74 lines
2.2 KiB
C
74 lines
2.2 KiB
C
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#ifndef LIBNAGIOS_FANOUT_H_INCLUDED
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#define LIBNAGIOS_FANOUT_H_INCLUDED
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#include "lnag-utils.h"
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/**
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* @file fanout.h
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* @brief Simple fanout table implementation
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*
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* Fanouts are useful to hold short-lived integer-indexed data where
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* the keyspan between smallest and largest key can be too large and
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* change too often for it to be practical to maintain a growing array.
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* If you think of it as a hash-table optimized for unsigned longs you've
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* got the right idea.
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*
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* @{
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*/
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NAGIOS_BEGIN_DECL
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/** Primary (opaque) type for this api */
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typedef struct fanout_table fanout_table;
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/**
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* Create a fanout table
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* @param[in] size The size of the table. Preferably a power of 2
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* @return Pointer to a newly created table
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*/
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extern fanout_table *fanout_create(unsigned long size);
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/**
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* Destroy a fanout table, with optional destructor.
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* This function will iterate over all the entries in the fanout
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* table and remove them, one by one. If 'destructor' is not NULL,
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* it will be called on each and every object in the table. Note that
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* 'free' is a valid destructor.
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*
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* @param[in] t The fanout table to destroy
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* @param[in] destructor Function to call on data pointers in table
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*/
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extern void fanout_destroy(fanout_table *t, void (*destructor)(void *));
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/**
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* Return a pointer from the fanout table t
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*
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* @param[in] t table to fetch from
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* @param[in] key key to fetch
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* @return NULL on errors; Pointer to data on success
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*/
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extern void *fanout_get(fanout_table *t, unsigned long key);
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/**
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* Add an entry to the fanout table.
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* Note that we don't check if the key is unique. If it isn't,
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* fanout_remove() will remove the latest added first.
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*
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* @param[in] t fanout table to add to
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* @param[in] key Key for this entry
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* @param[in] data Data to add. Must not be NULL
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* @return 0 on success, -1 on errors
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*/
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extern int fanout_add(fanout_table *t, unsigned long key, void *data);
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/**
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* Remove an entry from the fanout table and return its data.
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*
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* @param[in] t fanout table to look in
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* @param[in] key The key whose data we should locate
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* @return Pointer to the data stored on success; NULL on errors
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*/
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extern void *fanout_remove(fanout_table *t, unsigned long key);
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NAGIOS_END_DECL
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/** @} */
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#endif
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