Class: PG::TypeMapByOid

Inherits:

TypeMap

• Object
• TypeMap
• PG::TypeMapByOid

Includes:

PG::TypeMap::DefaultTypeMappable

Defined in:

ext/pg_type_map_by_oid.c,
ext/pg_type_map_by_oid.c

Overview

This type map casts values based on the type OID of the given column in the result set.

This type map is only suitable to cast values from PG::Result objects. Therefore only decoders might be assigned by the #add_coder method.

Fields with no match to any of the registered type OID / format combination are forwarded to the #default_type_map .

Direct Known Subclasses

BasicTypeMapBasedOnResult, BasicTypeMapForResults

Instance Method Summary

• #add_coder(coder) ⇒ Object

  Assigns a new PG::Coder object to the type map.

• #build_column_map(result) ⇒ Object

  This builds a PG::TypeMapByColumn that fits to the given PG::Result object based on it’s type OIDs and binary/text format.

• #coders ⇒ Array

  Array of all assigned PG::Coder objects.

• #max_rows_for_online_lookup ⇒ Integer
• #max_rows_for_online_lookup=(number) ⇒ Object

  Threshold for doing Hash lookups versus creation of a dedicated PG::TypeMapByColumn.

• #rm_coder(format, oid) ⇒ Object

  Removes a PG::Coder object from the type map based on the given oid and format codes.

Methods included from PG::TypeMap::DefaultTypeMappable

#default_type_map, #default_type_map=, #with_default_type_map

Instance Method Details

#add_coder(coder) ⇒ Object

Assigns a new PG::Coder object to the type map. The decoder is registered for type casts based on it’s PG::Coder#oid and PG::Coder#format attributes.

Later changes of the oid or format code within the coder object will have no effect to the type map.

# File 'ext/pg_type_map_by_oid.c', line 237

static VALUE
pg_tmbo_add_coder( VALUE self, VALUE coder )
{
	VALUE hash;
	t_tmbo *this = RTYPEDDATA_DATA( self );
	t_pg_coder *p_coder;
	struct pg_tmbo_oid_cache_entry *p_ce;

	rb_check_frozen(self);
	TypedData_Get_Struct(coder, t_pg_coder, &pg_coder_type, p_coder);

	if( p_coder->format < 0 || p_coder->format > 1 )
		rb_raise(rb_eArgError, "invalid format code %d", p_coder->format);

	/* Update cache entry */
	p_ce = CACHE_LOOKUP(this, p_coder->format, p_coder->oid);
	p_ce->oid = p_coder->oid;
	p_ce->p_coder = p_coder;
	/* Write coder into the hash of the given format */
	hash = this->format[p_coder->format].oid_to_coder;
	rb_hash_aset( hash, UINT2NUM(p_coder->oid), coder);

	return self;
}

#build_column_map(result) ⇒ Object

This builds a PG::TypeMapByColumn that fits to the given PG::Result object based on it’s type OIDs and binary/text format.

# File 'ext/pg_type_map_by_oid.c', line 347

static VALUE
pg_tmbo_build_column_map( VALUE self, VALUE result )
{
	t_tmbo *this = RTYPEDDATA_DATA( self );

	if ( !rb_obj_is_kind_of(result, rb_cPGresult) ) {
		rb_raise( rb_eTypeError, "wrong argument type %s (expected kind of PG::Result)",
				rb_obj_classname( result ) );
	}

	return pg_tmbo_build_type_map_for_result2( this, pgresult_get(result) );
}

#coders ⇒ Array

Array of all assigned PG::Coder objects.

Returns:

• (Array)

# File 'ext/pg_type_map_by_oid.c', line 300

static VALUE
pg_tmbo_coders( VALUE self )
{
	t_tmbo *this = RTYPEDDATA_DATA( self );

	return rb_ary_concat(
			rb_funcall(this->format[0].oid_to_coder, rb_intern("values"), 0),
			rb_funcall(this->format[1].oid_to_coder, rb_intern("values"), 0));
}

#max_rows_for_online_lookup ⇒ Integer

Returns:

• (Integer)

# File 'ext/pg_type_map_by_oid.c', line 332

static VALUE
pg_tmbo_max_rows_for_online_lookup_get( VALUE self )
{
	t_tmbo *this = RTYPEDDATA_DATA( self );
	return INT2NUM(this->max_rows_for_online_lookup);
}

#max_rows_for_online_lookup=(number) ⇒ Object

Threshold for doing Hash lookups versus creation of a dedicated PG::TypeMapByColumn. The type map will do Hash lookups for each result value, if the number of rows is below or equal number.

# File 'ext/pg_type_map_by_oid.c', line 319

static VALUE
pg_tmbo_max_rows_for_online_lookup_set( VALUE self, VALUE value )
{
	t_tmbo *this = RTYPEDDATA_DATA( self );
	rb_check_frozen(self);
	this->max_rows_for_online_lookup = NUM2INT(value);
	return value;
}

#rm_coder(format, oid) ⇒ Object

Removes a PG::Coder object from the type map based on the given oid and format codes.

Returns the removed coder object.

# File 'ext/pg_type_map_by_oid.c', line 271

static VALUE
pg_tmbo_rm_coder( VALUE self, VALUE format, VALUE oid )
{
	VALUE hash;
	VALUE coder;
	t_tmbo *this = RTYPEDDATA_DATA( self );
	int i_format = NUM2INT(format);
	struct pg_tmbo_oid_cache_entry *p_ce;

	rb_check_frozen(self);
	if( i_format < 0 || i_format > 1 )
		rb_raise(rb_eArgError, "invalid format code %d", i_format);

	/* Mark the cache entry as empty */
	p_ce = CACHE_LOOKUP(this, i_format, NUM2UINT(oid));
	p_ce->oid = 0;
	p_ce->p_coder = NULL;
	hash = this->format[i_format].oid_to_coder;
	coder = rb_hash_delete( hash, oid );

	return coder;
}