add tools::json for canonical json generation

moving this from backup::manifest, no functional changes

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
This commit is contained in:
Wolfgang Bumiller 2021-01-15 11:06:15 +01:00 committed by Thomas Lamprecht
parent a08a198577
commit 9ff747ef50
2 changed files with 50 additions and 0 deletions

View File

@ -28,6 +28,7 @@ pub mod format;
pub mod fs;
pub mod fuse_loop;
pub mod http;
pub mod json;
pub mod logrotate;
pub mod loopdev;
pub mod lru_cache;

49
src/tools/json.rs Normal file
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@ -0,0 +1,49 @@
use anyhow::{bail, Error};
use serde_json::Value;
// Generate canonical json
pub fn to_canonical_json(value: &Value) -> Result<Vec<u8>, Error> {
let mut data = Vec::new();
write_canonical_json(value, &mut data)?;
Ok(data)
}
pub fn write_canonical_json(value: &Value, output: &mut Vec<u8>) -> Result<(), Error> {
match value {
Value::Null => bail!("got unexpected null value"),
Value::String(_) | Value::Number(_) | Value::Bool(_) => {
serde_json::to_writer(output, &value)?;
}
Value::Array(list) => {
output.push(b'[');
let mut iter = list.iter();
if let Some(item) = iter.next() {
write_canonical_json(item, output)?;
for item in iter {
output.push(b',');
write_canonical_json(item, output)?;
}
}
output.push(b']');
}
Value::Object(map) => {
output.push(b'{');
let mut keys: Vec<&str> = map.keys().map(String::as_str).collect();
keys.sort();
let mut iter = keys.into_iter();
if let Some(key) = iter.next() {
serde_json::to_writer(&mut *output, &key)?;
output.push(b':');
write_canonical_json(&map[key], output)?;
for key in iter {
output.push(b',');
serde_json::to_writer(&mut *output, &key)?;
output.push(b':');
write_canonical_json(&map[key], output)?;
}
}
output.push(b'}');
}
}
Ok(())
}