mtp_opts Struct Reference

MTP configuration: device identity + one or more storage backends. More...

#include <classes/mtp.h>

Data Fields
int	read_only
	Nonzero -> reject host writes/deletes/edits.
const char *	name
	Model / device friendly name.
const char *	manufacturer
	DeviceInfo Manufacturer (may be NULL)
const char *	serial
	32 hex chars (NULL -> a built-in default)
int	winusb
	Nonzero -> advertise the Microsoft OS "MTP" Compatible ID.
int	n_stores
	Number of storages exposed (entries used in stores)
void *	stores [MTP_MAX_STORAGES]
	Per-storage backend contexts (e.g.
void(*	listdir )(void *store, const char *path, mtp_emit emit, void *ctx)
	List a directory: call emit once per entry it contains.
int(*	get_info )(void *store, const char *path, int *is_dir, uint64_t *size, uint32_t *mtime)
	Stat one object.
int(*	read )(void *store, const char *path, long off, uint8_t *buf, int want)
	Read from a file.
int(*	write )(void *store, const char *path, const uint8_t *data, int len)
	Create or overwrite a file with the given contents (whole-file write).
int(*	make_dir )(void *store, const char *path)
	Create a directory.
int(*	remove )(void *store, const char *path)
	Delete a file or empty directory.
int(*	rename )(void *store, const char *path, const char *newpath)
	Rename or move an object.
int(*	pwrite )(void *store, const char *path, long off, const uint8_t *data, int len)
	Partial in-place write (Android edit extension; may be NULL).
int(*	truncate )(void *store, const char *path, uint64_t size)
	Truncate a file to a new length (Android edit extension; may be NULL).
void(*	disk_usage )(void *store, uint64_t *total, uint64_t *freeb)
	Report the storage's capacity.
const char *(*	description )(void *store)
	Storage label shown to the host (may be NULL).
void(*	on_event )(void *user, const char *text)
	Human-readable log hook for MTP activity (may be NULL).
void *	user
	Opaque pointer passed to on_event.

Detailed Description

MTP configuration: device identity + one or more storage backends.

The class implements the MTP protocol and object model but performs no filesystem access - every storage operation is delegated to the callbacks below. Each callback's first argument is the per-storage context (one of stores[]). Paths are relative and "/"-separated; the empty string "" is that storage's root. Unless noted, the int callbacks return 0 on success and a negative value on failure.

Field Documentation

read_only

int mtp_opts::read_only

Nonzero -> reject host writes/deletes/edits.

name

const char* mtp_opts::name

Model / device friendly name.

manufacturer

const char* mtp_opts::manufacturer

DeviceInfo Manufacturer (may be NULL)

serial

const char* mtp_opts::serial

32 hex chars (NULL -> a built-in default)

winusb

int mtp_opts::winusb

Nonzero -> advertise the Microsoft OS "MTP" Compatible ID.

n_stores

int mtp_opts::n_stores

Number of storages exposed (entries used in stores)

stores

void* mtp_opts::stores[MTP_MAX_STORAGES]

Per-storage backend contexts (e.g.

a directory root)

listdir

void(* mtp_opts::listdir) (void *store, const char *path, mtp_emit emit, void *ctx)

List a directory: call emit once per entry it contains.

Parameters

store	the per-storage context.
path	directory path ("" = storage root).
emit	sink for entry names (see mtp_emit).
ctx	opaque pointer to pass back to emit.

get_info

int(* mtp_opts::get_info) (void *store, const char *path, int *is_dir, uint64_t *size, uint32_t *mtime)

Stat one object.

Parameters

	store	the per-storage context.
	path	object path.
[out]	is_dir	set non-zero for a directory, 0 for a file.
[out]	size	set to the file size in bytes.
[out]	mtime	set to the modification time (Unix epoch seconds).

Returns

0 if the object exists, < 0 if it is missing.

read

int(* mtp_opts::read) (void *store, const char *path, long off, uint8_t *buf, int want)

Read from a file.

Parameters

store	the per-storage context.
path	file path.
off	byte offset to read from.
buf	destination buffer.
want	maximum number of bytes to read.

Returns

bytes read (0 at end of file), or < 0 on error.

write

int(* mtp_opts::write) (void *store, const char *path, const uint8_t *data, int len)

Create or overwrite a file with the given contents (whole-file write).

Parameters

store	the per-storage context.
path	file path.
data	the file contents.
len	number of bytes in data.

Returns

0 on success, < 0 on error.

make_dir

int(* mtp_opts::make_dir) (void *store, const char *path)

Create a directory.

Parameters

store	the per-storage context.
path	directory path to create.

Returns

0 on success, < 0 on error.

remove

int(* mtp_opts::remove) (void *store, const char *path)

Delete a file or empty directory.

Parameters

store	the per-storage context.
path	object path to remove.

Returns

0 on success, < 0 on error.

rename

int(* mtp_opts::rename) (void *store, const char *path, const char *newpath)

Rename or move an object.

Parameters

store	the per-storage context.
path	existing object path.
newpath	new path.

Returns

0 on success, < 0 on error.

pwrite

int(* mtp_opts::pwrite) (void *store, const char *path, long off, const uint8_t *data, int len)

Partial in-place write (Android edit extension; may be NULL).

Parameters

store	the per-storage context.
path	file path.
off	byte offset to write at.
data	the bytes to write.
len	number of bytes in data.

Returns

0 on success, < 0 on error.

truncate

int(* mtp_opts::truncate) (void *store, const char *path, uint64_t size)

Truncate a file to a new length (Android edit extension; may be NULL).

Parameters

store	the per-storage context.
path	file path.
size	new length in bytes.

Returns

0 on success, < 0 on error.

disk_usage

void(* mtp_opts::disk_usage) (void *store, uint64_t *total, uint64_t *freeb)

Report the storage's capacity.

Parameters

	store	the per-storage context.
[out]	total	set to total bytes.
[out]	freeb	set to free bytes.

description

const char *(* mtp_opts::description) (void *store)

Storage label shown to the host (may be NULL).

Parameters

store

the per-storage context.

Returns

a NUL-terminated label, or NULL for a built-in default.

on_event

void(* mtp_opts::on_event) (void *user, const char *text)

Human-readable log hook for MTP activity (may be NULL).

Parameters

user	the user pointer.
text	a NUL-terminated description.

user

void* mtp_opts::user

Opaque pointer passed to on_event.

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The documentation for this struct was generated from the following file:

• classes/mtp.h