Gda.BlobOp

Subclasses:

None

Methods

Inherited:

GObject.Object (37)

Structs:

GObject.ObjectClass (5)

	get_length ()
	read (blob, offset, size)
	read_all (blob)
	write (blob, offset)
	write_all (blob)

Virtual Methods

Inherited:

GObject.Object (7)

	do_get_length ()
	do_read (blob, offset, size)
	do_write (blob, offset)
	do_write_all (blob)

Properties

None

Signals

Inherited:

GObject.Object (1)

Fields

Inherited:

GObject.Object (1)

Name	Type	Access	Description
object	GObject.Object	r

Class Details

class Gda.BlobOp(**kwargs)

Bases:

GObject.Object

Abstract:

Yes

Structure:

Gda.BlobOpClass

get_length()

Returns:

the length of the blob in bytes. In case of error, -1 is returned and the provider should have added an error (a Gda.ConnectionEvent) to the connection.

Return type:

int

read(blob, offset, size)

Parameters:

• blob (Gda.Blob) – a Gda.Blob to read data to

• offset (int) – offset to read from the start of the blob (starts at 0)

• size (int) – maximum number of bytes to read.

Returns:

the number of bytes actually read. In case of error, -1 is returned and the provider should have added an error to the connection.

Return type:

int

Reads a chunk of bytes from the BLOB accessible through self into blob.

read_all(blob)

Parameters:

blob (Gda.Blob) – a Gda.Blob to read data to

Returns:

True if blob->data contains the whole BLOB manipulated by self

Return type:

bool

Reads the whole contents of the blob manipulated by self into blob

write(blob, offset)

Parameters:

• blob (Gda.Blob) – a Gda.Blob which contains the data to write

• offset (int) – offset to write from the start of the blob (starts at 0)

Returns:

the number of bytes written. In case of error, -1 is returned and the provider should have added an error to the connection.

Return type:

int

Writes a chunk of bytes from a blob to the BLOB accessible through self, blob is unchanged after this call.

If blob has an associated Gda.BlobOp (ie. if blob->op is not None) then the data to be written using self is the data fetched using blob->op.

write_all(blob)

Parameters:

blob (Gda.Blob) – a Gda.Blob which contains the data to write

Returns:

True on success

Return type:

bool

Writes the whole contents of blob into the blob manipulated by self. If necessary the resulting blob is truncated from its previous length.

do_get_length() virtual

Returns:

the length of the blob in bytes. In case of error, -1 is returned and the provider should have added an error (a Gda.ConnectionEvent) to the connection.

Return type:

int

do_read(blob, offset, size) virtual

Parameters:

• blob (Gda.Blob) – a Gda.Blob to read data to

• offset (int) – offset to read from the start of the blob (starts at 0)

• size (int) – maximum number of bytes to read.

Returns:

the number of bytes actually read. In case of error, -1 is returned and the provider should have added an error to the connection.

Return type:

int

Reads a chunk of bytes from the BLOB accessible through op into blob.

do_write(blob, offset) virtual

Parameters:

• blob (Gda.Blob) – a Gda.Blob which contains the data to write

• offset (int) – offset to write from the start of the blob (starts at 0)

Returns:

the number of bytes written. In case of error, -1 is returned and the provider should have added an error to the connection.

Return type:

int

Writes a chunk of bytes from a blob to the BLOB accessible through op, blob is unchanged after this call.

If blob has an associated Gda.BlobOp (ie. if blob->op is not None) then the data to be written using op is the data fetched using blob->op.

do_write_all(blob) virtual

Parameters:

blob (Gda.Blob) – a Gda.Blob which contains the data to write

Returns:

True on success

Return type:

bool

Writes the whole contents of blob into the blob manipulated by op. If necessary the resulting blob is truncated from its previous length.