gencpp/project/dependencies/gen.string.hpp

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2023-07-24 15:19:37 -07:00
// Constant string with length.
struct StrC
{
sw Len;
char const* Ptr;
operator char const* () const
{
return Ptr;
}
};
#define txt_StrC( text ) StrC { sizeof( text ) - 1, text }
StrC to_StrC( char const* str )
{
return { str_len( str ), str };
}
sw StrC_len( char const* str )
{
return (sw) ( str - 1 );
}
// Dynamic String
// This is directly based off the ZPL string api.
// They used a header pattern
// I kept it for simplicty of porting but its not necessary to keep it that way.
struct String
{
struct Header
{
AllocatorInfo Allocator;
sw Length;
sw Capacity;
};
static
uw grow_formula( uw value )
{
// Using a very aggressive growth formula to reduce time mem_copying with recursive calls to append in this library.
return 4 * value + 8;
}
static
String make( AllocatorInfo allocator, char const* str )
{
sw length = str ? str_len( str ) : 0;
return make_length( allocator, str, length );
}
static
String make( AllocatorInfo allocator, StrC str )
{
return make_length( allocator, str.Ptr, str.Len );
}
static
String make_reserve( AllocatorInfo allocator, sw capacity )
{
constexpr sw header_size = sizeof( Header );
s32 alloc_size = header_size + capacity + 1;
void* allocation = alloc( allocator, alloc_size );
if ( allocation == nullptr )
return { nullptr };
mem_set( allocation, 0, alloc_size );
Header*
header = rcast(Header*, allocation);
header->Allocator = allocator;
header->Capacity = capacity;
header->Length = 0;
String result = { (char*)allocation + header_size };
return result;
}
static
String make_length( AllocatorInfo allocator, char const* str, sw length )
{
constexpr sw header_size = sizeof( Header );
s32 alloc_size = header_size + length + 1;
void* allocation = alloc( allocator, alloc_size );
if ( allocation == nullptr )
return { nullptr };
Header&
header = * rcast(Header*, allocation);
header = { allocator, length, length };
String result = { rcast( char*, allocation) + header_size };
if ( length && str )
mem_copy( result, str, length );
else
mem_set( result, 0, alloc_size - header_size );
result[ length ] = '\0';
return result;
}
static
String fmt( AllocatorInfo allocator, char* buf, sw buf_size, char const* fmt, ... );
static
String fmt_buf( AllocatorInfo allocator, char const* fmt, ... );
static
String join( AllocatorInfo allocator, char const** parts, sw num_parts, char const* glue )
{
String result = make( allocator, "" );
for ( sw idx = 0; idx < num_parts; ++idx )
{
result.append( parts[ idx ] );
if ( idx < num_parts - 1 )
result.append( glue );
}
return result;
}
static
bool are_equal( String lhs, String rhs )
{
if ( lhs.length() != rhs.length() )
return false;
for ( sw idx = 0; idx < lhs.length(); ++idx )
if ( lhs[ idx ] != rhs[ idx ] )
return false;
return true;
}
bool make_space_for( char const* str, sw add_len )
{
sw available = avail_space();
// NOTE: Return if there is enough space left
if ( available >= add_len )
{
return true;
}
else
{
sw new_len, old_size, new_size;
void* ptr;
void* new_ptr;
AllocatorInfo allocator = get_header().Allocator;
Header* header = nullptr;
new_len = grow_formula( length() + add_len );
ptr = & get_header();
old_size = size_of( Header ) + length() + 1;
new_size = size_of( Header ) + new_len + 1;
new_ptr = resize( allocator, ptr, old_size, new_size );
if ( new_ptr == nullptr )
return false;
header = zpl_cast( Header* ) new_ptr;
header->Allocator = allocator;
header->Capacity = new_len;
Data = rcast( char*, header + 1 );
return str;
}
}
bool append( char const* str )
{
return append( str, str_len( str ) );
}
bool append( char const* str, sw length )
{
if ( sptr(str) > 0 )
{
sw curr_len = this->length();
if ( ! make_space_for( str, length ) )
return false;
Header& header = get_header();
mem_copy( Data + curr_len, str, length );
Data[ curr_len + length ] = '\0';
header.Length = curr_len + length;
}
return str;
}
bool append( StrC str)
{
return append( str.Ptr, str.Len );
}
bool append( const String other )
{
return append( other.Data, other.length() );;
}
bool append_fmt( char const* fmt, ... );
sw avail_space() const
{
Header const&
header = * rcast( Header const*, Data - sizeof( Header ));
return header.Capacity - header.Length;
}
sw capacity() const
{
Header const&
header = * rcast( Header const*, Data - sizeof( Header ));
return header.Capacity;
}
void clear()
{
get_header().Length = 0;
}
String duplicate( AllocatorInfo allocator )
{
return make_length( allocator, Data, length() );
}
void free()
{
if ( ! Data )
return;
Header& header = get_header();
gen::free( header.Allocator, & header );
}
Header& get_header()
{
return *(Header*)(Data - sizeof(Header));
}
sw length() const
{
Header const&
header = * rcast( Header const*, Data - sizeof( Header ));
return header.Length;
}
void trim( char const* cut_set )
{
sw len = 0;
char* start_pos = Data;
char* end_pos = Data + length() - 1;
while ( start_pos <= end_pos && char_first_occurence( cut_set, *start_pos ) )
start_pos++;
while ( end_pos > start_pos && char_first_occurence( cut_set, *end_pos ) )
end_pos--;
len = scast( sw, ( start_pos > end_pos ) ? 0 : ( ( end_pos - start_pos ) + 1 ) );
if ( Data != start_pos )
mem_move( Data, start_pos, len );
Data[ len ] = '\0';
get_header().Length = len;
}
void trim_space()
{
return trim( " \t\r\n\v\f" );
}
// For-range support
char* begin()
{
return Data;
}
char* end()
{
Header const&
header = * rcast( Header const*, Data - sizeof( Header ));
return Data + header.Length;
}
operator bool()
{
return Data;
}
operator char* ()
{
return Data;
}
operator char const* () const
{
return Data;
}
operator StrC() const
{
return
{
length(),
Data
};
}
// Used with cached strings
// Essentially makes the string a string view.
String const& operator = ( String const& other ) const
{
if ( this == & other )
return *this;
String& this_ = ccast( String, *this );
this_.Data = other.Data;
return this_;
}
char& operator [] ( sw index )
{
return Data[ index ];
}
char const& operator [] ( sw index ) const
{
return Data[ index ];
}
char* Data = nullptr;
};
struct String_POD
{
char* Data;
operator String()
{
return * rcast(String*, this);
}
};
static_assert( sizeof( String_POD ) == sizeof( String ), "String is not a POD" );