diff options
Diffstat (limited to 'src/datacache/plugin_datacache_postgres.c')
-rw-r--r-- | src/datacache/plugin_datacache_postgres.c | 524 |
1 files changed, 524 insertions, 0 deletions
diff --git a/src/datacache/plugin_datacache_postgres.c b/src/datacache/plugin_datacache_postgres.c new file mode 100644 index 0000000..3486d76 --- /dev/null +++ b/src/datacache/plugin_datacache_postgres.c @@ -0,0 +1,524 @@ +/* + This file is part of GNUnet + (C) 2006, 2009, 2010 Christian Grothoff (and other contributing authors) + + GNUnet is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published + by the Free Software Foundation; either version 3, or (at your + option) any later version. + + GNUnet is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with GNUnet; see the file COPYING. If not, write to the + Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. +*/ + +/** + * @file datacache/plugin_datacache_postgres.c + * @brief postgres for an implementation of a database backend for the datacache + * @author Christian Grothoff + */ +#include "platform.h" +#include "gnunet_util_lib.h" +#include "gnunet_datacache_plugin.h" +#include <postgresql/libpq-fe.h> + +#define DEBUG_POSTGRES GNUNET_EXTRA_LOGGING + +/** + * Per-entry overhead estimate + */ +#define OVERHEAD (sizeof(GNUNET_HashCode) + 24) + +/** + * Context for all functions in this plugin. + */ +struct Plugin +{ + /** + * Our execution environment. + */ + struct GNUNET_DATACACHE_PluginEnvironment *env; + + /** + * Native Postgres database handle. + */ + PGconn *dbh; + +}; + + +/** + * Check if the result obtained from Postgres has + * the desired status code. If not, log an error, clear the + * result and return GNUNET_SYSERR. + * + * @return GNUNET_OK if the result is acceptable + */ +static int +check_result (struct Plugin *plugin, PGresult * ret, int expected_status, + const char *command, const char *args, int line) +{ + if (ret == NULL) + { + GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK, + "datastore-postgres", + "Postgres failed to allocate result for `%s:%s' at %d\n", + command, args, line); + return GNUNET_SYSERR; + } + if (PQresultStatus (ret) != expected_status) + { + GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK, + "datastore-postgres", + _("`%s:%s' failed at %s:%d with error: %s"), command, args, + __FILE__, line, PQerrorMessage (plugin->dbh)); + PQclear (ret); + return GNUNET_SYSERR; + } + return GNUNET_OK; +} + + +/** + * Run simple SQL statement (without results). + */ +static int +pq_exec (struct Plugin *plugin, const char *sql, int line) +{ + PGresult *ret; + + ret = PQexec (plugin->dbh, sql); + if (GNUNET_OK != + check_result (plugin, ret, PGRES_COMMAND_OK, "PQexec", sql, line)) + return GNUNET_SYSERR; + PQclear (ret); + return GNUNET_OK; +} + + +/** + * Prepare SQL statement. + */ +static int +pq_prepare (struct Plugin *plugin, const char *name, const char *sql, + int nparms, int line) +{ + PGresult *ret; + + ret = PQprepare (plugin->dbh, name, sql, nparms, NULL); + if (GNUNET_OK != + check_result (plugin, ret, PGRES_COMMAND_OK, "PQprepare", sql, line)) + return GNUNET_SYSERR; + PQclear (ret); + return GNUNET_OK; +} + + +/** + * @brief Get a database handle + * @return GNUNET_OK on success, GNUNET_SYSERR on error + */ +static int +init_connection (struct Plugin *plugin) +{ + char *conninfo; + PGresult *ret; + + /* Open database and precompile statements */ + if (GNUNET_OK != + GNUNET_CONFIGURATION_get_value_string (plugin->env->cfg, + "datacache-postgres", "CONFIG", + &conninfo)) + conninfo = NULL; + plugin->dbh = PQconnectdb (conninfo == NULL ? "" : conninfo); + GNUNET_free_non_null (conninfo); + if (NULL == plugin->dbh) + { + /* FIXME: warn about out-of-memory? */ + return GNUNET_SYSERR; + } + if (PQstatus (plugin->dbh) != CONNECTION_OK) + { + GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "datacache-postgres", + _("Unable to initialize Postgres: %s"), + PQerrorMessage (plugin->dbh)); + PQfinish (plugin->dbh); + plugin->dbh = NULL; + return GNUNET_SYSERR; + } + ret = + PQexec (plugin->dbh, + "CREATE TEMPORARY TABLE gn090dc (" + " type INTEGER NOT NULL DEFAULT 0," + " discard_time BIGINT NOT NULL DEFAULT 0," + " key BYTEA NOT NULL DEFAULT ''," + " value BYTEA NOT NULL DEFAULT '')" "WITH OIDS"); + if ((ret == NULL) || ((PQresultStatus (ret) != PGRES_COMMAND_OK) && (0 != strcmp ("42P07", /* duplicate table */ + PQresultErrorField + (ret, + PG_DIAG_SQLSTATE))))) + { + (void) check_result (plugin, ret, PGRES_COMMAND_OK, "CREATE TABLE", + "gn090dc", __LINE__); + PQfinish (plugin->dbh); + plugin->dbh = NULL; + return GNUNET_SYSERR; + } + if (PQresultStatus (ret) == PGRES_COMMAND_OK) + { + if ((GNUNET_OK != + pq_exec (plugin, "CREATE INDEX idx_key ON gn090dc (key)", __LINE__)) || + (GNUNET_OK != + pq_exec (plugin, "CREATE INDEX idx_dt ON gn090dc (discard_time)", + __LINE__))) + { + PQclear (ret); + PQfinish (plugin->dbh); + plugin->dbh = NULL; + return GNUNET_SYSERR; + } + } + PQclear (ret); +#if 1 + ret = + PQexec (plugin->dbh, + "ALTER TABLE gn090dc ALTER value SET STORAGE EXTERNAL"); + if (GNUNET_OK != + check_result (plugin, ret, PGRES_COMMAND_OK, "ALTER TABLE", "gn090dc", + __LINE__)) + { + PQfinish (plugin->dbh); + plugin->dbh = NULL; + return GNUNET_SYSERR; + } + PQclear (ret); + ret = PQexec (plugin->dbh, "ALTER TABLE gn090dc ALTER key SET STORAGE PLAIN"); + if (GNUNET_OK != + check_result (plugin, ret, PGRES_COMMAND_OK, "ALTER TABLE", "gn090dc", + __LINE__)) + { + PQfinish (plugin->dbh); + plugin->dbh = NULL; + return GNUNET_SYSERR; + } + PQclear (ret); +#endif + if ((GNUNET_OK != + pq_prepare (plugin, "getkt", + "SELECT discard_time,type,value FROM gn090dc " + "WHERE key=$1 AND type=$2 ", 2, __LINE__)) || + (GNUNET_OK != + pq_prepare (plugin, "getk", + "SELECT discard_time,type,value FROM gn090dc " + "WHERE key=$1", 1, __LINE__)) || + (GNUNET_OK != + pq_prepare (plugin, "getm", + "SELECT length(value),oid,key FROM gn090dc " + "ORDER BY discard_time ASC LIMIT 1", 0, __LINE__)) || + (GNUNET_OK != + pq_prepare (plugin, "delrow", "DELETE FROM gn090dc WHERE oid=$1", 1, + __LINE__)) || + (GNUNET_OK != + pq_prepare (plugin, "put", + "INSERT INTO gn090dc (type, discard_time, key, value) " + "VALUES ($1, $2, $3, $4)", 4, __LINE__))) + { + PQfinish (plugin->dbh); + plugin->dbh = NULL; + return GNUNET_SYSERR; + } + return GNUNET_OK; +} + + +/** + * Delete the row identified by the given rowid (qid + * in postgres). + * + * @return GNUNET_OK on success + */ +static int +delete_by_rowid (struct Plugin *plugin, uint32_t rowid) +{ + uint32_t brow = htonl (rowid); + const char *paramValues[] = { (const char *) &brow }; + int paramLengths[] = { sizeof (brow) }; + const int paramFormats[] = { 1 }; + PGresult *ret; + + ret = + PQexecPrepared (plugin->dbh, "delrow", 1, paramValues, paramLengths, + paramFormats, 1); + if (GNUNET_OK != + check_result (plugin, ret, PGRES_COMMAND_OK, "PQexecPrepared", "delrow", + __LINE__)) + { + return GNUNET_SYSERR; + } + PQclear (ret); + return GNUNET_OK; +} + + +/** + * Store an item in the datastore. + * + * @param cls closure (our "struct Plugin") + * @param key key to store data under + * @param size number of bytes in data + * @param data data to store + * @param type type of the value + * @param discard_time when to discard the value in any case + * @return 0 on error, number of bytes used otherwise + */ +static size_t +postgres_plugin_put (void *cls, const GNUNET_HashCode * key, size_t size, + const char *data, enum GNUNET_BLOCK_Type type, + struct GNUNET_TIME_Absolute discard_time) +{ + struct Plugin *plugin = cls; + PGresult *ret; + uint32_t btype = htonl (type); + uint64_t bexpi = GNUNET_TIME_absolute_hton (discard_time).abs_value__; + + const char *paramValues[] = { + (const char *) &btype, + (const char *) &bexpi, + (const char *) key, + (const char *) data + }; + int paramLengths[] = { + sizeof (btype), + sizeof (bexpi), + sizeof (GNUNET_HashCode), + size + }; + const int paramFormats[] = { 1, 1, 1, 1 }; + + ret = + PQexecPrepared (plugin->dbh, "put", 4, paramValues, paramLengths, + paramFormats, 1); + if (GNUNET_OK != + check_result (plugin, ret, PGRES_COMMAND_OK, "PQexecPrepared", "put", + __LINE__)) + return GNUNET_SYSERR; + PQclear (ret); + return size + OVERHEAD; +} + + +/** + * Iterate over the results for a particular key + * in the datastore. + * + * @param cls closure (our "struct Plugin") + * @param key + * @param type entries of which type are relevant? + * @param iter maybe NULL (to just count) + * @param iter_cls closure for iter + * @return the number of results found + */ +static unsigned int +postgres_plugin_get (void *cls, const GNUNET_HashCode * key, + enum GNUNET_BLOCK_Type type, + GNUNET_DATACACHE_Iterator iter, void *iter_cls) +{ + struct Plugin *plugin = cls; + uint32_t btype = htonl (type); + + const char *paramValues[] = { + (const char *) key, + (const char *) &btype, + }; + int paramLengths[] = { + sizeof (GNUNET_HashCode), + sizeof (btype), + }; + const int paramFormats[] = { 1, 1 }; + struct GNUNET_TIME_Absolute expiration_time; + uint32_t size; + unsigned int cnt; + unsigned int i; + PGresult *res; + + res = + PQexecPrepared (plugin->dbh, (type == 0) ? "getk" : "getkt", + (type == 0) ? 1 : 2, paramValues, paramLengths, + paramFormats, 1); + if (GNUNET_OK != + check_result (plugin, res, PGRES_TUPLES_OK, "PQexecPrepared", + (type == 0) ? "getk" : "getkt", __LINE__)) + { +#if DEBUG_POSTGRES + GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "datacache-postgres", + "Ending iteration (postgres error)\n"); +#endif + return 0; + } + + if (0 == (cnt = PQntuples (res))) + { + /* no result */ +#if DEBUG_POSTGRES + GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "datacache-postgres", + "Ending iteration (no more results)\n"); +#endif + PQclear (res); + return 0; + } + if (iter == NULL) + { + PQclear (res); + return cnt; + } + if ((3 != PQnfields (res)) || (sizeof (uint64_t) != PQfsize (res, 0)) || + (sizeof (uint32_t) != PQfsize (res, 1))) + { + GNUNET_break (0); + PQclear (res); + return 0; + } + for (i = 0; i < cnt; i++) + { + expiration_time.abs_value = + GNUNET_ntohll (*(uint64_t *) PQgetvalue (res, i, 0)); + type = ntohl (*(uint32_t *) PQgetvalue (res, i, 1)); + size = PQgetlength (res, i, 2); +#if DEBUG_POSTGRES + GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "datacache-postgres", + "Found result of size %u bytes and type %u in database\n", + (unsigned int) size, (unsigned int) type); +#endif + if (GNUNET_SYSERR == + iter (iter_cls, expiration_time, key, size, PQgetvalue (res, i, 2), + (enum GNUNET_BLOCK_Type) type)) + { +#if DEBUG_POSTGRES + GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "datacache-postgres", + "Ending iteration (client error)\n"); +#endif + PQclear (res); + return cnt; + } + } + PQclear (res); + return cnt; +} + + +/** + * Delete the entry with the lowest expiration value + * from the datacache right now. + * + * @param cls closure (our "struct Plugin") + * @return GNUNET_OK on success, GNUNET_SYSERR on error + */ +static int +postgres_plugin_del (void *cls) +{ + struct Plugin *plugin = cls; + uint32_t size; + uint32_t oid; + GNUNET_HashCode key; + PGresult *res; + + res = PQexecPrepared (plugin->dbh, "getm", 0, NULL, NULL, NULL, 1); + if (GNUNET_OK != + check_result (plugin, res, PGRES_TUPLES_OK, "PQexecPrepared", "getm", + __LINE__)) + { +#if DEBUG_POSTGRES + GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "datacache-postgres", + "Ending iteration (postgres error)\n"); +#endif + return 0; + } + if (0 == PQntuples (res)) + { + /* no result */ +#if DEBUG_POSTGRES + GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "datacache-postgres", + "Ending iteration (no more results)\n"); +#endif + PQclear (res); + return GNUNET_SYSERR; + } + if ((3 != PQnfields (res)) || (sizeof (size) != PQfsize (res, 0)) || + (sizeof (oid) != PQfsize (res, 1)) || + (sizeof (GNUNET_HashCode) != PQgetlength (res, 0, 2))) + { + GNUNET_break (0); + PQclear (res); + return 0; + } + size = ntohl (*(uint32_t *) PQgetvalue (res, 0, 0)); + oid = ntohl (*(uint32_t *) PQgetvalue (res, 0, 1)); + memcpy (&key, PQgetvalue (res, 0, 2), sizeof (GNUNET_HashCode)); + PQclear (res); + if (GNUNET_OK != delete_by_rowid (plugin, oid)) + return GNUNET_SYSERR; + plugin->env->delete_notify (plugin->env->cls, &key, size + OVERHEAD); + return GNUNET_OK; +} + + +/** + * Entry point for the plugin. + * + * @param cls closure (the "struct GNUNET_DATACACHE_PluginEnvironmnet") + * @return the plugin's closure (our "struct Plugin") + */ +void * +libgnunet_plugin_datacache_postgres_init (void *cls) +{ + struct GNUNET_DATACACHE_PluginEnvironment *env = cls; + struct GNUNET_DATACACHE_PluginFunctions *api; + struct Plugin *plugin; + + plugin = GNUNET_malloc (sizeof (struct Plugin)); + plugin->env = env; + + if (GNUNET_OK != init_connection (plugin)) + { + GNUNET_free (plugin); + return NULL; + } + + api = GNUNET_malloc (sizeof (struct GNUNET_DATACACHE_PluginFunctions)); + api->cls = plugin; + api->get = &postgres_plugin_get; + api->put = &postgres_plugin_put; + api->del = &postgres_plugin_del; + GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "datacache-postgres", + _("Postgres datacache running\n")); + return api; +} + + +/** + * Exit point from the plugin. + * + * @param cls closure (our "struct Plugin") + * @return NULL + */ +void * +libgnunet_plugin_datacache_postgres_done (void *cls) +{ + struct GNUNET_DATACACHE_PluginFunctions *api = cls; + struct Plugin *plugin = api->cls; + + PQfinish (plugin->dbh); + GNUNET_free (plugin); + GNUNET_free (api); + return NULL; +} + + + +/* end of plugin_datacache_postgres.c */ |