Function HSH_insert

src/gpre/hsh.cpp:109–149

//

void HSH_insert( gpre_sym* symbol)
{
	const int h = hash(symbol->sym_string);

	for (gpre_sym** next = &hash_table[h]; *next; next = &(*next)->sym_collision)
	{
		for (const gpre_sym* ptr = *next; ptr; ptr = ptr->sym_homonym)
		{
			if (ptr == symbol)
				return;
		}

		if (scompare(symbol->sym_string, (*next)->sym_string))
		{
			// insert in most recently seen order;
			// This is important for alias resolution in subqueries.
			// BUT insert tokens AFTER keyword!
			// In a lookup, keyword should be found first.
			// This assumes that KEYWORDS are inserted before any other token.
			// No one should be using a keywords as an alias anyway.

			if ((*next)->sym_type == SYM_keyword)
			{
				symbol->sym_homonym = (*next)->sym_homonym;
				symbol->sym_collision = NULL;
				(*next)->sym_homonym = symbol;
			}
			else
			{
				symbol->sym_homonym = *next;
				symbol->sym_collision = (*next)->sym_collision;
				(*next)->sym_collision = NULL;
				*next = symbol;
			}
			return;
		}
	}

	symbol->sym_collision = hash_table[h];
	hash_table[h] = symbol;
}


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