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 = 
'0.0.4'

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 26

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 24

def parsetree
  @parsetree
end

#query ⇒ Object (readonly)

Returns the value of attribute query.



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

def query
  @query
end

#warnings ⇒ Object (readonly)

Returns the value of attribute warnings.



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

def warnings
  @warnings
end

Class Method Details

._raw_parse(input) ⇒ Object 



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# File 'ext/pg_query/pg_query.c', line 31

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

  ctx = AllocSetContextCreate(TopMemoryContext,
                "RootContext",
                ALLOCSET_DEFAULT_MINSIZE,
                ALLOCSET_DEFAULT_INITSIZE,
                ALLOCSET_DEFAULT_MAXSIZE);
  MemoryContextSwitchTo(ctx);
  
  // Setup pipe for stderr redirection
  if (pipe(stderr_pipe) != 0)
    rb_raise(rb_eRuntimeError, "PgQuery._raw_parse: Could not allocate pipe for stderr redirection");

  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]);
  
  // Parse it!
  PG_TRY();
  {
    List *tree;
    char *str;
    
    str = StringValueCStr(input);
    tree = raw_parser(str);
    
    str = nodeToString(tree);
  
    // Save stderr for result
    read(stderr_pipe[0], stderr_buffer, STDERR_BUFFER_LEN);
  
    result = rb_ary_new();
    rb_ary_push(result, rb_tainted_str_new_cstr(str));
    rb_ary_push(result, rb_str_new2(stderr_buffer));
  
    pfree(str);
  }
  PG_CATCH();
  {
    error = CopyErrorData();
    FlushErrorState();
  }
  PG_END_TRY();
  
  // Restore stderr & return to previous PostgreSQL memory context
  dup2(stderr_global, STDERR_FILENO);
  MemoryContextSwitchTo(TopMemoryContext);
  MemoryContextDelete(ctx);
  
  // If we got an error, throw a ParseError exception
  if (error) raise_parse_error(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)
  
  parsetree = [] if parsetree == '<>'
  
  if !parsetree.nil? && !parsetree.empty?
    parsetree = parsetree_to_json(parsetree)
    parsetree = JSON.parse(parsetree, max_nesting: 1000)
  end
  
  warnings = []
  stderr.each_line do |line|
    next unless line[/^WARNING/]
    warnings << line.strip
  end
  
  PgQuery.new(query, parsetree, warnings)
end