Parsing commits
Read the source doc, to get familiar with the commit object format.
Parse key value list of commit object
Add KeyValueList struct to commit.rs
#[derive(Debug)]
pub struct KeyValueList {
map: BTreeMap<String, String>,
}We need to have a map as a BTreeMap, because we need to have entries sorted by their keys.
Add parse function to KeyValueList
impl KeyValueList {
pub fn new(map: BTreeMap<String, String>) -> Self {
KeyValueList { map }
}
pub fn parse(buf_reader: impl BufRead) -> Result<Self, KvlParseError> {
let mut map: BTreeMap<String, String> = BTreeMap::new();
let mut the_rest_is_message = false;
let mut message = String::new();
let mut prev_key = String::new();
for line in buf_reader.lines() {
let line = line.map_err(|_| KvlParseError::FailedToGetNextLine)?;
if line.is_empty() {
the_rest_is_message = true;
} else if the_rest_is_message {
message.push_str(line.as_str());
} else if let Some(char) = line.chars().next() {
if char == ' ' {
// Continuation of previous value
map.get_mut(&prev_key)
.unwrap()
.push_str(format!("\n{}", &line[1..]).as_str());
} else {
// New key value
let index = line.find(' ').ok_or(KvlParseError::KeyDelimiterNotFound)?;
let key = &line[0..index];
let value = &line[index + 1..];
map.insert(key.to_string(), value.to_string());
prev_key = key.to_string();
}
}
}
if the_rest_is_message {
map.insert("message".to_string(), message);
}
Ok(Self { map })
}
#[derive(Debug, Error)]
pub enum KvlParseError {
#[error("Failed to get the next line of the kvl")]
FailedToGetNextLine,
#[error("Failed to find the delimiter fo key/value")]
KeyDelimiterNotFound,
}pub enum ObjectParseError {
// ...
#[error(transparent)]
KvlParseError(#[from] KvlParseError),
Add serialize function to KeyValueList
impl KeyValueList {
//...
pub fn serialize(&self) -> String {
let mut buffer = String::new();
let mut message_value = None;
for (key, value) in &self.map {
if key == "message" {
message_value = Some(value);
continue;
}
if value.contains('\n') {
let multi_line_value = value
.lines()
.take(1)
.map(|v| format!("{}\n", v))
.chain(value.lines().skip(1).map(|line| format!(" {}\n", line)))
.collect::<String>();
buffer.push_str(format!("{} {}", key, &multi_line_value).as_str());
} else {
buffer.push_str(format!("{} {}\n", key, value).as_str());
}
}
if let Some(message_value) = message_value {
buffer.push_str(&format!("\n{}", &message_value));
}
buffer
}
}Implement AsRef for KeyValueList
impl AsRef<BTreeMap<String, String>> for KeyValueList {
fn as_ref(&self) -> &BTreeMap<String, String> {
&self.map
}
}Add unit tests
#[cfg(test)]
mod tests {
use std::{collections::BTreeMap, io::BufReader};
use super::KeyValueList;
#[test]
pub fn kvl_parse_should_parse_single_line_key_values_correctly() {
let raw = r#"tree 29ff16c9c14e2652b22f8b78bb08a5a07930c147
parent 206941306e8a8af65b66eaaaea388a7ae24d49a0
author Thibault Polge <thibault@thb.lt> 1527025023 +0200
committer Thibault Polge <thibault@thb.lt> 1527025044 +0200
gpgsig -----BEGIN PGP SIGNATURE-----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=lgTX
-----END PGP SIGNATURE-----
Create first draft"#;
let parsed_key_values = BTreeMap::from([
(
"tree".to_string(),
"29ff16c9c14e2652b22f8b78bb08a5a07930c147".to_string(),
),
(
"parent".to_string(),
"206941306e8a8af65b66eaaaea388a7ae24d49a0".to_string(),
),
(
"author".to_string(),
"Thibault Polge <thibault@thb.lt> 1527025023 +0200".to_string(),
),
(
"committer".to_string(),
"Thibault Polge <thibault@thb.lt> 1527025044 +0200".to_string(),
),
(
"gpgsig".to_string(),
"-----BEGIN PGP SIGNATURE-----\n\
\n\
iQIzBAABCAAdFiEExwXquOM8bWb4Q2zVGxM2FxoLkGQFAlsEjZQACgkQGxM2FxoL\n\
kGQdcBAAqPP+ln4nGDd2gETXjvOpOxLzIMEw4A9gU6CzWzm+oB8mEIKyaH0UFIPh\n\
rNUZ1j7/ZGFNeBDtT55LPdPIQw4KKlcf6kC8MPWP3qSu3xHqx12C5zyai2duFZUU\n\
wqOt9iCFCscFQYqKs3xsHI+ncQb+PGjVZA8+jPw7nrPIkeSXQV2aZb1E68wa2YIL\n\
3eYgTUKz34cB6tAq9YwHnZpyPx8UJCZGkshpJmgtZ3mCbtQaO17LoihnqPn4UOMr\n\
V75R/7FjSuPLS8NaZF4wfi52btXMSxO/u7GuoJkzJscP3p4qtwe6Rl9dc1XC8P7k\n\
NIbGZ5Yg5cEPcfmhgXFOhQZkD0yxcJqBUcoFpnp2vu5XJl2E5I/quIyVxUXi6O6c\n\
/obspcvace4wy8uO0bdVhc4nJ+Rla4InVSJaUaBeiHTW8kReSFYyMmDCzLjGIu1q\n\
doU61OM3Zv1ptsLu3gUE6GU27iWYj2RWN3e3HE4Sbd89IFwLXNdSuM0ifDLZk7AQ\n\
WBhRhipCCgZhkj9g2NEk7jRVslti1NdN5zoQLaJNqSwO1MtxTmJ15Ksk3QP6kfLB\n\
Q52UWybBzpaP9HEd4XnR+HuQ4k2K0ns2KgNImsNvIyFwbpMUyUWLMPimaV1DWUXo\n\
5SBjDB/V/W2JBFR+XKHFJeFwYhj7DD/ocsGr4ZMx/lgc8rjIBkI=\n\
=lgTX\n\
-----END PGP SIGNATURE-----"
.to_string(),
),
("message".to_string(), "Create first draft".to_string()),
]);
let kvl = KeyValueList::parse(BufReader::new(raw.as_bytes())).unwrap();
assert_eq!(parsed_key_values, *kvl.as_ref());
}
#[test]
fn serialize_should_work_if_it_doesnt_contain_message() {
let map = BTreeMap::from([
("key1".to_string(), "value1".to_string()),
("key2".to_string(), "value2".to_string()),
("key3".to_string(), "value3\nvalue3-1\nvalue3-2".to_string()),
]);
let kvl = KeyValueList::new(map);
let serialized = kvl.serialize();
let expected = r#"key1 value1
key2 value2
key3 value3
value3-1
value3-2
"#;
assert_eq!(expected, serialized);
}
#[test]
fn serialize_should_work_if_it_contains_message() {
let map = BTreeMap::from([
("key1".to_string(), "value1".to_string()),
("key2".to_string(), "value2".to_string()),
("key3".to_string(), "value3\nvalue3-1\nvalue3-2".to_string()),
("message".to_string(), "khar gav".to_string()),
]);
let kvl = KeyValueList::new(map);
let serialized = kvl.serialize();
let expected = r#"key1 value1
key2 value2
key3 value3
value3-1
value3-2
khar gav"#;
assert_eq!(expected, serialized);
}
}
Use KeyValueList in Commit object
#[derive(Debug)]
pub struct Commit {
pub kvl: KeyValueList,
}
impl Commit {
pub fn serialize(&self) -> String {
self.kvl.serialize()
}
pub fn deserialize(
buf_reader: &mut impl std::io::BufRead,
_object_header: super::Header,
) -> Result<Self, crate::error::ObjectParseError> {
Ok(Self {
kvl: KeyValueList::parse(buf_reader)?,
})
}
pub fn get_value(&self, key: &str) -> Option<&String> {
self.kvl.map.get(key)
}
}Last updated