lwatch.h

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#ifndef LWATCH_H
#define LWATCH_H

/*****************************************************************************/
/******************************** Documentation ******************************/
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/**
 * \file
 * Public interface for watching log files.
 */

/*****************************************************************************/
/******************************* Include Files *******************************/
/*****************************************************************************/

#include <sys/param.h>

#include "watch_database.h"

/*****************************************************************************/
/*********************************** Defines *********************************/
/*****************************************************************************/

/**
 * Base error code (minimum value) for log watch errors
 */
#define LWATCH_ERROR_BASE -4000
/**
 * Maximum error code for log watch errors
 */
#define LWATCH_ERROR_LIMIT (LWATCH_ERROR_BASE + 50)
/**
 * Return true if error code is within the range for log watch errors.
 *
 * \param[in] error The error code to test if it's a log watch error code.
 * \return    True if error code is a log watch error.
 */
#define IS_LWATCH_ERROR(error)  (((error) >= LWATCH_ERROR_BASE) && ((error) < LWATCH_ERROR_LIMIT))

#define LWATCH_ERROR_CANNOT_MONITOR        (LWATCH_ERROR_BASE + 1) /**< cannot monitor target */
#define LWATCH_ERROR_CANNOT_FIND_PATH_INFO (LWATCH_ERROR_BASE + 2) /**< cannot find path info */
#define LWATCH_ERROR_LOST_RENAME           (LWATCH_ERROR_BASE + 3) /**< one of the paths for a rename event is unknown */
#define LWATCH_ERROR_STAT_NOT_VALID        (LWATCH_ERROR_BASE + 4) /**< stat information is not valid */

/*****************************************************************************/
/******************************* Type Definitions ****************************/
/*****************************************************************************/

/**
 * The set of log watch event types.
 */
typedef enum {
    LWATCH_EVENT_CREATE,        /**< a file or directory was created */
    LWATCH_EVENT_DELETE,        /**< a file or directory was deleted */
    LWATCH_EVENT_RENAME,        /**< a file or directory was renamed */
    LWATCH_EVENT_MODIFY,        /**< a file or directory was modified */
    LWATCH_EVENT_OPEN,          /**< a file or directory was opened */
    LWATCH_EVENT_CLOSE          /**< a file or directory was closed */
} lwatch_event_type;

/**
 * Watch event. Changes to the filesystem are abstracted into events of this
 * type and sent to interested listeners. This decouples the subsystem used to
 * watch for filesystem changes from the code used to interpret the filesystem
 * change. See \ref WatchEventDoc.
 */
struct lwatch_event_t {
    lwatch_event_type event_type;     /**< the type of the event */
    union {
        char path[PATH_MAX];          /**< for anything other than a rename, this is
                                           the pathname associated with the event */
        struct {
            char prev_path[PATH_MAX]; /**< previous pathname for a rename, may be empty */
            char new_path[PATH_MAX];  /**< new pathname for a rename, may be empty */
        } rename;                     /**< if the event was a rename, these are the
                                           pair of pathnames, one of the two may be empty
                                           if we don't know what it was renamed from or to */
    };
};

/**
 * This callback is used when a watch event occurs. Parties interested in
 * receiving watch events register a callback of this type. When a watch event
 * occurs their callback is invoked passing the watch event to it.
 */
typedef int (*lwatch_event_callback_t)(struct lwatch_event_t *event);

/*****************************************************************************/
/*************************  External Global Variables  ***********************/
/*****************************************************************************/

/*****************************************************************************/
/****************************  Exported Functions  ***************************/
/*****************************************************************************/

int destroy_path_info(struct lwatch_path_info_t **ppath_info);
int update_stat_info(struct stat *cur_stat_info, struct lwatch_path_info_t *path_info);
bool is_log_backup(const char *path);

#endif

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