include/apr_dbm.h

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#ifndef APR_DBM_H
#define APR_DBM_H

#include "apu.h"
#include "apr.h"
#include "apr_errno.h"
#include "apr_pools.h"

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @package APR-UTIL DBM library
 */

/**
 * Structure for referencing a dbm
 * @defvar apr_dbm_t
 */
typedef struct apr_dbm_t apr_dbm_t;

/**
 * Structure for referencing the datum record within a dbm
 * @defvar apr_datum_t
 */
typedef struct
{
    char *dptr;
    apr_size_t dsize;
} apr_datum_t;

/* modes to open the DB */
#define APR_DBM_READONLY        1       /* open for read-only access */
#define APR_DBM_READWRITE       2       /* open for read-write access */
#define APR_DBM_RWCREATE        3       /* open for r/w, create if needed */

/**
 * Open a dbm file by file name
 * @param dbm The newly opened database
 * @param name The dbm file name to open
 * @param mode The flag value
 * <PRE>
 *           APR_DBM_READONLY   open for read-only access
 *           APR_DBM_READWRITE  open for read-write access
 *           APR_DBM_RWCREATE   open for r/w, create if needed
 * </PRE>
 * @param cntxt The pool to use when creating the dbm
 * @deffunc apr_status_t apr_dbm_open(apr_dbm_t **dbm, const char *name, int mode
 * @tip The dbm name may not be a true file name, as many dbm packages
 * append suffixes for seperate data and index files.
 */
APU_DECLARE(apr_status_t) apr_dbm_open(apr_dbm_t **dbm, const char *name, 
                                       int mode, apr_pool_t *cntxt);

/**
 * Close a dbm file previously opened by apr_dbm_open
 * @param dbm The database to close
 * @deffunc void apr_dbm_close(apr_dbm_t *dbm)
 */
APU_DECLARE(void) apr_dbm_close(apr_dbm_t *dbm);

/**
 * Fetch a dbm record value by key
 * @param dbm The database 
 * @param key The key datum to find this record
 * @param value The value datum retrieved for this record
 * @deffunc apr_status_t apr_dbm_fetch(apr_dbm_t *dbm, apr_datum_t key
 */
APU_DECLARE(apr_status_t) apr_dbm_fetch(apr_dbm_t *dbm, apr_datum_t key,
                                        apr_datum_t *pvalue);
/**
 * Store a dbm record value by key
 * @param dbm The database 
 * @param key The key datum to store this record by
 * @param value The value datum to store in this record
 * @deffunc apr_status_t apr_dbm_store(apr_dbm_t *dbm, apr_datum_t key, apr_datum_t value)
 */
APU_DECLARE(apr_status_t) apr_dbm_store(apr_dbm_t *dbm, apr_datum_t key, 
                                        apr_datum_t value);

/**
 * Delete a dbm record value by key
 * @param dbm The database 
 * @param key The key datum of the record to delete
 * @deffunc apr_status_t apr_dbm_delete(apr_dbm_t *dbm, apr_datum_t key)
 * @tip It is not an error to delete a non-existent record.
 */
APU_DECLARE(apr_status_t) apr_dbm_delete(apr_dbm_t *dbm, apr_datum_t key);

/**
 * Search for a key within the dbm
 * @param dbm The database 
 * @param key The datum describing a key to test
 * @deffunc int apr_dbm_exists(apr_dbm_t *dbm, apr_datum_t key)
 */
APU_DECLARE(int) apr_dbm_exists(apr_dbm_t *dbm, apr_datum_t key);

/**
 * Retrieve the first record key from a dbm
 * @param dbm The database 
 * @param key The key datum of the first record
 * @deffunc apr_status_t apr_dbm_firstkey(apr_dbm_t *dbm, apr_datum_t *pkey)
 */
APU_DECLARE(apr_status_t) apr_dbm_firstkey(apr_dbm_t *dbm, apr_datum_t *pkey);

/**
 * Retrieve the next record key from a dbm
 * @param dbm The database 
 * @param key The key datum of the next record
 * @deffunc apr_status_t apr_dbm_nextkey(apr_dbm_t *dbm, apr_datum_t *pkey)
 */
APU_DECLARE(apr_status_t) apr_dbm_nextkey(apr_dbm_t *dbm, apr_datum_t *pkey);

/**
 * Proactively toss any memory associated with the apr_datum_t.
 * @param dbm The database 
 * @param data The datum to free.
 * @deffunc void apr_dbm_freedatum(apr_dbm_t *dbm, apr_datum_t data)
 */
APU_DECLARE(void) apr_dbm_freedatum(apr_dbm_t *dbm, apr_datum_t data);

/**
 * Report more information when an apr_dbm function fails.
 * @param dbm The database
 * @param errcode A DBM-specific value for the error (for logging). If this
 *                isn't needed, it may be NULL.
 * @param errbuf Location to store the error text
 * @param errbufsize The size of the provided buffer
 * @return The errbuf parameter, for convenience.
 * @deffunc const char * apr_dbm_geterror(apr_dbm_t *dbm, int *errcode, char *errbuf, apr_size_t errbufsize)
 */
APU_DECLARE(char *) apr_dbm_geterror(apr_dbm_t *dbm, int *errcode,
                                     char *errbuf, apr_size_t errbufsize);

/**
 * If the specified file/path were passed to apr_dbm_open(), return the
 * actual file/path names which would be (created and) used. At most, two
 * files may be used; used2 may be NULL if only one file is used.
 * @param pool The pool for allocating used1 and used2.
 * @param pathname The path name to generate used-names from.
 * @param used1 The first pathname used by the apr_dbm implementation.
 * @param used2 The second pathname used by apr_dbm. If only one file is
 *              used by the specific implementation, this will be set to NULL.
 * @tip The dbm file(s) don't need to exist. This function only manipulates
 *      the pathnames.
 */
APU_DECLARE(void) apr_dbm_get_usednames(apr_pool_t *pool,
                                        const char *pathname,
                                        const char **used1,
                                        const char **used2);

#ifdef __cplusplus
}
#endif

#endif	/* !APR_DBM_H */