gnunet-service-dht_datacache.c File Reference

GNUnet DHT service's datacache integration. More...

#include "platform.h"
#include "gnunet_datacache_lib.h"
#include "gnunet-service-dht_datacache.h"
#include "gnunet-service-dht_neighbours.h"
#include "gnunet-service-dht_routing.h"
#include "gnunet-service-dht.h"

Include dependency graph for gnunet-service-dht_datacache.c:

Go to the source code of this file.

Data Structures
struct	GetRequestContext
	Context containing information about a GET request. More...
struct	SuccContext
	Closure for datacache_get_successors_iterator(). More...

Macros
#define	LOG(kind, ...)   GNUNET_log_from (kind, "dht-dhtcache", __VA_ARGS__)
#define	NUM_CLOSEST   42
	How many "closest" results to we return for migration when asked (at most)? More...

Functions
void	GDS_DATACACHE_handle_put (struct GNUNET_TIME_Absolute expiration, const struct GNUNET_HashCode *key, unsigned int put_path_length, const struct GNUNET_PeerIdentity *put_path, enum GNUNET_BLOCK_Type type, size_t data_size, const void *data)
	Handle a datum we've received from another peer. More...
static int	datacache_get_iterator (void *cls, const struct GNUNET_HashCode *key, size_t data_size, const char *data, enum GNUNET_BLOCK_Type type, struct GNUNET_TIME_Absolute exp, unsigned int put_path_length, const struct GNUNET_PeerIdentity *put_path)
	Iterator for local get request results,. More...
enum GNUNET_BLOCK_EvaluationResult	GDS_DATACACHE_handle_get (const struct GNUNET_HashCode *key, enum GNUNET_BLOCK_Type type, const void *xquery, size_t xquery_size, struct GNUNET_BLOCK_Group *bg, GDS_DATACACHE_GetCallback gc, void *gc_cls)
	Handle a GET request we've received from another peer. More...
static int	datacache_random_iterator (void *cls, const struct GNUNET_HashCode *key, size_t data_size, const char *data, enum GNUNET_BLOCK_Type type, struct GNUNET_TIME_Absolute exp, unsigned int path_info_len, const struct GNUNET_PeerIdentity *path_info)
	Function called with a random element from the datacache. More...
int	GDS_DATACACHE_get_random_key (struct GNUNET_HashCode *key)
	Obtain a random key from the datacache. More...
static int	datacache_get_successors_iterator (void *cls, const struct GNUNET_HashCode *key, size_t size, const char *data, enum GNUNET_BLOCK_Type type, struct GNUNET_TIME_Absolute exp, unsigned int put_path_length, const struct GNUNET_PeerIdentity *put_path)
	Iterator for local get request results,. More...
void	GDS_DATACACHE_get_successors (const struct GNUNET_HashCode *key, GDS_DATACACHE_SuccessorCallback cb, void *cb_cls)
	Handle a request for data close to a key that we have received from another peer. More...
void	GDS_DATACACHE_init ()
	Initialize datacache subsystem. More...
void	GDS_DATACACHE_done ()
	Shutdown datacache subsystem. More...

Variables
static struct GNUNET_DATACACHE_Handle *	datacache
	Handle to the datacache service (for inserting/retrieving data) More...

Detailed Description

GNUnet DHT service's datacache integration.

Author

Christian Grothoff

Nathan Evans

Definition in file gnunet-service-dht_datacache.c.

Macro Definition Documentation

LOG

#define LOG	(		kind,
			...
	)		GNUNET_log_from (kind, "dht-dhtcache", __VA_ARGS__)

Definition at line 33 of file gnunet-service-dht_datacache.c.

Referenced by datacache_get_iterator(), GDS_DATACACHE_handle_get(), and GDS_DATACACHE_handle_put().

NUM_CLOSEST

#define NUM_CLOSEST   42

How many "closest" results to we return for migration when asked (at most)?

Definition at line 39 of file gnunet-service-dht_datacache.c.

Referenced by GDS_DATACACHE_get_successors().

Function Documentation

GDS_DATACACHE_handle_put()

void GDS_DATACACHE_handle_put	(	struct GNUNET_TIME_Absolute	expiration,
		const struct GNUNET_HashCode *	key,
		unsigned int	put_path_length,
		const struct GNUNET_PeerIdentity *	put_path,
		enum GNUNET_BLOCK_Type	type,
		size_t	data_size,
		const void *	data
	)

Handle a datum we've received from another peer.

Cache if possible.

Parameters

expiration	when will the reply expire
key	the query this reply is for
put_path_length	number of peers in put_path
put_path	path the reply took on put
type	type of the reply
data_size	number of bytes in data
data	application payload data

Definition at line 60 of file gnunet-service-dht_datacache.c.

References _, GDS_stats, gettext_noop, GNUNET_break, GNUNET_CRYPTO_hash_matching_bits(), GNUNET_DATACACHE_put(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_ERROR_TYPE_WARNING, GNUNET_h2s(), GNUNET_log, GNUNET_MAX_MESSAGE_SIZE, GNUNET_NO, GNUNET_STATISTICS_update(), LOG, and my_identity_hash.

Referenced by handle_dht_local_put(), handle_dht_p2p_put(), and process_reply_with_path().

{
  int r;

  if (NULL == datacache)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                _ ("%s request received, but have no datacache!\n"), "PUT");
    return;
  }
  if (data_size >= GNUNET_MAX_MESSAGE_SIZE)
  {
    GNUNET_break (0);
    return;
  }
  /* Put size is actual data size plus struct overhead plus path length (if any) */
  GNUNET_STATISTICS_update (GDS_stats,
                            gettext_noop ("# ITEMS stored in datacache"),
                            1,
                            GNUNET_NO);
  r = GNUNET_DATACACHE_put (datacache,
                            key,
                            GNUNET_CRYPTO_hash_matching_bits (key,
                                                              &my_identity_hash),
                            data_size,
                            data,
                            type,
                            expiration,
                            put_path_length,
                            put_path);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "DATACACHE PUT for key %s [%lu] completed (%d) after %u hops\n",
       GNUNET_h2s (key),
       (unsigned long) data_size,
       r,
       put_path_length);
}

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datacache_get_iterator()

static int datacache_get_iterator ( void *  cls, const struct GNUNET_HashCode *  key, size_t  data_size, const char *  data, enum GNUNET_BLOCK_Type  type, struct GNUNET_TIME_Absolute  exp, unsigned int  put_path_length, const struct GNUNET_PeerIdentity *  put_path  )

static

Iterator for local get request results,.

Parameters

cls	closure for iterator, a struct GetRequestContext
exp	when does this value expire?
key	the key this data is stored under
data_size	the size of the data identified by key
data	the actual data
type	the type of the data
put_path_length	number of peers in put_path
put_path	path the reply took on put

Returns

GNUNET_OK to continue iteration, anything else to stop iteration.

Definition at line 162 of file gnunet-service-dht_datacache.c.

References _, GetRequestContext::bg, ctx, GetRequestContext::eval, GetRequestContext::gc, GetRequestContext::gc_cls, GDS_block_context, GDS_stats, gettext_noop, GNUNET_BLOCK_EO_LOCAL_SKIP_CRYPTO, GNUNET_BLOCK_evaluate(), GNUNET_BLOCK_EVALUATION_OK_DUPLICATE, GNUNET_BLOCK_EVALUATION_OK_LAST, GNUNET_BLOCK_EVALUATION_OK_MORE, GNUNET_BLOCK_EVALUATION_REQUEST_INVALID, GNUNET_BLOCK_EVALUATION_REQUEST_VALID, GNUNET_BLOCK_EVALUATION_RESULT_INVALID, GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT, GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED, GNUNET_break, GNUNET_break_op, GNUNET_ERROR_TYPE_DEBUG, GNUNET_ERROR_TYPE_WARNING, GNUNET_h2s(), GNUNET_log, GNUNET_NO, GNUNET_OK, GNUNET_STATISTICS_update(), GNUNET_SYSERR, GNUNET_TIME_absolute_get_remaining(), LOG, GetRequestContext::xquery, and GetRequestContext::xquery_size.

Referenced by GDS_DATACACHE_handle_get().

{
  static char non_null;
  struct GetRequestContext *ctx = cls;
  enum GNUNET_BLOCK_EvaluationResult eval;

  if (0 == GNUNET_TIME_absolute_get_remaining (exp).rel_value_us)
  {
    GNUNET_break (0);  /* why does datacache return expired values? */
    return GNUNET_OK;   /* skip expired record */
  }
  if ((NULL == data) &&
      (0 == data_size))
    data = &non_null; /* point anywhere, but not to NULL */

  eval
    = GNUNET_BLOCK_evaluate (GDS_block_context,
                             type,
                             ctx->bg,
                             GNUNET_BLOCK_EO_LOCAL_SKIP_CRYPTO,
                             key,
                             ctx->xquery,
                             ctx->xquery_size,
                             data,
                             data_size);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "Found reply for query %s in datacache, evaluation result is %d\n",
       GNUNET_h2s (key),
       (int) eval);
  ctx->eval = eval;
  switch (eval)
  {
  case GNUNET_BLOCK_EVALUATION_OK_MORE:
  case GNUNET_BLOCK_EVALUATION_OK_LAST:
    /* forward to local clients */
    GNUNET_STATISTICS_update (GDS_stats,
                              gettext_noop
                                ("# Good RESULTS found in datacache"), 1,
                              GNUNET_NO);
    ctx->gc (ctx->gc_cls,
             type,
             exp,
             key,
             put_path_length, put_path,
             0, NULL,
             data, data_size);
    break;

  case GNUNET_BLOCK_EVALUATION_OK_DUPLICATE:
    GNUNET_STATISTICS_update (GDS_stats,
                              gettext_noop (
                                "# Duplicate RESULTS found in datacache"),
                              1,
                              GNUNET_NO);
    break;

  case GNUNET_BLOCK_EVALUATION_RESULT_INVALID:
    GNUNET_STATISTICS_update (GDS_stats,
                              gettext_noop (
                                "# Invalid RESULTS found in datacache"),
                              1,
                              GNUNET_NO);
    break;

  case GNUNET_BLOCK_EVALUATION_RESULT_IRRELEVANT:
    GNUNET_STATISTICS_update (GDS_stats,
                              gettext_noop (
                                "# Irrelevant RESULTS found in datacache"),
                              1,
                              GNUNET_NO);
    break;

  case GNUNET_BLOCK_EVALUATION_REQUEST_VALID:
    GNUNET_break (0);
    break;

  case GNUNET_BLOCK_EVALUATION_REQUEST_INVALID:
    GNUNET_break_op (0);
    return GNUNET_SYSERR;

  case GNUNET_BLOCK_EVALUATION_TYPE_NOT_SUPPORTED:
    GNUNET_STATISTICS_update (GDS_stats,
                              gettext_noop (
                                "# Unsupported RESULTS found in datacache"),
                              1,
                              GNUNET_NO);
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                _ ("Unsupported block type (%u) in local response!\n"),
                type);
    break;
  }
  return (eval == GNUNET_BLOCK_EVALUATION_OK_LAST) ? GNUNET_NO : GNUNET_OK;
}

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GDS_DATACACHE_handle_get()

enum GNUNET_BLOCK_EvaluationResult GDS_DATACACHE_handle_get	(	const struct GNUNET_HashCode *	key,
		enum GNUNET_BLOCK_Type	type,
		const void *	xquery,
		size_t	xquery_size,
		struct GNUNET_BLOCK_Group *	bg,
		GDS_DATACACHE_GetCallback	gc,
		void *	gc_cls
	)

Handle a GET request we've received from another peer.

Parameters

key	the query
type	requested data type
xquery	extended query
xquery_size	number of bytes in xquery
bg	block group to use for reply evaluation
gc	function to call on the results
gc_cls	closure for gc

Returns

evaluation result for the local replies

Definition at line 277 of file gnunet-service-dht_datacache.c.

References GetRequestContext::bg, datacache_get_iterator(), GetRequestContext::eval, GetRequestContext::gc, GetRequestContext::gc_cls, GDS_stats, gettext_noop, GNUNET_BLOCK_EVALUATION_REQUEST_VALID, GNUNET_DATACACHE_get(), GNUNET_ERROR_TYPE_DEBUG, GNUNET_h2s(), GNUNET_NO, GNUNET_STATISTICS_update(), GetRequestContext::key, LOG, GetRequestContext::xquery, and GetRequestContext::xquery_size.

Referenced by handle_dht_local_get(), and handle_dht_p2p_get().

{
  struct GetRequestContext ctx;
  unsigned int r;

  if (NULL == datacache)
    return GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
  GNUNET_STATISTICS_update (GDS_stats,
                            gettext_noop ("# GET requests given to datacache"),
                            1,
                            GNUNET_NO);
  ctx.eval = GNUNET_BLOCK_EVALUATION_REQUEST_VALID;
  ctx.key = *key;
  ctx.xquery = xquery;
  ctx.xquery_size = xquery_size;
  ctx.bg = bg;
  ctx.gc = gc;
  ctx.gc_cls = gc_cls;
  r = GNUNET_DATACACHE_get (datacache,
                            key,
                            type,
                            &datacache_get_iterator,
                            &ctx);
  LOG (GNUNET_ERROR_TYPE_DEBUG,
       "DATACACHE GET for key %s completed (%d). %u results found.\n",
       GNUNET_h2s (key),
       ctx.eval,
       r);
  return ctx.eval;
}

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datacache_random_iterator()

static int datacache_random_iterator ( void *  cls, const struct GNUNET_HashCode *  key, size_t  data_size, const char *  data, enum GNUNET_BLOCK_Type  type, struct GNUNET_TIME_Absolute  exp, unsigned int  path_info_len, const struct GNUNET_PeerIdentity *  path_info  )

static

Function called with a random element from the datacache.

Stores the key in the closure.

Parameters

cls	a struct GNUNET_HashCode *, where to store the key
key	key for the content
data_size	number of bytes in data
data	content stored
type	type of the content
exp	when will the content expire?
path_info_len	number of entries in path_info
path_info	a path through the network

Returns

GNUNET_OK to continue iterating, GNUNET_SYSERR to abort

Definition at line 330 of file gnunet-service-dht_datacache.c.

References GNUNET_OK, and GetRequestContext::key.

Referenced by GDS_DATACACHE_get_random_key().

{
  struct GNUNET_HashCode *dest = cls;

  *dest = *key;
  return GNUNET_OK; /* should actually not matter which we return */
}

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GDS_DATACACHE_get_random_key()

int GDS_DATACACHE_get_random_key

(

struct GNUNET_HashCode *

key

)

Obtain a random key from the datacache.

Used by Whanau for load-balancing.

Parameters

[out]

key

where to store the key of a random element, randomized by PRNG if datacache is empty

Returns

GNUNET_OK on success, GNUNET_SYSERR if the datacache is empty

Definition at line 355 of file gnunet-service-dht_datacache.c.

References datacache_random_iterator(), GNUNET_CRYPTO_hash_create_random(), GNUNET_CRYPTO_QUALITY_NONCE, GNUNET_DATACACHE_get_random(), GNUNET_OK, and GNUNET_SYSERR.

{
  if (0 ==
      GNUNET_DATACACHE_get_random (datacache,
                                   &datacache_random_iterator,
                                   key))
  {
    /* randomize key in this case */
    GNUNET_CRYPTO_hash_create_random (GNUNET_CRYPTO_QUALITY_NONCE,
                                      key);
    return GNUNET_SYSERR;
  }
  return GNUNET_OK;
}

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datacache_get_successors_iterator()

static int datacache_get_successors_iterator ( void *  cls, const struct GNUNET_HashCode *  key, size_t  size, const char *  data, enum GNUNET_BLOCK_Type  type, struct GNUNET_TIME_Absolute  exp, unsigned int  put_path_length, const struct GNUNET_PeerIdentity *  put_path  )

static

Iterator for local get request results,.

Parameters

cls	closure with the struct GNUNET_HashCode * with the trail ID
key	the key this data is stored under
size	the size of the data identified by key
data	the actual data
type	the type of the data
exp	when does this value expire?
put_path_length	number of peers in put_path
put_path	path the reply took on put

Returns

GNUNET_OK to continue iteration, anything else to stop iteration.

Definition at line 403 of file gnunet-service-dht_datacache.c.

References SuccContext::cb, SuccContext::cb_cls, GNUNET_DHT_RO_RECORD_ROUTE, GNUNET_OK, and sc.

Referenced by GDS_DATACACHE_get_successors().

{
  const struct SuccContext *sc = cls;

  /* NOTE: The datacache currently does not store the RO from
     the original 'put', so we don't know the 'correct' option
     at this point anymore.  Thus, we conservatively assume
     that recording is desired (for now). */
  sc->cb (sc->cb_cls,
          GNUNET_DHT_RO_RECORD_ROUTE,
          key,
          type,
          put_path_length, put_path,
          exp,
          data,
          size);
  return GNUNET_OK;
}

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GDS_DATACACHE_get_successors()

void GDS_DATACACHE_get_successors	(	const struct GNUNET_HashCode *	key,
		GDS_DATACACHE_SuccessorCallback	cb,
		void *	cb_cls
	)

Handle a request for data close to a key that we have received from another peer.

Parameters

key	the location at which the peer is looking for data that is close
cb	function to call with the result
cb_cls	closure for cb

Definition at line 439 of file gnunet-service-dht_datacache.c.

References SuccContext::cb, SuccContext::cb_cls, datacache_get_successors_iterator(), GNUNET_DATACACHE_get_closest(), and NUM_CLOSEST.

{
  struct SuccContext sc;

  sc.cb = cb;
  sc.cb_cls = cb_cls;
  (void) GNUNET_DATACACHE_get_closest (datacache,
                                       key,
                                       NUM_CLOSEST,
                                       &datacache_get_successors_iterator,
                                       &sc);
}

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GDS_DATACACHE_init()

void GDS_DATACACHE_init

(

void

)

Initialize datacache subsystem.

Definition at line 459 of file gnunet-service-dht_datacache.c.

References GDS_cfg, and GNUNET_DATACACHE_create().

Referenced by run().

{
  datacache = GNUNET_DATACACHE_create (GDS_cfg, "dhtcache");
}

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GDS_DATACACHE_done()

void GDS_DATACACHE_done

(

void

)

Shutdown datacache subsystem.

Definition at line 469 of file gnunet-service-dht_datacache.c.

References GNUNET_DATACACHE_destroy().

Referenced by shutdown_task().

{
  if (NULL != datacache)
  {
    GNUNET_DATACACHE_destroy (datacache);
    datacache = NULL;
  }
}

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Variable Documentation

datacache

struct GNUNET_DATACACHE_Handle* datacache

static

Handle to the datacache service (for inserting/retrieving data)

Definition at line 44 of file gnunet-service-dht_datacache.c.