libvips

vips_connection_filename ()

const char *
vips_connection_filename (VipsConnection *connection);

vips_connection_nick ()

const char *
vips_connection_nick (VipsConnection *connection);

vips_pipe_read_limit_set ()

void
vips_pipe_read_limit_set (gint64 limit);

If a source does not support mmap or seek and the source is used with a loader that can only work from memory, then the data will be automatically read into memory to EOF before the loader starts. This can produce high memory use if the descriptor represents a large object.

Use vips_pipe_read_limit_set() to limit the size of object that will be read in this way. The default is 1GB.

Set a value of -1 to mean no limit.

See also: --vips-pipe-read-limit and the environment variable VIPS_PIPE_READ_LIMIT.

vips_source_new_from_descriptor ()

VipsSource *
vips_source_new_from_descriptor (int descriptor);

Create an source attached to a file descriptor. descriptor is closed with close() when source is finalized.

vips_source_new_from_file ()

VipsSource *
vips_source_new_from_file (const char *filename);

Create an source attached to a file.

If this descriptor does not support mmap and the source is used with a loader that can only work from memory, then the data will be automatically read into memory to EOF before the loader starts. This can produce high memory use if the descriptor represents a large object.

Use vips_pipe_read_limit_set() to limit the size of object that will be read in this way. The default is 1GB.

vips_source_new_from_blob ()

VipsSource *
vips_source_new_from_blob (VipsBlob *blob);

Create a source attached to an area of memory.

vips_source_new_from_target ()

VipsSource *
vips_source_new_from_target (VipsTarget *target);

Create a source from a temp target that has been written to.

vips_source_new_from_memory ()

VipsSource *
vips_source_new_from_memory (const void *data,
                             size_t size);

Create a source attached to an area of memory.

You must not free data while the source is active.

vips_source_new_from_options ()

VipsSource *
vips_source_new_from_options (const char *options);

Create a source from an option string.

vips_source_minimise ()

void
vips_source_minimise (VipsSource *source);

Minimise the source. As many resources as can be safely removed are removed. Use vips_source_unminimise() to restore the source if you wish to use it again.

Loaders should call this in response to the minimise signal on their output image.

vips_source_unminimise ()

int
vips_source_unminimise (VipsSource *source);

Restore the source after minimisation. This is called at the start of every source method, so loaders should not usually need this.

See also: vips_source_minimise().

vips_source_decode ()

int
vips_source_decode (VipsSource *source);

Signal the end of header read and the start of the pixel decode phase. After this, you can no longer seek on this source.

Loaders should call this at the end of header read.

See also: vips_source_unminimise().

vips_source_read ()

gint64
vips_source_read (VipsSource *source,
                  void *data,
                  size_t length);

Read up to length bytes from source 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(2).

vips_source_is_mappable ()

gboolean
vips_source_is_mappable (VipsSource *source);

Some sources can be efficiently mapped into memory. You can still use vips_source_map() if this function returns FALSE, but it will be slow.

vips_source_is_file ()

gboolean
vips_source_is_file (VipsSource *source);

Test if this source is a simple file with support for seek. Named pipes, for example, will fail this test. If TRUE, you can use vips_connection_filename() to find the filename.

Use this to add basic source support for older loaders which can only work on files.

vips_source_map ()

const void *
vips_source_map (VipsSource *source,
                 size_t *length);

Map the source entirely into memory and return a pointer to the start. If length_out is non-NULL, the source size is written to it.

This operation can take a long time. Use vips_source_is_mappable() to check if a source can be mapped efficiently.

The pointer is valid for as long as source is alive.

vips_source_map_blob ()

VipsBlob *
vips_source_map_blob (VipsSource *source);

Just like vips_source_map(), but return a VipsBlob containing the pointer. source will stay alive as long as the result is alive.

vips_source_seek ()

gint64
vips_source_seek (VipsSource *source,
                  gint64 offset,
                  int whence);

Move the file read position. You can't call this after pixel decode starts. The arguments are exactly as lseek(2).

vips_source_rewind ()

int
vips_source_rewind (VipsSource *source);

Rewind the source to the start.

You can't always do this after the pixel decode phase starts -- for example, pipe-like sources can't be rewound.

vips_source_sniff_at_most ()

gint64
vips_source_sniff_at_most (VipsSource *source,
                           unsigned char **data,
                           size_t length);

Attempt to sniff at most length bytes from the start of the source. A pointer to the bytes is returned in data . The number of bytes actually read is returned -- it may be less than length if the file is shorter than length . A negative number indicates a read error.

vips_source_sniff ()

unsigned char *
vips_source_sniff (VipsSource *source,
                   size_t length);

Return a pointer to the first few bytes of the file. If the file is too short, return NULL.

vips_source_length ()

gint64
vips_source_length (VipsSource *source);

Return the length in bytes of the source. Unseekable sources, for example pipes, will have to be read entirely into memory before the length can be found, so this operation can take a long time.

vips_source_custom_new ()

VipsSourceCustom *
vips_source_custom_new (void);

Create a VipsSourceCustom. Attach signals to implement read and seek.

vips_g_input_stream_new_from_source ()

GInputStream *
vips_g_input_stream_new_from_source (VipsSource *source);

Create a new GInputStream wrapping a VipsSource. This is useful for loaders like SVG and PDF which support GInput methods.

vips_source_g_input_stream_new ()

VipsSourceGInputStream *
vips_source_g_input_stream_new (GInputStream *stream);

Create a VipsSourceGInputStream which wraps stream .

vips_target_new_to_descriptor ()

VipsTarget *
vips_target_new_to_descriptor (int descriptor);

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

See also: vips_target_new_to_file().

vips_target_new_to_file ()

VipsTarget *
vips_target_new_to_file (const char *filename);

Create a target attached to a file.

vips_target_new_to_memory ()

VipsTarget *
vips_target_new_to_memory (void);

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

See also: vips_target_new_to_file().

vips_target_new_temp ()

VipsTarget *
vips_target_new_temp (VipsTarget *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.

See also: vips_target_new_to_file().

vips_target_write ()

int
vips_target_write (VipsTarget *target,
                   const void *data,
                   size_t length);

Write length bytes from buffer to the output.

vips_target_read ()

gint64
vips_target_read (VipsTarget *target,
                  void *buffer,
                  size_t length);

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(2).

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

vips_target_seek ()

gint64
vips_target_seek (VipsTarget *target,
                  gint64 offset,
                  int whence);

Seek the target. This behaves exactly as lseek(2).

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

vips_target_end ()

int
vips_target_end (VipsTarget *target);

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.

vips_target_steal ()

unsigned char *
vips_target_steal (VipsTarget *target,
                   size_t *length);

Memory targets only (see vips_target_new_to_memory()). Steal all data written to the target so far, and call vips_target_end().

You must free the returned pointer with g_free().

The data is NOT automatically null-terminated. vips_target_putc() a '\0' before calling this to get a null-terminated string.

You can't call this after vips_target_end(), since that moves the data to a blob, and we can't steal from that in case the pointer has been be shared.

You can't call this function more than once.

vips_target_steal_text ()

char *
vips_target_steal_text (VipsTarget *target);

As vips_target_steal_text(), but return a null-terminated string.

vips_target_putc ()

int
vips_target_putc (VipsTarget *target,
                  int ch);

Write a single character ch to target . See the macro VIPS_TARGET_PUTC() for a faster way to do this.

VIPS_TARGET_PUTC()

#define             VIPS_TARGET_PUTC(S, C)

vips_target_writes ()

int
vips_target_writes (VipsTarget *target,
                    const char *str);

Write a null-terminated string to target .

vips_target_writef ()

int
vips_target_writef (VipsTarget *target,
                    const char *fmt,
                    ...);

Format the string and write to target .

vips_target_write_amp ()

int
vips_target_write_amp (VipsTarget *target,
                       const char *str);

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

XML rules:

vips_target_custom_new ()

VipsTargetCustom *
vips_target_custom_new (void);

Create a VipsTargetCustom. Attach signals to implement write and finish.

VipsSourceGInputStream

typedef struct {
	VipsSource parent_instance;
} VipsSourceGInputStream;

VipsSourceGInputStreamClass

typedef struct {
	VipsSourceClass parent_class;
} VipsSourceGInputStreamClass;

VIPS_TARGET_BUFFER_SIZE

#define VIPS_TARGET_BUFFER_SIZE (8500)

VIPS_TARGET_CUSTOM_BUFFER_SIZE

#define VIPS_TARGET_CUSTOM_BUFFER_SIZE (4096)

The “descriptor” property

  “descriptor”               int

File descriptor for read or write.

Owner: VipsConnection

Flags: Read / Write

Allowed values: [-1,1000000000]

Default value: 0

The “filename” property

  “filename”                 char *

Name of file to open.

Owner: VipsConnection

Flags: Read / Write

Default value: NULL

The “blob” property

  “blob”                     VipsBlob *

Blob to load from.

Owner: VipsSource

Flags: Read / Write

The “blob” property

  “blob”                     VipsBlob *

Blob to save to.

Owner: VipsTarget

Flags: Read / Write

The “memory” property

  “memory”                   gboolean

File descriptor should output to memory.

Owner: VipsTarget

Flags: Read / Write

Default value: FALSE

The “read” signal

gint64
user_function (VipsSourceCustom *source_custom,
               gpointer          buffer,
               gint64            size,
               gpointer          user_data)

This signal is emitted to read bytes from the source into buffer .

Flags: Action

The “seek” signal

gint64
user_function (VipsSourceCustom *source_custom,
               gint64            offset,
               int               whence,
               gpointer          user_data)

This signal is emitted to seek the source. The handler should change the source position appropriately.

The handler for an unseekable source should always return -1.

Flags: Action

The “end” signal

int
user_function (VipsTargetCustom *target_custom,
               gpointer          user_data)

This signal is emitted at the end of write. The target should do any finishing necessary.

Flags: Action

The “finish” signal

void
user_function (VipsTargetCustom *target_custom,
               gpointer          user_data)

Deprecated for VipsTargetCustom::end.

Flags: Action

The “read” signal

gint64
user_function (VipsTargetCustom *target_custom,
               gpointer          buffer,
               gint64            size,
               gpointer          user_data)

This signal is emitted to read bytes from the target into buffer .

The handler for an unreadable target should always return -1.

Flags: Action

The “seek” signal

gint64
user_function (VipsTargetCustom *target_custom,
               gint64            offset,
               int               whence,
               gpointer          user_data)

This signal is emitted to seek the target. The handler should change the target position appropriately.

The handler for an unseekable target should always return -1.

Flags: Action

The “write” signal

gint64
user_function (VipsTargetCustom *target_custom,
               gpointer          data,
               gint64            length,
               gpointer          user_data)

This signal is emitted to write bytes to the target.

Flags: Action