qhash.cpp File Reference

#include "qhash.h"
#include <qbitarray.h>
#include <qstring.h>
#include <stdlib.h>

Go to the source code of this file.

Functions
static int	countBits (int hint)
static uint	hash (const uchar *p, int n)
static uint	hash (const QChar *p, int n)
static int	primeForNumBits (int numBits)
uint	qHash (const QByteArray &key)
	Returns the hash value for the key. More...
uint	qHash (const QString &key)
uint	qHash (const QStringRef &key)
uint	qHash (const QBitArray &bitArray)

Variables
const int	MinNumBits = 4
static const uchar	prime_deltas []

Function Documentation

countBits()

static int countBits ( int  hint )

static

Definition at line 144 of file qhash.cpp.

Referenced by QHashData::rehash().

{
    int numBits = 0;
    int bits = hint;

    while (bits > 1) {
        bits >>= 1;
        numBits++;
    }

    if (numBits >= (int)sizeof(prime_deltas)) {
        numBits = sizeof(prime_deltas) - 1;
    } else if (primeForNumBits(numBits) < hint) {
        ++numBits;
    }
    return numBits;
}

hash() [1/2]

static uint hash ( const uchar *  p, int  n  )

static

Definition at line 68 of file qhash.cpp.

Referenced by QPatternist::XsdStateMachine< XsdSchemaToken::NodeName >::addTransition(), QMetaObject::changeGuard(), cleanup_cmaps(), QObjectPrivate::clearGuards(), convert_RGB_to_Indexed8(), digestMd5ResponseHelper(), QTranslatorPrivate::do_translate(), QResourceRoot::findNode(), QResourceRoot::findOffset(), QApplication::font(), QGLMaskTextureCache::getMask(), QPatternist::XsdParticleChecker::hasDuplicatedElements(), hasDuplicatedElementsInternal(), QDeclarativeDebugService::idForObject(), internalParticleLookupMap(), QDeclarativeDebugService::objectForId(), operator<<(), QProcessEnvironmentPrivate::OrderedMutexLocker::OrderedMutexLocker(), QApplication::palette(), QXmlStreamReaderPrivate::parse(), qEncodeHmacMd5(), qHash(), qStringFromUcs2Le(), qt_CoCreateGuid(), qt_delete_glyph_hash(), qt_fallback_font_family(), qt_gl_choose_cmap(), qt_transparent_pixel(), qt_x11_set_fallback_font_family(), QVariant::QVariant(), QMetaObject::removeGuard(), QDeclarativeWorkerScriptEnginePrivate::scriptValueToVariant(), QTextControl::setExtraSelections(), QApplication::setFont(), QApplicationPrivate::setPalette_helper(), QPatternist::XsdSchemaContext::setupBuiltinTypesFacetList(), QNetworkDiskCachePrivate::uniqueFileName(), unregWinClasses(), QPropertyAnimation::updateState(), QPatternist::TokenLookup::value(), and QDeclarativeWorkerScriptEnginePrivate::variantToScriptValue().

{
    uint h = 0;

    while (n--) {
        h = (h << 4) + *p++;
        h ^= (h & 0xf0000000) >> 23;
        h &= 0x0fffffff;
    }
    return h;
}

hash() [2/2]

static uint hash ( const QChar *  p, int  n  )

static

Definition at line 80 of file qhash.cpp.

{
    uint h = 0;

    while (n--) {
        h = (h << 4) + (*p++).unicode();
        h ^= (h & 0xf0000000) >> 23;
        h &= 0x0fffffff;
    }
    return h;
}

primeForNumBits()

static int primeForNumBits ( int  numBits )

inlinestatic

Definition at line 135 of file qhash.cpp.

Referenced by countBits(), and QHashData::rehash().

{
    return (1 << numBits) + prime_deltas[numBits];
}

qHash() [1/4]

uint qHash

(

const QByteArray &

key

)

Returns the hash value for the key.

Definition at line 92 of file qhash.cpp.

{
    return hash(reinterpret_cast<const uchar *>(key.constData()), key.size());
}

qHash() [2/4]

uint qHash ( const QString &  key )

related

Definition at line 97 of file qhash.cpp.

Referenced by qHash().

{
    return hash(key.unicode(), key.size());
}

qHash() [3/4]

uint qHash

(

const QStringRef &

key

)

Definition at line 102 of file qhash.cpp.

{
    return hash(key.unicode(), key.size());
}

qHash() [4/4]

uint qHash ( const QBitArray &  bitArray )

related

Definition at line 107 of file qhash.cpp.

{
    int m = bitArray.d.size() - 1;
    uint result = hash(reinterpret_cast<const uchar *>(bitArray.d.constData()), qMax(0, m));

    // deal with the last 0 to 7 bits manually, because we can't trust that
    // the padding is initialized to 0 in bitArray.d
    int n = bitArray.size();
    if (n & 0x7)
        result = ((result << 4) + bitArray.d.at(m)) & ((1 << n) - 1);
    return result;
}

Variable Documentation

MinNumBits

const int MinNumBits = 4

Definition at line 166 of file qhash.cpp.

Referenced by QHashData::rehash().

prime_deltas

const uchar prime_deltas[]

static

Initial value:

= {
    0,  0,  1,  3,  1,  5,  3,  3,  1,  9,  7,  5,  3,  9, 25,  3,
    1, 21,  3, 21,  7, 15,  9,  5,  3, 29, 15,  0,  0,  0,  0,  0
}

Definition at line 130 of file qhash.cpp.

Referenced by countBits(), and primeForNumBits().