Introduce a basic schema diff function

This commit is contained in:
Clément Renault 2019-09-04 16:32:55 +02:00
parent 32d8b4b83f
commit e86a547e93
No known key found for this signature in database
GPG Key ID: 92ADA4E935E71FA4

View File

@ -215,11 +215,155 @@ impl fmt::Display for SchemaAttr {
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum Diff {
IdentChange {
old: String,
new: String,
},
AttrMove {
name: String,
old: usize,
new: usize,
},
AttrPropsChange {
name: String,
old: SchemaProps,
new: SchemaProps,
},
NewAttr {
name: String,
pos: usize,
props: SchemaProps,
},
RemovedAttr {
name: String,
},
}
pub fn diff(old: &Schema, new: &Schema) -> Vec<Diff> {
use Diff::{AttrMove, AttrPropsChange, IdentChange, NewAttr, RemovedAttr};
let mut differences = Vec::new();
let old = old.to_builder();
let new = new.to_builder();
// check if the old identifier differs from the new one
if old.identifier != new.identifier {
let old = old.identifier;
let new = new.identifier;
differences.push(IdentChange { old, new });
}
// compare all old attributes positions
// and properties with the new ones
for (pos, (name, props)) in old.attributes.iter().enumerate() {
match new.attributes.get_full(name) {
Some((npos, _, nprops)) => {
if pos != npos {
let name = name.clone();
differences.push(AttrMove {
name,
old: pos,
new: npos,
});
}
if props != nprops {
let name = name.clone();
differences.push(AttrPropsChange {
name,
old: *props,
new: *nprops,
});
}
}
None => differences.push(RemovedAttr { name: name.clone() }),
}
}
// retrieve all attributes that
// were not present in the old schema
for (pos, (name, props)) in new.attributes.iter().enumerate() {
if !old.attributes.contains_key(name) {
let name = name.clone();
differences.push(NewAttr {
name,
pos,
props: *props,
});
}
}
differences
}
#[cfg(test)]
mod tests {
use super::*;
use std::error::Error;
#[test]
fn difference() {
use Diff::{AttrMove, AttrPropsChange, IdentChange, NewAttr, RemovedAttr};
let mut builder = SchemaBuilder::with_identifier("id");
builder.new_attribute("alpha", DISPLAYED);
builder.new_attribute("beta", DISPLAYED | INDEXED);
builder.new_attribute("gamma", INDEXED);
builder.new_attribute("omega", INDEXED);
let old = builder.build();
let mut builder = SchemaBuilder::with_identifier("kiki");
builder.new_attribute("beta", DISPLAYED | INDEXED);
builder.new_attribute("alpha", DISPLAYED | INDEXED);
builder.new_attribute("delta", RANKED);
builder.new_attribute("gamma", DISPLAYED);
let new = builder.build();
let differences = diff(&old, &new);
let expected = &[
IdentChange {
old: format!("id"),
new: format!("kiki"),
},
AttrMove {
name: format!("alpha"),
old: 0,
new: 1,
},
AttrPropsChange {
name: format!("alpha"),
old: DISPLAYED,
new: DISPLAYED | INDEXED,
},
AttrMove {
name: format!("beta"),
old: 1,
new: 0,
},
AttrMove {
name: format!("gamma"),
old: 2,
new: 3,
},
AttrPropsChange {
name: format!("gamma"),
old: INDEXED,
new: DISPLAYED,
},
RemovedAttr {
name: format!("omega"),
},
NewAttr {
name: format!("delta"),
pos: 2,
props: RANKED,
},
];
assert_eq!(&differences, expected)
}
#[test]
fn serialize_deserialize() -> bincode::Result<()> {
let mut builder = SchemaBuilder::with_identifier("id");