mirror of
https://github.com/SerenityOS/serenity
synced 2024-07-22 02:26:11 +00:00
26e81ad574
`AK::String` can now be reversed via AK::String::reverse(). This makes life a lot easier for functions like `itoa()`, where the output ends up being backwards. Very much not like the normal STL (which requires an `std::reverse` object) way of doing things. A call to reverse returns a new `AK::String` so as to not upset any of the possible references to the same `StringImpl` shared between Strings.
90 lines
2 KiB
C++
90 lines
2 KiB
C++
#pragma once
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#include <AK/RefCounted.h>
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#include <AK/RefPtr.h>
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#include <AK/Types.h>
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#include <AK/kmalloc.h>
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namespace AK {
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enum ShouldChomp {
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NoChomp,
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Chomp
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};
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class StringImpl : public RefCounted<StringImpl> {
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public:
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static NonnullRefPtr<StringImpl> create_uninitialized(int length, char*& buffer);
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static RefPtr<StringImpl> create(const char* cstring, ShouldChomp = NoChomp);
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static RefPtr<StringImpl> create(const char* cstring, int length, ShouldChomp = NoChomp);
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NonnullRefPtr<StringImpl> to_lowercase() const;
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NonnullRefPtr<StringImpl> to_uppercase() const;
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void operator delete(void* ptr)
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{
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kfree(ptr);
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}
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static StringImpl& the_empty_stringimpl();
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~StringImpl();
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int length() const { return m_length; }
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const char* characters() const { return &m_inline_buffer[0]; }
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char operator[](int i) const
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{
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ASSERT(i >= 0 && i < m_length);
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return characters()[i];
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}
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unsigned hash() const
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{
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if (!m_has_hash)
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compute_hash();
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return m_hash;
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}
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NonnullRefPtr<StringImpl> reversed() const;
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private:
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enum ConstructTheEmptyStringImplTag {
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ConstructTheEmptyStringImpl
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};
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explicit StringImpl(ConstructTheEmptyStringImplTag)
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{
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m_inline_buffer[0] = '\0';
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}
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enum ConstructWithInlineBufferTag {
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ConstructWithInlineBuffer
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};
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StringImpl(ConstructWithInlineBufferTag, int length);
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void compute_hash() const;
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int m_length { 0 };
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mutable unsigned m_hash { 0 };
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mutable bool m_has_hash { false };
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char m_inline_buffer[0];
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};
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inline constexpr u32 string_hash(const char* characters, int length)
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{
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u32 hash = 0;
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for (int i = 0; i < length; ++i) {
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hash += (u32)characters[i];
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hash += (hash << 10);
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hash ^= (hash >> 6);
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}
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hash += hash << 3;
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hash ^= hash >> 11;
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hash += hash << 15;
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return hash;
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}
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}
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using AK::Chomp;
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using AK::string_hash;
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using AK::StringImpl;
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