1use std::slice::SliceIndex;
2
3#[cfg(feature = "gvariant")]
4use crate::signature_parser::SignatureParser;
5use crate::{Basic, EncodingFormat, Error, ObjectPath, Result, Signature};
6
7#[cfg(unix)]
8use crate::Fd;
9
10/// The prefix of ARRAY type signature, as a character. Provided for manual signature creation.
11pub const ARRAY_SIGNATURE_CHAR: char = 'a';
12/// The prefix of ARRAY type signature, as a string. Provided for manual signature creation.
13pub const ARRAY_SIGNATURE_STR: &str = "a";
14pub(crate) const ARRAY_ALIGNMENT_DBUS: usize = 4;
15/// The opening character of STRUCT type signature. Provided for manual signature creation.
16pub const STRUCT_SIG_START_CHAR: char = '(';
17/// The closing character of STRUCT type signature. Provided for manual signature creation.
18pub const STRUCT_SIG_END_CHAR: char = ')';
19/// The opening character of STRUCT type signature, as a string. Provided for manual signature
20/// creation.
21pub const STRUCT_SIG_START_STR: &str = "(";
22/// The closing character of STRUCT type signature, as a string. Provided for manual signature
23/// creation.
24pub const STRUCT_SIG_END_STR: &str = ")";
25pub(crate) const STRUCT_ALIGNMENT_DBUS: usize = 8;
26/// The opening character of DICT_ENTRY type signature. Provided for manual signature creation.
27pub const DICT_ENTRY_SIG_START_CHAR: char = '{';
28/// The closing character of DICT_ENTRY type signature. Provided for manual signature creation.
29pub const DICT_ENTRY_SIG_END_CHAR: char = '}';
30/// The opening character of DICT_ENTRY type signature, as a string. Provided for manual signature
31/// creation.
32pub const DICT_ENTRY_SIG_START_STR: &str = "{";
33/// The closing character of DICT_ENTRY type signature, as a string. Provided for manual signature
34/// creation.
35pub const DICT_ENTRY_SIG_END_STR: &str = "}";
36pub(crate) const DICT_ENTRY_ALIGNMENT_DBUS: usize = 8;
37/// The VARIANT type signature. Provided for manual signature creation.
38pub const VARIANT_SIGNATURE_CHAR: char = 'v';
39/// The VARIANT type signature, as a string. Provided for manual signature creation.
40pub const VARIANT_SIGNATURE_STR: &str = "v";
41pub(crate) const VARIANT_ALIGNMENT_DBUS: usize = 1;
42#[cfg(feature = "gvariant")]
43pub(crate) const VARIANT_ALIGNMENT_GVARIANT: usize = 8;
44/// The prefix of MAYBE (GVariant-specific) type signature, as a character. Provided for manual
45/// signature creation.
46#[cfg(feature = "gvariant")]
47pub const MAYBE_SIGNATURE_CHAR: char = 'm';
48/// The prefix of MAYBE (GVariant-specific) type signature, as a string. Provided for manual
49/// signature creation.
50#[cfg(feature = "gvariant")]
51pub const MAYBE_SIGNATURE_STR: &str = "m";
52
53pub(crate) fn padding_for_n_bytes(value: usize, align: usize) -> usize {
54 let len_rounded_up: usize = value.wrapping_add(align).wrapping_sub(1) & !align.wrapping_sub(1);
55
56 len_rounded_up.wrapping_sub(value)
57}
58
59pub(crate) fn usize_to_u32(value: usize) -> u32 {
60 assert!(
61 value <= (std::u32::MAX as usize),
62 "{} too large for `u32`",
63 value,
64 );
65
66 value as u32
67}
68
69pub(crate) fn usize_to_u8(value: usize) -> u8 {
70 assert!(
71 value <= (std::u8::MAX as usize),
72 "{} too large for `u8`",
73 value,
74 );
75
76 value as u8
77}
78
79pub(crate) fn f64_to_f32(value: f64) -> f32 {
80 assert!(
81 value <= (std::f32::MAX as f64),
82 "{} too large for `f32`",
83 value,
84 );
85
86 value as f32
87}
88
89// `signature` must be **one** complete and correct signature. Expect panics otherwise!
90pub(crate) fn alignment_for_signature(
91 signature: &Signature<'_>,
92 format: EncodingFormat,
93) -> Result<usize> {
94 let alignment = match signature
95 .as_bytes()
96 .first()
97 .map(|b| *b as char)
98 .ok_or_else(|| -> Error { serde::de::Error::invalid_length(0, &">= 1 character") })?
99 {
100 u8::SIGNATURE_CHAR => u8::alignment(format),
101 bool::SIGNATURE_CHAR => bool::alignment(format),
102 i16::SIGNATURE_CHAR => i16::alignment(format),
103 u16::SIGNATURE_CHAR => u16::alignment(format),
104 i32::SIGNATURE_CHAR => i32::alignment(format),
105 u32::SIGNATURE_CHAR => u32::alignment(format),
106 #[cfg(unix)]
107 Fd::SIGNATURE_CHAR => u32::alignment(format),
108 i64::SIGNATURE_CHAR => i64::alignment(format),
109 u64::SIGNATURE_CHAR => u64::alignment(format),
110 f64::SIGNATURE_CHAR => f64::alignment(format),
111 <&str>::SIGNATURE_CHAR => <&str>::alignment(format),
112 ObjectPath::SIGNATURE_CHAR => ObjectPath::alignment(format),
113 Signature::SIGNATURE_CHAR => Signature::alignment(format),
114 VARIANT_SIGNATURE_CHAR => match format {
115 EncodingFormat::DBus => VARIANT_ALIGNMENT_DBUS,
116 #[cfg(feature = "gvariant")]
117 EncodingFormat::GVariant => VARIANT_ALIGNMENT_GVARIANT,
118 },
119 ARRAY_SIGNATURE_CHAR => alignment_for_array_signature(signature, format)?,
120 STRUCT_SIG_START_CHAR => alignment_for_struct_signature(signature, format)?,
121 DICT_ENTRY_SIG_START_CHAR => alignment_for_dict_entry_signature(signature, format)?,
122 #[cfg(feature = "gvariant")]
123 MAYBE_SIGNATURE_CHAR => alignment_for_maybe_signature(signature, format)?,
124 _ => {
125 return Err(serde::de::Error::invalid_value(
126 serde::de::Unexpected::Str(signature),
127 &"a valid signature",
128 ))
129 }
130 };
131
132 Ok(alignment)
133}
134
135#[cfg(feature = "gvariant")]
136pub(crate) fn is_fixed_sized_signature<'a>(signature: &'a Signature<'a>) -> Result<bool> {
137 match signature
138 .as_bytes()
139 .first()
140 .map(|b| *b as char)
141 .ok_or_else(|| -> Error { serde::de::Error::invalid_length(0, &">= 1 character") })?
142 {
143 u8::SIGNATURE_CHAR
144 | bool::SIGNATURE_CHAR
145 | i16::SIGNATURE_CHAR
146 | u16::SIGNATURE_CHAR
147 | i32::SIGNATURE_CHAR
148 | u32::SIGNATURE_CHAR
149 | i64::SIGNATURE_CHAR
150 | u64::SIGNATURE_CHAR
151 | f64::SIGNATURE_CHAR => Ok(true),
152 #[cfg(unix)]
153 Fd::SIGNATURE_CHAR => Ok(true),
154 STRUCT_SIG_START_CHAR => is_fixed_sized_struct_signature(signature),
155 DICT_ENTRY_SIG_START_CHAR => is_fixed_sized_dict_entry_signature(signature),
156 _ => Ok(false),
157 }
158}
159
160// Given an &str, create an owned (String-based) Signature w/ appropriate capacity
161macro_rules! signature_string {
162 ($signature:expr) => {{
163 let mut s = String::with_capacity(255);
164 s.push_str($signature);
165
166 Signature::from_string_unchecked(s)
167 }};
168}
169
170macro_rules! check_child_value_signature {
171 ($expected_signature:expr, $child_signature:expr, $child_name:literal) => {{
172 if $child_signature != $expected_signature {
173 let unexpected = format!("{} with signature `{}`", $child_name, $child_signature,);
174 let expected = format!("{} with signature `{}`", $child_name, $expected_signature);
175
176 return Err(serde::de::Error::invalid_type(
177 serde::de::Unexpected::Str(&unexpected),
178 &expected.as_str(),
179 ));
180 }
181 }};
182}
183
184fn alignment_for_single_child_type_signature(
185 #[allow(unused)] signature: &Signature<'_>,
186 format: EncodingFormat,
187 dbus_align: usize,
188) -> Result<usize> {
189 match format {
190 EncodingFormat::DBus => Ok(dbus_align),
191 #[cfg(feature = "gvariant")]
192 EncodingFormat::GVariant => {
193 let child_signature = signature.slice(1..);
194
195 alignment_for_signature(&child_signature, format)
196 }
197 }
198}
199
200fn alignment_for_array_signature(
201 signature: &Signature<'_>,
202 format: EncodingFormat,
203) -> Result<usize> {
204 alignment_for_single_child_type_signature(signature, format, ARRAY_ALIGNMENT_DBUS)
205}
206
207#[cfg(feature = "gvariant")]
208fn alignment_for_maybe_signature(
209 signature: &Signature<'_>,
210 format: EncodingFormat,
211) -> Result<usize> {
212 alignment_for_single_child_type_signature(signature, format, 1)
213}
214
215fn alignment_for_struct_signature(
216 #[allow(unused)] signature: &Signature<'_>,
217 format: EncodingFormat,
218) -> Result<usize> {
219 match format {
220 EncodingFormat::DBus => Ok(STRUCT_ALIGNMENT_DBUS),
221 #[cfg(feature = "gvariant")]
222 EncodingFormat::GVariant => {
223 if signature.len() < 3 {
224 return Err(serde::de::Error::invalid_length(
225 signature.len(),
226 &">= 3 characters in struct signature",
227 ));
228 }
229 let inner_signature = Signature::from_str_unchecked(&signature[1..signature.len() - 1]);
230 let mut sig_parser = SignatureParser::new(inner_signature);
231 let mut alignment = 0;
232
233 while !sig_parser.done() {
234 let child_signature = sig_parser.parse_next_signature()?;
235
236 let child_alignment = alignment_for_signature(&child_signature, format)?;
237 if child_alignment > alignment {
238 alignment = child_alignment;
239
240 if alignment == 8 {
241 // 8 bytes is max alignment so we can short-circuit here
242 break;
243 }
244 }
245 }
246
247 Ok(alignment)
248 }
249 }
250}
251
252fn alignment_for_dict_entry_signature(
253 #[allow(unused)] signature: &Signature<'_>,
254 format: EncodingFormat,
255) -> Result<usize> {
256 match format {
257 EncodingFormat::DBus => Ok(DICT_ENTRY_ALIGNMENT_DBUS),
258 #[cfg(feature = "gvariant")]
259 EncodingFormat::GVariant => {
260 if signature.len() < 4 {
261 return Err(serde::de::Error::invalid_length(
262 signature.len(),
263 &">= 4 characters in dict entry signature",
264 ));
265 }
266 let key_signature = Signature::from_str_unchecked(&signature[1..2]);
267 let key_alignment = alignment_for_signature(&key_signature, format)?;
268 if key_alignment == 8 {
269 // 8 bytes is max alignment so we can short-circuit here
270 return Ok(8);
271 }
272
273 let value_signature = Signature::from_str_unchecked(&signature[2..signature.len() - 1]);
274 let value_alignment = alignment_for_signature(&value_signature, format)?;
275 if value_alignment > key_alignment {
276 Ok(value_alignment)
277 } else {
278 Ok(key_alignment)
279 }
280 }
281 }
282}
283
284#[cfg(feature = "gvariant")]
285fn is_fixed_sized_struct_signature<'a>(signature: &'a Signature<'a>) -> Result<bool> {
286 let inner_signature = Signature::from_str_unchecked(&signature[1..signature.len() - 1]);
287 let mut sig_parser = SignatureParser::new(inner_signature);
288 let mut fixed_sized = true;
289
290 while !sig_parser.done() {
291 let child_signature = sig_parser.parse_next_signature()?;
292
293 if !is_fixed_sized_signature(&child_signature)? {
294 // STRUCT is fixed-sized only if all its children are
295 fixed_sized = false;
296
297 break;
298 }
299 }
300
301 Ok(fixed_sized)
302}
303
304#[cfg(feature = "gvariant")]
305fn is_fixed_sized_dict_entry_signature<'a>(signature: &'a Signature<'a>) -> Result<bool> {
306 let key_signature = Signature::from_str_unchecked(&signature[1..2]);
307 if !is_fixed_sized_signature(&key_signature)? {
308 return Ok(false);
309 }
310
311 let value_signature = Signature::from_str_unchecked(&signature[2..signature.len() - 1]);
312
313 is_fixed_sized_signature(&value_signature)
314}
315
316/// Slice the given slice of bytes safely and return an error if the slice is too small.
317pub(crate) fn subslice<I, T>(input: &[T], index: I) -> Result<&I::Output>
318where
319 I: SliceIndex<[T]>,
320{
321 input.get(index).ok_or(err:Error::OutOfBounds)
322}
323