Remove unused code for parsing a postgresql.conf file

control_plane/src/postgresql_conf.rs

@@ -4,13 +4,10 @@
 /// NOTE: This doesn't implement the full, correct postgresql.conf syntax. Just
 /// enough to extract a few settings we need in Neon, assuming you don't do
 /// funny stuff like include-directives or funny escaping.
-use anyhow::{bail, Context, Result};
 use once_cell::sync::Lazy;
 use regex::Regex;
 use std::collections::HashMap;
 use std::fmt;
-use std::io::BufRead;
-use std::str::FromStr;
 
 /// In-memory representation of a postgresql.conf file
 #[derive(Default, Debug)]
@@ -19,84 +16,16 @@ pub struct PostgresConf {
     hash: HashMap<String, String>,
 }
 
-static CONF_LINE_RE: Lazy<Regex> = Lazy::new(|| Regex::new(r"^((?:\w|\.)+)\s*=\s*(\S+)$").unwrap());
-
 impl PostgresConf {
     pub fn new() -> PostgresConf {
         PostgresConf::default()
     }
 
-    /// Read file into memory
-    pub fn read(read: impl std::io::Read) -> Result<PostgresConf> {
-        let mut result = Self::new();
-
-        for line in std::io::BufReader::new(read).lines() {
-            let line = line?;
-
-            // Store each line in a vector, in original format
-            result.lines.push(line.clone());
-
-            // Also parse each line and insert key=value lines into a hash map.
-            //
-            // FIXME: This doesn't match exactly the flex/bison grammar in PostgreSQL.
-            // But it's close enough for our usage.
-            let line = line.trim();
-            if line.starts_with('#') {
-                // comment, ignore
-                continue;
-            } else if let Some(caps) = CONF_LINE_RE.captures(line) {
-                let name = caps.get(1).unwrap().as_str();
-                let raw_val = caps.get(2).unwrap().as_str();
-
-                if let Ok(val) = deescape_str(raw_val) {
-                    // Note: if there's already an entry in the hash map for
-                    // this key, this will replace it. That's the behavior what
-                    // we want; when PostgreSQL reads the file, each line
-                    // overrides any previous value for the same setting.
-                    result.hash.insert(name.to_string(), val.to_string());
-                }
-            }
-        }
-        Ok(result)
-    }
-
     /// Return the current value of 'option'
     pub fn get(&self, option: &str) -> Option<&str> {
         self.hash.get(option).map(|x| x.as_ref())
     }
 
-    /// Return the current value of a field, parsed to the right datatype.
-    ///
-    /// This calls the FromStr::parse() function on the value of the field. If
-    /// the field does not exist, or parsing fails, returns an error.
-    ///
-    pub fn parse_field<T>(&self, field_name: &str, context: &str) -> Result<T>
-    where
-        T: FromStr,
-        <T as FromStr>::Err: std::error::Error + Send + Sync + 'static,
-    {
-        self.get(field_name)
-            .with_context(|| format!("could not find '{}' option {}", field_name, context))?
-            .parse::<T>()
-            .with_context(|| format!("could not parse '{}' option {}", field_name, context))
-    }
-
-    pub fn parse_field_optional<T>(&self, field_name: &str, context: &str) -> Result<Option<T>>
-    where
-        T: FromStr,
-        <T as FromStr>::Err: std::error::Error + Send + Sync + 'static,
-    {
-        if let Some(val) = self.get(field_name) {
-            let result = val
-                .parse::<T>()
-                .with_context(|| format!("could not parse '{}' option {}", field_name, context))?;
-
-            Ok(Some(result))
-        } else {
-            Ok(None)
-        }
-    }
-
     ///
     /// Note: if you call this multiple times for the same option, the config
     /// file will a line for each call. It would be nice to have a function
@@ -154,48 +83,8 @@ fn escape_str(s: &str) -> String {
     }
 }
 
-/// De-escape a possibly-quoted value.
-///
-/// See `DeescapeQuotedString` function in PostgreSQL sources for how PostgreSQL
-/// does this.
-fn deescape_str(s: &str) -> Result<String> {
-    // If the string has a quote at the beginning and end, strip them out.
-    if s.len() >= 2 && s.starts_with('\'') && s.ends_with('\'') {
-        let mut result = String::new();
-
-        let mut iter = s[1..(s.len() - 1)].chars().peekable();
-        while let Some(c) = iter.next() {
-            let newc = if c == '\\' {
-                match iter.next() {
-                    Some('b') => '\x08',
-                    Some('f') => '\x0c',
-                    Some('n') => '\n',
-                    Some('r') => '\r',
-                    Some('t') => '\t',
-                    Some('0'..='7') => {
-                        // TODO
-                        bail!("octal escapes not supported");
-                    }
-                    Some(n) => n,
-                    None => break,
-                }
-            } else if c == '\'' && iter.peek() == Some(&'\'') {
-                // doubled quote becomes just one quote
-                iter.next().unwrap()
-            } else {
-                c
-            };
-
-            result.push(newc);
-        }
-        Ok(result)
-    } else {
-        Ok(s.to_string())
-    }
-}
-
 #[test]
-fn test_postgresql_conf_escapes() -> Result<()> {
+fn test_postgresql_conf_escapes() -> anyhow::Result<()> {
     assert_eq!(escape_str("foo bar"), "'foo bar'");
     // these don't need to be quoted
     assert_eq!(escape_str("foo"), "foo");
@@ -214,13 +103,5 @@ fn test_postgresql_conf_escapes() -> Result<()> {
     assert_eq!(escape_str("fo\\o"), "'fo\\\\o'");
     assert_eq!(escape_str("10 cats"), "'10 cats'");
 
-    // Test de-escaping
-    assert_eq!(deescape_str(&escape_str("foo"))?, "foo");
-    assert_eq!(deescape_str(&escape_str("fo'o\nba\\r"))?, "fo'o\nba\\r");
-    assert_eq!(deescape_str("'\\b\\f\\n\\r\\t'")?, "\x08\x0c\n\r\t");
-
-    // octal-escapes are currently not supported
-    assert!(deescape_str("'foo\\7\\07\\007'").is_err());
-
     Ok(())
 }