GNUnet  0.11.x
Data Structures | Macros | Functions
ibf.h File Reference
#include "platform.h"
#include "gnunet_util_lib.h"
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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. More...
 

Functions

void ibf_write_slice (const struct InvertibleBloomFilter *ibf, uint32_t start, uint64_t count, void *buf, uint8_t counter_max_length)
 Write buckets from an ibf to a buffer. More...
 
void ibf_read_slice (const void *buf, uint32_t start, uint64_t count, struct InvertibleBloomFilter *ibf, uint8_t counter_max_length)
 Read buckets from a buffer into an ibf. More...
 
struct IBF_Key ibf_key_from_hashcode (const struct GNUNET_HashCode *hash)
 Create a key from a hashcode. More...
 
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. More...
 
struct InvertibleBloomFilteribf_create (uint32_t size, uint8_t hash_num)
 Create an invertible bloom filter. More...
 
void ibf_insert (struct InvertibleBloomFilter *ibf, struct IBF_Key key)
 Insert a key into an IBF. More...
 
void ibf_remove (struct InvertibleBloomFilter *ibf, struct IBF_Key key)
 Remove a key from an IBF. More...
 
void ibf_subtract (struct InvertibleBloomFilter *ibf1, const struct InvertibleBloomFilter *ibf2)
 Subtract ibf2 from ibf1, storing the result in ibf1. More...
 
int ibf_decode (struct InvertibleBloomFilter *ibf, int *ret_side, struct IBF_Key *ret_id)
 Decode and remove an element from the IBF, if possible. More...
 
struct InvertibleBloomFilteribf_dup (const struct InvertibleBloomFilter *ibf)
 Create a copy of an IBF, the copy has to be destroyed properly. More...
 
void ibf_destroy (struct InvertibleBloomFilter *ibf)
 Destroy all resources associated with the invertible bloom filter. More...
 
uint8_t ibf_get_max_counter (struct InvertibleBloomFilter *ibf)
 Returns the minimal bytes needed to store the counter of the IBF. More...
 
void pack_counter (const struct InvertibleBloomFilter *ibf, uint32_t start, uint64_t count, uint8_t *buf, uint8_t counter_max_length)
 Packs the counter to transmit only the smallest possible amount of bytes and preventing overflow of the counter. More...
 
void unpack_counter (const struct InvertibleBloomFilter *ibf, uint32_t start, uint64_t count, uint8_t *buf, uint8_t counter_max_length)
 Unpacks the counter to transmit only the smallest possible amount of bytes and preventing overflow of the counter. More...
 

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 73 of file ibf.h.

Function Documentation

◆ ibf_write_slice()

void ibf_write_slice ( const struct InvertibleBloomFilter ibf,
uint32_t  start,
uint64_t  count,
void *  buf,
uint8_t  counter_max_length 
)

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

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
maxbit length of a counter for unpacking

Definition at line 323 of file ibf.c.

328 {
329  struct IBF_Key *key_dst;
330  struct IBF_KeyHash *key_hash_dst;
331 
332  GNUNET_assert (start + count <= ibf->size);
333 
334  /* copy keys */
335  key_dst = (struct IBF_Key *) buf;
336  GNUNET_memcpy (key_dst,
337  ibf->key_sum + start,
338  count * sizeof(*key_dst));
339  key_dst += count;
340  /* copy key hashes */
341  key_hash_dst = (struct IBF_KeyHash *) key_dst;
342  GNUNET_memcpy (key_hash_dst,
343  ibf->key_hash_sum + start,
344  count * sizeof(*key_hash_dst));
345  key_hash_dst += count;
346 
347  /* pack and copy counter */
348  pack_counter (ibf,
349  start,
350  count,
351  (uint8_t *) key_hash_dst,
352  counter_max_length);
353 
354 
355 }
static int start
Set if we are to start default services (including ARM).
Definition: gnunet-arm.c:39
static char buf[2048]
#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.
static unsigned int size
Size of the "table".
Definition: peer.c:67
void pack_counter(const struct InvertibleBloomFilter *ibf, uint32_t start, uint64_t count, uint8_t *buf, uint8_t counter_max_length)
Packs the counter to transmit only the smallest possible amount of bytes and preventing overflow of t...
Definition: ibf.c:369
struct IBF_KeyHash * key_hash_sum
Xor sums of the hashes of the keys of inserted elements.
Definition: ibf.h:105
struct IBF_Key * key_sum
Xor sums of the elements' keys, used to identify the elements.
Definition: ibf.h:99

References buf, GNUNET_assert, GNUNET_memcpy, InvertibleBloomFilter::key_hash_sum, InvertibleBloomFilter::key_sum, pack_counter(), size, and start.

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◆ ibf_read_slice()

void ibf_read_slice ( const void *  buf,
uint32_t  start,
uint64_t  count,
struct InvertibleBloomFilter ibf,
uint8_t  counter_max_length 
)

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
maxbit length of a counter for unpacking

Definition at line 523 of file ibf.c.

528 {
529  struct IBF_Key *key_src;
530  struct IBF_KeyHash *key_hash_src;
531  struct IBF_Count *count_src;
532 
533  GNUNET_assert (count > 0);
534  GNUNET_assert (start + count <= ibf->size);
535 
536  /* copy keys */
537  key_src = (struct IBF_Key *) buf;
538  GNUNET_memcpy (ibf->key_sum + start,
539  key_src,
540  count * sizeof *key_src);
541  key_src += count;
542  /* copy key hashes */
543  key_hash_src = (struct IBF_KeyHash *) key_src;
545  key_hash_src,
546  count * sizeof *key_hash_src);
547  key_hash_src += count;
548 
549  /* copy and unpack counts */
550  count_src = (struct IBF_Count *) key_hash_src;
551  unpack_counter (ibf,start,count,(uint8_t *) count_src,counter_max_length);
552 }
void unpack_counter(const struct InvertibleBloomFilter *ibf, uint32_t start, uint64_t count, uint8_t *buf, uint8_t counter_max_length)
Unpacks the counter to transmit only the smallest possible amount of bytes and preventing overflow of...
Definition: ibf.c:442

References buf, GNUNET_assert, GNUNET_memcpy, InvertibleBloomFilter::key_hash_sum, InvertibleBloomFilter::key_sum, size, start, and unpack_counter().

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◆ 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 1 of file ibf.c.

44 {
45  return *(struct IBF_Key *) hash;
46 }

Referenced by insert_iterator(), and register_hashcode().

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◆ 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 57 of file ibf.c.

59 {
60  struct IBF_Key *p;
61  unsigned int i;
62  const unsigned int keys_per_hashcode = sizeof(struct GNUNET_HashCode)
63  / sizeof(struct IBF_Key);
64 
65  p = (struct IBF_Key *) dst;
66  for (i = 0; i < keys_per_hashcode; i++)
67  *p++ = key;
68 }
struct GNUNET_HashCode key
The key used in the DHT.
static struct GNUNET_OS_Process * p
Helper process we started.
Definition: gnunet-qr.c:59
A 512-bit hashcode.

References key, and p.

Referenced by iter_hashcodes(), and register_hashcode().

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◆ 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 79 of file ibf.c.

80 {
81  struct InvertibleBloomFilter *ibf;
82 
83  GNUNET_assert (0 != size);
84 
85  ibf = GNUNET_new (struct InvertibleBloomFilter);
86  ibf->count = GNUNET_malloc_large (size * sizeof(uint8_t));
87  if (NULL == ibf->count)
88  {
89  GNUNET_free (ibf);
90  return NULL;
91  }
92  ibf->key_sum = GNUNET_malloc_large (size * sizeof(struct IBF_Key));
93  if (NULL == ibf->key_sum)
94  {
95  GNUNET_free (ibf->count);
96  GNUNET_free (ibf);
97  return NULL;
98  }
99  ibf->key_hash_sum = GNUNET_malloc_large (size * sizeof(struct IBF_KeyHash));
100  if (NULL == ibf->key_hash_sum)
101  {
102  GNUNET_free (ibf->key_sum);
103  GNUNET_free (ibf->count);
104  GNUNET_free (ibf);
105  return NULL;
106  }
107  ibf->size = size;
108  ibf->hash_num = hash_num;
109 
110  return ibf;
111 }
static unsigned int hash_num
#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.
Invertible bloom filter (IBF).
Definition: ibf.h:83
uint32_t size
How many cells does this IBF have?
Definition: ibf.h:87
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
uint8_t hash_num
In how many cells do we hash one element? Usually 4 or 3.
Definition: ibf.h:93

References InvertibleBloomFilter::count, GNUNET_assert, GNUNET_free, GNUNET_malloc_large, GNUNET_new, hash_num, InvertibleBloomFilter::hash_num, InvertibleBloomFilter::key_hash_sum, InvertibleBloomFilter::key_sum, InvertibleBloomFilter::size, and size.

Referenced by handle_union_p2p_ibf(), prepare_ibf(), run(), and strata_estimator_create().

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◆ 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 167 of file ibf.c.

168 {
169  int buckets[ibf->hash_num];
170 
171  GNUNET_assert (ibf->hash_num <= ibf->size);
172  ibf_get_indices (ibf, key, buckets);
173  ibf_insert_into (ibf, key, buckets, 1);
174 }
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:118
static void ibf_insert_into(struct InvertibleBloomFilter *ibf, struct IBF_Key key, const int *buckets, int side)
Definition: ibf.c:143

References GNUNET_assert, InvertibleBloomFilter::hash_num, ibf_get_indices(), ibf_insert_into(), key, and InvertibleBloomFilter::size.

Referenced by insert_iterator(), prepare_ibf_iterator(), and strata_estimator_insert().

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◆ 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 184 of file ibf.c.

185 {
186  int buckets[ibf->hash_num];
187 
188  GNUNET_assert (ibf->hash_num <= ibf->size);
189  ibf_get_indices (ibf, key, buckets);
190  ibf_insert_into (ibf, key, buckets, -1);
191 }

References GNUNET_assert, InvertibleBloomFilter::hash_num, ibf_get_indices(), ibf_insert_into(), key, and InvertibleBloomFilter::size.

Referenced by strata_estimator_remove().

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◆ 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 356 of file ibf.c.

358 {
359  int i;
360 
361  GNUNET_assert (ibf1->size == ibf2->size);
362  GNUNET_assert (ibf1->hash_num == ibf2->hash_num);
363 
364  for (i = 0; i < ibf1->size; i++)
365  {
366  ibf1->count[i].count_val -= ibf2->count[i].count_val;
367  ibf1->key_hash_sum[i].key_hash_val ^= ibf2->key_hash_sum[i].key_hash_val;
368  ibf1->key_sum[i].key_val ^= ibf2->key_sum[i].key_val;
369  }
370 }
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

References InvertibleBloomFilter::count, IBF_Count::count_val, GNUNET_assert, InvertibleBloomFilter::hash_num, InvertibleBloomFilter::key_hash_sum, IBF_KeyHash::key_hash_val, InvertibleBloomFilter::key_sum, IBF_Key::key_val, and InvertibleBloomFilter::size.

Referenced by decode_and_send(), run(), and strata_estimator_difference().

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◆ 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 228 of file ibf.c.

230 {
231  struct IBF_KeyHash hash;
232  int i;
233  int buckets[ibf->hash_num];
234 
235  GNUNET_assert (NULL != ibf);
236 
237  for (i = 0; i < ibf->size; i++)
238  {
239  int j;
240  int hit;
241 
242  /* we can only decode from pure buckets */
243  if ((1 != ibf->count[i].count_val) && (-1 != ibf->count[i].count_val))
244  continue;
245 
246  hash.key_hash_val = IBF_KEY_HASH_VAL (ibf->key_sum[i]);
247 
248  /* test if the hash matches the key */
249  if (hash.key_hash_val != ibf->key_hash_sum[i].key_hash_val)
250  continue;
251 
252  /* test if key in bucket hits its own location,
253  * if not, the key hash was subject to collision */
254  hit = GNUNET_NO;
255  ibf_get_indices (ibf, ibf->key_sum[i], buckets);
256  for (j = 0; j < ibf->hash_num; j++)
257  if (buckets[j] == i)
258  hit = GNUNET_YES;
259 
260  if (GNUNET_NO == hit)
261  continue;
262 
263  if (NULL != ret_side)
264  *ret_side = ibf->count[i].count_val;
265  if (NULL != ret_id)
266  *ret_id = ibf->key_sum[i];
267 
268  /* insert on the opposite side, effectively removing the element */
269  ibf_insert_into (ibf, ibf->key_sum[i], buckets, -ibf->count[i].count_val);
270 
271  return GNUNET_YES;
272  }
273 
274  if (GNUNET_YES == ibf_is_empty (ibf))
275  return GNUNET_NO;
276  return GNUNET_SYSERR;
277 }
@ GNUNET_YES
Definition: gnunet_common.h:97
@ GNUNET_NO
Definition: gnunet_common.h:94
@ GNUNET_SYSERR
Definition: gnunet_common.h:93
#define IBF_KEY_HASH_VAL(k)
Compute the key's hash from the key.
Definition: ibf.c:33
static int ibf_is_empty(struct InvertibleBloomFilter *ibf)
Test is the IBF is empty, i.e.
Definition: ibf.c:198

References InvertibleBloomFilter::count, IBF_Count::count_val, GNUNET_assert, GNUNET_NO, GNUNET_SYSERR, GNUNET_YES, InvertibleBloomFilter::hash_num, ibf_get_indices(), ibf_insert_into(), ibf_is_empty(), IBF_KEY_HASH_VAL, InvertibleBloomFilter::key_hash_sum, IBF_KeyHash::key_hash_val, InvertibleBloomFilter::key_sum, InvertibleBloomFilter::local_decoded_count, InvertibleBloomFilter::remote_decoded_count, and InvertibleBloomFilter::size.

Referenced by decode_and_send(), run(), and strata_estimator_difference().

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◆ 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 379 of file ibf.c.

380 {
381  struct InvertibleBloomFilter *copy;
382 
383  copy = GNUNET_malloc (sizeof *copy);
384  copy->hash_num = ibf->hash_num;
385  copy->size = ibf->size;
386  copy->key_hash_sum = GNUNET_memdup (ibf->key_hash_sum, ibf->size
387  * sizeof(struct IBF_KeyHash));
388  copy->key_sum = GNUNET_memdup (ibf->key_sum, ibf->size * sizeof(struct
389  IBF_Key));
390  copy->count = GNUNET_memdup (ibf->count, ibf->size * sizeof(struct
391  IBF_Count));
392  return copy;
393 }
#define GNUNET_malloc(size)
Wrapper around malloc.
#define GNUNET_memdup(buf, size)
Allocate and initialize a block of memory.

References InvertibleBloomFilter::count, GNUNET_malloc, GNUNET_memdup, InvertibleBloomFilter::hash_num, InvertibleBloomFilter::key_hash_sum, InvertibleBloomFilter::key_sum, and InvertibleBloomFilter::size.

Referenced by decode_and_send(), strata_estimator_difference(), and strata_estimator_dup().

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◆ 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 403 of file ibf.c.

404 {
405  GNUNET_free (ibf->key_sum);
406  GNUNET_free (ibf->key_hash_sum);
407  GNUNET_free (ibf->count);
408  GNUNET_free (ibf);
409 }

References InvertibleBloomFilter::count, GNUNET_free, InvertibleBloomFilter::key_hash_sum, and InvertibleBloomFilter::key_sum.

Referenced by _GSS_operation_destroy(), decode_and_send(), prepare_ibf(), strata_estimator_create(), strata_estimator_destroy(), strata_estimator_difference(), and union_op_cancel().

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◆ ibf_get_max_counter()

uint8_t ibf_get_max_counter ( struct InvertibleBloomFilter ibf)

Returns the minimal bytes needed to store the counter of the IBF.

Parameters
ibfthe IBF

Definition at line 298 of file ibf.c.

299 {
300  long long max_counter = 0;
301  for (uint64_t i = 0; i < ibf->size; i++)
302  {
303  if (ibf->count[i].count_val > max_counter)
304  {
305  max_counter = ibf->count[i].count_val;
306  }
307  }
308  return 64 - __builtin_clzll (max_counter);
309 }

References InvertibleBloomFilter::count, IBF_Count::count_val, and InvertibleBloomFilter::size.

Referenced by send_ibf().

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◆ pack_counter()

void pack_counter ( const struct InvertibleBloomFilter ibf,
uint32_t  start,
uint64_t  count,
uint8_t *  buf,
uint8_t  counter_max_length 
)

Packs the counter to transmit only the smallest possible amount of bytes and preventing overflow of the counter.

Parameters
ibfthe ibf to write
startwith which bucket to start
counthow many buckets to write
bufbuffer to write the data to
maxbit length of a counter for unpacking

Iterate over IBF bucket

Pack and compose counters to byte values

Shift bits if more than a byte has to be written or the store size is not empty

Pack data left in story before finishing

Definition at line 369 of file ibf.c.

374 {
375  uint8_t store_size = 0;
376  uint8_t store = 0;
377  uint16_t byte_ctr = 0;
378 
382  for (uint64_t i = start; i< (count + start);)
383  {
384  uint64_t count_val_to_write = ibf->count[i].count_val;
385  uint8_t count_len_to_write = counter_max_length;
386 
390  while ((count_len_to_write + store_size) >= 8)
391  {
392  uint8_t bit_shift = 0;
393 
398  if ((store_size > 0) || (count_len_to_write > 8))
399  {
400  uint8_t bit_unused = 8 - store_size;
401  bit_shift = count_len_to_write - bit_unused;
402  store = store << bit_unused;
403  }
404 
405  buf[byte_ctr] = ((count_val_to_write >> bit_shift) | store) & 0xFF;
406  byte_ctr++;
407  count_len_to_write -= (8 - store_size);
408  count_val_to_write = count_val_to_write & ((1ULL <<
409  count_len_to_write) - 1);
410  store = 0;
411  store_size = 0;
412  }
413  store = (store << count_len_to_write) | count_val_to_write;
414  store_size = store_size + count_len_to_write;
415  count_len_to_write = 0;
416  i++;
417  }
418 
422  if (store_size > 0)
423  {
424  buf[byte_ctr] = store << (8 - store_size);
425  byte_ctr++;
426  }
427 
428 }

References buf, InvertibleBloomFilter::count, IBF_Count::count_val, and start.

Referenced by ibf_write_slice().

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◆ unpack_counter()

void unpack_counter ( const struct InvertibleBloomFilter ibf,
uint32_t  start,
uint64_t  count,
uint8_t *  buf,
uint8_t  counter_max_length 
)

Unpacks the counter to transmit only the smallest possible amount of bytes and preventing overflow of the counter.

Parameters
ibfthe ibf to write
startwith which bucket to start
counthow many buckets to write
bufbuffer to write the data to
maxbit length of a counter for unpacking

Iterate over received bytes

Pack data left in story before finishing

Stop decoding when end is reached

Definition at line 442 of file ibf.c.

447 {
448  uint64_t ibf_counter_ctr = 0;
449  uint64_t store = 0;
450  uint64_t store_bit_ctr = 0;
451  uint64_t byte_ctr = 0;
452 
456  while (true)
457  {
458  uint8_t byte_read = buf[byte_ctr];
459  uint8_t bit_to_read_left = 8;
460  byte_ctr++;
461 
465  while (true)
466  {
470  if (ibf_counter_ctr > (count - 1))
471  return;
472 
473  /*
474  * Unpack the counter
475  */
476  if ((store_bit_ctr + bit_to_read_left) >= counter_max_length)
477  {
478  uint8_t bytes_used = counter_max_length - store_bit_ctr;
479  if (store_bit_ctr > 0)
480  {
481  store = store << bytes_used;
482  }
483 
484  uint8_t bytes_to_shift = bit_to_read_left - bytes_used;
485  uint64_t counter_part = byte_read >> bytes_to_shift;
486  store = store | counter_part;
487  ibf->count[ibf_counter_ctr + start].count_val = store;
488  byte_read = byte_read & ((1 << bytes_to_shift) - 1);
489  bit_to_read_left -= bytes_used;
490  ibf_counter_ctr++;
491  store = 0;
492  store_bit_ctr = 0;
493  }
494  else
495  {
496  store_bit_ctr += bit_to_read_left;
497  if (0 == store)
498  {
499  store = byte_read;
500  }
501  else
502  {
503  store = store << bit_to_read_left;
504  store = store | byte_read;
505  }
506  break;
507  }
508  }
509  }
510 }

References buf, InvertibleBloomFilter::count, IBF_Count::count_val, and start.

Referenced by ibf_read_slice().

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