Class: PG::Coder

Inherits:
Object
  • Object
show all
Defined in:
ext/pg_coder.c,
lib/pg/coder.rb,
ext/pg_coder.c

Overview

This is the base class for all type cast encoder and decoder classes.

It can be used for implicit type casts by a PG::TypeMap or to convert single values to/from their string representation by #encode and #decode.

Ruby nil values are not handled by encoders, but are always transmitted as SQL NULL value. Vice versa SQL NULL values are not handled by decoders, but are always returned as a nil value.

Direct Known Subclasses

CompositeCoder, CopyCoder, SimpleCoder

Defined Under Namespace

Modules: BinaryFormatting

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(params = {}) ⇒ Coder

Create a new coder object based on the attribute Hash.



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# File 'lib/pg/coder.rb', line 16

def initialize(params={})
	params.each do |key, val|
		send("#{key}=", val)
	end
end

Instance Attribute Details

#name ⇒ Object

Name of the coder or the corresponding data type.

This accessor is only used in PG::Coder#inspect .

Instance Method Details

#==(v) ⇒ Object 



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# File 'lib/pg/coder.rb', line 35

def ==(v)
	self.class == v.class && to_h == v.to_h
end

#decode(string, tuple = nil, field = nil) ⇒ Object

Decodes the given string representation into a Ruby object, without sending data to/from the database server.

A nil value is passed through and non String values are expected to have #to_str defined.



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# File 'ext/pg_coder.c', line 164

static VALUE
pg_coder_decode(int argc, VALUE *argv, VALUE self)
{
	char *val;
	VALUE tuple = -1;
	VALUE field = -1;
	VALUE res;
	t_pg_coder *this = DATA_PTR(self);

	if(argc < 1 || argc > 3){
		rb_raise(rb_eArgError, "wrong number of arguments (%i for 1..3)", argc);
	}else if(argc >= 3){
		tuple = NUM2INT(argv[1]);
		field = NUM2INT(argv[2]);
	}

	if( NIL_P(argv[0]) )
		return Qnil;

	val = StringValuePtr(argv[0]);
	if( !this->dec_func ){
		rb_raise(rb_eRuntimeError, "no decoder function defined");
	}

	res = this->dec_func(this, val, RSTRING_LEN(argv[0]), tuple, field, ENCODING_GET(argv[0]));
	OBJ_INFECT(res, argv[0]);

	return res;
}

#dup ⇒ Object 



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# File 'lib/pg/coder.rb', line 22

def dup
	self.class.new(to_h)
end

#encode(value) ⇒ Object

Encodes the given Ruby object into string representation, without sending data to/from the database server.

A nil value is passed through.



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# File 'ext/pg_coder.c', line 116

static VALUE
pg_coder_encode(VALUE self, VALUE value)
{
	VALUE res;
	VALUE intermediate;
	int len, len2;
	t_pg_coder *this = DATA_PTR(self);

	if( NIL_P(value) )
		return Qnil;

	if( !this->enc_func ){
		rb_raise(rb_eRuntimeError, "no encoder function defined");
	}

	len = this->enc_func( this, value, NULL, &intermediate );

	if( len == -1 ){
		/* The intermediate value is a String that can be used directly. */
		OBJ_INFECT(intermediate, value);
		return intermediate;
	}

	res = rb_str_new(NULL, len);
	len2 = this->enc_func( this, value, RSTRING_PTR(res), &intermediate);
	if( len < len2 ){
		rb_bug("%s: result length of first encoder run (%i) is less than second run (%i)",
			rb_obj_classname( self ), len, len2 );
	}
	rb_str_set_len( res, len2 );
	OBJ_INFECT(res, value);

	RB_GC_GUARD(intermediate);

	return res;
}

#format ⇒ Integer

The format code that is sent alongside with an encoded query parameter value.

Returns:

  • (Integer) 


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# File 'ext/pg_coder.c', line 249

static VALUE
pg_coder_format_get(VALUE self)
{
	t_pg_coder *this = DATA_PTR(self);
	return INT2NUM(this->format);
}

#format=(Integer) ⇒ Object

Specifies the format code that is sent alongside with an encoded query parameter value.

The default is 0.



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# File 'ext/pg_coder.c', line 234

static VALUE
pg_coder_format_set(VALUE self, VALUE format)
{
	t_pg_coder *this = DATA_PTR(self);
	this->format = NUM2INT(format);
	return format;
}

#inspect ⇒ Object 



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# File 'lib/pg/coder.rb', line 47

def inspect
	str = self.to_s
	oid_str = " oid=#{oid}" unless oid==0
	format_str = " format=#{format}" unless format==0
	name_str = " #{name.inspect}" if name
	str[-1,0] = "#{name_str} #{oid_str}#{format_str}"
	str
end

#marshal_dump ⇒ Object 



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# File 'lib/pg/coder.rb', line 39

def marshal_dump
	Marshal.dump(to_h)
end

#marshal_load(str) ⇒ Object 



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# File 'lib/pg/coder.rb', line 43

def marshal_load(str)
	initialize Marshal.load(str)
end

#oid ⇒ Integer

The type OID that is sent alongside with an encoded query parameter value.

Returns:

  • (Integer) 


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# File 'ext/pg_coder.c', line 218

static VALUE
pg_coder_oid_get(VALUE self)
{
	t_pg_coder *this = DATA_PTR(self);
	return UINT2NUM(this->oid);
}

#oid=(Integer) ⇒ Object

Specifies the type OID that is sent alongside with an encoded query parameter value.

The default is 0.



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# File 'ext/pg_coder.c', line 203

static VALUE
pg_coder_oid_set(VALUE self, VALUE oid)
{
	t_pg_coder *this = DATA_PTR(self);
	this->oid = NUM2UINT(oid);
	return oid;
}

#to_h ⇒ Object

Returns coder attributes as Hash.



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# File 'lib/pg/coder.rb', line 27

def to_h
	{
		oid: oid,
		format: format,
		name: name,
	}
end