUACIO* io);
#endif