Modulemd Compression Helpers (Private): Modulemd Reference Manual

## Modulemd Compression Helpers (Private) Modulemd Compression Helpers (Private) — Internal utility functions for working with compressed files. |

## Stability Level

Private, unless otherwise indicated

## Functions

void | mmd_Fclose ()
ModulemdCompressionTypeEnum | modulemd_detect_compression ()
const gchar * | modulemd_compression_suffix ()
gchar * | modulemd_get_rpmio_fmode ()
gint | compressed_stream_read_fn ()

## Description

## Functions

### mmd_Fclose ()

    void
    mmd_Fclose (FD_t fd);

Wrapper for rpmio's `Fclose()` function to use with ``G_DEFINE_AUTO_CLEANUP_FREE_FUNC()``

#### Parameters

fd | A FD_t from rpmio.h to be closed. | [in]

Since: 2.8

### modulemd_detect_compression ()

    ModulemdCompressionTypeEnum
    modulemd_detect_compression (const gchar *filename,
                                 int fd,
                                 GError **error);

#### Parameters

filename | The original filename that matches `fd` . | [in]
fd | An open file descriptor pointing at a real file. | [in]
error | A GError containing the reason this function failed. | [out]

#### Returns

The ModulemdCompressionTypeEnum detected from this file descriptor. In the event of an error, returns MODULEMD_COMPRESSION_TYPE_DETECTION_FAILED and sets `error` appropriately. Returns MODULEMD_COMPRESSION_TYPE_UNKNOWN_COMPRESSION if all detection methods complete but the type is still indeterminate.

Since: 2.8

### modulemd_compression_suffix ()

    const gchar *
    modulemd_compression_suffix (ModulemdCompressionTypeEnum comtype);

#### Parameters

comtype | A ModulemdCompressionTypeEnum. | [in]

#### Returns

A static string representing the filename suffix that a file of this compression type should have.

[transfer none]

Since: 2.8

### modulemd_get_rpmio_fmode ()

    gchar *
    modulemd_get_rpmio_fmode (const gchar *mode,
                              ModulemdCompressionTypeEnum comtype);

#### Parameters

mode | A mode argument that will be passed to `fopen(3)`. | [in]
comtype | A ModulemdCompressionTypeEnum. | [in]

#### Returns

A string suitable for passing to rpmio's ``Fopen()`` function. NULL if `mode` is NULL or the `comtype` is invalid.

[transfer full]

Since: 2.8

### compressed_stream_read_fn ()

    gint
    compressed_stream_read_fn (void *data,
                               unsigned char *buffer,
                               size_t size,
                               size_t *size_read);

A ModulemdReadHandler that uses rpmio's ``Fread()`` function to handle compressed files.

#### Parameters

data | A private pointer to the data being read. | [inout]
buffer | The buffer to write the data from the source. | [out]
size | The size of the buffer. | [in]
size_read | The actual number of bytes read from the source. | [out]

Since: 2.8