transmission/libtransmission/watchdir.c

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/*
* This file Copyright (C) 2015-2016 Mnemosyne LLC
*
* It may be used under the GNU GPL versions 2 or 3
* or any future license endorsed by Mnemosyne LLC.
*
*/
#include <assert.h>
#include <string.h> /* strcmp () */
#include <event2/event.h>
#include <event2/util.h>
#define __LIBTRANSMISSION_WATCHDIR_MODULE__
#include "transmission.h"
#include "error.h"
#include "error-types.h"
#include "file.h"
#include "log.h"
#include "ptrarray.h"
#include "utils.h"
#include "watchdir.h"
#include "watchdir-common.h"
/***
****
***/
#define log_debug(...) (!tr_logLevelIsActive (TR_LOG_DEBUG) ? (void) 0 : \
tr_logAddMessage (__FILE__, __LINE__, TR_LOG_DEBUG, "watchdir", __VA_ARGS__))
#define log_error(...) (!tr_logLevelIsActive (TR_LOG_ERROR) ? (void) 0 : \
tr_logAddMessage (__FILE__, __LINE__, TR_LOG_ERROR, "watchdir", __VA_ARGS__))
/***
****
***/
struct tr_watchdir
{
char * path;
tr_watchdir_cb callback;
void * callback_user_data;
struct event_base * event_base;
tr_watchdir_backend * backend;
tr_ptrArray active_retries;
};
/***
****
***/
static bool
is_regular_file (const char * dir,
const char * name)
{
char * const path = tr_buildPath (dir, name, NULL);
tr_sys_path_info path_info;
tr_error * error = NULL;
bool ret;
if ((ret = tr_sys_path_get_info (path, 0, &path_info, &error)))
{
ret = path_info.type == TR_SYS_PATH_IS_FILE;
}
else
{
if (!TR_ERROR_IS_ENOENT (error->code))
log_error ("Failed to get type of \"%s\" (%d): %s", path, error->code,
error->message);
tr_error_free (error);
}
tr_free (path);
return ret;
}
static const char *
watchdir_status_to_string (tr_watchdir_status status)
{
switch (status)
{
case TR_WATCHDIR_ACCEPT:
return "accept";
case TR_WATCHDIR_IGNORE:
return "ignore";
case TR_WATCHDIR_RETRY:
return "retry";
default:
return "???";
}
}
static tr_watchdir_status
tr_watchdir_process_impl (tr_watchdir_t handle,
const char * name)
{
/* File may be gone while we're retrying */
if (!is_regular_file (tr_watchdir_get_path (handle), name))
return TR_WATCHDIR_IGNORE;
const tr_watchdir_status ret = handle->callback (handle, name, handle->callback_user_data);
assert (ret == TR_WATCHDIR_ACCEPT ||
ret == TR_WATCHDIR_IGNORE ||
ret == TR_WATCHDIR_RETRY);
log_debug ("Callback decided to %s file \"%s\"", watchdir_status_to_string (ret), name);
return ret;
}
/***
****
***/
typedef struct tr_watchdir_retry
{
tr_watchdir_t handle;
char * name;
unsigned int counter;
struct event * timer;
struct timeval interval;
}
tr_watchdir_retry;
/* Non-static and mutable for unit tests */
unsigned int tr_watchdir_retry_limit = 3;
struct timeval tr_watchdir_retry_start_interval = { 1, 0 };
struct timeval tr_watchdir_retry_max_interval = { 10, 0 };
#define tr_watchdir_retries_init(r) (void) 0
#define tr_watchdir_retries_destroy(r) tr_ptrArrayDestruct ((r), (PtrArrayForeachFunc) &tr_watchdir_retry_free)
#define tr_watchdir_retries_insert(r, v) tr_ptrArrayInsertSorted ((r), (v), &compare_retry_names)
#define tr_watchdir_retries_remove(r, v) tr_ptrArrayRemoveSortedPointer ((r), (v), &compare_retry_names)
#define tr_watchdir_retries_find(r, v) tr_ptrArrayFindSorted ((r), (v), &compare_retry_names)
static int
compare_retry_names (const void * a,
const void * b)
{
return strcmp (((tr_watchdir_retry *) a)->name, ((tr_watchdir_retry *) b)->name);
}
static void
tr_watchdir_retry_free (tr_watchdir_retry * retry);
static void
tr_watchdir_on_retry_timer (evutil_socket_t fd UNUSED,
short type UNUSED,
void * context)
{
assert (context != NULL);
tr_watchdir_retry * const retry = context;
const tr_watchdir_t handle = retry->handle;
if (tr_watchdir_process_impl (handle, retry->name) == TR_WATCHDIR_RETRY)
{
if (++retry->counter < tr_watchdir_retry_limit)
{
evutil_timeradd (&retry->interval, &retry->interval, &retry->interval);
if (evutil_timercmp (&retry->interval, &tr_watchdir_retry_max_interval, >))
retry->interval = tr_watchdir_retry_max_interval;
evtimer_del (retry->timer);
evtimer_add (retry->timer, &retry->interval);
return;
}
log_error ("Failed to add (corrupted?) torrent file: %s", retry->name);
}
tr_watchdir_retries_remove (&handle->active_retries, retry);
tr_watchdir_retry_free (retry);
}
static tr_watchdir_retry *
tr_watchdir_retry_new (tr_watchdir_t handle,
const char * name)
{
tr_watchdir_retry * retry;
retry = tr_new0 (tr_watchdir_retry, 1);
retry->handle = handle;
retry->name = tr_strdup (name);
retry->timer = evtimer_new (handle->event_base, &tr_watchdir_on_retry_timer, retry);
retry->interval = tr_watchdir_retry_start_interval;
evtimer_add (retry->timer, &retry->interval);
return retry;
}
static void
tr_watchdir_retry_free (tr_watchdir_retry * retry)
{
if (retry == NULL)
return;
if (retry->timer != NULL)
{
evtimer_del (retry->timer);
event_free (retry->timer);
}
tr_free (retry->name);
tr_free (retry);
}
static void
tr_watchdir_retry_restart (tr_watchdir_retry * retry)
{
assert (retry != NULL);
evtimer_del (retry->timer);
retry->counter = 0;
retry->interval = tr_watchdir_retry_start_interval;
evtimer_add (retry->timer, &retry->interval);
}
/***
****
***/
tr_watchdir_t
tr_watchdir_new (const char * path,
tr_watchdir_cb callback,
void * callback_user_data,
struct event_base * event_base,
bool force_generic)
{
tr_watchdir_t handle;
handle = tr_new0 (struct tr_watchdir, 1);
handle->path = tr_strdup (path);
handle->callback = callback;
handle->callback_user_data = callback_user_data;
handle->event_base = event_base;
tr_watchdir_retries_init (&handle->active_retries);
if (!force_generic)
{
#ifdef WITH_INOTIFY
if (handle->backend == NULL)
handle->backend = tr_watchdir_inotify_new (handle);
#endif
#ifdef WITH_KQUEUE
if (handle->backend == NULL)
handle->backend = tr_watchdir_kqueue_new (handle);
#endif
#ifdef _WIN32
if (handle->backend == NULL)
handle->backend = tr_watchdir_win32_new (handle);
#endif
}
if (handle->backend == NULL)
handle->backend = tr_watchdir_generic_new (handle);
if (handle->backend == NULL)
{
tr_watchdir_free (handle);
handle = NULL;
}
else
{
assert (handle->backend->free_func != NULL);
}
return handle;
}
void
tr_watchdir_free (tr_watchdir_t handle)
{
if (handle == NULL)
return;
tr_watchdir_retries_destroy (&handle->active_retries);
if (handle->backend != NULL)
handle->backend->free_func (handle->backend);
tr_free (handle->path);
tr_free (handle);
}
const char *
tr_watchdir_get_path (tr_watchdir_t handle)
{
assert (handle != NULL);
return handle->path;
}
tr_watchdir_backend *
tr_watchdir_get_backend (tr_watchdir_t handle)
{
assert (handle != NULL);
return handle->backend;
}
struct event_base *
tr_watchdir_get_event_base (tr_watchdir_t handle)
{
assert (handle != NULL);
return handle->event_base;
}
/***
****
***/
void
tr_watchdir_process (tr_watchdir_t handle,
const char * name)
{
const tr_watchdir_retry search_key = { .name = (char *) name };
tr_watchdir_retry * existing_retry;
assert (handle != NULL);
if ((existing_retry = tr_watchdir_retries_find (&handle->active_retries, &search_key)) != NULL)
{
tr_watchdir_retry_restart (existing_retry);
return;
}
if (tr_watchdir_process_impl (handle, name) == TR_WATCHDIR_RETRY)
{
tr_watchdir_retry * retry = tr_watchdir_retry_new (handle, name);
tr_watchdir_retries_insert (&handle->active_retries, retry);
}
}
void
tr_watchdir_scan (tr_watchdir_t handle,
tr_ptrArray * dir_entries)
{
tr_sys_dir_t dir;
const char * name;
tr_ptrArray new_dir_entries = TR_PTR_ARRAY_INIT_STATIC;
const PtrArrayCompareFunc name_compare_func = (PtrArrayCompareFunc) &strcmp;
tr_error * error = NULL;
if ((dir = tr_sys_dir_open (handle->path, &error)) == TR_BAD_SYS_DIR)
{
log_error ("Failed to open directory \"%s\" (%d): %s", handle->path,
error->code, error->message);
tr_error_free (error);
return;
}
while ((name = tr_sys_dir_read_name (dir, &error)) != NULL)
{
if (strcmp (name, ".") == 0 || strcmp (name, "..") == 0)
continue;
if (dir_entries != NULL)
{
tr_ptrArrayInsertSorted (&new_dir_entries, tr_strdup (name), name_compare_func);
if (tr_ptrArrayFindSorted (dir_entries, name, name_compare_func) != NULL)
continue;
}
tr_watchdir_process (handle, name);
}
if (error != NULL)
{
log_error ("Failed to read directory \"%s\" (%d): %s", handle->path,
error->code, error->message);
tr_error_free (error);
}
tr_sys_dir_close (dir, NULL);
if (dir_entries != NULL)
{
tr_ptrArrayDestruct (dir_entries, &tr_free);
*dir_entries = new_dir_entries;
}
}