hotfix_message/
message.rs

1use std::io::Write;
2
3use crate::FieldType;
4use crate::HardCodedFixFieldDefinition;
5use crate::builder::SOH;
6use crate::encoder::Encode;
7use crate::error::EncodingResult;
8use crate::field_map::{Field, FieldMap};
9use crate::parts::{Body, Header, Part, RepeatingGroup, Trailer};
10use crate::session_fields::{BEGIN_STRING, BODY_LENGTH, CHECK_SUM, MSG_TYPE};
11use hotfix_dictionary::{FieldLocation, IsFieldDefinition};
12
13pub struct Message {
14    pub(crate) header: Header,
15    pub(crate) body: Body,
16    pub(crate) trailer: Trailer,
17}
18
19impl Message {
20    pub fn new(begin_string: &str, message_type: &str) -> Self {
21        let mut msg = Self {
22            header: Header::default(),
23            body: Body::default(),
24            trailer: Trailer::default(),
25        };
26        msg.set(BEGIN_STRING, begin_string);
27        msg.set(MSG_TYPE, message_type);
28
29        msg
30    }
31
32    pub(crate) fn with_header(header: Header) -> Self {
33        Self {
34            header,
35            body: Body::default(),
36            trailer: Trailer::default(),
37        }
38    }
39
40    pub fn encode(&mut self, config: &Config) -> EncodingResult<Vec<u8>> {
41        let mut buffer = Vec::new();
42
43        self.trailer.pop(CHECK_SUM);
44        let body_length = self.header.calculate_length()
45            + self.body.calculate_length()
46            + self.trailer.calculate_length();
47        self.set(BODY_LENGTH, format!("{body_length}").as_str());
48        let check_sum_start = buffer.len();
49
50        let starting_fields = vec![BEGIN_STRING.tag(), BODY_LENGTH.tag(), MSG_TYPE.tag()];
51        self.header
52            .fields
53            .write(config, &mut buffer, &starting_fields)?;
54        self.body.fields.write(config, &mut buffer, &[])?;
55        self.trailer.fields.write(config, &mut buffer, &[])?;
56
57        let checksum = buffer.as_slice()[check_sum_start..]
58            .iter()
59            .fold(0u8, |acc, &x| acc.wrapping_add(x));
60        let checksum_value = format!("{checksum:03}");
61        self.set(CHECK_SUM, checksum_value.as_str());
62        buffer.write_all(b"10=")?;
63        buffer.write_all(checksum_value.as_bytes())?;
64        buffer.push(config.separator);
65
66        Ok(buffer)
67    }
68
69    pub fn header(&self) -> &Header {
70        &self.header
71    }
72
73    pub fn header_mut(&mut self) -> &mut Header {
74        &mut self.header
75    }
76
77    pub fn trailer(&self) -> &Trailer {
78        &self.trailer
79    }
80
81    pub fn get_group(
82        &self,
83        start_field: &HardCodedFixFieldDefinition,
84        index: usize,
85    ) -> Option<&RepeatingGroup> {
86        let tag = start_field.tag();
87        match start_field.location {
88            FieldLocation::Header => self.header.get_group(tag, index),
89            FieldLocation::Body => self.body.get_group(tag, index),
90            FieldLocation::Trailer => self.trailer.get_group(tag, index),
91        }
92    }
93}
94
95impl Part for Message {
96    fn get_field_map(&self) -> &FieldMap {
97        self.body.get_field_map()
98    }
99
100    fn get_field_map_mut(&mut self) -> &mut FieldMap {
101        self.body.get_field_map_mut()
102    }
103
104    fn set<'a, V>(&'a mut self, field_definition: &HardCodedFixFieldDefinition, value: V)
105    where
106        V: FieldType<'a>,
107    {
108        let field = Field::new(field_definition.tag(), value.to_bytes());
109
110        match field_definition.location {
111            FieldLocation::Header => self.header.store_field(field),
112            FieldLocation::Body => self.body.store_field(field),
113            FieldLocation::Trailer => self.trailer.store_field(field),
114        };
115    }
116}
117
118#[derive(Clone, Copy)]
119pub struct Config {
120    pub(crate) separator: u8,
121}
122
123impl Config {
124    pub const fn with_separator(separator: u8) -> Self {
125        Self { separator }
126    }
127}
128
129impl Default for Config {
130    fn default() -> Self {
131        Self { separator: SOH }
132    }
133}
hotfix_message/message.rs

hotfix_message/
message.rs
