Viewing file:  rpmstrpool.h (3.94 KB) -rw-r--r--
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#ifndef _RPMSTRPOOL_H
#define _RPMSTRPOOL_H
/** \ingroup rpmstrpool
* \file rpmio/rpmstrpool.h
*
* String pools manipulation helper functions
*
*/
#include <rpm/rpmtypes.h>
#ifdef __cplusplus
extern "C" {
#endif
/** \ingroup rpmstrpool
* Create a new, empty string pool.
* @return new string pool
*/
rpmstrPool rpmstrPoolCreate(void);
/** \ingroup rpmstrpool
* Free a string pool and its contents. While other references exist,
* this only decrements the reference count.
* @param pool string pool
* @return NULL always
*/
rpmstrPool rpmstrPoolFree(rpmstrPool pool);
/** \ingroup rpmstrpool
* Reference a string pool
* @param pool string pool
* @return new string pool reference
*/
rpmstrPool rpmstrPoolLink(rpmstrPool pool);
/** \ingroup rpmstrpool
* Freeze a string pool: new strings cannot be added to a frozen pool.
* If keephash is 0, memory usage is minimized but string -> id lookups
* are no longer possible and unfreezing is an expensive operation.
* Id -> string lookups are always possible on a frozen pool too.
* @param pool string pool
* @param keephash should string -> id hash be kept around?
*/
void rpmstrPoolFreeze(rpmstrPool pool, int keephash);
/** \ingroup rpmstrpool
* Unfreeze a string pool to allow new additions again.
* If keephash was not specified on freezing, this requires rehashing
* the entire pool contents.
* @param pool string pool
*/
void rpmstrPoolUnfreeze(rpmstrPool pool);
/** \ingroup rpmstrpool
* Look up the id of a string. If create is specified the string is
* added to the pool if it does not already exist. Creation can only
* fail if the pool is in frozen state.
* @param pool string pool
* @param s \0-terminated string to look up
* @param create should an id be created if not already present?
* @return id of the string or 0 for not found
*/
rpmsid rpmstrPoolId(rpmstrPool pool, const char *s, int create);
/** \ingroup rpmstrpool
* Look up the id of a string with predetermined length. The string does
* not have to be \0-terminated. If create is specified the string is
* added to the pool if it does not already exist. Creation can only
* fail if the pool is in frozen state.
* @param pool string pool
* @param s string to look up
* @param slen number of characters from s to consider
* @param create should an id be created if not already present?
* @return id of the string or 0 for not found
*/
rpmsid rpmstrPoolIdn(rpmstrPool pool, const char *s, size_t slen, int create);
/** \ingroup rpmstrpool
* Look up a string by its pool id.
* @param pool string pool
* @param sid pool id of a string
* @return pointer to the string or NULL for invalid id
*/
const char * rpmstrPoolStr(rpmstrPool pool, rpmsid sid);
/** \ingroup rpmstrpool
* Return length of a string by its pool id. The result is equal to
* calling strlen() on a string retrieved through rpmstrPoolStr(), but
* the pool might be able to optimize the calculation.
* @param pool string pool
* @param sid pool id of a string
* @return length of the string, 0 for invalid pool or id
*/
size_t rpmstrPoolStrlen(rpmstrPool pool, rpmsid sid);
/** \ingroup rpmstrpool
* Compare two strings for equality by their ids. The result is equal to
* calling rstreq() on two strings retrieved through rpmstrPoolStr() but
* when the id's are within the same pool, this runs in constant time.
* @param poolA string pool of the first string
* @param sidA pool id of the first string
* @param poolB string pool of the second string
* @param sidB pool id of the second string
* @return 1 if strings are equal, 0 otherwise
*/
int rpmstrPoolStreq(rpmstrPool poolA, rpmsid sidA,
rpmstrPool poolB, rpmsid sidB);
/** \ingroup rpmstrpool
* Return the number of strings stored in the pool. This number is
* also the highest legal id for the pool.
* @param pool string pool
* @return number of strings in the pool
*/
rpmsid rpmstrPoolNumStr(rpmstrPool pool);
#ifdef __cplusplus
}
#endif
#endif /* _RPMSIDPOOL_H */
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