valkey_module/
redismodule.rs

1use std::borrow::Borrow;
2use std::convert::TryFrom;
3use std::ffi::CString;
4use std::fmt::Display;
5use std::ops::Deref;
6use std::os::raw::{c_char, c_int, c_void};
7use std::ptr::{null_mut, NonNull};
8use std::slice;
9use std::str;
10use std::str::Utf8Error;
11use std::string::FromUtf8Error;
12use std::{fmt, ptr};
13
14use serde::de::{Error, SeqAccess};
15
16pub use crate::raw;
17pub use crate::rediserror::ValkeyError;
18pub use crate::redisvalue::ValkeyValue;
19use crate::Context;
20
21/// A short-hand type that stores a [std::result::Result] with custom
22/// type and [RedisError].
23pub type ValkeyResult<T = ValkeyValue> = Result<T, ValkeyError>;
24/// A [RedisResult] with [ValkeyValue].
25pub type ValkeyValueResult = ValkeyResult<ValkeyValue>;
26
27impl From<ValkeyValue> for ValkeyValueResult {
28    fn from(v: ValkeyValue) -> Self {
29        Ok(v)
30    }
31}
32
33impl From<ValkeyError> for ValkeyValueResult {
34    fn from(v: ValkeyError) -> Self {
35        Err(v)
36    }
37}
38
39pub const VALKEY_OK: ValkeyValueResult = Ok(ValkeyValue::SimpleStringStatic("OK"));
40pub const TYPE_METHOD_VERSION: u64 = raw::REDISMODULE_TYPE_METHOD_VERSION as u64;
41
42pub trait NextArg {
43    fn next_arg(&mut self) -> Result<ValkeyString, ValkeyError>;
44    fn next_string(&mut self) -> Result<String, ValkeyError>;
45    fn next_str<'a>(&mut self) -> Result<&'a str, ValkeyError>;
46    fn next_i64(&mut self) -> Result<i64, ValkeyError>;
47    fn next_u64(&mut self) -> Result<u64, ValkeyError>;
48    fn next_f64(&mut self) -> Result<f64, ValkeyError>;
49    fn done(&mut self) -> Result<(), ValkeyError>;
50}
51
52impl<T> NextArg for T
53where
54    T: Iterator<Item = ValkeyString>,
55{
56    #[inline]
57    fn next_arg(&mut self) -> Result<ValkeyString, ValkeyError> {
58        self.next().ok_or(ValkeyError::WrongArity)
59    }
60
61    #[inline]
62    fn next_string(&mut self) -> Result<String, ValkeyError> {
63        self.next()
64            .map_or(Err(ValkeyError::WrongArity), |v| Ok(v.to_string_lossy()))
65    }
66
67    #[inline]
68    fn next_str<'a>(&mut self) -> Result<&'a str, ValkeyError> {
69        self.next()
70            .map_or(Err(ValkeyError::WrongArity), |v| v.try_as_str())
71    }
72
73    #[inline]
74    fn next_i64(&mut self) -> Result<i64, ValkeyError> {
75        self.next()
76            .map_or(Err(ValkeyError::WrongArity), |v| v.parse_integer())
77    }
78
79    #[inline]
80    fn next_u64(&mut self) -> Result<u64, ValkeyError> {
81        self.next()
82            .map_or(Err(ValkeyError::WrongArity), |v| v.parse_unsigned_integer())
83    }
84
85    #[inline]
86    fn next_f64(&mut self) -> Result<f64, ValkeyError> {
87        self.next()
88            .map_or(Err(ValkeyError::WrongArity), |v| v.parse_float())
89    }
90
91    /// Return an error if there are any more arguments
92    #[inline]
93    fn done(&mut self) -> Result<(), ValkeyError> {
94        self.next().map_or(Ok(()), |_| Err(ValkeyError::WrongArity))
95    }
96}
97
98#[allow(clippy::not_unsafe_ptr_arg_deref)]
99pub fn decode_args(
100    ctx: *mut raw::RedisModuleCtx,
101    argv: *mut *mut raw::RedisModuleString,
102    argc: c_int,
103) -> Vec<ValkeyString> {
104    if argv.is_null() {
105        return Vec::new();
106    }
107    unsafe { slice::from_raw_parts(argv, argc as usize) }
108        .iter()
109        .map(|&arg| ValkeyString::new(NonNull::new(ctx), arg))
110        .collect()
111}
112
113///////////////////////////////////////////////////
114
115#[derive(Debug)]
116pub struct ValkeyString {
117    ctx: *mut raw::RedisModuleCtx,
118    pub inner: *mut raw::RedisModuleString,
119}
120
121impl ValkeyString {
122    pub(crate) fn take(mut self) -> *mut raw::RedisModuleString {
123        let inner = self.inner;
124        self.inner = std::ptr::null_mut();
125        inner
126    }
127
128    pub fn new(
129        ctx: Option<NonNull<raw::RedisModuleCtx>>,
130        inner: *mut raw::RedisModuleString,
131    ) -> Self {
132        let ctx = ctx.map_or(std::ptr::null_mut(), |v| v.as_ptr());
133        raw::string_retain_string(ctx, inner);
134        Self { ctx, inner }
135    }
136
137    /// In general, [RedisModuleString] is none atomic ref counted object.
138    /// So it is not safe to clone it if Valkey GIL is not held.
139    /// [Self::safe_clone] gets a context reference which indicates that Valkey GIL is held.
140    pub fn safe_clone(&self, _ctx: &Context) -> Self {
141        // RedisString are *not* atomic ref counted, so we must get a lock indicator to clone them.
142        // Alos notice that Valkey allows us to create RedisModuleString with NULL context
143        // so we use [std::ptr::null_mut()] instead of the curren RedisString context.
144        // We do this because we can not promise the new RedisString will not outlive the current
145        // context and we want them to be independent.
146        raw::string_retain_string(ptr::null_mut(), self.inner);
147        Self {
148            ctx: ptr::null_mut(),
149            inner: self.inner,
150        }
151    }
152
153    #[allow(clippy::not_unsafe_ptr_arg_deref)]
154    pub fn create<T: Into<Vec<u8>>>(ctx: Option<NonNull<raw::RedisModuleCtx>>, s: T) -> Self {
155        let ctx = ctx.map_or(std::ptr::null_mut(), |v| v.as_ptr());
156        let str = CString::new(s).unwrap();
157        let inner = unsafe {
158            raw::RedisModule_CreateString.unwrap()(ctx, str.as_ptr(), str.as_bytes().len())
159        };
160
161        Self { ctx, inner }
162    }
163
164    #[allow(clippy::not_unsafe_ptr_arg_deref)]
165    pub fn create_from_slice(ctx: *mut raw::RedisModuleCtx, s: &[u8]) -> Self {
166        let inner = unsafe {
167            raw::RedisModule_CreateString.unwrap()(ctx, s.as_ptr().cast::<c_char>(), s.len())
168        };
169
170        Self { ctx, inner }
171    }
172
173    /// Creates a ValkeyString from a &str and retains it.  This is useful in cases where Modules need to pass ownership of a ValkeyString to the core engine without it being freed when we drop a ValkeyString
174    pub fn create_and_retain(arg: &str) -> ValkeyString {
175        let arg = ValkeyString::create(None, arg);
176        raw::string_retain_string(null_mut(), arg.inner);
177        arg
178    }
179
180    pub const fn from_redis_module_string(
181        ctx: *mut raw::RedisModuleCtx,
182        inner: *mut raw::RedisModuleString,
183    ) -> Self {
184        // Need to avoid string_retain_string
185        Self { ctx, inner }
186    }
187
188    #[allow(clippy::not_unsafe_ptr_arg_deref)]
189    pub fn from_ptr<'a>(ptr: *const raw::RedisModuleString) -> Result<&'a str, Utf8Error> {
190        str::from_utf8(Self::string_as_slice(ptr))
191    }
192
193    pub fn append(&mut self, s: &str) -> raw::Status {
194        raw::string_append_buffer(self.ctx, self.inner, s)
195    }
196
197    #[must_use]
198    pub fn len(&self) -> usize {
199        let mut len: usize = 0;
200        raw::string_ptr_len(self.inner, &mut len);
201        len
202    }
203
204    #[must_use]
205    pub fn is_empty(&self) -> bool {
206        let mut len: usize = 0;
207        raw::string_ptr_len(self.inner, &mut len);
208        len == 0
209    }
210
211    pub fn try_as_str<'a>(&self) -> Result<&'a str, ValkeyError> {
212        Self::from_ptr(self.inner).map_err(|_| ValkeyError::Str("Couldn't parse as UTF-8 string"))
213    }
214
215    #[must_use]
216    pub fn as_slice(&self) -> &[u8] {
217        Self::string_as_slice(self.inner)
218    }
219
220    #[allow(clippy::not_unsafe_ptr_arg_deref)]
221    pub fn string_as_slice<'a>(ptr: *const raw::RedisModuleString) -> &'a [u8] {
222        let mut len: libc::size_t = 0;
223        let bytes = unsafe { raw::RedisModule_StringPtrLen.unwrap()(ptr, &mut len) };
224
225        unsafe { slice::from_raw_parts(bytes.cast::<u8>(), len) }
226    }
227
228    /// Performs lossy conversion of a `RedisString` into an owned `String. This conversion
229    /// will replace any invalid UTF-8 sequences with U+FFFD REPLACEMENT CHARACTER, which
230    /// looks like this: �.
231    ///
232    /// # Panics
233    ///
234    /// Will panic if `RedisModule_StringPtrLen` is missing in redismodule.h
235    #[must_use]
236    pub fn to_string_lossy(&self) -> String {
237        String::from_utf8_lossy(self.as_slice()).into_owned()
238    }
239
240    pub fn parse_unsigned_integer(&self) -> Result<u64, ValkeyError> {
241        let val = self.parse_integer()?;
242        u64::try_from(val)
243            .map_err(|_| ValkeyError::Str("Couldn't parse negative number as unsigned integer"))
244    }
245
246    pub fn parse_integer(&self) -> Result<i64, ValkeyError> {
247        let mut val: i64 = 0;
248        match raw::string_to_longlong(self.inner, &mut val) {
249            raw::Status::Ok => Ok(val),
250            raw::Status::Err => Err(ValkeyError::Str("Couldn't parse as integer")),
251        }
252    }
253
254    pub fn parse_float(&self) -> Result<f64, ValkeyError> {
255        let mut val: f64 = 0.0;
256        match raw::string_to_double(self.inner, &mut val) {
257            raw::Status::Ok => Ok(val),
258            raw::Status::Err => Err(ValkeyError::Str("Couldn't parse as float")),
259        }
260    }
261
262    // TODO: Valkey allows storing and retrieving any arbitrary bytes.
263    // However rust's String and str can only store valid UTF-8.
264    // Implement these to allow non-utf8 bytes to be consumed:
265    // pub fn into_bytes(self) -> Vec<u8> {}
266    // pub fn as_bytes(&self) -> &[u8] {}
267}
268
269impl Drop for ValkeyString {
270    fn drop(&mut self) {
271        if !self.inner.is_null() {
272            unsafe {
273                raw::RedisModule_FreeString.unwrap()(self.ctx, self.inner);
274            }
275        }
276    }
277}
278
279impl PartialEq for ValkeyString {
280    fn eq(&self, other: &Self) -> bool {
281        self.cmp(other).is_eq()
282    }
283}
284
285impl Eq for ValkeyString {}
286
287impl PartialOrd for ValkeyString {
288    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
289        Some(self.cmp(other))
290    }
291}
292
293impl Ord for ValkeyString {
294    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
295        raw::string_compare(self.inner, other.inner)
296    }
297}
298
299impl core::hash::Hash for ValkeyString {
300    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
301        self.as_slice().hash(state);
302    }
303}
304
305impl Display for ValkeyString {
306    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
307        write!(f, "{}", self.to_string_lossy())
308    }
309}
310
311impl Borrow<str> for ValkeyString {
312    fn borrow(&self) -> &str {
313        // RedisString might not be UTF-8 safe
314        self.try_as_str().unwrap_or("<Invalid UTF-8 data>")
315    }
316}
317
318impl Clone for ValkeyString {
319    fn clone(&self) -> Self {
320        let inner =
321            // Valkey allows us to create RedisModuleString with NULL context
322            // so we use [std::ptr::null_mut()] instead of the curren RedisString context.
323            // We do this because we can not promise the new RedisString will not outlive the current
324            // context and we want them to be independent.
325            unsafe { raw::RedisModule_CreateStringFromString.unwrap()(ptr::null_mut(), self.inner) };
326        Self::from_redis_module_string(ptr::null_mut(), inner)
327    }
328}
329
330impl From<ValkeyString> for String {
331    fn from(rs: ValkeyString) -> Self {
332        rs.to_string_lossy()
333    }
334}
335
336impl Deref for ValkeyString {
337    type Target = [u8];
338
339    fn deref(&self) -> &Self::Target {
340        self.as_slice()
341    }
342}
343
344impl From<ValkeyString> for Vec<u8> {
345    fn from(rs: ValkeyString) -> Self {
346        rs.as_slice().to_vec()
347    }
348}
349
350impl serde::Serialize for ValkeyString {
351    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
352    where
353        S: serde::Serializer,
354    {
355        serializer.serialize_bytes(self.as_slice())
356    }
357}
358
359struct RedisStringVisitor;
360
361impl<'de> serde::de::Visitor<'de> for RedisStringVisitor {
362    type Value = ValkeyString;
363
364    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
365        formatter.write_str("A bytes buffer")
366    }
367
368    fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
369    where
370        E: Error,
371    {
372        Ok(ValkeyString::create(None, v))
373    }
374
375    fn visit_seq<V>(self, mut visitor: V) -> Result<Self::Value, V::Error>
376    where
377        V: SeqAccess<'de>,
378    {
379        let mut v = if let Some(size_hint) = visitor.size_hint() {
380            Vec::with_capacity(size_hint)
381        } else {
382            Vec::new()
383        };
384        while let Some(elem) = visitor.next_element()? {
385            v.push(elem);
386        }
387
388        Ok(ValkeyString::create(None, v.as_slice()))
389    }
390}
391
392impl<'de> serde::Deserialize<'de> for ValkeyString {
393    fn deserialize<D>(deserializer: D) -> Result<ValkeyString, D::Error>
394    where
395        D: serde::Deserializer<'de>,
396    {
397        deserializer.deserialize_bytes(RedisStringVisitor)
398    }
399}
400
401///////////////////////////////////////////////////
402
403#[derive(Debug)]
404pub struct RedisBuffer {
405    buffer: *mut c_char,
406    len: usize,
407}
408
409impl RedisBuffer {
410    pub const fn new(buffer: *mut c_char, len: usize) -> Self {
411        Self { buffer, len }
412    }
413
414    pub fn to_string(&self) -> Result<String, FromUtf8Error> {
415        String::from_utf8(self.as_ref().to_vec())
416    }
417}
418
419impl AsRef<[u8]> for RedisBuffer {
420    fn as_ref(&self) -> &[u8] {
421        unsafe { slice::from_raw_parts(self.buffer as *const u8, self.len) }
422    }
423}
424
425impl Drop for RedisBuffer {
426    fn drop(&mut self) {
427        unsafe {
428            raw::RedisModule_Free.unwrap()(self.buffer.cast::<c_void>());
429        }
430    }
431}
valkey_module/redismodule.rs

valkey_module/
redismodule.rs
