Class: PgQuery

Inherits:
Object
  • Object
show all
Defined in:
lib/pg_query/parse.rb,
lib/pg_query/version.rb,
lib/pg_query/parse_error.rb

Defined Under Namespace

Classes: ParseError

Constant Summary collapse

VERSION = 
'0.3.2'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(query, parsetree, warnings = []) ⇒ PgQuery

Returns a new instance of PgQuery.



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# File 'lib/pg_query/parse.rb', line 25

def initialize(query, parsetree, warnings = [])
  @query = query
  @parsetree = parsetree
  @warnings = warnings
end

Instance Attribute Details

#parsetree ⇒ Object (readonly)

Returns the value of attribute parsetree.



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# File 'lib/pg_query/parse.rb', line 23

def parsetree
  @parsetree
end

#query ⇒ Object (readonly)

Returns the value of attribute query.



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# File 'lib/pg_query/parse.rb', line 22

def query
  @query
end

#warnings ⇒ Object (readonly)

Returns the value of attribute warnings.



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# File 'lib/pg_query/parse.rb', line 24

def warnings
  @warnings
end

Class Method Details

._raw_parse(input) ⇒ Object

#define DEBUG



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# File 'ext/pg_query/pg_query.c', line 36

static VALUE pg_query_raw_parse(VALUE self, VALUE input)
{
	Check_Type(input, T_STRING);
	
	MemoryContext ctx = NULL;
	VALUE result = Qnil;
	VALUE error = Qnil;
	char stderr_buffer[STDERR_BUFFER_LEN + 1] = {0};
#ifndef DEBUG
	int stderr_global;
	int stderr_pipe[2];
#endif

	ctx = AllocSetContextCreate(TopMemoryContext,
								"pg_query_raw_parse",
								ALLOCSET_DEFAULT_MINSIZE,
								ALLOCSET_DEFAULT_INITSIZE,
								ALLOCSET_DEFAULT_MAXSIZE);
	MemoryContextSwitchTo(ctx);
	
#ifndef DEBUG
	// Setup pipe for stderr redirection
	if (pipe(stderr_pipe) != 0)
		rb_raise(rb_eIOError, "Failed to open pipe, too many open file descriptors");

	fcntl(stderr_pipe[0], F_SETFL, fcntl(stderr_pipe[0], F_GETFL) | O_NONBLOCK);
	
	// Redirect stderr to the pipe
	stderr_global = dup(STDERR_FILENO);
	dup2(stderr_pipe[1], STDERR_FILENO);
	close(stderr_pipe[1]);
#endif
	
	// Parse it!
	PG_TRY();
	{
		List *tree;
		char *str;
		
		str = StringValueCStr(input);
		tree = raw_parser(str);
		
		str = nodeToJSONString(tree);
	
#ifndef DEBUG
		// Save stderr for result
		read(stderr_pipe[0], stderr_buffer, STDERR_BUFFER_LEN);
#endif

		result = rb_ary_new();
		rb_ary_push(result, rb_str_new2(str));
		rb_ary_push(result, rb_str_new2(stderr_buffer));
	
		pfree(str);
	}
	PG_CATCH();
	{
		ErrorData* error_data = CopyErrorData();
		error = new_parse_error(error_data);
		FlushErrorState();
	}
	PG_END_TRY();
	
#ifndef DEBUG
	// Restore stderr, close pipe
	dup2(stderr_global, STDERR_FILENO);
	close(stderr_pipe[0]);
	close(stderr_global);
#endif

	// Return to previous PostgreSQL memory context
	MemoryContextSwitchTo(TopMemoryContext);
	MemoryContextDelete(ctx);
	
	// If we got an error, throw it
	if (!NIL_P(error)) rb_exc_raise(error);
	
	return result;
}

.normalize(input) ⇒ Object 



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# File 'ext/pg_query/pg_query.c', line 408

static VALUE pg_query_normalize(VALUE self, VALUE input)
{
	Check_Type(input, T_STRING);
	
	MemoryContext ctx = NULL;
	VALUE result = Qnil;
	VALUE error = Qnil;
	
	ctx = AllocSetContextCreate(TopMemoryContext,
								"pg_query_normalize",
								ALLOCSET_DEFAULT_MINSIZE,
								ALLOCSET_DEFAULT_INITSIZE,
								ALLOCSET_DEFAULT_MAXSIZE);
	MemoryContextSwitchTo(ctx);
	
	PG_TRY();
	{
		List *tree;
		char *str;
		pgssConstLocations jstate;
		int query_len;
		
		/* Parse query */
		str = StringValueCStr(input);
		tree = raw_parser(str);
		
		/* Set up workspace for constant recording */
		jstate.clocations_buf_size = 32;
		jstate.clocations = (pgssLocationLen *)
			palloc(jstate.clocations_buf_size * sizeof(pgssLocationLen));
		jstate.clocations_count = 0;
		
		/* Walk tree and record const locations */
		const_record_walker((Node *) tree, &jstate);
		
		/* Normalize query */
		query_len = (int) strlen(str);
		str = generate_normalized_query(&jstate, str, &query_len, PG_UTF8);
	
		result = rb_str_new2(str);
	
		pfree(str);
	}
	PG_CATCH();
	{
		ErrorData* error_data = CopyErrorData();
		error = new_parse_error(error_data);
		FlushErrorState();
	}
	PG_END_TRY();
	
	MemoryContextSwitchTo(TopMemoryContext);
	MemoryContextDelete(ctx);
	
	// If we got an error, throw it
	if (!NIL_P(error)) rb_exc_raise(error);
	
	return result;
}

.parse(query) ⇒ Object 



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# File 'lib/pg_query/parse.rb', line 4

def self.parse(query)
  parsetree, stderr = _raw_parse(query)

  begin
    parsetree = JSON.parse(parsetree, max_nesting: 1000)
  rescue JSON::ParserError => e
    raise ParseError.new("Failed to parse JSON", -1)
  end

  warnings = []
  stderr.each_line do |line|
    next unless line[/^WARNING/]
    warnings << line.strip
  end

  PgQuery.new(query, parsetree, warnings)
end

Instance Method Details

#aliases ⇒ Object 



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# File 'lib/pg_query/parse.rb', line 36

def aliases
  load_tables_and_aliases! if @aliases.nil?
  @aliases
end

#tables ⇒ Object 



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# File 'lib/pg_query/parse.rb', line 31

def tables
  load_tables_and_aliases! if @tables.nil?
  @tables
end