max/nix-super
1
0
Fork 0
mirror of https://github.com/privatevoid-net/nix-super.git synced 2024-11-30 01:26:15 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

* Maintain the count field properly.

Browse source
This commit is contained in:
Eelco Dolstra 2006-05-03 23:17:42 +00:00
parent db0d865ec4
commit b803fb95cb
1 changed files with 44 additions and 29 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

73
table/aterm-map.cc
View file

@ -23,7 +23,7 @@ private:
KeyValue * hashTable;
/* Current size of the hash table. */
unsigned int size;
unsigned int capacity;
/* Number of elements in the hash table. */
unsigned int count;
@ -49,6 +49,8 @@ public:
void remove(ATerm key);
unsigned int size();
private:
void init(unsigned int expectedCount);
@ -56,7 +58,7 @@ private:
void resizeTable(unsigned int expectedCount);
void copy(KeyValue * elements, unsigned int size);
void copy(KeyValue * elements, unsigned int capacity);
inline unsigned int hash1(ATerm key) const;
inline unsigned int hash2(ATerm key) const;
@ -72,7 +74,7 @@ ATermMap::ATermMap(unsigned int expectedCount)
ATermMap::ATermMap(const ATermMap & map)
{
init(map.maxCount);
copy(map.hashTable, map.size);
copy(map.hashTable, map.capacity);
}
@ -81,7 +83,7 @@ ATermMap & ATermMap::operator = (const ATermMap & map)
if (this == &map) return *this;
free();
init(map.maxCount);
copy(map.hashTable, map.size);
copy(map.hashTable, map.capacity);
return *this;
}
@ -95,7 +97,7 @@ ATermMap::~ATermMap()
void ATermMap::init(unsigned int expectedCount)
{
assert(sizeof(ATerm) * 2 == sizeof(KeyValue));
size = 0;
capacity = 0;
count = 0;
maxCount = 0;
hashTable = 0;
@ -133,20 +135,20 @@ void ATermMap::resizeTable(unsigned int expectedCount)
// cout << maxCount << " " << size << endl;
// cout << (double) size / maxCount << endl;
unsigned int oldSize = size;
unsigned int oldCapacity = capacity;
KeyValue * oldHashTable = hashTable;
maxCount = expectedCount;
size = roundToPowerOf2(maxCount * maxLoadFactor);
hashTable = (KeyValue *) calloc(sizeof(KeyValue), size);
ATprotectArray((ATerm *) hashTable, size * 2);
capacity = roundToPowerOf2(maxCount * maxLoadFactor);
hashTable = (KeyValue *) calloc(sizeof(KeyValue), capacity);
ATprotectArray((ATerm *) hashTable, capacity * 2);
// cout << size << endl;
// cout << capacity << endl;
/* Re-hash the elements in the old table. */
if (oldSize != 0) {
if (oldCapacity != 0) {
count = 0;
copy(oldHashTable, oldSize);
copy(oldHashTable, oldCapacity);
ATunprotectArray((ATerm *) oldHashTable);
::free(oldHashTable);
nrResizes++;
@ -154,9 +156,9 @@ void ATermMap::resizeTable(unsigned int expectedCount)
}
void ATermMap::copy(KeyValue * elements, unsigned int size)
void ATermMap::copy(KeyValue * elements, unsigned int capacity)
{
for (unsigned int i = 0; i < size; ++i)
for (unsigned int i = 0; i < capacity; ++i)
if (elements[i].value) /* i.e., non-empty, non-deleted element */
set(elements[i].key, elements[i].value);
}
@ -174,10 +176,10 @@ unsigned int ATermMap::hash1(ATerm key) const
/* Approximately equal to:
double d = key2 * 0.6180339887;
unsigned int h = (int) (size * (d - floor(d)));
unsigned int h = (int) (capacity * (d - floor(d)));
*/
unsigned int h = (size * ((key2 * knuth) & ((1 << shift) - 1))) >> shift;
unsigned int h = (capacity * ((key2 * knuth) & ((1 << shift) - 1))) >> shift;
return h;
}
@ -186,9 +188,10 @@ unsigned int ATermMap::hash1(ATerm key) const
unsigned int ATermMap::hash2(ATerm key) const
{
unsigned int key2 = ((unsigned int) key) >> 2;
/* Note: the result must be relatively prime to `size' (which is a
power of 2), so we make sure that the result is always odd. */
unsigned int h = ((key2 * 134217689) & (size - 1)) | 1;
/* Note: the result must be relatively prime to `capacity' (which
is a power of 2), so we make sure that the result is always
odd. */
unsigned int h = ((key2 * 134217689) & (capacity - 1)) | 1;
return h;
}
@ -199,21 +202,21 @@ static unsigned int nrSetProbes = 0;
void ATermMap::set(ATerm key, ATerm value)
{
if (count == maxCount) resizeTable(size * 2 / maxLoadFactor);
if (count == maxCount) resizeTable(capacity * 2 / maxLoadFactor);
nrItemsSet++;
for (unsigned int i = 0, h = hash1(key); i < size;
++i, h = (h + hash2(key)) & (size - 1))
for (unsigned int i = 0, h = hash1(key); i < capacity;
++i, h = (h + hash2(key)) & (capacity - 1))
{
// assert(h < size);
// assert(h < capacity);
nrSetProbes++;
/* Note: to see whether a slot is free, we check
hashTable[h].value, not hashTable[h].key, since we use
value == 0 to mark deleted slots. */
if (hashTable[h].value == 0 || hashTable[h].key == key) {
if (hashTable[h].value == 0) count++;
hashTable[h].key = key;
hashTable[h].value = value;
count++;
return;
}
}
@ -229,8 +232,8 @@ static unsigned int nrGetProbes = 0;
ATerm ATermMap::get(ATerm key) const
{
nrItemsGet++;
for (unsigned int i = 0, h = hash1(key); i < size;
++i, h = (h + hash2(key)) & (size - 1))
for (unsigned int i = 0, h = hash1(key); i < capacity;
++i, h = (h + hash2(key)) & (capacity - 1))
{
nrGetProbes++;
if (hashTable[h].key == 0) return 0;
@ -242,18 +245,27 @@ ATerm ATermMap::get(ATerm key) const
void ATermMap::remove(ATerm key)
{
for (unsigned int i = 0, h = hash1(key); i < size;
++i, h = (h + hash2(key)) & (size - 1))
for (unsigned int i = 0, h = hash1(key); i < capacity;
++i, h = (h + hash2(key)) & (capacity - 1))
{
if (hashTable[h].key == 0) return;
if (hashTable[h].key == key) {
hashTable[h].value = 0;
if (hashTable[h].value != 0) {
hashTable[h].value = 0;
count--;
}
return;
}
}
}
unsigned int ATermMap::size()
{
return count; /* STL nomenclature */
}
int main(int argc, char * * argv)
{
ATerm bottomOfStack;
@ -295,8 +307,11 @@ int main(int argc, char * * argv)
map.set(keys[i], values[i]);
// cerr << "INSERT: " << keys[i] << " " << values[i] << endl;
}
unsigned int size = map.size();
assert(size <= n);
values[n - 1] = 0;
map.remove(keys[n - 1]);
assert(map.size() == size - 1);
for (unsigned int i = 0; i < n; ++i) {
if (map.get(keys[i]) != values[i]) {
for (unsigned int j = i + 1; j < n; ++j)