Symbol table package. More...

Macros
#define	ST_OUT_OF_MEM -10000
	Value returned if memory is exhausted.

#define	ST_DEFAULT_MAX_DENSITY 5
	Default value for the maximum table density. More...

#define	ST_DEFAULT_INIT_TABLE_SIZE 11
	Default value for the initial table size. More...

#define	ST_DEFAULT_GROW_FACTOR 2.0
	Default table growth factor. More...

#define	ST_DEFAULT_REORDER_FLAG 0
	Default table reorder flag. More...

#define	st_is_member(table, key) st_lookup(table,key,(void **) 0)
	Checks whethere `key` is in `table`. More...

#define	st_foreach_item(table, gen, key, value) for(gen=st_init_gen(table); st_gen(gen,key,value) \|\| (st_free_gen(gen),0);)
	Iteration macro. More...

#define	st_foreach_item_int(table, gen, key, value) for(gen=st_init_gen(table); st_gen_int(gen,key,value) \|\| (st_free_gen(gen),0);)
	Iteration macro. More...

Typedefs
typedef struct st_table	st_table
	Type of symbol tables.

typedef struct st_generator	st_generator
	Type of symbol table generators.

typedef enum st_retval(*	st_foreach_t) (void , void , void *)
	Type for function passed to st_foreach.

typedef int(*	st_compare_t) (void const , void const )
	Type of comparison functions.

typedef int(*	st_hash_t) (void const *, int)
	Type of hash functions.

typedef int(*	st_compare_arg_t) (void const , void const , void const *)
	Type of comparison functions with extra argument.

typedef int(*	st_hash_arg_t) (void const , int, void const )
	Type of hash functions with extra argument.

Enumerations
enum	st_retval { ST_CONTINUE, ST_STOP, ST_DELETE }
	Type of return values for iterators.

Functions
st_table *	st_init_table_with_params (st_compare_t, st_hash_t, int, int, double, int)
	Create a table with given parameters. More...

st_table *	st_init_table (st_compare_t, st_hash_t)
	Creates and initializes a table. More...

st_table *	st_init_table_with_params_and_arg (st_compare_arg_t, st_hash_arg_t, void const *, int, int, double, int)
	Creates and initializes a table. More...

st_table *	st_init_table_with_arg (st_compare_arg_t, st_hash_arg_t, void const *)
	Creates and initializes a table. More...

void	st_free_table (st_table *)
	Free a table. More...

int	st_lookup (st_table , void const , void **)
	Lookup up `key` in `table`. More...

int	st_lookup_int (st_table , void const , int *)
	Lookup up `key` in `table`. More...

int	st_insert (st_table , void , void *)
	Insert value in `table` under the key `key`. More...

int	st_add_direct (st_table , void , void *)
	Place 'value' in 'table' under the key 'key'. More...

int	st_find_or_add (st_table , void , void ***)
	Lookup `key` in `table`; if not found, create an entry. More...

int	st_find (st_table , void const , void ***)
	Lookup `key` in `table`. More...

st_table *	st_copy (st_table const *)
	Returns a copy of old_table and all its members. More...

int	st_delete (st_table , void , void *)
	Deletes the entry with the key pointed to by `keyp`. More...

int	st_delete_int (st_table , void , int )
	Deletes the entry with the key pointed to by `keyp`. More...

int	st_count (st_table const *)
	Returns the number of entries in the table `table`. More...

int	st_foreach (st_table , st_foreach_t, void )
	Iterates over the elements of a table. More...

int	st_strhash (void const *, int)
	String hash function. More...

int	st_numhash (void const *, int)
	Integral number hash function. More...

int	st_ptrhash (void const *, int)
	Pointer hash function. More...

int	st_numcmp (void const , void const )
	Integral number comparison function. More...

int	st_ptrcmp (void const , void const )
	Pointer comparison function. More...

st_generator *	st_init_gen (st_table const *)
	Initializes a generator. More...

int	st_gen (st_generator , void , void *)
	Returns the next (key, value) pair in the generation sequence. More...

int	st_gen_int (st_generator , void , int )
	Returns the next (key, value) pair in the generation sequence. More...

void	st_free_gen (st_generator *)
	Reclaims the resources associated with `gen`. More...

Detailed Description

Symbol table package.

The st library provides functions to create, maintain, and query symbol tables.

Copyright

Permission is hereby granted, without written agreement and without license or royalty fees, to use, copy, modify, and distribute this software and its documentation for any purpose, provided that the above copyright notice and the following two paragraphs appear in all copies of this software.

IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

Copyright

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

Neither the name of the University of Colorado nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Macro Definition Documentation

◆ ST_DEFAULT_GROW_FACTOR

#define ST_DEFAULT_GROW_FACTOR 2.0

Default table growth factor.

See also: st_init_table_with_params

◆ ST_DEFAULT_INIT_TABLE_SIZE

#define ST_DEFAULT_INIT_TABLE_SIZE 11

Default value for the initial table size.

See also: st_init_table_with_params

◆ ST_DEFAULT_MAX_DENSITY

#define ST_DEFAULT_MAX_DENSITY 5

Default value for the maximum table density.

See also: st_init_table_with_params

◆ ST_DEFAULT_REORDER_FLAG

#define ST_DEFAULT_REORDER_FLAG 0

Default table reorder flag.

See also: st_init_table_with_params

◆ st_foreach_item

#define st_foreach_item	(	table,
		gen,
		key,
		value
	)	for(gen=st_init_gen(table); st_gen(gen,key,value) \|\| (st_free_gen(gen),0);)

Iteration macro.

An iteration macro which loops over all the entries in table, setting key to point to the key and value to the associated value (if it is not nil). gen is a generator variable used internally. Sample usage:

void *key, *value;
st_generator *gen;

st_foreach_item(table, gen, &key, &value) {
    process_item(value);
}

Side effects None

See also: st_foreach_item_int st_foreach

◆ st_foreach_item_int

#define st_foreach_item_int	(	table,
		gen,
		key,
		value
	)	for(gen=st_init_gen(table); st_gen_int(gen,key,value) \|\| (st_free_gen(gen),0);)

Iteration macro.

An iteration macro which loops over all the entries in table, setting key to point to the key and value to the associated value (if it is not nil). value is assumed to be a pointer to an integer. gen is a generator variable used internally. Sample usage:

void *key;
int value;
st_generator *gen;

st_foreach_item_int(table, gen, &key, &value) {
    process_item(value);
}

Side effects None

See also: st_foreach_item st_foreach

◆ st_is_member

#define st_is_member	(	table,
		key
	)	st_lookup(table,key,(void **) 0)

Checks whethere key is in table.

Returns 1 if there is an entry under key in table, 0 otherwise.

Side effects None

See also: st_lookup

Function Documentation

◆ st_add_direct()

int st_add_direct	(	st_table *	table,
		void *	key,
		void *	value
	)

Place 'value' in 'table' under the key 'key'.

This is done without checking if 'key' is in 'table' already. This should only be used if you are sure there is not already an entry for 'key', since it is undefined which entry you would later get from st_lookup or st_find_or_add.

Returns: 1 if successful; ST_OUT_OF_MEM otherwise.

Side effects None

See also: st_lookup st_find_or_add

◆ st_copy()

st_table* st_copy ( st_table const * old_table )

Returns a copy of old_table and all its members.

(st_table *) 0 is returned if there was insufficient memory to do the copy.

Side effects None

◆ st_count()

int st_count ( st_table const * table )

Returns the number of entries in the table table.

Side effects None

◆ st_delete()

int st_delete	(	st_table *	table,
		void **	keyp,
		void **	value
	)

Deletes the entry with the key pointed to by keyp.

If the entry is found, 1 is returned, the variable pointed by keyp is set to the actual key and the variable pointed by value is set to the corresponding entry. (This allows the freeing of the associated storage.) If the entry is not found, then 0 is returned and nothing is changed.

Side effects The locations pointed by keyp and value are modified.

See also: st_delete_int

◆ st_delete_int()

int st_delete_int	(	st_table *	table,
		void **	keyp,
		int *	value
	)

Deletes the entry with the key pointed to by keyp.

value must be a pointer to an integer. If the entry is found, 1 is returned, the variable pointed by keyp is set to the actual key and the variable pointed by value is set to the corresponding entry. (This allows the freeing of the associated storage.) If the entry is not found, then 0 is returned and nothing is changed.

Side effects The locations pointed by keyp and value are modified.

See also: st_delete

◆ st_find()

int st_find	(	st_table *	table,
		void const *	key,
		void ***	slot
	)

Lookup key in table.

Like st_find_or_add, but does not create an entry if one is not found.

Side effects The location pointed by slot is modified.

See also: st_find_or_add

◆ st_find_or_add()

int st_find_or_add	(	st_table *	table,
		void *	key,
		void ***	slot
	)

Lookup key in table; if not found, create an entry.

In either case set slot to point to the field in the entry where the value is stored. The value associated with key may then be changed by accessing directly through slot. As an example:

void **slot;
void *key;
void *value = item_ptr // ptr to a malloc'd structure

if (st_find_or_add(table, key, &slot) == 1) {
    FREE(*slot); // free the old value of the record
}
 slot = value;  // attach the new value to the record

This replaces the equivelent code:

if (st_lookup(table, key, &ovalue) == 1) {
    FREE(ovalue);
}
st_insert(table, key, value);

Returns: 1 if an entry already existed, 0 if it did not exist and creation was successful; ST_OUT_OF_MEM otherwise.

Side effects The location pointed by slot is modified.

See also: st_find

◆ st_foreach()

int st_foreach	(	st_table *	table,
		st_foreach_t	func,
		void *	arg
	)

Iterates over the elements of a table.

For each (key, value) record in table, st_foreach calls func with the arguments

(*func)(key, value, arg)

If func returns ST_CONTINUE, st_foreach continues processing entries. If func returns ST_STOP, st_foreach stops processing and returns immediately. If func returns ST_DELETE, then the entry is deleted from the symbol table and st_foreach continues. In the case of ST_DELETE, it is func's responsibility to free the key and value, if necessary. The order in which the records are visited will be seemingly random.

Returns: 1 if all items in the table were generated and 0 if the generation sequence was aborted using ST_STOP.

Side effects None

See also: st_foreach_item st_foreach_item_int

◆ st_free_gen()

void st_free_gen ( st_generator * gen )

Reclaims the resources associated with gen.

After generating all items in a generation sequence, this routine must be called to reclaim the resources associated with gen.

Side effects None

See also: st_init_gen

◆ st_free_table()

void st_free_table ( st_table * table )

Free a table.

Any internal storage associated with table is freed. It is the user's responsibility to free any storage associated with the pointers he placed in the table (by perhaps using st_foreach).

Side effects None

See also: st_init_table st_init_table_with_params

◆ st_gen()

int st_gen	(	st_generator *	gen,
		void **	key_p,
		void **	value_p
	)

Returns the next (key, value) pair in the generation sequence.

Given a generator returned by st_init_gen(), this routine returns the next (key, value) pair in the generation sequence. The pointer value_p can be zero which means no value will be returned. When there are no more items in the generation sequence, the routine returns 0.

While using a generation sequence, deleting any (key, value) pair other than the one just generated may cause a fatal error when st_gen() is called later in the sequence and is therefore not recommended.

Side effects The locations pointed by key_p and value_p are modified.

See also: st_gen_int

◆ st_gen_int()

int st_gen_int	(	st_generator *	gen,
		void **	key_p,
		int *	value_p
	)

Returns the next (key, value) pair in the generation sequence.

Given a generator returned by st_init_gen(), this routine returns the next (key, value) pair in the generation sequence. value_p must be a pointer to an integer. The pointer value_p can be zero which means no value will be returned. When there are no more items in the generation sequence, the routine returns 0.

Side effects The locations pointed by key_p and value_p are modified.

See also: st_gen

◆ st_init_gen()

st_generator* st_init_gen ( st_table const * table )

Initializes a generator.

Returns a generator handle which when used with st_gen() will progressively return each (key, value) record in table.

Side effects None

See also: st_free_gen

◆ st_init_table()

st_table* st_init_table	(	st_compare_t	compare,
		st_hash_t	hash
	)

Creates and initializes a table.

Creates and initializes a table with the comparison function compare_fn and hash function hash_fn. compare_fn is

int compare_fn(const void *key1, const void *key2)

It returns <,=,> 0 depending on whether key1 <,=,> key2 by some measure.

hash_fn is

int hash_fn(void *key, int modulus)

It returns an integer between 0 and modulus-1 such that if compare_fn(key1,key2) == 0 then hash_fn(key1) == hash_fn(key2).

There are five predefined hash and comparison functions in st. For keys as numbers:

st_numhash(key, modulus) { return (unsigned int) key % modulus; }
st_numcmp(x,y) { return (int) x - (int) y; }

For keys as pointers:

st_ptrhash(key, modulus) { return ((unsigned int) key/4) % modulus }
st_ptrcmp(x,y) { return (int) x - (int) y; }

For keys as strings:

st_strhash(x,y) - a reasonable hashing function for strings
strcmp(x,y) - the standard library function

It is recommended to use these particular functions if they fit your needs, since st will recognize certain of them and run more quickly because of it.

Side effects None

See also: st_init_table_with_params st_free_table

◆ st_init_table_with_arg()

st_table* st_init_table_with_arg	(	st_compare_arg_t	compare,
		st_hash_arg_t	hash,
		void const *	arg
	)

Creates and initializes a table.

Like st_init_table, but the comparison and hash functions are passed an extra parameter arg that is registered in the table at initialization.

See also: st_init_table st_init_table_with_params_and_arg

◆ st_init_table_with_params()

st_table* st_init_table_with_params	(	st_compare_t	compare,
		st_hash_t	hash,
		int	size,
		int	density,
		double	grow_factor,
		int	reorder_flag
	)

Create a table with given parameters.

The full blown table initializer. compare and hash are the same as in st_init_table. density is the largest the average number of entries per hash bin there should be before the table is grown. grow_factor is the factor the table is grown by when it becomes too full. size is the initial number of bins to be allocated for the hash table. If reorder_flag is non-zero, then every time an entry is found, it is moved to the top of the chain.

st_init_table(compare, hash) is equivelent to

st_init_table_with_params(compare, hash, ST_DEFAULT_INIT_TABLE_SIZE,
                          ST_DEFAULT_MAX_DENSITY, ST_DEFAULT_GROW_FACTOR,
                          ST_DEFAULT_REORDER_FLAG);

Side effects None

See also: st_init_table st_free_table

◆ st_init_table_with_params_and_arg()

st_table* st_init_table_with_params_and_arg	(	st_compare_arg_t	compare,
		st_hash_arg_t	hash,
		void const *	arg,
		int	size,
		int	density,
		double	growth_factor,
		int	reorder_flag
	)

Creates and initializes a table.

Like st_init_table_with_params, but the comparison and hash functions are passed an extra parameter arg that is registered in the table at initialization.

See also: st_init_table_with_params

◆ st_insert()

int st_insert	(	st_table *	table,
		void *	key,
		void *	value
	)

Insert value in table under the key key.

Returns: 1 if there was an entry already under the key; 0 if there was no entry under the key and insertion was successful; ST_OUT_OF_MEM otherwise. In either of the first two cases the new value is added.

Side effects None

◆ st_lookup()

int st_lookup	(	st_table *	table,
		void const *	key,
		void **	value
	)

Lookup up key in table.

If an entry is found, 1 is returned and if value is not nil, the variable it points to is set to the associated value. If an entry is not found, 0 is returned and the variable pointed by value is unchanged.

Side effects The location pointed by value is modified.

See also: st_lookup_int

◆ st_lookup_int()

int st_lookup_int	(	st_table *	table,
		void const *	key,
		int *	value
	)

Lookup up key in table.

If an entry is found, 1 is returned and if value is not nil, the variable it points to is set to the associated integer value. If an entry is not found, 0 is return and the variable pointed by value is unchanged.

Side effects The location pointed by value is modified.

See also: st_lookup

◆ st_numcmp()

int st_numcmp	(	void const *	x,
		void const *	y
	)

Integral number comparison function.

Side effects None

See also: st_init_table st_numhash

◆ st_numhash()

int st_numhash	(	void const *	x,
		int	size
	)

Integral number hash function.

Side effects None

See also: st_init_table st_numcmp

◆ st_ptrcmp()

int st_ptrcmp	(	void const *	x,
		void const *	y
	)

Pointer comparison function.

Side effects None

See also: st_init_table st_ptrhash

◆ st_ptrhash()

int st_ptrhash	(	void const *	x,
		int	size
	)

Pointer hash function.

Side effects None

See also: st_init_table st_ptrcmp

◆ st_strhash()

int st_strhash	(	void const *	string,
		int	modulus
	)

String hash function.

Side effects None

See also: st_init_table

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ ST_DEFAULT_GROW_FACTOR

◆ ST_DEFAULT_INIT_TABLE_SIZE

◆ ST_DEFAULT_MAX_DENSITY

◆ ST_DEFAULT_REORDER_FLAG

◆ st_foreach_item

◆ st_foreach_item_int

◆ st_is_member

Function Documentation

◆ st_add_direct()

◆ st_copy()

◆ st_count()

◆ st_delete()

◆ st_delete_int()

◆ st_find()

◆ st_find_or_add()

◆ st_foreach()

◆ st_free_gen()

◆ st_free_table()

◆ st_gen()

◆ st_gen_int()

◆ st_init_gen()

◆ st_init_table()

◆ st_init_table_with_arg()

◆ st_init_table_with_params()

◆ st_init_table_with_params_and_arg()

◆ st_insert()

◆ st_lookup()

◆ st_lookup_int()

◆ st_numcmp()

◆ st_numhash()

◆ st_ptrcmp()

◆ st_ptrhash()

◆ st_strhash()