Vips.Target¶

Subclasses:: Vips.TargetCustom

Methods¶

Inherited:: Vips.Connection (2), Vips.Object (27), GObject.Object (37)
Structs:: Vips.ObjectClass (1), GObject.ObjectClass (5)

class	`new_temp` (based_on)
class	`new_to_descriptor` (descriptor)
class	`new_to_file` (filename)
class	`new_to_memory` ()
	`end` ()
	`putc` (ch)
	`read` (buffer, length)
	`seek` (offset, whence)
	`steal` ()
	`steal_text` ()
	`write` (data, length)
	`write_amp` (str)
	`writes` (str)

Virtual Methods¶

Inherited:: Vips.Object (9), GObject.Object (7)

	`do_end` ()
	`do_finish` ()
	`do_read` (buffer, length)
	`do_seek` (offset, whence)
	`do_write` (data, length)

Properties¶

Inherited:: Vips.Connection (2), Vips.Object (2)

Name	Type	Flags	Short Description
`blob`	`Vips.Blob`	r/w	Blob to save to
`memory`	`bool`	r/w	File descriptor should output to memory

Signals¶

Inherited:: Vips.Object (4), GObject.Object (1)

Fields¶

Inherited:: Vips.Object (4), GObject.Object (1)

Name	Type	Access
blob	`Vips.Blob`	r
delete_on_close	`bool`	r
delete_on_close_filename	`str`	r
ended	`bool`	r
memory	`bool`	r
memory_buffer	`GLib.String`	r
output_buffer	`bytes`	r
parent_object	`Vips.Connection`	r
position	`int`	r
write_point	`int`	r

Class Details¶

class Vips.Target(**kwargs)¶

Bases:: Vips.Connection
Abstract:: No
Structure:: Vips.TargetClass

A [class`Target`] provides a unified interface for writing data to various output destinations.

This target could be a socket, file, memory area, or any other destination that accepts byte data.

classmethod new_temp(based_on)¶

Parameters:: based_on (Vips.Target) – base the temporary target on this target
Returns:: a new target.
Return type:: Vips.Target

Create a temporary target – either a temporary file on disc, or an area in memory, depending on what sort of target based_on is.

::: seealso [ctor`Target`.new_to_file].

classmethod new_to_descriptor(descriptor)¶

Parameters:: descriptor (int) – write to this file descriptor
Returns:: a new target.
Return type:: Vips.Target

Create a target attached to a file descriptor. descriptor is kept open until the target is finalized.

::: seealso [ctor`Target`.new_to_file].

classmethod new_to_file(filename)¶

Parameters:: filename (str) – write to this file
Returns:: a new target.
Return type:: Vips.Target

Create a target attached to a file.

classmethod new_to_memory()¶

Returns:: a new target.
Return type:: Vips.Target

Create a target which will write to a memory area. Read from blob to get memory.

::: seealso [ctor`Target`.new_to_file].

end()¶

Returns:: 0 on success, -1 on error.
Return type:: int

Call this at the end of write to make the target do any cleaning up. You can call it many times.

After a target has been ended, further writes will do nothing.

putc(ch)¶

Parameters:: ch (int) – character to write
Returns:: 0 on success, -1 on error.
Return type:: int

Write a single character ch to self. See the macro [funcTARGET_PUTC] for a faster way to do this.

read(buffer, length)¶

Parameters:

buffer (object or None) – store bytes here
length (int) – length of buffer in bytes

Returns:

the number of bytes read, 0 on end of file, -1 on error.

Return type:

int

Read up to length bytes from self and store the bytes in buffer. Return the number of bytes actually read. If all bytes have been read from the file, return 0.

Arguments exactly as read()).

Reading from a target sounds weird, but libtiff needs this for multi-page writes. This method will fail for targets like pipes.

seek(offset, whence)¶

Parameters:

offset (int) – offset to seek to
whence (int) – seek relative to beginning, offset, or end

Returns:

the new offset, -1 on error.

Return type:

int

Seek the target. This behaves exactly as lseek()).

Seeking a target sounds weird, but libtiff needs this. This method will fail for targets like pipes.

steal()¶

Returns:: the data
Return type:: bytes

Memory targets only (see [ctor`Target`.new_to_memory]). Steal all data written to the target so far, and call [method`Target`.end].

You must free the returned pointer with [func`GLib`.free].

The data is NOT automatically null-terminated. Use [method`Target`.putc] with a ‘\0’ before calling this to get a null-terminated string.

You can’t call this after [method`Target`.end], since that moves the data to a blob, and we can’t steal from that in case the pointer has been shared.

You can’t call this function more than once.

steal_text()¶

Returns:: target contents as a null-terminated string.
Return type:: str

As [method`Target`.steal], but return a null-terminated string.

write(data, length)¶

Parameters:

data (object or None) – data to write
length (int) – length of data in bytes

Returns:

0 on success, -1 on error.

Return type:

int

Write length bytes from data to the output.

write_amp(str)¶

Parameters:: str (str) – string to write
Returns:: 0 on success, -1 on error.
Return type:: int

Write str to self, but escape stuff that xml hates in text. Our argument string is utf-8.

XML rules:

We must escape &<>
Don’t escape \n, \t, \r
Do escape the other ASCII codes.

writes(str)¶

Parameters:: str (str) – string to write
Returns:: 0 on success, and -1 on error.
Return type:: int

Write a null-terminated string to self.

do_end() virtual¶

Returns:: 0 on success, -1 on error.
Return type:: int

Call this at the end of write to make the target do any cleaning up. You can call it many times.

After a target has been ended, further writes will do nothing.

do_finish() virtual¶

do_read(buffer, length) virtual¶

Parameters:

buffer (object or None) – store bytes here
length (int) – length of buffer in bytes

Returns:

the number of bytes read, 0 on end of file, -1 on error.

Return type:

int

Read up to length bytes from target and store the bytes in buffer. Return the number of bytes actually read. If all bytes have been read from the file, return 0.

Arguments exactly as read()).

Reading from a target sounds weird, but libtiff needs this for multi-page writes. This method will fail for targets like pipes.

do_seek(offset, whence) virtual¶

Parameters:

offset (int) – offset to seek to
whence (int) – seek relative to beginning, offset, or end

Returns:

the new offset, -1 on error.

Return type:

int

Seek the target. This behaves exactly as lseek()).

Seeking a target sounds weird, but libtiff needs this. This method will fail for targets like pipes.

do_write(data, length) virtual¶

Parameters:

data (object or None) –
length (int) –

Return type:

int

Property Details¶

Vips.Target.props.blob¶

Name:: blob
Type:: Vips.Blob
Default Value:: None
Flags:: READABLE, WRITABLE

Blob to save to

Vips.Target.props.memory¶

Name:: memory
Type:: bool
Default Value:: False
Flags:: READABLE, WRITABLE

File descriptor should output to memory