diff options
Diffstat (limited to '')
| -rw-r--r-- | libparted/timer.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/libparted/timer.c b/libparted/timer.c new file mode 100644 index 0000000..b913150 --- /dev/null +++ b/libparted/timer.c @@ -0,0 +1,244 @@ +/* + libparted - a library for manipulating disk partitions + Copyright (C) 2001, 2007, 2009-2014, 2019-2023 Free Software Foundation, + Inc. + + 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 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +/** \file timer.c */ + +/** + * \addtogroup PedTimer + * + * \brief A PedTimer keeps track of the progress of a single (possibly + * compound) operation. + * + * The user of libparted constructs a PedTimer, and passes it to libparted + * functions that are likely to be expensive operations + * (like ped_file_system_resize). Use of timers is optional... you may + * pass NULL instead. + * + * When you create a PedTimer, you must specify a timer handler function. + * This will be called when there's an update on how work is progressing. + * + * Timers may be nested. When a timer is constructed, you can choose + * to assign it a parent, along with an estimate of what proportion of + * the total (parent's) time will be used in the nested operation. In + * this case, the nested timer's handler is internal to libparted, + * and simply updates the parent's progress, and calls its handler. + * + * @{ + */ + + +#include <config.h> +#include <parted/parted.h> +#include <parted/debug.h> + +typedef struct { + PedTimer* parent; + float nest_frac; + float start_frac; +} NestedContext; + + +/** + * \brief Creates a timer. + * + * Context will be passed in the \p context + * argument to the \p handler, when it is invoked. + * + * \return a new PedTimer + */ +PedTimer* +ped_timer_new (PedTimerHandler* handler, void* context) +{ + PedTimer* timer; + + PED_ASSERT (handler != NULL); + + timer = (PedTimer*) ped_malloc (sizeof (PedTimer)); + if (!timer) + return NULL; + + timer->handler = handler; + timer->context = context; + ped_timer_reset (timer); + return timer; +} + + +/** + * \brief Destroys a \p timer. + */ +void +ped_timer_destroy (PedTimer* timer) +{ + if (!timer) + return; + + free (timer); +} + +/* This function is used by ped_timer_new_nested() as the timer->handler + * function. + */ +static void +_nest_handler (PedTimer* timer, void* context) +{ + NestedContext* ncontext = (NestedContext*) context; + + ped_timer_update ( + ncontext->parent, + ncontext->start_frac + ncontext->nest_frac * timer->frac); +} + + +/** + * \brief Creates a new nested timer. + * + * This function creates a "nested" timer that describes the progress + * of a subtask. \p parent is the parent timer, and \p nested_frac is + * the estimated proportion (between 0 and 1) of the time that will be + * spent doing the nested timer's operation. The timer should only be + * constructed immediately prior to starting the nested operation. + * (It will be inaccurate, otherwise). + * Updates to the progress of the subtask are propagated + * back through to the parent task's timer. + * + * \return nested timer + */ +PedTimer* +ped_timer_new_nested (PedTimer* parent, float nest_frac) +{ + NestedContext* context; + + if (!parent) + return NULL; + + PED_ASSERT (nest_frac >= 0.0f); + PED_ASSERT (nest_frac <= 1.0f); + + context = (NestedContext*) ped_malloc (sizeof (NestedContext)); + if (!context) + return NULL; + context->parent = parent; + context->nest_frac = nest_frac; + context->start_frac = parent->frac; + + return ped_timer_new (_nest_handler, context); +} + +/** + * \brief Destroys a nested \p timer. + */ +void +ped_timer_destroy_nested (PedTimer* timer) +{ + if (!timer) + return; + + free (timer->context); + ped_timer_destroy (timer); +} + +/** + * \internal + * + * \brief This function calls the update handler, making sure that it has + * the latest time. + * + * First it updates \p timer->now and recomputes \p timer->predicted_end, + * and then calls the handler. + */ +void +ped_timer_touch (PedTimer* timer) +{ + if (!timer) + return; + + timer->now = time (NULL); + if (timer->now > timer->predicted_end) + timer->predicted_end = timer->now; + + timer->handler (timer, timer->context); +} + +/** + * \internal + * + * \brief This function sets the \p timer into a "start of task" position. + * + * It resets the \p timer, by setting \p timer->start and \p timer->now + * to the current time. + */ +void +ped_timer_reset (PedTimer* timer) +{ + if (!timer) + return; + + timer->start = timer->now = timer->predicted_end = time (NULL); + timer->state_name = NULL; + timer->frac = 0; + + ped_timer_touch (timer); +} + +/** + * \internal + * + * \brief This function tells a \p timer what fraction \p frac of the task + * has been completed. + * + * Sets the new \p timer->frac, and calls ped_timer_touch(). + */ +void +ped_timer_update (PedTimer* timer, float frac) +{ + if (!timer) + return; + + timer->now = time (NULL); + timer->frac = frac; + + if (frac) + timer->predicted_end + = timer->start + + (long) ((timer->now - timer->start) / frac); + + ped_timer_touch (timer); +} + +/** + * \internal + * + * \brief This function changes the description of the current task that the + * \p timer describes. + * + * Sets a new name - \p state_name - for the current "phase" of the operation, + * and calls ped_timer_touch(). + */ +void +ped_timer_set_state_name (PedTimer* timer, const char* state_name) +{ + if (!timer) + return; + + timer->state_name = state_name; + ped_timer_touch (timer); +} + +/** @} */ |