pbs-tools/src/json.rs

   1 use anyhow::{bail, Error};
   2 use serde_json::Value;
   3
   4 // Generate canonical json
   5 pub fn to_canonical_json(value: &Value) -> Result<Vec<u8>, Error> {
   6     let mut data = Vec::new();
   7     write_canonical_json(value, &mut data)?;
   8     Ok(data)
   9 }
  10
  11 pub fn write_canonical_json(value: &Value, output: &mut Vec<u8>) -> Result<(), Error> {
  12     match value {
  13         Value::Null => bail!("got unexpected null value"),
  14         Value::String(_) | Value::Number(_) | Value::Bool(_) => {
  15             serde_json::to_writer(output, &value)?;
  16         }
  17         Value::Array(list) => {
  18             output.push(b'[');
  19             let mut iter = list.iter();
  20             if let Some(item) = iter.next() {
  21                 write_canonical_json(item, output)?;
  22                 for item in iter {
  23                     output.push(b',');
  24                     write_canonical_json(item, output)?;
  25                 }
  26             }
  27             output.push(b']');
  28         }
  29         Value::Object(map) => {
  30             output.push(b'{');
  31             let mut keys: Vec<&str> = map.keys().map(String::as_str).collect();
  32             keys.sort_unstable();
  33             let mut iter = keys.into_iter();
  34             if let Some(key) = iter.next() {
  35                 serde_json::to_writer(&mut *output, &key)?;
  36                 output.push(b':');
  37                 write_canonical_json(&map[key], output)?;
  38                 for key in iter {
  39                     output.push(b',');
  40                     serde_json::to_writer(&mut *output, &key)?;
  41                     output.push(b':');
  42                     write_canonical_json(&map[key], output)?;
  43                 }
  44             }
  45             output.push(b'}');
  46         }
  47     }
  48     Ok(())
  49 }