-copied block-related functions from namestore to namecache

1 files changed, 608 insertions, 0 deletions

diff --git a/src/namecache/plugin_namecache_sqlite.c b/src/namecache/plugin_namecache_sqlite.c
new file mode 100644
index 000000000..7eb8b4503
--- /dev/null
+++ b/src/namecache/plugin_namecache_sqlite.c
@@ -0,0 +1,608 @@
+ /*
+  * This file is part of GNUnet
+  * (C) 2009-2013 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 namecache/plugin_namecache_sqlite.c
+ * @brief sqlite-based namecache backend
+ * @author Christian Grothoff
+ */
+
+#include "platform.h"
+#include "gnunet_namecache_plugin.h"
+#include "gnunet_namecache_service.h"
+#include "gnunet_gnsrecord_lib.h"
+#include "namecache.h"
+#include <sqlite3.h>
+
+/**
+ * After how many ms "busy" should a DB operation fail for good?  A
+ * low value makes sure that we are more responsive to requests
+ * (especially PUTs).  A high value guarantees a higher success rate
+ * (SELECTs in iterate can take several seconds despite LIMIT=1).
+ *
+ * The default value of 1s should ensure that users do not experience
+ * huge latencies while at the same time allowing operations to
+ * succeed with reasonable probability.
+ */
+#define BUSY_TIMEOUT_MS 1000
+
+
+/**
+ * Log an error message at log-level 'level' that indicates
+ * a failure of the command 'cmd' on file 'filename'
+ * with the message given by strerror(errno).
+ */
+#define LOG_SQLITE(db, level, cmd) do { GNUNET_log_from (level, "namecache-sqlite", _("`%s' failed at %s:%d with error: %s\n"), cmd, __FILE__, __LINE__, sqlite3_errmsg(db->dbh)); } while(0)
+
+#define LOG(kind,...) GNUNET_log_from (kind, "namecache-sqlite", __VA_ARGS__)
+
+
+/**
+ * Context for all functions in this plugin.
+ */
+struct Plugin
+{
+
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+  /**
+   * Database filename.
+   */
+  char *fn;
+
+  /**
+   * Native SQLite database handle.
+   */
+  sqlite3 *dbh;
+
+  /**
+   * Precompiled SQL for caching a block
+   */
+  sqlite3_stmt *cache_block;
+
+  /**
+   * Precompiled SQL for deleting an older block
+   */
+  sqlite3_stmt *delete_block;
+
+  /**
+   * Precompiled SQL for looking up a block
+   */
+  sqlite3_stmt *lookup_block;
+
+  /**
+   * Precompiled SQL for removing expired blocks
+   */
+  sqlite3_stmt *expire_blocks;
+
+
+};
+
+
+/**
+ * @brief Prepare a SQL statement
+ *
+ * @param dbh handle to the database
+ * @param zSql SQL statement, UTF-8 encoded
+ * @param ppStmt set to the prepared statement
+ * @return 0 on success
+ */
+static int
+sq_prepare (sqlite3 * dbh, const char *zSql, sqlite3_stmt ** ppStmt)
+{
+  char *dummy;
+  int result;
+
+  result =
+      sqlite3_prepare_v2 (dbh, zSql, strlen (zSql), ppStmt,
+                          (const char **) &dummy);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "Prepared `%s' / %p: %d\n", zSql, *ppStmt, result);
+  return result;
+}
+
+
+/**
+ * Create our database indices.
+ *
+ * @param dbh handle to the database
+ */
+static void
+create_indices (sqlite3 * dbh)
+{
+  /* create indices */
+  if ( (SQLITE_OK !=
+        sqlite3_exec (dbh, "CREATE INDEX IF NOT EXISTS ir_query_hash ON ns096blocks (query,expiration_time)",
+                      NULL, NULL, NULL)) ||
+       (SQLITE_OK !=
+        sqlite3_exec (dbh, "CREATE INDEX IF NOT EXISTS ir_block_expiration ON ns096blocks (expiration_time)",
+                      NULL, NULL, NULL)) )
+    LOG (GNUNET_ERROR_TYPE_ERROR,
+         "Failed to create indices: %s\n", sqlite3_errmsg (dbh));
+}
+
+
+#if 0
+#define CHECK(a) GNUNET_break(a)
+#define ENULL NULL
+#else
+#define ENULL &e
+#define ENULL_DEFINED 1
+#define CHECK(a) if (! a) { GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "%s\n", e); sqlite3_free(e); }
+#endif
+
+
+/**
+ * Initialize the database connections and associated
+ * data structures (create tables and indices
+ * as needed as well).
+ *
+ * @param plugin the plugin context (state for this module)
+ * @return #GNUNET_OK on success
+ */
+static int
+database_setup (struct Plugin *plugin)
+{
+  sqlite3_stmt *stmt;
+  char *afsdir;
+#if ENULL_DEFINED
+  char *e;
+#endif
+
+  if (GNUNET_OK !=
+      GNUNET_CONFIGURATION_get_value_filename (plugin->cfg, "namecache-sqlite",
+                                               "FILENAME", &afsdir))
+  {
+    GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR,
+                               "namecache-sqlite", "FILENAME");
+    return GNUNET_SYSERR;
+  }
+  if (GNUNET_OK != GNUNET_DISK_file_test (afsdir))
+  {
+    if (GNUNET_OK != GNUNET_DISK_directory_create_for_file (afsdir))
+    {
+      GNUNET_break (0);
+      GNUNET_free (afsdir);
+      return GNUNET_SYSERR;
+    }
+  }
+  /* afsdir should be UTF-8-encoded. If it isn't, it's a bug */
+  plugin->fn = afsdir;
+
+  /* Open database and precompile statements */
+  if (sqlite3_open (plugin->fn, &plugin->dbh) != SQLITE_OK)
+  {
+    LOG (GNUNET_ERROR_TYPE_ERROR,
+         _("Unable to initialize SQLite: %s.\n"),
+         sqlite3_errmsg (plugin->dbh));
+    return GNUNET_SYSERR;
+  }
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA temp_store=MEMORY", NULL, NULL,
+                       ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA synchronous=NORMAL", NULL, NULL,
+                       ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA legacy_file_format=OFF", NULL, NULL,
+                       ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA auto_vacuum=INCREMENTAL", NULL,
+                       NULL, ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA encoding=\"UTF-8\"", NULL,
+                       NULL, ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA locking_mode=EXCLUSIVE", NULL, NULL,
+                       ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA count_changes=OFF", NULL, NULL,
+                       ENULL));
+  CHECK (SQLITE_OK ==
+         sqlite3_exec (plugin->dbh, "PRAGMA page_size=4092", NULL, NULL,
+                       ENULL));
+
+  CHECK (SQLITE_OK == sqlite3_busy_timeout (plugin->dbh, BUSY_TIMEOUT_MS));
+
+
+  /* Create tables */
+  CHECK (SQLITE_OK ==
+         sq_prepare (plugin->dbh,
+                     "SELECT 1 FROM sqlite_master WHERE tbl_name = 'ns096blocks'",
+                     &stmt));
+  if ((sqlite3_step (stmt) == SQLITE_DONE) &&
+      (sqlite3_exec
+       (plugin->dbh,
+        "CREATE TABLE ns096blocks ("
+        " query BLOB NOT NULL DEFAULT '',"
+        " block BLOB NOT NULL DEFAULT '',"
+        " expiration_time INT8 NOT NULL DEFAULT 0"
+        ")",
+        NULL, NULL, NULL) != SQLITE_OK))
+  {
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR, "sqlite3_exec");
+    sqlite3_finalize (stmt);
+    return GNUNET_SYSERR;
+  }
+  sqlite3_finalize (stmt);
+  create_indices (plugin->dbh);
+
+  if ((sq_prepare
+       (plugin->dbh,
+        "INSERT INTO ns096blocks (query,block,expiration_time) VALUES (?, ?, ?)",
+        &plugin->cache_block) != SQLITE_OK) ||
+      (sq_prepare
+       (plugin->dbh,
+        "DELETE FROM ns096blocks WHERE expiration_time<?",
+        &plugin->expire_blocks) != SQLITE_OK) ||
+      (sq_prepare
+       (plugin->dbh,
+        "DELETE FROM ns096blocks WHERE query=? AND expiration_time<=?",
+        &plugin->delete_block) != SQLITE_OK) ||
+      (sq_prepare
+       (plugin->dbh,
+        "SELECT block FROM ns096blocks WHERE query=? ORDER BY expiration_time DESC LIMIT 1",
+        &plugin->lookup_block) != SQLITE_OK)
+      )
+  {
+    LOG_SQLITE (plugin,GNUNET_ERROR_TYPE_ERROR, "precompiling");
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
+
+/**
+ * Shutdown database connection and associate data
+ * structures.
+ * @param plugin the plugin context (state for this module)
+ */
+static void
+database_shutdown (struct Plugin *plugin)
+{
+  int result;
+  sqlite3_stmt *stmt;
+
+  if (NULL != plugin->cache_block)
+    sqlite3_finalize (plugin->cache_block);
+  if (NULL != plugin->lookup_block)
+    sqlite3_finalize (plugin->lookup_block);
+  if (NULL != plugin->expire_blocks)
+    sqlite3_finalize (plugin->expire_blocks);
+  if (NULL != plugin->delete_block)
+    sqlite3_finalize (plugin->delete_block);
+  result = sqlite3_close (plugin->dbh);
+  if (result == SQLITE_BUSY)
+  {
+    LOG (GNUNET_ERROR_TYPE_WARNING,
+         _("Tried to close sqlite without finalizing all prepared statements.\n"));
+    stmt = sqlite3_next_stmt (plugin->dbh, NULL);
+    while (stmt != NULL)
+    {
+      GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite",
+                       "Closing statement %p\n", stmt);
+      result = sqlite3_finalize (stmt);
+      if (result != SQLITE_OK)
+        GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING, "sqlite",
+                         "Failed to close statement %p: %d\n", stmt, result);
+      stmt = sqlite3_next_stmt (plugin->dbh, NULL);
+    }
+    result = sqlite3_close (plugin->dbh);
+  }
+  if (SQLITE_OK != result)
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR, "sqlite3_close");
+
+  GNUNET_free_non_null (plugin->fn);
+}
+
+
+/**
+ * Removes any expired block.
+ *
+ * @param plugin the plugin
+ */
+static void
+namecache_sqlite_expire_blocks (struct Plugin *plugin)
+{
+  struct GNUNET_TIME_Absolute now;
+  int n;
+
+  now = GNUNET_TIME_absolute_get ();
+  if (SQLITE_OK != sqlite3_bind_int64 (plugin->expire_blocks,
+                                       1, now.abs_value_us))
+  {
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    if (SQLITE_OK != sqlite3_reset (plugin->expire_blocks))
+      LOG_SQLITE (plugin,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    return;
+  }
+  n = sqlite3_step (plugin->expire_blocks);
+  if (SQLITE_OK != sqlite3_reset (plugin->expire_blocks))
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_reset");
+  switch (n)
+  {
+  case SQLITE_DONE:
+    GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite", "Records expired\n");
+    return;
+  case SQLITE_BUSY:
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    return;
+  default:
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    return;
+  }
+}
+
+
+/**
+ * Cache a block in the datastore.
+ *
+ * @param cls closure (internal context for the plugin)
+ * @param block block to cache
+ * @return #GNUNET_OK on success, else #GNUNET_SYSERR
+ */
+static int
+namecache_sqlite_cache_block (void *cls,
+                              const struct GNUNET_NAMESTORE_Block *block)
+{
+  struct Plugin *plugin = cls;
+  struct GNUNET_HashCode query;
+  struct GNUNET_TIME_Absolute expiration;
+  int64_t dval;
+  size_t block_size;
+  int n;
+
+  namecache_sqlite_expire_blocks (plugin);
+  GNUNET_CRYPTO_hash (&block->derived_key,
+                      sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey),
+                      &query);
+  expiration = GNUNET_TIME_absolute_ntoh (block->expiration_time);
+  dval = (int64_t) expiration.abs_value_us;
+  if (dval < 0)
+    dval = INT64_MAX;
+  block_size = ntohl (block->purpose.size) +
+    sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey) +
+    sizeof (struct GNUNET_CRYPTO_EcdsaSignature);
+  if (block_size > 64 * 65536)
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+
+  /* delete old version of the block */
+  if ( (SQLITE_OK !=
+        sqlite3_bind_blob (plugin->delete_block, 1,
+                           &query, sizeof (struct GNUNET_HashCode),
+                           SQLITE_STATIC)) ||
+       (SQLITE_OK !=
+        sqlite3_bind_int64 (plugin->delete_block,
+                            2, dval)) )
+  {
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    if (SQLITE_OK != sqlite3_reset (plugin->delete_block))
+      LOG_SQLITE (plugin,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    return GNUNET_SYSERR;
+  }
+  n = sqlite3_step (plugin->delete_block);
+  switch (n)
+  {
+  case SQLITE_DONE:
+    GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "sqlite", "Old block deleted\n");
+    break;
+  case SQLITE_BUSY:
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    break;
+  default:
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    break;
+  }
+  if (SQLITE_OK != sqlite3_reset (plugin->delete_block))
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_reset");
+
+  /* insert new version of the block */
+  if ((SQLITE_OK !=
+       sqlite3_bind_blob (plugin->cache_block, 1,
+                          &query, sizeof (struct GNUNET_HashCode),
+                          SQLITE_STATIC)) ||
+      (SQLITE_OK !=
+       sqlite3_bind_blob (plugin->cache_block, 2,
+                          block, block_size,
+                          SQLITE_STATIC)) ||
+      (SQLITE_OK !=
+       sqlite3_bind_int64 (plugin->cache_block, 3,
+                           dval)))
+  {
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    if (SQLITE_OK != sqlite3_reset (plugin->cache_block))
+      LOG_SQLITE (plugin,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    return GNUNET_SYSERR;
+
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Caching block under derived key `%s'\n",
+              GNUNET_h2s_full (&query));
+  n = sqlite3_step (plugin->cache_block);
+  if (SQLITE_OK != sqlite3_reset (plugin->cache_block))
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_reset");
+  switch (n)
+  {
+  case SQLITE_DONE:
+    LOG (GNUNET_ERROR_TYPE_DEBUG,
+         "Record stored\n");
+    return GNUNET_OK;
+  case SQLITE_BUSY:
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    return GNUNET_NO;
+  default:
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_step");
+    return GNUNET_SYSERR;
+  }
+}
+
+
+/**
+ * Get the block for a particular zone and label in the
+ * datastore.  Will return at most one result to the iterator.
+ *
+ * @param cls closure (internal context for the plugin)
+ * @param query hash of public key derived from the zone and the label
+ * @param iter function to call with the result
+ * @param iter_cls closure for @a iter
+ * @return #GNUNET_OK on success, #GNUNET_NO if there were no results, #GNUNET_SYSERR on error
+ */
+static int
+namecache_sqlite_lookup_block (void *cls,
+                               const struct GNUNET_HashCode *query,
+                               GNUNET_NAMECACHE_BlockCallback iter, void *iter_cls)
+{
+  struct Plugin *plugin = cls;
+  int ret;
+  int sret;
+  size_t block_size;
+  const struct GNUNET_NAMESTORE_Block *block;
+
+  if (SQLITE_OK != sqlite3_bind_blob (plugin->lookup_block, 1,
+                                      query, sizeof (struct GNUNET_HashCode),
+                                      SQLITE_STATIC))
+  {
+    LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_bind_XXXX");
+    if (SQLITE_OK != sqlite3_reset (plugin->lookup_block))
+      LOG_SQLITE (plugin,
+                  GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                  "sqlite3_reset");
+    return GNUNET_SYSERR;
+  }
+  ret = GNUNET_NO;
+  if (SQLITE_ROW == (sret = sqlite3_step (plugin->lookup_block)))
+  {
+    block = sqlite3_column_blob (plugin->lookup_block, 0);
+    block_size = sqlite3_column_bytes (plugin->lookup_block, 0);
+    if ( (block_size < sizeof (struct GNUNET_NAMESTORE_Block)) ||
+         (ntohl (block->purpose.size) +
+          sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey) +
+          sizeof (struct GNUNET_CRYPTO_EcdsaSignature) != block_size) )
+    {
+      GNUNET_break (0);
+      ret = GNUNET_SYSERR;
+    }
+    else
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "Found block under derived key `%s'\n",
+                  GNUNET_h2s_full (query));
+      iter (iter_cls, block);
+      ret = GNUNET_YES;
+    }
+  }
+  else
+  {
+    if (SQLITE_DONE != sret)
+    {
+      LOG_SQLITE (plugin, GNUNET_ERROR_TYPE_ERROR, "sqlite_step");
+      ret = GNUNET_SYSERR;
+    }
+    else
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+                  "No block found under derived key `%s'\n",
+                  GNUNET_h2s_full (query));
+    }
+  }
+  if (SQLITE_OK != sqlite3_reset (plugin->lookup_block))
+    LOG_SQLITE (plugin,
+                GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+                "sqlite3_reset");
+  return ret;
+}
+
+
+/**
+ * Entry point for the plugin.
+ *
+ * @param cls the "struct GNUNET_NAMECACHE_PluginEnvironment*"
+ * @return NULL on error, otherwise the plugin context
+ */
+void *
+libgnunet_plugin_namecache_sqlite_init (void *cls)
+{
+  static struct Plugin plugin;
+  const struct GNUNET_CONFIGURATION_Handle *cfg = cls;
+  struct GNUNET_NAMECACHE_PluginFunctions *api;
+
+  if (NULL != plugin.cfg)
+    return NULL;                /* can only initialize once! */
+  memset (&plugin, 0, sizeof (struct Plugin));
+  plugin.cfg = cfg;
+  if (GNUNET_OK != database_setup (&plugin))
+  {
+    database_shutdown (&plugin);
+    return NULL;
+  }
+  api = GNUNET_new (struct GNUNET_NAMECACHE_PluginFunctions);
+  api->cls = &plugin;
+  api->cache_block = &namecache_sqlite_cache_block;
+  api->lookup_block = &namecache_sqlite_lookup_block;
+  LOG (GNUNET_ERROR_TYPE_INFO,
+       _("Sqlite database running\n"));
+  return api;
+}
+
+
+/**
+ * Exit point from the plugin.
+ *
+ * @param cls the plugin context (as returned by "init")
+ * @return always NULL
+ */
+void *
+libgnunet_plugin_namecache_sqlite_done (void *cls)
+{
+  struct GNUNET_NAMECACHE_PluginFunctions *api = cls;
+  struct Plugin *plugin = api->cls;
+
+  database_shutdown (plugin);
+  plugin->cfg = NULL;
+  GNUNET_free (api);
+  LOG (GNUNET_ERROR_TYPE_DEBUG,
+       "sqlite plugin is finished\n");
+  return NULL;
+}
+
+/* end of plugin_namecache_sqlite.c */