GNUnet debian-0.24.3-29-g453fda2cf
 
Loading...
Searching...
No Matches
ibf.h File Reference

invertible bloom filter More...

#include "platform.h"
#include "gnunet_util_lib.h"
Include dependency graph for ibf.h:
This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures

struct  IBF_Key
 Keys that can be inserted into and removed from an IBF. More...
 
struct  IBF_KeyHash
 Hash of an IBF key. More...
 
struct  IBF_Count
 Type of the count field of IBF buckets. More...
 
struct  InvertibleBloomFilter
 Invertible bloom filter (IBF). More...
 

Macros

#define IBF_BUCKET_SIZE
 Size of one ibf bucket in bytes.
 

Functions

void ibf_write_slice (const struct InvertibleBloomFilter *ibf, uint32_t start, uint32_t count, void *buf)
 Write buckets from an ibf to a buffer.
 
void ibf_read_slice (const void *buf, uint32_t start, uint32_t count, struct InvertibleBloomFilter *ibf)
 Read buckets from a buffer into an ibf.
 
struct IBF_Key ibf_key_from_hashcode (const struct GNUNET_HashCode *hash)
 Create a key from a hashcode.
 
void ibf_hashcode_from_key (struct IBF_Key key, struct GNUNET_HashCode *dst)
 Create a hashcode from a key, by replicating the key until the hascode is filled.
 
struct InvertibleBloomFilteribf_create (uint32_t size, uint8_t hash_num)
 Create an invertible bloom filter.
 
void ibf_insert (struct InvertibleBloomFilter *ibf, struct IBF_Key key)
 Insert a key into an IBF.
 
void ibf_remove (struct InvertibleBloomFilter *ibf, struct IBF_Key key)
 Remove a key from an IBF.
 
void ibf_subtract (struct InvertibleBloomFilter *ibf1, const struct InvertibleBloomFilter *ibf2)
 Subtract ibf2 from ibf1, storing the result in ibf1.
 
int ibf_decode (struct InvertibleBloomFilter *ibf, int *ret_side, struct IBF_Key *ret_id)
 Decode and remove an element from the IBF, if possible.
 
struct InvertibleBloomFilteribf_dup (const struct InvertibleBloomFilter *ibf)
 Create a copy of an IBF, the copy has to be destroyed properly.
 
void ibf_destroy (struct InvertibleBloomFilter *ibf)
 Destroy all resources associated with the invertible bloom filter.
 

Detailed Description

invertible bloom filter

Author
Florian Dold
Florian Dold
Elias Summermatter

Definition in file ibf.h.

Macro Definition Documentation

◆ IBF_BUCKET_SIZE

#define IBF_BUCKET_SIZE
Value:
(sizeof(struct IBF_Count) + sizeof(struct IBF_Key) \
+ sizeof(struct IBF_KeyHash))
Type of the count field of IBF buckets.
Definition ibf.h:64
Hash of an IBF key.
Definition ibf.h:55
Keys that can be inserted into and removed from an IBF.
Definition ibf.h:46

Size of one ibf bucket in bytes.

Definition at line 72 of file ibf.h.

82{
86 uint32_t size;
87
92 uint8_t hash_num;
93
98 struct IBF_Key *key_sum;
99
104 struct IBF_KeyHash *key_hash_sum;
105
111 struct IBF_Count *count;
112};
113
114
124void
125ibf_write_slice (const struct InvertibleBloomFilter *ibf,
126 uint32_t start,
127 uint32_t count,
128 void *buf);
129
130
139void
140ibf_read_slice (const void *buf,
141 uint32_t start,
142 uint32_t count,
143 struct InvertibleBloomFilter *ibf);
144
145
152struct IBF_Key
153ibf_key_from_hashcode (const struct GNUNET_HashCode *hash);
154
155
163void
165
166
175ibf_create (uint32_t size, uint8_t hash_num);
176
177
184void
185ibf_insert (struct InvertibleBloomFilter *ibf, struct IBF_Key key);
186
187
194void
195ibf_remove (struct InvertibleBloomFilter *ibf, struct IBF_Key key);
196
197
205void
207 const struct InvertibleBloomFilter *ibf2);
208
209
222int
224 int *ret_side,
225 struct IBF_Key *ret_id);
226
227
234ibf_dup (const struct InvertibleBloomFilter *ibf);
235
236
243void
245
246
247
248#if 0 /* keep Emacsens' auto-indent happy */
249{
250#endif
251#ifdef __cplusplus
252}
253#endif
254
255#endif
void ibf_subtract(struct InvertibleBloomFilter *ibf1, const struct InvertibleBloomFilter *ibf2)
Subtract ibf2 from ibf1, storing the result in ibf1.
Definition ibf.c:357
int ibf_decode(struct InvertibleBloomFilter *ibf, int *ret_side, struct IBF_Key *ret_id)
Decode and remove an element from the IBF, if possible.
Definition ibf.c:229
void ibf_read_slice(const void *buf, uint32_t start, uint32_t count, struct InvertibleBloomFilter *ibf)
Read buckets from a buffer into an ibf.
Definition ibf.c:324
struct IBF_Key ibf_key_from_hashcode(const struct GNUNET_HashCode *hash)
Create a key from a hashcode.
Definition ibf.c:44
void ibf_write_slice(const struct InvertibleBloomFilter *ibf, uint32_t start, uint32_t count, void *buf)
Write buckets from an ibf to a buffer.
Definition ibf.c:291
void ibf_hashcode_from_key(struct IBF_Key key, struct GNUNET_HashCode *dst)
Create a hashcode from a key, by replicating the key until the hascode is filled.
Definition ibf.c:58
void ibf_insert(struct InvertibleBloomFilter *ibf, struct IBF_Key key)
Insert a key into an IBF.
Definition ibf.c:168
struct InvertibleBloomFilter * ibf_dup(const struct InvertibleBloomFilter *ibf)
Create a copy of an IBF, the copy has to be destroyed properly.
Definition ibf.c:380
struct InvertibleBloomFilter * ibf_create(uint32_t size, uint8_t hash_num)
Create an invertible bloom filter.
Definition ibf.c:80
void ibf_remove(struct InvertibleBloomFilter *ibf, struct IBF_Key key)
Remove a key from an IBF.
Definition ibf.c:185
void ibf_destroy(struct InvertibleBloomFilter *ibf)
Destroy all resources associated with the invertible bloom filter.
Definition ibf.c:404
static int start
Set if we are to start default services (including ARM).
Definition gnunet-arm.c:38
struct GNUNET_HashCode key
The key used in the DHT.
static unsigned int hash_num
static unsigned int size
Size of the "table".
Definition peer.c:68
A 512-bit hashcode.
Invertible bloom filter (IBF).
Definition ibf.h:83

Function Documentation

◆ ibf_write_slice()

void ibf_write_slice ( const struct InvertibleBloomFilter ibf,
uint32_t  start,
uint32_t  count,
void *  buf 
)

Write buckets from an ibf to a buffer.

Exactly (IBF_BUCKET_SIZE*ibf->size) bytes are written to buf.

Parameters
ibfthe ibf to write
startwith which bucket to start
counthow many buckets to write
bufbuffer to write the data to

Definition at line 291 of file ibf.c.

293{
294 struct IBF_Key *key_dst;
295 struct IBF_KeyHash *key_hash_dst;
296 struct IBF_Count *count_dst;
297
298 GNUNET_assert (start + count <= ibf->size);
299
300 /* copy keys */
301 key_dst = (struct IBF_Key *) buf;
302 GNUNET_memcpy (key_dst, ibf->key_sum + start, count * sizeof *key_dst);
303 key_dst += count;
304 /* copy key hashes */
305 key_hash_dst = (struct IBF_KeyHash *) key_dst;
306 GNUNET_memcpy (key_hash_dst, ibf->key_hash_sum + start, count
307 * sizeof *key_hash_dst);
308 key_hash_dst += count;
309 /* copy counts */
310 count_dst = (struct IBF_Count *) key_hash_dst;
311 GNUNET_memcpy (count_dst, ibf->count + start, count * sizeof *count_dst);
312}
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
struct IBF_KeyHash * key_hash_sum
Xor sums of the hashes of the keys of inserted elements.
Definition ibf.h:105
struct IBF_Count * count
How many times has a bucket been hit? Can be negative, as a result of IBF subtraction.
Definition ibf.h:112
struct IBF_Key * key_sum
Xor sums of the elements' keys, used to identify the elements.
Definition ibf.h:99

References InvertibleBloomFilter::count, GNUNET_assert, GNUNET_memcpy, InvertibleBloomFilter::key_hash_sum, InvertibleBloomFilter::key_sum, size, and start.

Referenced by send_ibf(), send_ibf(), strata_estimator_write(), and strata_estimator_write().

Here is the caller graph for this function:

◆ ibf_read_slice()

void ibf_read_slice ( const void *  buf,
uint32_t  start,
uint32_t  count,
struct InvertibleBloomFilter ibf 
)

Read buckets from a buffer into an ibf.

Parameters
bufpointer to the buffer to read from
startwhich bucket to start at
counthow many buckets to read
ibfthe ibf to write to
bufpointer to the buffer to read from
startwhich bucket to start at
counthow many buckets to read
ibfthe ibf to read from

Definition at line 324 of file ibf.c.

326{
327 struct IBF_Key *key_src;
328 struct IBF_KeyHash *key_hash_src;
329 struct IBF_Count *count_src;
330
331 GNUNET_assert (count > 0);
332 GNUNET_assert (start + count <= ibf->size);
333
334 /* copy keys */
335 key_src = (struct IBF_Key *) buf;
336 GNUNET_memcpy (ibf->key_sum + start, key_src, count * sizeof *key_src);
337 key_src += count;
338 /* copy key hashes */
339 key_hash_src = (struct IBF_KeyHash *) key_src;
340 GNUNET_memcpy (ibf->key_hash_sum + start, key_hash_src, count
341 * sizeof *key_hash_src);
342 key_hash_src += count;
343 /* copy counts */
344 count_src = (struct IBF_Count *) key_hash_src;
345 GNUNET_memcpy (ibf->count + start, count_src, count * sizeof *count_src);
346}

References InvertibleBloomFilter::count, GNUNET_assert, GNUNET_memcpy, InvertibleBloomFilter::key_hash_sum, InvertibleBloomFilter::key_sum, size, and start.

Referenced by handle_union_p2p_ibf(), handle_union_p2p_ibf(), strata_estimator_read(), and strata_estimator_read().

Here is the caller graph for this function:

◆ ibf_key_from_hashcode()

struct IBF_Key ibf_key_from_hashcode ( const struct GNUNET_HashCode hash)

Create a key from a hashcode.

Parameters
hashthe hashcode
Returns
a key

Definition at line 44 of file ibf.c.

45{
46 return *(struct IBF_Key *) hash;
47}

◆ ibf_hashcode_from_key()

void ibf_hashcode_from_key ( struct IBF_Key  key,
struct GNUNET_HashCode dst 
)

Create a hashcode from a key, by replicating the key until the hascode is filled.

Parameters
keythe key
dsthashcode to store the result in

Definition at line 58 of file ibf.c.

60{
61 struct IBF_Key *p;
62 unsigned int i;
63 const unsigned int keys_per_hashcode = sizeof(struct GNUNET_HashCode)
64 / sizeof(struct IBF_Key);
65
66 p = (struct IBF_Key *) dst;
67 for (i = 0; i < keys_per_hashcode; i++)
68 *p++ = key;
69}
static struct GNUNET_OS_Process * p
Helper process we started.
Definition gnunet-uri.c:38

◆ ibf_create()

struct InvertibleBloomFilter * ibf_create ( uint32_t  size,
uint8_t  hash_num 
)

Create an invertible bloom filter.

Parameters
sizenumber of IBF buckets
hash_numnumber of buckets one element is hashed in, usually 3 or 4
Returns
the newly created invertible bloom filter, NULL on error
Parameters
sizenumber of IBF buckets
hash_numnumber of buckets one element is hashed in
Returns
the newly created invertible bloom filter, NULL on error

Definition at line 80 of file ibf.c.

81{
82 struct InvertibleBloomFilter *ibf;
83
84 GNUNET_assert (0 != size);
85
86 ibf = GNUNET_new (struct InvertibleBloomFilter);
87 ibf->count = GNUNET_malloc_large (size * sizeof(uint8_t));
88 if (NULL == ibf->count)
89 {
90 GNUNET_free (ibf);
91 return NULL;
92 }
93 ibf->key_sum = GNUNET_malloc_large (size * sizeof(struct IBF_Key));
94 if (NULL == ibf->key_sum)
95 {
96 GNUNET_free (ibf->count);
97 GNUNET_free (ibf);
98 return NULL;
99 }
100 ibf->key_hash_sum = GNUNET_malloc_large (size * sizeof(struct IBF_KeyHash));
101 if (NULL == ibf->key_hash_sum)
102 {
103 GNUNET_free (ibf->key_sum);
104 GNUNET_free (ibf->count);
105 GNUNET_free (ibf);
106 return NULL;
107 }
108 ibf->size = size;
109 ibf->hash_num = hash_num;
110
111 return ibf;
112}
#define GNUNET_malloc_large(size)
Wrapper around malloc.
#define GNUNET_new(type)
Allocate a struct or union of the given type.
#define GNUNET_free(ptr)
Wrapper around free.
uint32_t size
How many cells does this IBF have?
Definition ibf.h:87
uint8_t hash_num
In how many cells do we hash one element? Usually 4 or 3.
Definition ibf.h:93

◆ ibf_insert()

void ibf_insert ( struct InvertibleBloomFilter ibf,
struct IBF_Key  key 
)

Insert a key into an IBF.

Parameters
ibfthe IBF
keythe element's hash code

Definition at line 168 of file ibf.c.

169{
170 int buckets[ibf->hash_num];
171
172 GNUNET_assert (ibf->hash_num <= ibf->size);
173 ibf_get_indices (ibf, key, buckets);
174 ibf_insert_into (ibf, key, buckets, 1);
175}
static void ibf_get_indices(const struct InvertibleBloomFilter *ibf, struct IBF_Key key, int *dst)
Store unique bucket indices for the specified key in dst.
Definition ibf.c:119
static void ibf_insert_into(struct InvertibleBloomFilter *ibf, struct IBF_Key key, const int *buckets, int side)
Definition ibf.c:144

◆ ibf_remove()

void ibf_remove ( struct InvertibleBloomFilter ibf,
struct IBF_Key  key 
)

Remove a key from an IBF.

Parameters
ibfthe IBF
keythe element's hash code

Definition at line 185 of file ibf.c.

186{
187 int buckets[ibf->hash_num];
188
189 GNUNET_assert (ibf->hash_num <= ibf->size);
190 ibf_get_indices (ibf, key, buckets);
191 ibf_insert_into (ibf, key, buckets, -1);
192}

◆ ibf_subtract()

void ibf_subtract ( struct InvertibleBloomFilter ibf1,
const struct InvertibleBloomFilter ibf2 
)

Subtract ibf2 from ibf1, storing the result in ibf1.

The two IBF's must have the same parameters size and hash_num.

Parameters
ibf1IBF that is subtracted from
ibf2IBF that will be subtracted from ibf1

Definition at line 357 of file ibf.c.

359{
360 int i;
361
362 GNUNET_assert (ibf1->size == ibf2->size);
363 GNUNET_assert (ibf1->hash_num == ibf2->hash_num);
364
365 for (i = 0; i < ibf1->size; i++)
366 {
367 ibf1->count[i].count_val -= ibf2->count[i].count_val;
369 ibf1->key_sum[i].key_val ^= ibf2->key_sum[i].key_val;
370 }
371}
int8_t count_val
Definition ibf.h:65
uint32_t key_hash_val
Definition ibf.h:56
uint64_t key_val
Definition ibf.h:47

◆ ibf_decode()

int ibf_decode ( struct InvertibleBloomFilter ibf,
int *  ret_side,
struct IBF_Key ret_id 
)

Decode and remove an element from the IBF, if possible.

Parameters
ibfthe invertible bloom filter to decode
ret_sidesign of the cell's count where the decoded element came from. A negative sign indicates that the element was recovered resides in an IBF that was previously subtracted from.
ret_idreceives the hash code of the decoded element, if successful
Returns
GNUNET_YES if decoding an element was successful, GNUNET_NO if the IBF is empty, GNUNET_SYSERR if the decoding has failed
Parameters
ibfthe invertible bloom filter to decode
ret_sidesign of the cell's count where the decoded element came from. A negative sign indicates that the element was recovered resides in an IBF that was previously subtracted from.
ret_idreceives the hash code of the decoded element, if successful
Returns
GNUNET_YES if decoding an element was successful, GNUNET_NO if the IBF is empty, GNUNET_SYSERR if the decoding has failed

Definition at line 229 of file ibf.c.

231{
232 struct IBF_KeyHash hash;
233 int i;
234 int buckets[ibf->hash_num];
235
236 GNUNET_assert (NULL != ibf);
237
238 for (i = 0; i < ibf->size; i++)
239 {
240 int j;
241 int hit;
242
243 /* we can only decode from pure buckets */
244 if ((1 != ibf->count[i].count_val) && (-1 != ibf->count[i].count_val))
245 continue;
246
247 hash.key_hash_val = IBF_KEY_HASH_VAL (ibf->key_sum[i]);
248
249 /* test if the hash matches the key */
250 if (hash.key_hash_val != ibf->key_hash_sum[i].key_hash_val)
251 continue;
252
253 /* test if key in bucket hits its own location,
254 * if not, the key hash was subject to collision */
255 hit = GNUNET_NO;
256 ibf_get_indices (ibf, ibf->key_sum[i], buckets);
257 for (j = 0; j < ibf->hash_num; j++)
258 if (buckets[j] == i)
259 hit = GNUNET_YES;
260
261 if (GNUNET_NO == hit)
262 continue;
263
264 if (NULL != ret_side)
265 *ret_side = ibf->count[i].count_val;
266 if (NULL != ret_id)
267 *ret_id = ibf->key_sum[i];
268
269 /* insert on the opposite side, effectively removing the element */
270 ibf_insert_into (ibf, ibf->key_sum[i], buckets, -ibf->count[i].count_val);
271
272 return GNUNET_YES;
273 }
274
275 if (GNUNET_YES == ibf_is_empty (ibf))
276 return GNUNET_NO;
277 return GNUNET_SYSERR;
278}
#define IBF_KEY_HASH_VAL(k)
Compute the key's hash from the key.
Definition ibf.c:34
static int ibf_is_empty(struct InvertibleBloomFilter *ibf)
Test is the IBF is empty, i.e.
Definition ibf.c:199
@ GNUNET_YES
@ GNUNET_NO
@ GNUNET_SYSERR

◆ ibf_dup()

struct InvertibleBloomFilter * ibf_dup ( const struct InvertibleBloomFilter ibf)

Create a copy of an IBF, the copy has to be destroyed properly.

Parameters
ibfthe IBF to copy

Definition at line 380 of file ibf.c.

381{
382 struct InvertibleBloomFilter *copy;
383
384 copy = GNUNET_malloc (sizeof *copy);
385 copy->hash_num = ibf->hash_num;
386 copy->size = ibf->size;
387 copy->key_hash_sum = GNUNET_memdup (ibf->key_hash_sum, ibf->size
388 * sizeof(struct IBF_KeyHash));
389 copy->key_sum = GNUNET_memdup (ibf->key_sum, ibf->size * sizeof(struct
390 IBF_Key));
391 copy->count = GNUNET_memdup (ibf->count, ibf->size * sizeof(struct
392 IBF_Count));
393 return copy;
394}
#define GNUNET_malloc(size)
Wrapper around malloc.
#define GNUNET_memdup(buf, size)
Allocate and initialize a block of memory.

◆ ibf_destroy()

void ibf_destroy ( struct InvertibleBloomFilter ibf)

Destroy all resources associated with the invertible bloom filter.

No more ibf_*-functions may be called on ibf after calling destroy.

Parameters
ibfthe intertible bloom filter to destroy

Definition at line 404 of file ibf.c.

405{
406 GNUNET_free (ibf->key_sum);
408 GNUNET_free (ibf->count);
409 GNUNET_free (ibf);
410}