ladybird/AK/StringImpl.h

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#pragma once
#include "RetainPtr.h"
#include "Retainable.h"
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#include "Types.h"
namespace AK {
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enum ShouldChomp
{
NoChomp,
Chomp
};
class StringImpl : public Retainable<StringImpl> {
public:
static Retained<StringImpl> create_uninitialized(ssize_t length, char*& buffer);
static RetainPtr<StringImpl> create(const char* cstring, ShouldChomp = NoChomp);
static RetainPtr<StringImpl> create(const char* cstring, ssize_t length, ShouldChomp = NoChomp);
Retained<StringImpl> to_lowercase() const;
Retained<StringImpl> to_uppercase() const;
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static StringImpl& the_empty_stringimpl();
~StringImpl();
ssize_t length() const { return m_length; }
const char* characters() const { return m_characters; }
char operator[](ssize_t i) const
{
ASSERT(i >= 0 && i < m_length);
return m_characters[i];
}
unsigned hash() const
{
if (!m_hasHash)
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compute_hash();
return m_hash;
}
private:
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enum ConstructTheEmptyStringImplTag
{
ConstructTheEmptyStringImpl
};
explicit StringImpl(ConstructTheEmptyStringImplTag)
: m_characters("")
{
}
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enum ConstructWithInlineBufferTag
{
ConstructWithInlineBuffer
};
StringImpl(ConstructWithInlineBufferTag, ssize_t length);
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void compute_hash() const;
ssize_t m_length { 0 };
mutable bool m_hasHash { false };
const char* m_characters { nullptr };
mutable unsigned m_hash { 0 };
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char m_inline_buffer[0];
};
inline dword string_hash(const char* characters, int length)
{
dword hash = 0;
for (int i = 0; i < length; ++i) {
hash += (dword)characters[i];
hash += (hash << 10);
hash ^= (hash >> 6);
}
hash += hash << 3;
hash ^= hash >> 11;
hash += hash << 15;
return hash;
}
}
using AK::Chomp;
using AK::string_hash;
using AK::StringImpl;