Apache Portable Runtime
apr_dbm.h
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13  * See the License for the specific language governing permissions and
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15  */
16 
17 #ifndef APR_DBM_H
18 #define APR_DBM_H
19 
20 #include "apu.h"
21 #include "apr.h"
22 #include "apr_errno.h"
23 #include "apu_errno.h"
24 #include "apr_pools.h"
25 #include "apr_file_info.h"
26 
27 #ifdef __cplusplus
28 extern "C" {
29 #endif
30 
31 /**
32  * @file apr_dbm.h
33  * @brief APR-UTIL DBM library
34  */
35 /**
36  * @defgroup APR_Util_DBM DBM routines
37  * @ingroup APR
38  * @{
39  */
40 /**
41  * Structure representing a dbm driver.
42  */
43 typedef struct apr_dbm_driver_t apr_dbm_driver_t;
44 
45 /**
46  * Structure for referencing a dbm
47  */
48 typedef struct apr_dbm_t apr_dbm_t;
49 
50 /**
51  * Structure for referencing the datum record within a dbm
52  */
53 typedef struct
54 {
55  /** pointer to the 'data' to retrieve/store in the DBM */
56  char *dptr;
57  /** size of the 'data' to retrieve/store in the DBM */
58  apr_size_t dsize;
59 } apr_datum_t;
60 
61 /* modes to open the DB */
62 #define APR_DBM_READONLY 1 /**< open for read-only access */
63 #define APR_DBM_READWRITE 2 /**< open for read-write access */
64 #define APR_DBM_RWCREATE 3 /**< open for r/w, create if needed */
65 #define APR_DBM_RWTRUNC 4 /**< open for r/w, truncating an existing
66  DB if present */
67 
68 /**
69  * apr_dm_get_driver: get the driver struct for a name
70  *
71  * If the driver cannot be found, or cannot be opened, details of the
72  * error are returned in apu_err_t.
73  *
74  * @param driver - pointer to driver struct.
75  * @param name - driver name
76  * @param result - result and error message on failure
77  * @param pool - (process) pool to register cleanup
78  * @return APR_SUCCESS for success
79  * @return APR_ENOTIMPL for no driver (when DSO not enabled)
80  * @return APR_EDSOOPEN if DSO driver file can't be opened
81  * @return APR_ESYMNOTFOUND if the driver file doesn't contain a driver
82  */
84  const char *name, const apu_err_t **result, apr_pool_t *pool);
85 
86 /**
87  * Open a dbm file by file name and type of DBM
88  * @param dbm The newly opened database
89  * @param type The type of the DBM (not all may be available at run time)
90  * <pre>
91  * db for Berkeley DB files
92  * lmdb for LMDB files
93  * gdbm for GDBM files
94  * ndbm for NDBM files
95  * sdbm for SDBM files (always available)
96  * default for the default DBM type
97  * </pre>
98  * @param name The dbm file name to open
99  * @param mode The flag value
100  * <PRE>
101  * APR_DBM_READONLY open for read-only access
102  * APR_DBM_READWRITE open for read-write access
103  * APR_DBM_RWCREATE open for r/w, create if needed
104  * APR_DBM_RWTRUNC open for r/w, truncate if already there
105  * </PRE>
106  * @param perm Permissions to apply to if created
107  * @param cntxt The pool to use when creating the dbm
108  * @remark The dbm name may not be a true file name, as many dbm packages
109  * append suffixes for seperate data and index files.
110  * @bug In apr-util 0.9 and 1.x, the type arg was case insensitive. This
111  * was highly inefficient, and as of 2.x the dbm name must be provided in
112  * the correct case (lower case for all bundled providers)
113  */
114 
116  const char *name,
117  apr_int32_t mode, apr_fileperms_t perm,
118  apr_pool_t *cntxt);
119 
120 /**
121  * Open a dbm file by file name and driver
122  * @param pdb The newly opened database
123  * @param driver The dbm driver to use
124  * @param name The dbm file name to open
125  * @param mode The flag value
126  * <PRE>
127  * APR_DBM_READONLY open for read-only access
128  * APR_DBM_READWRITE open for read-write access
129  * APR_DBM_RWCREATE open for r/w, create if needed
130  * APR_DBM_RWTRUNC open for r/w, truncate if already there
131  * </PRE>
132  * @param perm Permissions to apply to if created
133  * @param pool The pool to use when creating the dbm
134  * @remark The dbm name may not be a true file name, as many dbm packages
135  * append suffixes for separate data and index files.
136  */
138  const apr_dbm_driver_t *driver,
139  const char *name, apr_int32_t mode,
141 
142 /**
143  * Open a dbm file by file name
144  * @param dbm The newly opened database
145  * @param name The dbm file name to open
146  * @param mode The flag value
147  * <PRE>
148  * APR_DBM_READONLY open for read-only access
149  * APR_DBM_READWRITE open for read-write access
150  * APR_DBM_RWCREATE open for r/w, create if needed
151  * APR_DBM_RWTRUNC open for r/w, truncate if already there
152  * </PRE>
153  * @param perm Permissions to apply to if created
154  * @param cntxt The pool to use when creating the dbm
155  * @remark The dbm name may not be a true file name, as many dbm packages
156  * append suffixes for separate data and index files.
157  * @warning DBM drivers do not guarantee thread-safe or cross-process
158  * locking; multiple threads or processes reading and writing
159  * concurrently to the database is not safe and results in
160  * undefined behaviour (likely database corruption and possible
161  * crashes).
162  */
164  apr_int32_t mode, apr_fileperms_t perm,
165  apr_pool_t *cntxt);
166 
167 /**
168  * Close a dbm file previously opened by apr_dbm_open
169  * @param dbm The database to close
170  */
172 
173 /**
174  * Fetch a dbm record value by key
175  * @param dbm The database
176  * @param key The key datum to find this record
177  * @param pvalue The value datum retrieved for this record
178  */
180  apr_datum_t *pvalue);
181 /**
182  * Store a dbm record value by key
183  * @param dbm The database
184  * @param key The key datum to store this record by
185  * @param value The value datum to store in this record
186  */
188  apr_datum_t value);
189 
190 /**
191  * Delete a dbm record value by key
192  * @param dbm The database
193  * @param key The key datum of the record to delete
194  * @remark It is not an error to delete a non-existent record.
195  */
197 
198 /**
199  * Search for a key within the dbm
200  * @param dbm The database
201  * @param key The datum describing a key to test
202  */
204 
205 /**
206  * Retrieve the first record key from a dbm
207  * @param dbm The database
208  * @param pkey The key datum of the first record
209  */
211 
212 /**
213  * Retrieve the next record key from a dbm
214  * @param dbm The database
215  * @param pkey The key datum of the next record
216  */
218 
219 /**
220  * Proactively toss any memory associated with the apr_datum_t.
221  * @param dbm The database
222  * @param data The datum to free.
223  */
225 
226 /**
227  * Report more information when an apr_dbm function fails.
228  * @param dbm The database
229  * @param errcode A DBM-specific value for the error (for logging). If this
230  * isn't needed, it may be NULL.
231  * @param errbuf Location to store the error text
232  * @param errbufsize The size of the provided buffer
233  * @return The errbuf parameter, for convenience.
234  */
236  char *errbuf, apr_size_t errbufsize);
237 /**
238  * If the specified file/path were passed to apr_dbm_open(), return the
239  * actual file/path names which would be (created and) used. At most, two
240  * files may be used; used2 may be NULL if only one file is used.
241  * @param pool The pool for allocating used1 and used2.
242  * @param type The type of DBM you require info on @see apr_dbm_open_ex
243  * @param pathname The path name to generate used-names from.
244  * @param used1 The first pathname used by the apr_dbm implementation.
245  * @param used2 The second pathname used by apr_dbm. If only one file is
246  * used by the specific implementation, this will be set to NULL.
247  * @return An error if the specified type is invalid.
248  * @remark The dbm file(s) don't need to exist. This function only manipulates
249  * the pathnames.
250  */
252  const char *type,
253  const char *pathname,
254  const char **used1,
255  const char **used2);
256 
257 /**
258  * If the specified file/path were passed to apr_dbm_open(), return the
259  * actual file/path names which would be (created and) used. At most, two
260  * files may be used; used2 may be NULL if only one file is used.
261  * @param pool The pool for allocating used1 and used2.
262  * @param pathname The path name to generate used-names from.
263  * @param used1 The first pathname used by the apr_dbm implementation.
264  * @param used2 The second pathname used by apr_dbm. If only one file is
265  * used by the specific implementation, this will be set to NULL.
266  * @remark The dbm file(s) don't need to exist. This function only manipulates
267  * the pathnames.
268  */
270  const char *pathname,
271  const char **used1,
272  const char **used2);
273 
274 /** @} */
275 #ifdef __cplusplus
276 }
277 #endif
278 
279 #endif /* !APR_DBM_H */
APR Platform Definitions.
APR Error Codes.
APR File Information.
APR memory allocation.
APR-Util Error Codes.
apr_status_t apr_dbm_store(apr_dbm_t *dbm, apr_datum_t key, apr_datum_t value)
void apr_dbm_get_usednames(apr_pool_t *pool, const char *pathname, const char **used1, const char **used2)
int apr_dbm_exists(apr_dbm_t *dbm, apr_datum_t key)
apr_status_t apr_dbm_delete(apr_dbm_t *dbm, apr_datum_t key)
char * apr_dbm_geterror(apr_dbm_t *dbm, int *errcode, char *errbuf, apr_size_t errbufsize)
apr_status_t apr_dbm_open2(apr_dbm_t **pdb, const apr_dbm_driver_t *driver, const char *name, apr_int32_t mode, apr_fileperms_t perm, apr_pool_t *pool)
apr_status_t apr_dbm_get_usednames_ex(apr_pool_t *pool, const char *type, const char *pathname, const char **used1, const char **used2)
apr_status_t apr_dbm_nextkey(apr_dbm_t *dbm, apr_datum_t *pkey)
void apr_dbm_close(apr_dbm_t *dbm)
apr_status_t apr_dbm_open(apr_dbm_t **dbm, const char *name, apr_int32_t mode, apr_fileperms_t perm, apr_pool_t *cntxt)
apr_status_t apr_dbm_get_driver(const apr_dbm_driver_t **driver, const char *name, const apu_err_t **result, apr_pool_t *pool)
apr_status_t apr_dbm_fetch(apr_dbm_t *dbm, apr_datum_t key, apr_datum_t *pvalue)
void apr_dbm_freedatum(apr_dbm_t *dbm, apr_datum_t data)
apr_status_t apr_dbm_firstkey(apr_dbm_t *dbm, apr_datum_t *pkey)
apr_status_t apr_dbm_open_ex(apr_dbm_t **dbm, const char *type, const char *name, apr_int32_t mode, apr_fileperms_t perm, apr_pool_t *cntxt)
int apr_status_t
Definition: apr_errno.h:44
apr_int32_t apr_fileperms_t
Definition: apr_file_info.h:125
#define APR_DECLARE(type)
Definition: apr.h:516
struct apr_pool_t apr_pool_t
Definition: apr_pools.h:60
Definition: apr_dbm.h:54
apr_size_t dsize
Definition: apr_dbm.h:58
char * dptr
Definition: apr_dbm.h:56
Definition: apr_dbm_private.h:47
Definition: apr_dbm_private.h:94
int errcode
Definition: apr_dbm_private.h:102
const apr_dbm_driver_t * type
Definition: apr_dbm_private.h:107
apr_pool_t * pool
Definition: apr_dbm_private.h:96
Definition: apu_errno.h:289