mwilliams
1626223e97
Empty FixedStringMaps would do a malloc of at least 9 bytes, and IndexedStringMap would do a 1 byte malloc, and a malloc of at least 9 bytes. We have a lot of typically empty maps in our data structures.
105 linhas
3.5 KiB
C++
105 linhas
3.5 KiB
C++
/*
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+----------------------------------------------------------------------+
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| HipHop for PHP |
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+----------------------------------------------------------------------+
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| Copyright (c) 2010-2013 Facebook, Inc. (http://www.facebook.com) |
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+----------------------------------------------------------------------+
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| This source file is subject to version 3.01 of the PHP license, |
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| that is bundled with this package in the file LICENSE, and is |
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| available through the world-wide-web at the following url: |
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| http://www.php.net/license/3_01.txt |
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| If you did not receive a copy of the PHP license and are unable to |
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| obtain it through the world-wide-web, please send a note to |
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| license@php.net so we can mail you a copy immediately. |
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+----------------------------------------------------------------------+
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*/
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#include "hphp/runtime/vm/fixed_string_map.h"
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#include "hphp/runtime/vm/core_types.h"
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#include "hphp/runtime/base/macros.h"
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namespace HPHP {
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TRACE_SET_MOD(runtime);
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///////////////////////////////////////////////////////////////////////////////
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class Func;
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static const StringData* null_key;
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inline bool strEqual(bool case_sensitive,
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const StringData* sd1, const StringData* sd2) {
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if (sd1 == sd2) return true;
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if (sd1->size() != sd2->size()) return false;
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return case_sensitive ?
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(0 == memcmp(sd1->data(), sd2->data(), sd1->size())) :
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bstrcaseeq(sd1->data(), sd2->data(), sd1->size());
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}
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template <typename V, bool case_sensitive>
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FixedStringMap<V, case_sensitive>::~FixedStringMap() {
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if (m_table != (Elm*)&null_key) {
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free(m_table);
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}
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}
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template <typename V, bool case_sensitive>
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void FixedStringMap<V, case_sensitive>::init(int num) {
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if (!num) {
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m_table = (Elm*)&null_key;
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m_mask = 0;
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return;
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}
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static const double kLoadFactor = 0.80;
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int capac = 1;
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while (num >= kLoadFactor * capac) {
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capac *= 2;
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}
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TRACE(1, "FixedStringMap::init: %d -> %d\n", num, capac);
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assert(!m_table);
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m_table = (Elm*)calloc(capac * sizeof(Elm), 1);
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assert(m_table);
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m_mask = capac - 1;
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}
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template <typename V, bool case_sensitive>
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void FixedStringMap<V, case_sensitive>::add(const StringData* sd, const V& v) {
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assert(sd->isStatic());
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Elm* elm = &m_table[sd->hash() & m_mask];
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UNUSED unsigned numProbes = 0;
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while (elm->sd) {
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assert(numProbes++ < m_mask + 1);
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// Semantics for multiple insertion: new value wins.
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if (strEqual(case_sensitive, elm->sd, sd)) break;
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if (UNLIKELY(++elm == &m_table[m_mask + 1])) elm = m_table;
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}
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elm->sd = sd;
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elm->data = v;
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}
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template <typename V, bool case_sensitive>
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V* FixedStringMap<V, case_sensitive>::find(const StringData* sd) const {
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Elm* elm = &m_table[sd->hash() & m_mask];
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UNUSED unsigned numProbes = 0;
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for(;;) {
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assert(numProbes++ < m_mask + 1);
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if (UNLIKELY(nullptr == elm->sd)) return nullptr;
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if (strEqual(case_sensitive, elm->sd, sd)) return &elm->data;
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if (UNLIKELY(++elm == &m_table[m_mask + 1])) elm = m_table;
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}
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}
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template class FixedStringMap<Slot, false>;
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template class FixedStringMap<Slot, true>;
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template class FixedStringMap<Id, false>;
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template class FixedStringMap<Id, true>;
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template class FixedStringMap<Func*, false>;
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template class FixedStringMap<unsigned char* /* TCA */, true>;
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///////////////////////////////////////////////////////////////////////////////
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}
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