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/*
* Copyright (C) 2013-2017 Tobias Brunner
* Copyright (C) 2007 Martin Willi
* HSR Hochschule fuer Technik Rapperswil
*
* 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 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* 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.
*/
/**
* @defgroup enumerator enumerator
* @{ @ingroup collections
*/
#ifndef ENUMERATOR_H_
#define ENUMERATOR_H_
typedef struct enumerator_t enumerator_t;
#include <utils/utils.h>
/**
* Enumerator interface, allows enumeration over collections.
*/
struct enumerator_t {
/**
* Enumerate collection.
*
* The enumerate() method takes a variable number of pointer arguments
* where the enumerated values get written to.
*
* @note Just assigning the generic enumerator_enumerate_default() function
* that calls the enumerator's venumerate() method is usually enough.
*
* @param ... variable list of enumerated items, implementation dependent
* @return TRUE if pointers returned
*/
bool (*enumerate)(enumerator_t *this, ...);
/**
* Enumerate collection.
*
* The venumerate() method takes a variable argument list containing
* pointers where the enumerated values get written to.
*
* To simplify the implementation the VA_ARGS_VGET() macro may be used.
*
* @param args variable list of enumerated items, implementation dependent
* @return TRUE if pointers returned
*/
bool (*venumerate)(enumerator_t *this, va_list args);
/**
* Destroy an enumerator_t instance.
*/
void (*destroy)(enumerator_t *this);
};
/**
* Generic implementation of enumerator_t::enumerate() that simply calls
* the enumerator's venumerate() method.
*
* @param enumerator the enumerator
* @param ... arguments passed to enumerate()
*/
bool enumerator_enumerate_default(enumerator_t *enumerator, ...);
/**
* Create an enumerator which enumerates over nothing
*
* @return an enumerator over no values
*/
enumerator_t* enumerator_create_empty();
/**
* Create an enumerator which enumerates over a single item
*
* @param item item to enumerate
* @param cleanup cleanup function called on destroy with the item
* @return an enumerator over a single value
*/
enumerator_t *enumerator_create_single(void *item, void (*cleanup)(void *item));
/**
* Create an enumerator over files/subdirectories in a directory.
*
* This enumerator_t.enumerate() function returns a (to the directory) relative
* filename (as a char*), an absolute filename (as a char*) and a file status
* (to a struct stat), which all may be NULL. "." and ".." entries are
* skipped.
*
* Example:
*
* @code
char *rel, *abs;
struct stat st;
enumerator_t *e;
e = enumerator_create_directory("/tmp");
if (e)
{
while (e->enumerate(e, &rel, &abs, &st))
{
if (S_ISDIR(st.st_mode) && *rel != '.')
{
printf("%s\n", abs);
}
}
e->destroy(e);
}
@endcode
*
* @param path path of the directory
* @return the directory enumerator, NULL on failure
*/
enumerator_t* enumerator_create_directory(const char *path);
/**
* Create an enumerator over files/directories matching a file pattern.
*
* This enumerator_t.enumerate() function returns the filename (as a char*),
* and a file status (to a struct stat), which both may be NULL.
*
* Example:
*
* @code
char *file;
struct stat st;
enumerator_t *e;
e = enumerator_create_glob("/etc/ipsec.*.conf");
if (e)
{
while (e->enumerate(e, &file, &st))
{
if (S_ISREG(st.st_mode))
{
printf("%s\n", file);
}
}
e->destroy(e);
}
@endcode
*
* @param pattern file pattern to match
* @return the enumerator, NULL if not supported
*/
enumerator_t* enumerator_create_glob(const char *pattern);
/**
* Create an enumerator over tokens of a string.
*
* Tokens are separated by one of the characters in sep and trimmed by the
* characters in trim.
*
* @param string string to parse
* @param sep separator characters
* @param trim characters to trim from tokens
* @return enumerator over char* tokens
*/
enumerator_t* enumerator_create_token(const char *string, const char *sep,
const char *trim);
/**
* Creates an enumerator which enumerates over enumerated enumerators :-).
*
* The outer enumerator is expected to return objects that, when passed to
* inner_contructor, will create a new enumerator that will be enumerated until
* completion (to this enumerator will the pointer arguments that are passed to
* this enumerator be forwarded) at which point a new element from the outer
* enumerator is requested to create a new inner enumerator.
*
* @param outer outer enumerator
* @param inner_constructor constructor to create inner enumerator
* @param data data to pass to each inner_constructor call
* @param destructor destructor function to clean up data after use
* @return the nested enumerator
*/
enumerator_t *enumerator_create_nested(enumerator_t *outer,
enumerator_t *(*inner_constructor)(void *outer, void *data),
void *data, void (*destructor)(void *data));
/**
* Creates an enumerator which filters/maps output of another enumerator.
*
* The filter function receives the user supplied "data" followed by the
* original enumerator, followed by the arguments passed to the outer
* enumerator. It returns TRUE to deliver the values assigned to these
* arguments to the caller of enumerate() and FALSE to end the enumeration.
* Filtering items is simple as the filter function may just skip enumerated
* items from the original enumerator.
*
* @param orig original enumerator to wrap, gets destroyed
* @param filter filter function
* @param data user data to supply to filter
* @param destructor destructor function to clean up data after use
* @return the filtered enumerator
*/
enumerator_t *enumerator_create_filter(enumerator_t *orig,
bool (*filter)(void *data, enumerator_t *orig, va_list args),
void *data, void (*destructor)(void *data));
/**
* Create an enumerator wrapper which does a cleanup on destroy.
*
* @param wrapped wrapped enumerator
* @param cleanup cleanup function called on destroy
* @param data user data to supply to cleanup
* @return the enumerator with cleanup
*/
enumerator_t *enumerator_create_cleaner(enumerator_t *wrapped,
void (*cleanup)(void *data), void *data);
#endif /** ENUMERATOR_H_ @}*/
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