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remove the symbol type, use the symbol table for strings
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the symbol type was confusing, and with te removal of #authority
and #ambient, there is now no reason to keep them.

They were a separate kind of string with less operations, that were
interned in the symbol table. That symbol table is used to reduce the
token's size (not repeating strings, referring to them through integers)
and in the Datalog engine for faster unification (it's faster to compare
two integers than two strings).

Now that symbols are gone, the Datalog engine has been modified to use
the symbol table for strings, using the symbols performance boost for
all strings
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@Geal
Geal committed Sep 6, 2021
1 parent 834c14d commit 1decc95
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Showing 12 changed files with 329 additions and 343 deletions.
4 changes: 0 additions & 4 deletions examples/testcases.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1541,9 +1541,6 @@ fn expressions<T: Rng + CryptoRng>(
//date equal
builder.add_authority_check("check if 2020-12-04T09:46:41+00:00 == 2020-12-04T09:46:41+00:00");

//symbol equal
builder.add_authority_check("check if #abc == #abc");

//bytes equal
builder.add_authority_check("check if hex:12ab == hex:12ab");

Expand All @@ -1553,7 +1550,6 @@ fn expressions<T: Rng + CryptoRng>(
builder.add_authority_check("check if [true, false, true].contains(true)");
builder.add_authority_check("check if [\"abc\", \"def\"].contains(\"abc\")");
builder.add_authority_check("check if [hex:12ab, hex:34de].contains(hex:34de)");
builder.add_authority_check("check if [#hello, #world].contains(#hello)");

let biscuit = builder.build_with_rng(rng).unwrap();
token = print_blocks(&biscuit);
Expand Down
54 changes: 31 additions & 23 deletions src/datalog/expression.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -23,11 +23,11 @@ pub enum Unary {
}

impl Unary {
fn evaluate(&self, value: ID) -> Option<ID> {
fn evaluate(&self, value: ID, symbols: &SymbolTable) -> Option<ID> {
match (self, value) {
(Unary::Negate, ID::Bool(b)) => Some(ID::Bool(!b)),
(Unary::Parens, i) => Some(i),
(Unary::Length, ID::Str(s)) => Some(ID::Integer(s.len() as i64)),
(Unary::Length, ID::Str(i)) => symbols.get_s(i).map(|s| ID::Integer(s.len() as i64)),
(Unary::Length, ID::Bytes(s)) => Some(ID::Integer(s.len() as i64)),
(Unary::Length, ID::Set(s)) => Some(ID::Integer(s.len() as i64)),
_ => {
Expand Down Expand Up @@ -68,7 +68,7 @@ pub enum Binary {
}

impl Binary {
fn evaluate(&self, left: ID, right: ID) -> Option<ID> {
fn evaluate(&self, left: ID, right: ID, symbols: &SymbolTable) -> Option<ID> {
match (self, left, right) {
// integer
(Binary::LessThan, ID::Integer(i), ID::Integer(j)) => Some(ID::Bool(i < j)),
Expand All @@ -83,14 +83,23 @@ impl Binary {

// string
(Binary::Prefix, ID::Str(s), ID::Str(pref)) => {
Some(ID::Bool(s.as_str().starts_with(pref.as_str())))
match (symbols.get_s(s), symbols.get_s(pref)) {
(Some(s), Some(pref)) => Some(ID::Bool(s.starts_with(pref))),
_ => None,
}
}
(Binary::Suffix, ID::Str(s), ID::Str(suff)) => {
Some(ID::Bool(s.as_str().ends_with(suff.as_str())))
match (symbols.get_s(s), symbols.get_s(suff)) {
(Some(s), Some(suff)) => Some(ID::Bool(s.ends_with(suff))),
_ => None,
}
}
(Binary::Regex, ID::Str(s), ID::Str(r)) => Some(ID::Bool(
Regex::new(&r).map(|re| re.is_match(&s)).unwrap_or(false),
)),
(Binary::Regex, ID::Str(s), ID::Str(r)) => match (symbols.get_s(s), symbols.get_s(r)) {
(Some(s), Some(r)) => Some(ID::Bool(
Regex::new(&r).map(|re| re.is_match(&s)).unwrap_or(false),
)),
_ => None,
},
(Binary::Equal, ID::Str(i), ID::Str(j)) => Some(ID::Bool(i == j)),

// date
Expand All @@ -101,7 +110,6 @@ impl Binary {
(Binary::Equal, ID::Date(i), ID::Date(j)) => Some(ID::Bool(i == j)),

// symbol
(Binary::Equal, ID::Symbol(i), ID::Symbol(j)) => Some(ID::Bool(i == j)),

// byte array
(Binary::Equal, ID::Bytes(i), ID::Bytes(j)) => Some(ID::Bool(i == j)),
Expand Down Expand Up @@ -130,9 +138,6 @@ impl Binary {
(Binary::Contains, ID::Set(set), ID::Bytes(i)) => {
Some(ID::Bool(set.contains(&ID::Bytes(i))))
}
(Binary::Contains, ID::Set(set), ID::Symbol(i)) => {
Some(ID::Bool(set.contains(&ID::Symbol(i))))
}

// boolean
(Binary::And, ID::Bool(i), ID::Bool(j)) => Some(ID::Bool(i & j)),
Expand Down Expand Up @@ -168,7 +173,7 @@ impl Binary {
}

impl Expression {
pub fn evaluate(&self, values: &HashMap<u32, ID>) -> Option<ID> {
pub fn evaluate(&self, values: &HashMap<u32, ID>, symbols: &SymbolTable) -> Option<ID> {
let mut stack: Vec<ID> = Vec::new();

for op in self.ops.iter() {
Expand All @@ -187,16 +192,18 @@ impl Expression {
//println!("expected a value on the stack");
return None;
}
Some(id) => match unary.evaluate(id) {
Some(id) => match unary.evaluate(id, symbols) {
Some(res) => stack.push(res),
None => return None,
},
},
Op::Binary(binary) => match (stack.pop(), stack.pop()) {
(Some(right_id), Some(left_id)) => match binary.evaluate(left_id, right_id) {
Some(res) => stack.push(res),
None => return None,
},
(Some(right_id), Some(left_id)) => {
match binary.evaluate(left_id, right_id, symbols) {
Some(res) => stack.push(res),
None => return None,
}
}
_ => {
//println!("expected two values on the stack");
return None;
Expand Down Expand Up @@ -264,12 +271,13 @@ mod tests {
let e = Expression { ops };
println!("print: {}", e.print(&symbols).unwrap());

let res = e.evaluate(&values);
let res = e.evaluate(&values, &symbols);
assert_eq!(res, Some(ID::Bool(true)));
}

#[test]
fn checked() {
let symbols = SymbolTable::new();
let ops = vec![
Op::Value(ID::Integer(1)),
Op::Value(ID::Integer(0)),
Expand All @@ -278,7 +286,7 @@ mod tests {

let values = HashMap::new();
let e = Expression { ops };
let res = e.evaluate(&values);
let res = e.evaluate(&values, &symbols);
assert_eq!(res, None);

let ops = vec![
Expand All @@ -289,7 +297,7 @@ mod tests {

let values = HashMap::new();
let e = Expression { ops };
let res = e.evaluate(&values);
let res = e.evaluate(&values, &symbols);
assert_eq!(res, None);

let ops = vec![
Expand All @@ -300,7 +308,7 @@ mod tests {

let values = HashMap::new();
let e = Expression { ops };
let res = e.evaluate(&values);
let res = e.evaluate(&values, &symbols);
assert_eq!(res, None);

let ops = vec![
Expand All @@ -311,7 +319,7 @@ mod tests {

let values = HashMap::new();
let e = Expression { ops };
let res = e.evaluate(&values);
let res = e.evaluate(&values, &symbols);
assert_eq!(res, None);
}

Expand Down
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