ObjFW  Check-in [6712442fad]

Overview
Comment:Revert several OFHashMap related commits.

This reverts:
* "Add a per-hashtable seed."
(cd49c7fcb4b8dca62dccdbf6545d37d86b639eef)
* "OFMapTable: Reseed on resize."
(5b545165691cd9ad838c9125b02ff7c857bd4b99)
* "Add of_random()."
(9810f191b4e8c1612e7e55095c87e589660fbdba)
* "OFMapTable: Rotate hash by a random number of bits"
(3bef412217232d01f202794f7175c130afa1df8f)

It turned out that these were slowing down all classes based on
OFHashMap significantly. As there is still no proof that the seeded
one-at-a-time hash is vulnerable to DoS, these changes were overly
paranoid. While overly paranoid is usually ok, it is not if it severely
impacts performance.

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SHA3-256: 6712442fad3b6214a6292b266b0318dbaabe6ccc829258f104b3cd26a3545195
User & Date: js on 2012-12-07 13:57:13
Other Links: manifest | tags
Context
2012-12-07
14:50
quicksort: Reduce used space. check-in: a747ad5478 user: js tags: trunk
13:57
Revert several OFHashMap related commits. check-in: 6712442fad user: js tags: trunk
02:11
Make GCC happy by declaring private methods. check-in: bff1f8e5a7 user: js tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Modified src/OFMapTable.h from [91b9317d21] to [dcccbffbc5].

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 */
@interface OFMapTable: OFObject <OFCopying, OFFastEnumeration>
{
	of_map_table_functions_t keyFunctions, valueFunctions;
	struct of_map_table_bucket **buckets;
	uint32_t minCapacity, capacity, count;
	unsigned long mutations;
	uint32_t seed;
	uint8_t rotate;
}

/*!
 * @brief Creates a new OFMapTable with the specified key and value functions.
 *
 * @param keyFunctions A structure of functions for handling keys
 * @param valueFunctions A structure of functions for handling values








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 */
@interface OFMapTable: OFObject <OFCopying, OFFastEnumeration>
{
	of_map_table_functions_t keyFunctions, valueFunctions;
	struct of_map_table_bucket **buckets;
	uint32_t minCapacity, capacity, count;
	unsigned long mutations;


}

/*!
 * @brief Creates a new OFMapTable with the specified key and value functions.
 *
 * @param keyFunctions A structure of functions for handling keys
 * @param valueFunctions A structure of functions for handling values
︙︙

Modified src/OFMapTable.m from [fda4d04529] to [458807374d].

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 * Public License, either version 2 or 3, which can be found in the file
 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#include "config.h"

#include <stdlib.h>
#include <string.h>

#include <assert.h>

#include <sys/time.h>

#import "OFMapTable.h"
#import "OFEnumerator.h"

#import "OFEnumerationMutationException.h"
#import "OFInvalidArgumentException.h"
#import "OFNotImplementedException.h"
#import "OFOutOfRangeException.h"








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 * Public License, either version 2 or 3, which can be found in the file
 * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
 * file.
 */

#include "config.h"


#include <string.h>

#include <assert.h>



#import "OFMapTable.h"
#import "OFEnumerator.h"

#import "OFEnumerationMutationException.h"
#import "OFInvalidArgumentException.h"
#import "OFNotImplementedException.h"
#import "OFOutOfRangeException.h"
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		minCapacity = capacity;

		buckets = [self allocMemoryWithSize: sizeof(*buckets)
					      count: capacity];

		memset(buckets, 0, capacity * sizeof(*buckets));

		if (of_hash_seed != 0) {
			seed = of_random();
			rotate = of_random() & 0x1F;
		}
	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}








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		minCapacity = capacity;

		buckets = [self allocMemoryWithSize: sizeof(*buckets)
					      count: capacity];

		memset(buckets, 0, capacity * sizeof(*buckets));





	} @catch (id e) {
		[self release];
		@throw e;
	}

	return self;
}
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	@try {
		uint32_t i;

		for (i = 0; i < capacity; i++)
			if (buckets[i] != NULL && buckets[i] != &deleted)
				[copy OF_setValue: buckets[i]->value
					   forKey: buckets[i]->key
					     hash: OF_ROR(
						       buckets[i]->hash ^ seed,
						       rotate)];
	} @catch (id e) {
		[copy release];
		@throw e;
	}

	copy->minCapacity = MIN_CAPACITY;









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	@try {
		uint32_t i;

		for (i = 0; i < capacity; i++)
			if (buckets[i] != NULL && buckets[i] != &deleted)
				[copy OF_setValue: buckets[i]->value
					   forKey: buckets[i]->key

					     hash: buckets[i]->hash];

	} @catch (id e) {
		[copy release];
		@throw e;
	}

	copy->minCapacity = MIN_CAPACITY;
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	uint32_t i, hash, last;

	if (key == NULL)
		@throw [OFInvalidArgumentException
		    exceptionWithClass: [self class]
			      selector: _cmd];

	hash = OF_ROL(keyFunctions.hash(key) ^ seed, rotate);
	last = capacity;

	for (i = hash & (capacity - 1); i < last && buckets[i] != NULL; i++) {
		if (buckets[i] == &deleted)
			continue;

		if (keyFunctions.equal(buckets[i]->key, key))








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	uint32_t i, hash, last;

	if (key == NULL)
		@throw [OFInvalidArgumentException
		    exceptionWithClass: [self class]
			      selector: _cmd];

	hash = keyFunctions.hash(key);
	last = capacity;

	for (i = hash & (capacity - 1); i < last && buckets[i] != NULL; i++) {
		if (buckets[i] == &deleted)
			continue;

		if (keyFunctions.equal(buckets[i]->key, key))
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	}

	return NULL;
}

- (void)OF_resizeForCount: (uint32_t)newCount
{
	uint32_t i, fullness, newCapacity, newSeed = 0, seedUpdate = 0;
	struct of_map_table_bucket **newBuckets;
	uint8_t newRotate = 0;

	if (newCount > UINT32_MAX || newCount > UINT32_MAX / sizeof(*buckets) ||
	    newCount > UINT32_MAX / 8)
		@throw [OFOutOfRangeException exceptionWithClass: [self class]];

	fullness = newCount * 8 / capacity;









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	}

	return NULL;
}

- (void)OF_resizeForCount: (uint32_t)newCount
{
	uint32_t i, fullness, newCapacity;
	struct of_map_table_bucket **newBuckets;


	if (newCount > UINT32_MAX || newCount > UINT32_MAX / sizeof(*buckets) ||
	    newCount > UINT32_MAX / 8)
		@throw [OFOutOfRangeException exceptionWithClass: [self class]];

	fullness = newCount * 8 / capacity;
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	newBuckets = [self allocMemoryWithSize: sizeof(*newBuckets)
					 count: newCapacity];

	for (i = 0; i < newCapacity; i++)
		newBuckets[i] = NULL;

	if (of_hash_seed != 0) {
		newSeed = of_random();
		seedUpdate = seed ^ newSeed;

		newRotate = of_random() & 0x1F;
	}

	for (i = 0; i < capacity; i++) {
		if (buckets[i] != NULL && buckets[i] != &deleted) {
			uint32_t j, last;

			buckets[i]->hash = OF_ROL(
			    OF_ROR(buckets[i]->hash, rotate) ^ seedUpdate,
			    newRotate);

			last = newCapacity;

			j = buckets[i]->hash & (newCapacity - 1);
			for (; j < last && newBuckets[j] != NULL; j++);

			/* In case the last bucket is already used */
			if (j >= last) {








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	newBuckets = [self allocMemoryWithSize: sizeof(*newBuckets)
					 count: newCapacity];

	for (i = 0; i < newCapacity; i++)
		newBuckets[i] = NULL;








	for (i = 0; i < capacity; i++) {
		if (buckets[i] != NULL && buckets[i] != &deleted) {
			uint32_t j, last;





			last = newCapacity;

			j = buckets[i]->hash & (newCapacity - 1);
			for (; j < last && newBuckets[j] != NULL; j++);

			/* In case the last bucket is already used */
			if (j >= last) {
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			newBuckets[j] = buckets[i];
		}
	}

	[self freeMemory: buckets];
	buckets = newBuckets;
	capacity = newCapacity;
	seed = newSeed;
	rotate = newRotate;
}

- (void)OF_setValue: (void*)value
	     forKey: (void*)key
	       hash: (uint32_t)hash
{
	uint32_t i, last, seededHash;
	void *old;

	if (key == NULL || value == NULL)
		@throw [OFInvalidArgumentException
		    exceptionWithClass: [self class]
			      selector: _cmd];

	last = capacity;
	seededHash = OF_ROL(hash ^ seed, rotate);

	for (i = seededHash & (capacity - 1); i < last && buckets[i] != NULL;
	    i++) {
		if (buckets[i] == &deleted)
			continue;

		if (keyFunctions.equal(buckets[i]->key, key))
			break;
	}

	/* In case the last bucket is already used */
	if (i >= last) {
		last = seededHash & (capacity - 1);

		for (i = 0; i < last && buckets[i] != NULL; i++) {
			if (buckets[i] == &deleted)
				continue;

			if (keyFunctions.equal(buckets[i]->key, key))
				break;
		}
	}

	/* Key not in dictionary */
	if (i >= last || buckets[i] == NULL || buckets[i] == &deleted ||
	    !keyFunctions.equal(buckets[i]->key, key)) {
		struct of_map_table_bucket *bucket;

		[self OF_resizeForCount: count + 1];
		seededHash = OF_ROL(hash ^ seed, rotate);

		mutations++;
		last = capacity;

		for (i = seededHash & (capacity - 1); i < last &&
		    buckets[i] != NULL && buckets[i] != &deleted; i++);

		/* In case the last bucket is already used */
		if (i >= last) {
			last = seededHash & (capacity - 1);

			for (i = 0; i < last && buckets[i] != NULL &&
			    buckets[i] != &deleted; i++);
		}

		if (i >= last)
			@throw [OFOutOfRangeException








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			newBuckets[j] = buckets[i];
		}
	}

	[self freeMemory: buckets];
	buckets = newBuckets;
	capacity = newCapacity;


}

- (void)OF_setValue: (void*)value
	     forKey: (void*)key
	       hash: (uint32_t)hash
{
	uint32_t i, last;
	void *old;

	if (key == NULL || value == NULL)
		@throw [OFInvalidArgumentException
		    exceptionWithClass: [self class]
			      selector: _cmd];

	last = capacity;


	for (i = hash & (capacity - 1); i < last && buckets[i] != NULL; i++) {

		if (buckets[i] == &deleted)
			continue;

		if (keyFunctions.equal(buckets[i]->key, key))
			break;
	}

	/* In case the last bucket is already used */
	if (i >= last) {
		last = hash & (capacity - 1);

		for (i = 0; i < last && buckets[i] != NULL; i++) {
			if (buckets[i] == &deleted)
				continue;

			if (keyFunctions.equal(buckets[i]->key, key))
				break;
		}
	}

	/* Key not in dictionary */
	if (i >= last || buckets[i] == NULL || buckets[i] == &deleted ||
	    !keyFunctions.equal(buckets[i]->key, key)) {
		struct of_map_table_bucket *bucket;

		[self OF_resizeForCount: count + 1];


		mutations++;
		last = capacity;

		for (i = hash & (capacity - 1); i < last &&
		    buckets[i] != NULL && buckets[i] != &deleted; i++);

		/* In case the last bucket is already used */
		if (i >= last) {
			last = hash & (capacity - 1);

			for (i = 0; i < last && buckets[i] != NULL &&
			    buckets[i] != &deleted; i++);
		}

		if (i >= last)
			@throw [OFOutOfRangeException
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			bucket->value = valueFunctions.retain(value);
		} @catch (id e) {
			keyFunctions.release(key);
			[self freeMemory: bucket];
			@throw e;
		}

		bucket->hash = seededHash;

		buckets[i] = bucket;
		count++;

		return;
	}









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			bucket->value = valueFunctions.retain(value);
		} @catch (id e) {
			keyFunctions.release(key);
			[self freeMemory: bucket];
			@throw e;
		}

		bucket->hash = hash;

		buckets[i] = bucket;
		count++;

		return;
	}
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	uint32_t i, hash, last;

	if (key == NULL)
		@throw [OFInvalidArgumentException
		    exceptionWithClass: [self class]
			      selector: _cmd];

	hash = OF_ROL(keyFunctions.hash(key) ^ seed, rotate);
	last = capacity;

	for (i = hash & (capacity - 1); i < last && buckets[i] != NULL; i++) {
		if (buckets[i] == &deleted)
			continue;

		if (keyFunctions.equal(buckets[i]->key, key)) {








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	uint32_t i, hash, last;

	if (key == NULL)
		@throw [OFInvalidArgumentException
		    exceptionWithClass: [self class]
			      selector: _cmd];

	hash = keyFunctions.hash(key);
	last = capacity;

	for (i = hash & (capacity - 1); i < last && buckets[i] != NULL; i++) {
		if (buckets[i] == &deleted)
			continue;

		if (keyFunctions.equal(buckets[i]->key, key)) {
︙︙

Modified src/OFObject.h from [b44a7c59ae] to [c663f1ca8f].

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#import "OFObject+Serialization.h"

#ifdef __cplusplus
extern "C" {
#endif
extern id of_alloc_object(Class class_, size_t extraSize, size_t extraAlignment,
    void **extra);
extern uint32_t of_random(void);
extern size_t of_pagesize;
extern size_t of_num_cpus;
extern uint32_t of_hash_seed;
#ifdef __cplusplus
}
#endif








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#import "OFObject+Serialization.h"

#ifdef __cplusplus
extern "C" {
#endif
extern id of_alloc_object(Class class_, size_t extraSize, size_t extraAlignment,
    void **extra);

extern size_t of_pagesize;
extern size_t of_num_cpus;
extern uint32_t of_hash_seed;
#ifdef __cplusplus
}
#endif

Modified src/OFObject.m from [0307a15aa9] to [ce3e8ba58d].

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	if OF_UNLIKELY (extra != NULL)
		*extra = (char*)instance + instanceSize + extraAlignment;

	return instance;
}

uint32_t
of_random()
{
#if defined(OF_HAVE_ARC4RANDOM)
	return arc4random();
#elif defined(OF_HAVE_RANDOM)
	static BOOL initialized = NO;

	if (!initialized) {
		struct timeval t;

		gettimeofday(&t, NULL);
		srandom((unsigned)(t.tv_sec ^ t.tv_usec));
		initialized = YES;
	}

	return (uint32_t)((random() << 16) | (random() & 0xFFFF));
#else
	static BOOL initialized = NO;

	if (!initialized) {
		struct timeval t;

		gettimeofday(&t, NULL);
		srand((unsigned)(t.tv_sec ^ t.tv_usec));
		initialized = YES;
	}

	return (rand() << 16) | (rand() & 0xFFFF);
#endif
}

const char*
_NSPrintForDebugger(id object)
{
	return [[object description]
	    cStringWithEncoding: OF_STRING_ENCODING_NATIVE];
}









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	if OF_UNLIKELY (extra != NULL)
		*extra = (char*)instance + instanceSize + extraAlignment;

	return instance;
}

































const char*
_NSPrintForDebugger(id object)
{
	return [[object description]
	    cStringWithEncoding: OF_STRING_ENCODING_NATIVE];
}
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		of_pagesize = 4096;
# ifdef _SC_NPROCESSORS_CONF
	if ((of_num_cpus = sysconf(_SC_NPROCESSORS_CONF)) < 1)
# endif
		of_num_cpus = 1;
#endif


	of_hash_seed = of_random();











}

+ (void)initialize
{
}

+ alloc








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		of_pagesize = 4096;
# ifdef _SC_NPROCESSORS_CONF
	if ((of_num_cpus = sysconf(_SC_NPROCESSORS_CONF)) < 1)
# endif
		of_num_cpus = 1;
#endif

#if defined(OF_HAVE_ARC4RANDOM)
	of_hash_seed = arc4random();
#elif defined(OF_HAVE_RANDOM)
	struct timeval t;
	gettimeofday(&t, NULL);
	srandom((unsigned)(t.tv_sec ^ t.tv_usec));
	of_hash_seed = (uint32_t)((random() << 16) | (random() & 0xFFFF));
#else
	struct timeval t;
	gettimeofday(&t, NULL);
	srand((unsigned)(t.tv_sec ^ t.tv_usec));
	of_hash_seed = (uint32_t)((rand() << 16) | (rand() & 0xFFFF));
#endif
}

+ (void)initialize
{
}

+ alloc
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Modified src/macros.h from [6b2bc955be] to [ba733f14be].

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#if defined(__MACH__) && defined(__arm__)
# define OF_IOS
#endif

#define OF_ROL(value, bits)						\
	(((value) << ((bits) % (sizeof(value) * 8))) |			\
	(value) >> (sizeof(value) * 8 - ((bits) % (sizeof(value) * 8))))
#define OF_ROR(value, bits)						\
	(((value) >> ((bits) % (sizeof(value) * 8))) |			\
	(value) << (sizeof(value) * 8 - ((bits) % (sizeof(value) * 8))))

#define OF_HASH_INIT(hash) hash = of_hash_seed
#define OF_HASH_ADD(hash, byte)			\
	{					\
		hash += (uint8_t)(byte);	\
		hash += (hash << 10);		\
		hash ^= (hash >> 6);		\








<
<
<








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#if defined(__MACH__) && defined(__arm__)
# define OF_IOS
#endif

#define OF_ROL(value, bits)						\
	(((value) << ((bits) % (sizeof(value) * 8))) |			\
	(value) >> (sizeof(value) * 8 - ((bits) % (sizeof(value) * 8))))




#define OF_HASH_INIT(hash) hash = of_hash_seed
#define OF_HASH_ADD(hash, byte)			\
	{					\
		hash += (uint8_t)(byte);	\
		hash += (hash << 10);		\
		hash ^= (hash >> 6);		\
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