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 = 
'0.2.8'

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 



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# File 'ext/pg_query/pg_query.c', line 33

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};
  int stderr_global;
  int stderr_pipe[2];

  ctx = AllocSetContextCreate(TopMemoryContext,
                "pg_query_raw_parse",
                ALLOCSET_DEFAULT_MINSIZE,
                ALLOCSET_DEFAULT_INITSIZE,
                ALLOCSET_DEFAULT_MAXSIZE);
  MemoryContextSwitchTo(ctx);
  
  // 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]);
  
  // Parse it!
  PG_TRY();
  {
    List *tree;
    char *str;
    
    str = StringValueCStr(input);
    tree = raw_parser(str);
    
    str = nodeToJSONString(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();
  {
    ErrorData* error_data = CopyErrorData();
    error = new_parse_error(error_data);
    FlushErrorState();
  }
  PG_END_TRY();
  
  // Restore stderr, close pipe & return to previous PostgreSQL memory context
  dup2(stderr_global, STDERR_FILENO);
  close(stderr_pipe[0]);
  close(stderr_global);
  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 395

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_tainted_str_new_cstr(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