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Diffstat (limited to 'include/apr_dbd.h')
| -rw-r--r-- | include/apr_dbd.h | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/include/apr_dbd.h b/include/apr_dbd.h new file mode 100644 index 0000000..3fd19e1 --- /dev/null +++ b/include/apr_dbd.h @@ -0,0 +1,359 @@ +/* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/* Overview of what this is and does: + * http://www.apache.org/~niq/dbd.html + */ + +#ifndef APR_DBD_H +#define APR_DBD_H + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @file apr_dbd.h + * @brief APR-UTIL DBD library + */ +/** + * @defgroup APR_Util_DBD DBD routines + * @ingroup APR_Util + * @{ + */ + +/* These are opaque structs. Instantiation is up to each backend */ +typedef struct apr_dbd_driver_t apr_dbd_driver_t; +typedef struct apr_dbd_t apr_dbd_t; +typedef struct apr_dbd_transaction_t apr_dbd_transaction_t; +typedef struct apr_dbd_results_t apr_dbd_results_t; +typedef struct apr_dbd_row_t apr_dbd_row_t; +typedef struct apr_dbd_prepared_t apr_dbd_prepared_t; + +/** apr_dbd_init: perform once-only initialisation. Call once only. + * + * @param pool - pool to register any shutdown cleanups, etc + */ +APU_DECLARE(apr_status_t) apr_dbd_init(apr_pool_t *pool); + +/** apr_dbd_get_driver: get the driver struct for a name + * + * @param pool - (process) pool to register cleanup + * @param name - driver name + * @param driver - pointer to driver struct. + * @return APR_SUCCESS for success + * @return APR_ENOTIMPL for no driver (when DSO not enabled) + * @return APR_EDSOOPEN if DSO driver file can't be opened + * @return APR_ESYMNOTFOUND if the driver file doesn't contain a driver + */ +APU_DECLARE(apr_status_t) apr_dbd_get_driver(apr_pool_t *pool, const char *name, + const apr_dbd_driver_t **driver); + +/** apr_dbd_open: open a connection to a backend + * + * @param pool - working pool + * @param params - arguments to driver (implementation-dependent) + * @param handle - pointer to handle to return + * @param driver - driver struct. + * @return APR_SUCCESS for success + * @return APR_EGENERAL if driver exists but connection failed + * @remarks PostgreSQL: the params is passed directly to the PQconnectdb() + * function (check PostgreSQL documentation for more details on the syntax). + * @remarks SQLite2: the params is split on a colon, with the first part used + * as the filename and second part converted to an integer and used as file + * mode. + * @remarks SQLite3: the params is passed directly to the sqlite3_open() + * function as a filename to be opened (check SQLite3 documentation for more + * details). + * @remarks MySQL: the params can have "host", "port", "user", "pass", + * "dbname", "sock", "flags" "fldsz" and "group" keys, each followed by an + * equal sign and a value. Such key/value pairs can be delimited by space, + * CR, LF, tab, semicolon, vertical bar or comma. For now, "flags" can only + * recognise CLIENT_FOUND_ROWS (check MySQL manual for details). The value + * associated with "fldsz" determines maximum amount of memory (in bytes) for + * each of the fields in the result set of prepared statements. By default, + * this value is 1 MB. The value associated with "group" determines which + * group from configuration file to use (see MYSQL_READ_DEFAULT_GROUP option + * of mysql_options() in MySQL manual). + */ +APU_DECLARE(apr_status_t) apr_dbd_open(const apr_dbd_driver_t *driver, + apr_pool_t *pool, const char *params, + apr_dbd_t **handle); + +/** apr_dbd_close: close a connection to a backend + * + * @param handle - handle to close + * @param driver - driver struct. + * @return APR_SUCCESS for success or error status + */ +APU_DECLARE(apr_status_t) apr_dbd_close(const apr_dbd_driver_t *driver, + apr_dbd_t *handle); + +/* apr-function-shaped versions of things */ + +/** apr_dbd_name: get the name of the driver + * + * @param driver - the driver + * @return - name + */ +APU_DECLARE(const char*) apr_dbd_name(const apr_dbd_driver_t *driver); + +/** apr_dbd_native_handle: get native database handle of the underlying db + * + * @param driver - the driver + * @param handle - apr_dbd handle + * @return - native handle + */ +APU_DECLARE(void*) apr_dbd_native_handle(const apr_dbd_driver_t *driver, + apr_dbd_t *handle); + +/** check_conn: check status of a database connection + * + * @param driver - the driver + * @param pool - working pool + * @param handle - the connection to check + * @return APR_SUCCESS or error + */ +APU_DECLARE(int) apr_dbd_check_conn(const apr_dbd_driver_t *driver, apr_pool_t *pool, + apr_dbd_t *handle); + +/** apr_dbd_set_dbname: select database name. May be a no-op if not supported. + * + * @param driver - the driver + * @param pool - working pool + * @param handle - the connection + * @param name - the database to select + * @return 0 for success or error code + */ +APU_DECLARE(int) apr_dbd_set_dbname(const apr_dbd_driver_t *driver, apr_pool_t *pool, + apr_dbd_t *handle, const char *name); + +/** apr_dbd_transaction_start: start a transaction. May be a no-op. + * + * @param driver - the driver + * @param pool - a pool to use for error messages (if any). + * @param handle - the db connection + * @param trans - ptr to a transaction. May be null on entry + * @return 0 for success or error code + * @remarks If any of the query/select calls during a transaction return + * non-zero status code, the transaction will inherit this code and any + * further query/select calls will fail immediately. + */ +APU_DECLARE(int) apr_dbd_transaction_start(const apr_dbd_driver_t *driver, + apr_pool_t *pool, + apr_dbd_t *handle, + apr_dbd_transaction_t **trans); + +/** apr_dbd_transaction_end: end a transaction + * (commit on success, rollback on error). + * May be a no-op. + * + * @param driver - the driver + * @param handle - the db connection + * @param trans - the transaction. + * @return 0 for success or error code + */ +APU_DECLARE(int) apr_dbd_transaction_end(const apr_dbd_driver_t *driver, + apr_pool_t *pool, + apr_dbd_transaction_t *trans); + +/** apr_dbd_query: execute an SQL query that doesn't return a result set + * + * @param driver - the driver + * @param handle - the connection + * @param nrows - number of rows affected. + * @param statement - the SQL statement to execute + * @return 0 for success or error code + */ +APU_DECLARE(int) apr_dbd_query(const apr_dbd_driver_t *driver, apr_dbd_t *handle, + int *nrows, const char *statement); + +/** apr_dbd_select: execute an SQL query that returns a result set + * + * @param driver - the driver + * @param pool - pool to allocate the result set + * @param handle - the connection + * @param res - pointer to result set pointer. May point to NULL on entry + * @param statement - the SQL statement to execute + * @param random - 1 to support random access to results (seek any row); + * 0 to support only looping through results in order + * (async access - faster) + * @return 0 for success or error code + */ +APU_DECLARE(int) apr_dbd_select(const apr_dbd_driver_t *driver, apr_pool_t *pool, + apr_dbd_t *handle, apr_dbd_results_t **res, + const char *statement, int random); + +/** apr_dbd_num_cols: get the number of columns in a results set + * + * @param driver - the driver + * @param res - result set. + * @return number of columns + */ +APU_DECLARE(int) apr_dbd_num_cols(const apr_dbd_driver_t *driver, + apr_dbd_results_t *res); + +/** apr_dbd_num_tuples: get the number of rows in a results set + * of a synchronous select + * + * @param driver - the driver + * @param res - result set. + * @return number of rows, or -1 if the results are asynchronous + */ +APU_DECLARE(int) apr_dbd_num_tuples(const apr_dbd_driver_t *driver, + apr_dbd_results_t *res); + +/** apr_dbd_get_row: get a row from a result set + * + * @param driver - the driver + * @param pool - pool to allocate the row + * @param res - result set pointer + * @param row - pointer to row pointer. May point to NULL on entry + * @param rownum - row number, or -1 for "next row". Ignored if random + * access is not supported. + * @return 0 for success, -1 for rownum out of range or data finished + */ +APU_DECLARE(int) apr_dbd_get_row(const apr_dbd_driver_t *driver, apr_pool_t *pool, + apr_dbd_results_t *res, apr_dbd_row_t **row, + int rownum); + +/** apr_dbd_get_entry: get an entry from a row + * + * @param driver - the driver + * @param row - row pointer + * @param col - entry number + * @return value from the row, or NULL if col is out of bounds. + */ +APU_DECLARE(const char*) apr_dbd_get_entry(const apr_dbd_driver_t *driver, + apr_dbd_row_t *row, int col); + +/** apr_dbd_error: get current error message (if any) + * + * @param driver - the driver + * @param handle - the connection + * @param errnum - error code from operation that returned an error + * @return the database current error message, or message for errnum + * (implementation-dependent whether errnum is ignored) + */ +APU_DECLARE(const char*) apr_dbd_error(const apr_dbd_driver_t *driver, + apr_dbd_t *handle, int errnum); + +/** apr_dbd_escape: escape a string so it is safe for use in query/select + * + * @param driver - the driver + * @param pool - pool to alloc the result from + * @param string - the string to escape + * @param handle - the connection + * @return the escaped, safe string + */ +APU_DECLARE(const char*) apr_dbd_escape(const apr_dbd_driver_t *driver, + apr_pool_t *pool, const char *string, + apr_dbd_t *handle); + +/** apr_dbd_prepare: prepare a statement + * + * @param driver - the driver + * @param pool - pool to alloc the result from + * @param handle - the connection + * @param query - the SQL query + * @param label - A label for the prepared statement. + * use NULL for temporary prepared statements + * (eg within a Request in httpd) + * @param statement - statement to prepare. May point to null on entry. + * @return 0 for success or error code + * @remarks To specify parameters of the prepared query, use %s in place of + * database specific parameter syntax (e.g. for PostgreSQL, this would be $1, + * $2, for SQLite3 this would be ? etc.). For instance: "SELECT name FROM + * customers WHERE name=%s" would be a query that this function understands. + * Some drivers may support different data types using printf-like format: + * for example %d (e.g. PostgreSQL) or %f for numeric data. + */ +APU_DECLARE(int) apr_dbd_prepare(const apr_dbd_driver_t *driver, apr_pool_t *pool, + apr_dbd_t *handle, const char *query, + const char *label, + apr_dbd_prepared_t **statement); + + +/** apr_dbd_pquery: query using a prepared statement + args + * + * @param driver - the driver + * @param pool - working pool + * @param handle - the connection + * @param nrows - number of rows affected. + * @param statement - the prepared statement to execute + * @param nargs - number of args to prepared statement + * @param args - args to prepared statement + * @return 0 for success or error code + */ +APU_DECLARE(int) apr_dbd_pquery(const apr_dbd_driver_t *driver, apr_pool_t *pool, + apr_dbd_t *handle, int *nrows, + apr_dbd_prepared_t *statement, int nargs, + const char **args); + +/** apr_dbd_pselect: select using a prepared statement + args + * + * @param driver - the driver + * @param pool - working pool + * @param handle - the connection + * @param res - pointer to query results. May point to NULL on entry + * @param statement - the prepared statement to execute + * @param random - Whether to support random-access to results + * @param nargs - number of args to prepared statement + * @param args - args to prepared statement + * @return 0 for success or error code + */ +APU_DECLARE(int) apr_dbd_pselect(const apr_dbd_driver_t *driver, apr_pool_t *pool, + apr_dbd_t *handle, apr_dbd_results_t **res, + apr_dbd_prepared_t *statement, int random, + int nargs, const char **args); + +/** apr_dbd_pvquery: query using a prepared statement + args + * + * @param driver - the driver + * @param pool - working pool + * @param handle - the connection + * @param nrows - number of rows affected. + * @param statement - the prepared statement to execute + * @param ... - varargs list + * @return 0 for success or error code + */ +APU_DECLARE(int) apr_dbd_pvquery(const apr_dbd_driver_t *driver, apr_pool_t *pool, + apr_dbd_t *handle, int *nrows, + apr_dbd_prepared_t *statement, ...); + +/** apr_dbd_pvselect: select using a prepared statement + args + * + * @param driver - the driver + * @param pool - working pool + * @param handle - the connection + * @param res - pointer to query results. May point to NULL on entry + * @param statement - the prepared statement to execute + * @param random - Whether to support random-access to results + * @param ... - varargs list + * @return 0 for success or error code + */ +APU_DECLARE(int) apr_dbd_pvselect(const apr_dbd_driver_t *driver, apr_pool_t *pool, + apr_dbd_t *handle, apr_dbd_results_t **res, + apr_dbd_prepared_t *statement, int random, + ...); + +/** @} */ + +#ifdef __cplusplus +} +#endif + +#endif |