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-rw-r--r--src/datacache/datacache.c304
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diff --git a/src/datacache/datacache.c b/src/datacache/datacache.c
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+/*
+ This file is part of GNUnet
+ (C) 2004, 2005, 2006, 2007, 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 2, 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/datacache.c
+ * @brief datacache API implementation
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_datacache_lib.h"
+#include "gnunet_statistics_service.h"
+#include "gnunet_datacache_plugin.h"
+
+#define DEBUG_DATACACHE GNUNET_EXTRA_LOGGING
+
+#define LOG(kind,...) GNUNET_log_from (kind, "datacache", __VA_ARGS__)
+
+#define LOG_STRERROR_FILE(kind,op,fn) GNUNET_log_from_strerror_file (kind, "datacache", op, fn)
+
+/**
+ * Internal state of the datacache library.
+ */
+struct GNUNET_DATACACHE_Handle
+{
+
+ /**
+ * Bloomfilter to quickly tell if we don't have the content.
+ */
+ struct GNUNET_CONTAINER_BloomFilter *filter;
+
+ /**
+ * Our configuration.
+ */
+ const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+ /**
+ * Opaque handle for the statistics service.
+ */
+ struct GNUNET_STATISTICS_Handle *stats;
+
+ /**
+ * Configuration section to use.
+ */
+ char *section;
+
+ /**
+ * API of the transport as returned by the plugin's
+ * initialization function.
+ */
+ struct GNUNET_DATACACHE_PluginFunctions *api;
+
+ /**
+ * Short name for the plugin (i.e. "sqlite").
+ */
+ char *short_name;
+
+ /**
+ * Name of the library (i.e. "gnunet_plugin_datacache_sqlite").
+ */
+ char *lib_name;
+
+ /**
+ * Name for the bloom filter file.
+ */
+ char *bloom_name;
+
+ /**
+ * Environment provided to our plugin.
+ */
+ struct GNUNET_DATACACHE_PluginEnvironment env;
+
+ /**
+ * How much space is in use right now?
+ */
+ unsigned long long utilization;
+
+};
+
+
+/**
+ * Function called by plugins to notify the datacache
+ * about content deletions.
+ *
+ * @param cls closure
+ * @param key key of the content that was deleted
+ * @param size number of bytes that were made available
+ */
+static void
+env_delete_notify (void *cls, const GNUNET_HashCode * key, size_t size)
+{
+ struct GNUNET_DATACACHE_Handle *h = cls;
+
+#if DEBUG_DATACACHE
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Content under key `%s' discarded\n",
+ GNUNET_h2s (key));
+#endif
+ GNUNET_assert (h->utilization >= size);
+ h->utilization -= size;
+ GNUNET_CONTAINER_bloomfilter_remove (h->filter, key);
+ GNUNET_STATISTICS_update (h->stats, gettext_noop ("# bytes stored"), -size,
+ GNUNET_NO);
+}
+
+
+/**
+ * Create a data cache.
+ *
+ * @param cfg configuration to use
+ * @param section section in the configuration that contains our options
+ * @return handle to use to access the service
+ */
+struct GNUNET_DATACACHE_Handle *
+GNUNET_DATACACHE_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ const char *section)
+{
+ unsigned int bf_size;
+ unsigned long long quota;
+ struct GNUNET_DATACACHE_Handle *ret;
+ char *libname;
+ char *name;
+
+ if (GNUNET_OK !=
+ GNUNET_CONFIGURATION_get_value_size (cfg, section, "QUOTA", &quota))
+ {
+ LOG (GNUNET_ERROR_TYPE_ERROR,
+ _("No `%s' specified for `%s' in configuration!\n"), "QUOTA", section);
+ return NULL;
+ }
+ if (GNUNET_OK !=
+ GNUNET_CONFIGURATION_get_value_string (cfg, section, "DATABASE", &name))
+ {
+ LOG (GNUNET_ERROR_TYPE_ERROR,
+ _("No `%s' specified for `%s' in configuration!\n"), "DATABASE",
+ section);
+ return NULL;
+ }
+ bf_size = quota / 32; /* 8 bit per entry, 1 bit per 32 kb in DB */
+
+ ret = GNUNET_malloc (sizeof (struct GNUNET_DATACACHE_Handle));
+ ret->bloom_name = GNUNET_DISK_mktemp ("gnunet-datacachebloom");
+ if (NULL != ret->bloom_name)
+ {
+ ret->filter = GNUNET_CONTAINER_bloomfilter_load (ret->bloom_name, quota / 1024, /* 8 bit per entry in DB, expect 1k entries */
+ 5);
+ }
+ if (NULL == ret->filter)
+ {
+ ret->filter = GNUNET_CONTAINER_bloomfilter_init (NULL, bf_size, 5); /* approx. 3% false positives at max use */
+ }
+ if (NULL == ret->filter)
+ {
+ GNUNET_free (name);
+ GNUNET_free (ret->bloom_name);
+ GNUNET_free (ret);
+ return NULL;
+ }
+ ret->stats = GNUNET_STATISTICS_create ("datacache", cfg);
+ ret->section = GNUNET_strdup (section);
+ ret->env.cfg = cfg;
+ ret->env.delete_notify = &env_delete_notify;
+ ret->env.section = ret->section;
+ ret->env.cls = ret;
+ ret->env.delete_notify = &env_delete_notify;
+ ret->env.quota = quota;
+ LOG (GNUNET_ERROR_TYPE_INFO, _("Loading `%s' datacache plugin\n"), name);
+ GNUNET_asprintf (&libname, "libgnunet_plugin_datacache_%s", name);
+ ret->short_name = name;
+ ret->lib_name = libname;
+ ret->api = GNUNET_PLUGIN_load (libname, &ret->env);
+ if (ret->api == NULL)
+ {
+ LOG (GNUNET_ERROR_TYPE_ERROR,
+ _("Failed to load datacache plugin for `%s'\n"), name);
+ GNUNET_DATACACHE_destroy (ret);
+ return NULL;
+ }
+ return ret;
+}
+
+
+/**
+ * Destroy a data cache (and free associated resources).
+ *
+ * @param h handle to the datastore
+ */
+void
+GNUNET_DATACACHE_destroy (struct GNUNET_DATACACHE_Handle *h)
+{
+ if (h->filter != NULL)
+ GNUNET_CONTAINER_bloomfilter_free (h->filter);
+ if (h->api != NULL)
+ GNUNET_break (NULL == GNUNET_PLUGIN_unload (h->lib_name, h->api));
+ GNUNET_free (h->lib_name);
+ GNUNET_free (h->short_name);
+ GNUNET_free (h->section);
+ if (h->bloom_name != NULL)
+ {
+ if (0 != UNLINK (h->bloom_name))
+ GNUNET_log_from_strerror_file (GNUNET_ERROR_TYPE_WARNING, "datacache",
+ "unlink", h->bloom_name);
+ GNUNET_free (h->bloom_name);
+ }
+ GNUNET_STATISTICS_destroy (h->stats, GNUNET_NO);
+ GNUNET_free (h);
+}
+
+
+/**
+ * Store an item in the datastore.
+ *
+ * @param h handle to the datacache
+ * @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 GNUNET_OK on success, GNUNET_SYSERR on error (full, etc.)
+ */
+int
+GNUNET_DATACACHE_put (struct GNUNET_DATACACHE_Handle *h,
+ const GNUNET_HashCode * key, size_t size,
+ const char *data, enum GNUNET_BLOCK_Type type,
+ struct GNUNET_TIME_Absolute discard_time)
+{
+ uint32_t used;
+
+ used = h->api->put (h->api->cls, key, size, data, type, discard_time);
+ if (used == 0)
+ {
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+#if DEBUG_DATACACHE
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Stored data under key `%s' in cache\n",
+ GNUNET_h2s (key));
+#endif
+ GNUNET_STATISTICS_update (h->stats, gettext_noop ("# bytes stored"), size,
+ GNUNET_NO);
+ GNUNET_CONTAINER_bloomfilter_add (h->filter, key);
+ while (h->utilization + used > h->env.quota)
+ GNUNET_assert (GNUNET_OK == h->api->del (h->api->cls));
+ h->utilization += used;
+ return GNUNET_OK;
+}
+
+
+/**
+ * Iterate over the results for a particular key
+ * in the datacache.
+ *
+ * @param h handle to the datacache
+ * @param key what to look up
+ * @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
+ */
+unsigned int
+GNUNET_DATACACHE_get (struct GNUNET_DATACACHE_Handle *h,
+ const GNUNET_HashCode * key, enum GNUNET_BLOCK_Type type,
+ GNUNET_DATACACHE_Iterator iter, void *iter_cls)
+{
+ GNUNET_STATISTICS_update (h->stats, gettext_noop ("# requests received"), 1,
+ GNUNET_NO);
+#if DEBUG_DATACACHE
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Processing request for key `%s'\n",
+ GNUNET_h2s (key));
+#endif
+ if (GNUNET_OK != GNUNET_CONTAINER_bloomfilter_test (h->filter, key))
+ {
+ GNUNET_STATISTICS_update (h->stats,
+ gettext_noop
+ ("# requests filtered by bloom filter"), 1,
+ GNUNET_NO);
+#if DEBUG_DATACACHE
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Bloomfilter filters request for key `%s'\n",
+ GNUNET_h2s (key));
+#endif
+ return 0; /* can not be present */
+ }
+ return h->api->get (h->api->cls, key, type, iter, iter_cls);
+}
+
+
+
+/* end of datacache_api.c */
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-11-21 13:44:02 +0000