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/*
This file is part of gnunet-fuse.
Copyright (C) 2012 Christian Grothoff (and other contributing authors)
gnunet-fuse 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 3, or (at your
option) any later version.
gnunet-fuse 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
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* @file fuse/gfs_download.h
* @brief download files using FS
* @author Christian Grothoff
*/
#include "gfs_download.h"
/**
* Context for a download operation.
*/
struct Context
{
/**
* Information about the file we are downloading.
*/
struct GNUNET_FUSE_PathInfo *path_info;
/**
* Download handle.
*/
struct GNUNET_FS_DownloadContext *dc;
/**
* FS handle.
*/
struct GNUNET_FS_Handle *fs;
/**
* Start offset.
*/
off_t start_offset;
/**
* Number of bytes to download.
*/
uint64_t length;
/**
* Return value for the operation, 0 on success.
*/
int ret;
};
/**
* Task run when we shut down.
*
* @param cls our 'struct Context'
* @param tc scheduler context (unused)
*/
static void
shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
struct Context *ctx = cls;
if (NULL != ctx->dc)
{
GNUNET_FS_download_stop (ctx->dc, GNUNET_YES);
ctx->dc = NULL;
}
if (NULL != ctx->fs)
{
GNUNET_FS_stop (ctx->fs);
ctx->fs = NULL;
}
}
/**
* Function called from FS with progress information.
*
* @param cls our 'struct Context'
* @param info progress information
* @return NULL
*/
static void *
progress_cb (void *cls, const struct GNUNET_FS_ProgressInfo *info)
{
struct Context *ctx = cls;
char *s;
switch (info->status)
{
case GNUNET_FS_STATUS_DOWNLOAD_START:
GNUNET_break (info->value.download.dc == ctx->dc);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Started download `%s'.\n",
info->value.download.filename);
break;
case GNUNET_FS_STATUS_DOWNLOAD_PROGRESS:
GNUNET_break (info->value.download.dc == ctx->dc);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Downloading `%s' at %llu/%llu\n",
info->value.download.filename,
(unsigned long long) info->value.download.completed,
(unsigned long long) info->value.download.size);
break;
case GNUNET_FS_STATUS_DOWNLOAD_ERROR:
GNUNET_break (info->value.download.dc == ctx->dc);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Error downloading: %s.\n",
info->value.download.specifics.error.message);
GNUNET_SCHEDULER_shutdown ();
break;
case GNUNET_FS_STATUS_DOWNLOAD_COMPLETED:
GNUNET_break (info->value.download.dc == ctx->dc);
s =
GNUNET_STRINGS_byte_size_fancy (info->value.download.completed *
1000000LL /
(info->value.download.
duration.rel_value_us + 1));
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Downloading `%s' done (%s/s).\n",
info->value.download.filename, s);
GNUNET_free (s);
ctx->ret = 0;
GNUNET_SCHEDULER_shutdown ();
break;
case GNUNET_FS_STATUS_DOWNLOAD_STOPPED:
GNUNET_SCHEDULER_shutdown ();
break;
case GNUNET_FS_STATUS_DOWNLOAD_ACTIVE:
case GNUNET_FS_STATUS_DOWNLOAD_INACTIVE:
break;
default:
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("Unexpected status: %d\n"), info->status);
break;
}
return NULL;
}
/**
* Main task run by the helper process which downloads the file.
*
* @param cls 'struct Context' with information about the download
* @param tc scheduler context
*/
static void
download_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
struct Context *ctx = cls;
ctx->fs = GNUNET_FS_start (cfg, "gnunet-fuse", &progress_cb, ctx,
GNUNET_FS_FLAGS_NONE,
GNUNET_FS_OPTIONS_DOWNLOAD_PARALLELISM, 1,
GNUNET_FS_OPTIONS_REQUEST_PARALLELISM, 1,
GNUNET_FS_OPTIONS_END);
if (NULL == ctx->fs)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR, _("Could not initialize `%s' subsystem.\n"), "FS");
return;
}
ctx->dc = GNUNET_FS_download_start (ctx->fs,
ctx->path_info->uri, ctx->path_info->meta,
ctx->path_info->tmpfile, NULL,
(uint64_t) ctx->start_offset,
ctx->length,
anonymity_level,
GNUNET_FS_DOWNLOAD_OPTION_NONE,
NULL, NULL);
if (NULL == ctx->dc)
{
GNUNET_FS_stop (ctx->fs);
ctx->fs = NULL;
return;
}
GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
&shutdown_task, ctx);
}
/**
* Download a file. Blocks until we're done.
*
* @param path_info information about the file to download
* @param start_offset offset of the first byte to download
* @param length number of bytes to download from 'start_offset'
* @return GNUNET_OK on success
*/
int
GNUNET_FUSE_download_file (struct GNUNET_FUSE_PathInfo *path_info,
off_t start_offset,
uint64_t length)
{
struct Context ctx;
pid_t pid;
int status;
int ret;
/* lock to prevent two processes from downloading / manipulating the
same file at the same time */
GNUNET_mutex_lock (path_info->lock);
pid = fork ();
if (-1 == pid)
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "fork");
GNUNET_mutex_unlock (path_info->lock);
return GNUNET_SYSERR;
}
if (0 != pid)
{
while ( (-1 == (ret = waitpid (pid, &status, 0))) &&
(EINTR == errno) ) ;
if (pid != ret)
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "waitpid");
(void) kill (pid, SIGKILL);
(void) waitpid (pid, &status, 0);
GNUNET_mutex_unlock (path_info->lock);
return GNUNET_SYSERR;
}
GNUNET_mutex_unlock (path_info->lock);
if ( (WIFEXITED (status)) &&
(0 == WEXITSTATUS (status)) )
return GNUNET_OK;
return GNUNET_SYSERR;
}
memset (&ctx, 0, sizeof (ctx));
ctx.ret = 1;
ctx.path_info = path_info;
ctx.start_offset = start_offset;
ctx.length = length;
GNUNET_SCHEDULER_run (&download_task, &ctx);
_exit (ctx.ret);
}
/* end of gfs_download.c */
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