io.cpp

/** \file io.c

Utilities for io redirection.
	
*/
#include "config.h"


#include <stdlib.h>
#include <stdio.h>
#include <wchar.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <set>
#include <algorithm>

#ifdef HAVE_SYS_TERMIOS_H
#include <sys/termios.h>
#endif

#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif

#include <unistd.h>
#include <fcntl.h>

#if HAVE_NCURSES_H
#include <ncurses.h>
#else
#include <curses.h>
#endif

#if HAVE_TERMIO_H
#include <termio.h>
#endif

#if HAVE_TERM_H
#include <term.h>
#elif HAVE_NCURSES_TERM_H
#include <ncurses/term.h>
#endif

#include "fallback.h"
#include "util.h"

#include "wutil.h"
#include "exec.h"
#include "common.h"
#include "io.h"


void io_buffer_read( io_data_t *d )
{
	exec_close(d->param1.pipe_fd[1] );

	if( d->io_mode == IO_BUFFER )
	{		
/*		if( fcntl( d->param1.pipe_fd[0], F_SETFL, 0 ) )
		{
			wperror( L"fcntl" );
			return;
			}	*/
		debug( 4, L"io_buffer_read: blocking read on fd %d", d->param1.pipe_fd[0] );
		while(1)
		{
			char b[4096];
			long l;
			l=read_blocked( d->param1.pipe_fd[0], b, 4096 );
			if( l==0 )
			{
				break;
			}
			else if( l<0 )
			{
				/*
				  exec_read_io_buffer is only called on jobs that have
				  exited, and will therefore never block. But a broken
				  pipe seems to cause some flags to reset, causing the
				  EOF flag to not be set. Therefore, EAGAIN is ignored
				  and we exit anyway.
				*/
				if( errno != EAGAIN )
				{
					debug( 1, 
						   _(L"An error occured while reading output from code block on file descriptor %d"), 
						   d->param1.pipe_fd[0] );
					wperror( L"io_buffer_read" );				
				}
				
				break;				
			}
			else
			{				
				d->out_buffer_append( b, l );				
			}
		}
	}
}


io_data_t *io_buffer_create( bool is_input )
{
    bool success = true;
	io_data_t *buffer_redirect = new io_data_t;
	buffer_redirect->out_buffer_create();
	buffer_redirect->io_mode = IO_BUFFER;
	buffer_redirect->is_input = is_input ? true : false;
	buffer_redirect->fd=is_input?0:1;
	
	if( exec_pipe( buffer_redirect->param1.pipe_fd ) == -1 )
	{
		debug( 1, PIPE_ERROR );
		wperror (L"pipe");
		success = false;
	}
	else if( fcntl( buffer_redirect->param1.pipe_fd[0],
					F_SETFL,
					O_NONBLOCK ) )
	{
		debug( 1, PIPE_ERROR );
		wperror( L"fcntl" );
		success = false;
	}
    
    if (! success)
    {
        delete buffer_redirect;
        buffer_redirect = NULL;
    }
    
	return buffer_redirect;
}

void io_buffer_destroy( io_data_t *io_buffer )
{

	/**
	   If this is an input buffer, then io_read_buffer will not have
	   been called, and we need to close the output fd as well.
	*/
	if( io_buffer->is_input )
	{
		exec_close(io_buffer->param1.pipe_fd[1] );
	}

	exec_close( io_buffer->param1.pipe_fd[0] );

	/*
	  Dont free fd for writing. This should already be free'd before
	  calling exec_read_io_buffer on the buffer
	*/
	delete io_buffer;
}

void io_chain_t::remove(const io_data_t *element)
{
    // See if you can guess why std::find doesn't work here
    for (io_chain_t::iterator iter = this->begin(); iter != this->end(); ++iter)
    {
        if (*iter == element)
        {
            this->erase(iter);
            break;
        }
    }
}

io_chain_t io_chain_t::duplicate() const
{
    io_chain_t result;
    result.reserve(this->size());
    for (io_chain_t::const_iterator iter = this->begin(); iter != this->end(); iter++)
    {
        const io_data_t *io = *iter;
        result.push_back(new io_data_t(*io));
    }
    return result;
}

void io_chain_t::duplicate_prepend(const io_chain_t &src)
{
    /* Prepend a duplicate of src before this. Start by inserting a bunch of NULLs (so we only have to reallocate once) and then replace them. */
    this->insert(this->begin(), src.size(), NULL);
    for (size_t idx = 0; idx < src.size(); idx++)
    {
        const io_data_t *src_data = src.at(idx);
        this->at(idx) = new io_data_t(*src_data);
    }
}

void io_chain_t::destroy()
{
    for (size_t idx = 0; idx < this->size(); idx++)
    {
        delete this->at(idx);
    }
    this->clear();
}

void io_remove(io_chain_t &list, const io_data_t *element)
{
    list.remove(element);
}

io_chain_t io_duplicate(const io_chain_t &chain)
{
    return chain.duplicate();
}

void io_print(const io_chain_t &chain)
{
    if (chain.empty())
    {
        fprintf(stderr, "Empty chain %p\n", &chain);
        return;
    }
    
    fprintf(stderr, "Chain %p (%ld items):\n", &chain, (long)chain.size());
    for (size_t i=0; i < chain.size(); i++) {
        const io_data_t *io = chain.at(i);
        fprintf(stderr, "\t%lu: fd:%d, input:%s, ", (unsigned long)i, io->fd, io->is_input ? "yes" : "no");
        switch (io->io_mode)
        {
            case IO_FILE:
                fprintf(stderr, "file (%s)\n", io->filename_cstr);
                break;
            case IO_PIPE:
                fprintf(stderr, "pipe {%d, %d}\n", io->param1.pipe_fd[0], io->param1.pipe_fd[1]);
                break;
            case IO_FD:
                fprintf(stderr, "FD map %d -> %d\n", io->param1.old_fd, io->fd);
                break;
            case IO_BUFFER:
                fprintf(stderr, "buffer %p (size %lu)\n", io->out_buffer_ptr(), io->out_buffer_size());
                break;
            case IO_CLOSE:
                fprintf(stderr, "close %d\n", io->fd);
                break;
        }
    }
}

void io_duplicate_prepend( const io_chain_t &src, io_chain_t &dst )
{
    return dst.duplicate_prepend(src);
}

void io_chain_destroy(io_chain_t &chain) 
{
    chain.destroy();
}

/* Return the last IO for the given fd */
const io_data_t *io_chain_t::get_io_for_fd(int fd) const
{
    size_t idx = this->size();
    while (idx--)
    {
        const io_data_t *data = this->at(idx);
        if (data->fd == fd) {
            return data;
        }
    }
    return NULL;
}

io_data_t *io_chain_t::get_io_for_fd(int fd)
{
    size_t idx = this->size();
    while (idx--)
    {
        io_data_t *data = this->at(idx);
        if (data->fd == fd) {
            return data;
        }
    }
    return NULL;
}

/* The old function returned the last match, so we mimic that. */
const io_data_t *io_chain_get(const io_chain_t &src, int fd)
{
    return src.get_io_for_fd(fd);
}

io_data_t *io_chain_get(io_chain_t &src, int fd)
{
    return src.get_io_for_fd(fd);
}

io_chain_t::io_chain_t(io_data_t *data) : std::vector<io_data_t *>(1, data)
{

}

io_chain_t::io_chain_t() : std::vector<io_data_t *>()
{
}