rocketmq_remoting/protocol/
command_custom_header.rs

1// Copyright 2023 The RocketMQ Rust Authors
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use std::any::Any;
16use std::collections::HashMap;
17
18use cheetah_string::CheetahString;
19
20use crate::rocketmq_serializable::RocketMQSerializable;
21
22pub trait CommandCustomHeader: AsAny {
23    /// Checks the fields of the implementing type.  
24    ///  
25    /// Returns a `Result` indicating whether the fields are valid or not.  
26    /// If the fields are valid, the `Ok` variant is returned with an empty `()` value.  
27    /// If the fields are invalid, an `Err` variant is returned with an associated `Error` value.  
28    fn check_fields(&self) -> anyhow::Result<(), anyhow::Error> {
29        Ok(())
30    }
31
32    /// Converts the implementing type to a map.  
33    ///  
34    /// Returns an `Option` that contains a `HashMap` of string keys and string values,  
35    /// representing the implementing type's fields.  
36    /// If the conversion is successful, a non-empty map is returned.  
37    /// If the conversion fails, `None` is returned.  
38    fn to_map(&self) -> Option<HashMap<CheetahString, CheetahString>>;
39
40    /// Writes the provided `key` to the `out` buffer if the `value` is not empty.
41    ///
42    /// # Arguments
43    ///
44    /// * `out` - A mutable reference to a `BytesMut` buffer where the `key` will be written.
45    /// * `key` - A string slice that represents the key to be written.
46    /// * `value` - A string slice that represents the value associated with the key.
47    ///
48    /// # Behavior
49    ///
50    /// If `value` is not empty, the function will write the `key` to the `out` buffer twice,
51    /// first with a short length prefix and then with a long length prefix.
52    fn write_if_not_null(&self, out: &mut bytes::BytesMut, key: &str, value: &str) {
53        if !value.is_empty() {
54            RocketMQSerializable::write_str(out, true, key);
55            RocketMQSerializable::write_str(out, false, value);
56        }
57    }
58
59    /// A placeholder function for fast encoding.
60    ///
61    /// This function currently does nothing and can be overridden by implementing types.
62    fn encode_fast(&mut self, _out: &mut bytes::BytesMut) {}
63
64    /// A placeholder function for fast decoding.
65    ///
66    /// This function currently does nothing and can be overridden by implementing types.
67    ///
68    /// # Arguments
69    ///
70    /// * `_fields` - A reference to a `HashMap` that contains the fields to be decoded.
71    fn decode_fast(&mut self, _fields: &HashMap<CheetahString, CheetahString>) -> rocketmq_error::RocketMQResult<()> {
72        Ok(())
73    }
74
75    /// Indicates whether the implementing type supports fast codec.
76    ///
77    /// # Returns
78    ///
79    /// This function returns `false` by default, indicating that the implementing type does not
80    /// support fast codec. This can be overridden by implementing types.
81    fn support_fast_codec(&self) -> bool {
82        false
83    }
84
85    /// Retrieves the value associated with the specified field from the provided map.
86    ///
87    /// # Arguments
88    ///
89    /// * `map` - A reference to a `HashMap` containing `CheetahString` keys and values.
90    /// * `field` - A reference to a `CheetahString` representing the field to retrieve.
91    ///
92    /// # Returns
93    ///
94    /// * `Ok(CheetahString)` - If the field is found in the map, returns the associated value.
95    /// * `Err(RocketMQError::Serialization)` - If the field is not found in the map, returns an
96    ///   error indicating the field is required.
97    ///
98    /// # Errors
99    ///
100    /// This function returns a `SerializationError::DecodeFailed` if the specified field is
101    /// not found in the map.
102    #[inline(always)]
103    fn get_and_check_not_none(
104        &self,
105        map: &HashMap<CheetahString, CheetahString>,
106        field: &CheetahString,
107    ) -> rocketmq_error::RocketMQResult<CheetahString> {
108        match map.get(field) {
109            Some(value) => Ok(value.clone()),
110            None => Err(rocketmq_error::RocketMQError::Serialization(
111                rocketmq_error::SerializationError::DecodeFailed {
112                    format: "header",
113                    message: format!("The field {field} is required."),
114                },
115            )),
116        }
117    }
118}
119
120pub trait AsAny: Any {
121    fn as_any_mut(&mut self) -> &mut dyn Any;
122
123    fn as_any(&self) -> &dyn Any;
124}
125
126impl<T: CommandCustomHeader> AsAny for T {
127    fn as_any_mut(&mut self) -> &mut dyn Any {
128        self
129    }
130
131    fn as_any(&self) -> &dyn Any {
132        self
133    }
134}
135
136pub trait FromMap {
137    type Error: From<rocketmq_error::RocketMQError>;
138
139    type Target;
140    /// Converts the implementing type from a map.
141    ///
142    /// Returns an instance of `Self::Target` that is created from the provided map.
143    fn from(map: &HashMap<CheetahString, CheetahString>) -> Result<Self::Target, Self::Error>;
144}
rocketmq_remoting/protocol/command_custom_header.rs

rocketmq_remoting/protocol/
command_custom_header.rs
