D-Bus  1.8.1
Data Structures | Functions
Type signature parsing

Parsing D-Bus type signatures. More...

Data Structures

struct  DBusSignatureIter
 DBusSignatureIter struct; contains no public fields. More...
 

Functions

void dbus_signature_iter_init (DBusSignatureIter *iter, const char *signature)
 Initializes a DBusSignatureIter for reading a type signature. More...
 
int dbus_signature_iter_get_current_type (const DBusSignatureIter *iter)
 Returns the current type pointed to by the iterator. More...
 
char * dbus_signature_iter_get_signature (const DBusSignatureIter *iter)
 Returns the signature of the single complete type starting at the given iterator. More...
 
int dbus_signature_iter_get_element_type (const DBusSignatureIter *iter)
 Convenience function for returning the element type of an array; This function allows you to avoid initializing a sub-iterator and getting its current type. More...
 
dbus_bool_t dbus_signature_iter_next (DBusSignatureIter *iter)
 Skip to the next value on this "level". More...
 
void dbus_signature_iter_recurse (const DBusSignatureIter *iter, DBusSignatureIter *subiter)
 Initialize a new iterator pointing to the first type in the current container. More...
 
dbus_bool_t dbus_signature_validate (const char *signature, DBusError *error)
 Check a type signature for validity. More...
 
dbus_bool_t dbus_signature_validate_single (const char *signature, DBusError *error)
 Check that a type signature is both valid and contains exactly one complete type. More...
 
dbus_bool_t dbus_type_is_container (int typecode)
 A "container type" can contain basic types, or nested container types. More...
 
dbus_bool_t dbus_type_is_basic (int typecode)
 A "basic type" is a somewhat arbitrary concept, but the intent is to include those types that are fully-specified by a single typecode, with no additional type information or nested values. More...
 
dbus_bool_t dbus_type_is_fixed (int typecode)
 Tells you whether values of this type can change length if you set them to some other value. More...
 
dbus_bool_t dbus_type_is_valid (int typecode)
 Return TRUE if the argument is a valid typecode. More...
 

Detailed Description

Parsing D-Bus type signatures.

Function Documentation

DBUS_EXPORT int dbus_signature_iter_get_current_type ( const DBusSignatureIter iter)

Returns the current type pointed to by the iterator.

If the iterator is pointing at a type code such as 's', then it will be returned directly.

However, when the parser encounters a container type start character such as '(' for a structure, the corresponding type for the container will be returned, e.g. DBUS_TYPE_STRUCT, not '('. In this case, you should initialize a sub-iterator with dbus_signature_iter_recurse() to parse the container type.

Parameters
iterpointer to an iterator
Returns
current type (e.g. DBUS_TYPE_STRING, DBUS_TYPE_ARRAY)

Definition at line 92 of file dbus-signature.c.

References _dbus_first_type_in_signature_c_str(), and DBusSignatureRealIter::pos.

Referenced by dbus_signature_iter_get_element_type(), dbus_signature_iter_recurse(), and dbus_signature_validate_single().

DBUS_EXPORT int dbus_signature_iter_get_element_type ( const DBusSignatureIter iter)

Convenience function for returning the element type of an array; This function allows you to avoid initializing a sub-iterator and getting its current type.

Undefined behavior results if you invoke this function when the current type of the iterator is not DBUS_TYPE_ARRAY.

Parameters
iterpointer to an iterator
Returns
current array element type

Definition at line 146 of file dbus-signature.c.

References _dbus_first_type_in_signature_c_str(), dbus_signature_iter_get_current_type(), DBUS_TYPE_ARRAY, DBUS_TYPE_INVALID, and DBusSignatureRealIter::pos.

DBUS_EXPORT char * dbus_signature_iter_get_signature ( const DBusSignatureIter iter)

Returns the signature of the single complete type starting at the given iterator.

For example, if the iterator is pointing at the start of "(ii)ii" (which is "a struct of two ints, followed by an int, followed by an int"), then "(ii)" would be returned. If the iterator is pointing at one of the "i" then just that "i" would be returned.

Parameters
iterpointer to an iterator
Returns
current signature; or NULL if no memory. Should be freed with dbus_free()

Definition at line 112 of file dbus-signature.c.

References _dbus_string_append_len(), _dbus_string_free(), _dbus_string_init(), _dbus_string_steal_data(), _dbus_type_signature_next(), NULL, and DBusSignatureRealIter::pos.

DBUS_EXPORT void dbus_signature_iter_init ( DBusSignatureIter iter,
const char *  signature 
)

Initializes a DBusSignatureIter for reading a type signature.

This function is not safe to use on invalid signatures; be sure to validate potentially invalid signatures with dbus_signature_validate before using this function.

Parameters
iterpointer to an iterator to initialize
signaturethe type signature

Definition at line 67 of file dbus-signature.c.

References FALSE, DBusSignatureRealIter::finished, DBusSignatureRealIter::in_array, and DBusSignatureRealIter::pos.

Referenced by dbus_signature_validate_single().

DBUS_EXPORT dbus_bool_t dbus_signature_iter_next ( DBusSignatureIter iter)

Skip to the next value on this "level".

e.g. the next field in a struct, the next value in an array. Returns FALSE at the end of the current container.

Parameters
iterthe iterator
Returns
FALSE if nothing more to read at or below this level

Definition at line 164 of file dbus-signature.c.

References _dbus_type_signature_next(), DBUS_DICT_ENTRY_END_CHAR, DBUS_STRUCT_END_CHAR, DBUS_TYPE_INVALID, FALSE, DBusSignatureRealIter::finished, DBusSignatureRealIter::in_array, DBusSignatureRealIter::pos, and TRUE.

Referenced by dbus_signature_validate_single().

DBUS_EXPORT void dbus_signature_iter_recurse ( const DBusSignatureIter iter,
DBusSignatureIter subiter 
)

Initialize a new iterator pointing to the first type in the current container.

The results are undefined when calling this if the current type is a non-container (i.e. if dbus_type_is_container() returns FALSE for the result of dbus_signature_iter_get_current_type()).

Parameters
iterthe current interator
subiteran iterator to initialize pointing to the first child

Definition at line 207 of file dbus-signature.c.

References dbus_signature_iter_get_current_type(), DBUS_TYPE_ARRAY, dbus_type_is_container(), FALSE, DBusSignatureRealIter::in_array, DBusSignatureRealIter::pos, and TRUE.

DBUS_EXPORT dbus_bool_t dbus_signature_validate ( const char *  signature,
DBusError error 
)

Check a type signature for validity.

Remember that NULL can always be passed instead of a DBusError*, if you don't care about having an error name and message.

Parameters
signaturea potentially invalid type signature
errorerror return
Returns
TRUE if signature is valid or FALSE if an error is set

Definition at line 233 of file dbus-signature.c.

References _dbus_string_get_length(), _dbus_string_init_const(), _dbus_validate_signature_with_reason(), DBUS_ERROR_INVALID_SIGNATURE, dbus_set_error(), DBUS_VALID, FALSE, and TRUE.

Referenced by dbus_signature_validate_single().

DBUS_EXPORT dbus_bool_t dbus_signature_validate_single ( const char *  signature,
DBusError error 
)

Check that a type signature is both valid and contains exactly one complete type.

"One complete type" means a single basic type, array, struct, or dictionary, though the struct or array may be arbitrarily recursive and complex. More than one complete type would mean for example "ii" or two integers in sequence.

Parameters
signaturea potentially invalid type signature
errorerror return
Returns
TRUE if signature is valid and has exactly one complete type

Definition at line 264 of file dbus-signature.c.

References DBUS_ERROR_INVALID_SIGNATURE, dbus_set_error(), dbus_signature_iter_get_current_type(), dbus_signature_iter_init(), dbus_signature_iter_next(), dbus_signature_validate(), DBUS_TYPE_INVALID, FALSE, and TRUE.

DBUS_EXPORT dbus_bool_t dbus_type_is_basic ( int  typecode)

A "basic type" is a somewhat arbitrary concept, but the intent is to include those types that are fully-specified by a single typecode, with no additional type information or nested values.

So all numbers and strings are basic types and structs, arrays, and variants are not basic types. DBUS_TYPE_INVALID is not a basic type.

It is an error to pass an invalid type-code, other than DBUS_TYPE_INVALID, to this function. The valid type-codes are defined by dbus-protocol.h and can be checked with dbus_type_is_valid().

Parameters
typecodeeither a valid type-code or DBUS_TYPE_INVALID
Returns
TRUE if type is basic

Definition at line 318 of file dbus-signature.c.

References DBUS_TYPE_INVALID, dbus_type_is_valid(), and FALSE.

Referenced by _dbus_marshal_read_basic(), _dbus_marshal_write_basic(), _dbus_message_iter_get_args_valist(), _dbus_type_reader_set_basic(), _dbus_validate_signature_with_reason(), dbus_message_append_args_valist(), and dbus_message_iter_append_basic().

DBUS_EXPORT dbus_bool_t dbus_type_is_container ( int  typecode)

A "container type" can contain basic types, or nested container types.

DBUS_TYPE_INVALID is not a container type.

It is an error to pass an invalid type-code, other than DBUS_TYPE_INVALID, to this function. The valid type-codes are defined by dbus-protocol.h and can be checked with dbus_type_is_valid().

Parameters
typecodeeither a valid type-code or DBUS_TYPE_INVALID
Returns
TRUE if type is a container

Definition at line 294 of file dbus-signature.c.

References DBUS_TYPE_INVALID, dbus_type_is_valid(), and FALSE.

Referenced by dbus_message_iter_open_container(), and dbus_signature_iter_recurse().

DBUS_EXPORT dbus_bool_t dbus_type_is_fixed ( int  typecode)

Tells you whether values of this type can change length if you set them to some other value.

For this purpose, you assume that the first byte of the old and new value would be in the same location, so alignment padding is not a factor.

This function is useful to determine whether dbus_message_iter_get_fixed_array() may be used.

Some structs are fixed-size (if they contain only fixed-size types) but struct is not considered a fixed type for purposes of this function.

It is an error to pass an invalid type-code, other than DBUS_TYPE_INVALID, to this function. The valid type-codes are defined by dbus-protocol.h and can be checked with dbus_type_is_valid().

Parameters
typecodeeither a valid type-code or DBUS_TYPE_INVALID
Returns
FALSE if the type can occupy different lengths

Definition at line 349 of file dbus-signature.c.

References DBUS_TYPE_BOOLEAN, DBUS_TYPE_BYTE, DBUS_TYPE_DOUBLE, DBUS_TYPE_INT16, DBUS_TYPE_INT32, DBUS_TYPE_INT64, DBUS_TYPE_INVALID, dbus_type_is_valid(), DBUS_TYPE_UINT16, DBUS_TYPE_UINT32, DBUS_TYPE_UINT64, DBUS_TYPE_UNIX_FD, FALSE, and TRUE.

Referenced by _dbus_marshal_write_fixed_multi(), _dbus_message_iter_get_args_valist(), _dbus_type_reader_read_fixed_multi(), _dbus_type_reader_set_basic(), _dbus_type_writer_write_fixed_multi(), dbus_message_append_args_valist(), dbus_message_iter_append_fixed_array(), and dbus_message_iter_get_fixed_array().

DBUS_EXPORT dbus_bool_t dbus_type_is_valid ( int  typecode)

Return TRUE if the argument is a valid typecode.

DBUS_TYPE_INVALID surprisingly enough is not considered valid, and random unknown bytes aren't either. This function is safe with untrusted data.

Parameters
typecodea potential type-code
Returns
TRUE if valid

Definition at line 383 of file dbus-signature.c.

References DBUS_TYPE_ARRAY, DBUS_TYPE_BOOLEAN, DBUS_TYPE_BYTE, DBUS_TYPE_DICT_ENTRY, DBUS_TYPE_DOUBLE, DBUS_TYPE_INT16, DBUS_TYPE_INT32, DBUS_TYPE_INT64, DBUS_TYPE_OBJECT_PATH, DBUS_TYPE_SIGNATURE, DBUS_TYPE_STRING, DBUS_TYPE_STRUCT, DBUS_TYPE_UINT16, DBUS_TYPE_UINT32, DBUS_TYPE_UINT64, DBUS_TYPE_UNIX_FD, DBUS_TYPE_VARIANT, FALSE, and TRUE.

Referenced by _dbus_validate_signature_with_reason(), dbus_connection_can_send_type(), dbus_type_is_basic(), dbus_type_is_container(), and dbus_type_is_fixed().