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use flatbuffers::{read_scalar_at, SIZE_UOFFSET, UOffsetT};
use std::collections::HashMap;
use std::fmt;
use std::fs::File;
use std::io::Read;
use std::path::Path;
use zkinterface_generated::zkinterface::{
BilinearConstraint,
Circuit,
get_size_prefixed_root_as_root,
Root,
Variables,
};
pub fn parse_call(call_msg: &[u8]) -> Option<(Circuit, Vec<Variable>)> {
let call = get_size_prefixed_root_as_root(call_msg).message_as_circuit()?;
let input_var_ids = call.connections()?.variable_ids()?.safe_slice();
let assigned = if call.witness_generation() {
let bytes = call.connections()?.values()?;
let stride = bytes.len() / input_var_ids.len();
(0..input_var_ids.len()).map(|i|
Variable {
id: input_var_ids[i],
value: &bytes[stride * i..stride * (i + 1)],
}
).collect()
} else {
vec![]
};
Some((call, assigned))
}
pub fn is_contiguous(mut first_id: u64, ids: &[u64]) -> bool {
for id in ids {
if *id != first_id { return false; }
first_id += 1;
}
true
}
pub fn read_size_prefix(buf: &[u8]) -> usize {
if buf.len() < SIZE_UOFFSET { return 0; }
let size = read_scalar_at::<UOffsetT>(buf, 0) as usize;
SIZE_UOFFSET + size
}
pub fn split_messages(mut buf: &[u8]) -> Vec<&[u8]> {
let mut bufs = vec![];
loop {
let size = read_size_prefix(buf);
if size == 0 { break; }
bufs.push(&buf[..size]);
buf = &buf[size..];
}
bufs
}
#[derive(Clone, Debug)]
pub struct Messages {
pub messages: Vec<Vec<u8>>,
pub first_id: u64,
}
impl Messages {
pub fn new(first_id: u64) -> Messages {
Messages {
messages: vec![],
first_id,
}
}
pub fn push_message(&mut self, buf: Vec<u8>) -> Result<(), String> {
self.messages.push(buf);
Ok(())
}
pub fn read_file<P: AsRef<Path>>(&mut self, path: P) -> Result<(), String> {
let mut file = File::open(&path).unwrap();
let mut buf = Vec::new();
file.read_to_end(&mut buf).unwrap();
println!("loaded {:?} ({} bytes)", path.as_ref(), buf.len());
self.push_message(buf).unwrap();
Ok(())
}
pub fn last_circuit(&self) -> Option<Circuit> {
let returns = self.circuits();
if returns.len() > 0 {
Some(returns[returns.len() - 1])
} else { None }
}
pub fn circuits(&self) -> Vec<Circuit> {
let mut returns = vec![];
for message in self {
match message.message_as_circuit() {
Some(ret) => returns.push(ret),
None => continue,
};
}
returns
}
pub fn connection_variables(&self) -> Option<Vec<Variable>> {
let connections = self.last_circuit()?.connections()?;
collect_connection_variables(&connections, self.first_id)
}
pub fn private_variables(&self) -> Option<Vec<Variable>> {
let circuit = self.last_circuit()?;
let mut vars = collect_unassigned_private_variables(
&circuit.connections()?,
self.first_id,
circuit.free_variable_id())?;
let mut values = HashMap::with_capacity(vars.len());
for assigned_var in self.iter_assignment() {
values.insert(assigned_var.id, assigned_var.value);
}
if values.len() > 0 {
for var in vars.iter_mut() {
if let Some(value) = values.get(&var.id) {
var.value = value;
}
}
}
Some(vars)
}
}
pub fn collect_connection_variables<'a>(conn: &Variables<'a>, first_id: u64) -> Option<Vec<Variable<'a>>> {
let var_ids = conn.variable_ids()?.safe_slice();
let values = match conn.values() {
Some(values) => values,
None => &[],
};
let stride = values.len() / var_ids.len();
let vars = (0..var_ids.len())
.filter(|&i|
var_ids[i] >= first_id
).map(|i|
Variable {
id: var_ids[i],
value: &values[stride * i..stride * (i + 1)],
}
).collect();
Some(vars)
}
pub fn collect_unassigned_private_variables<'a>(conn: &Variables<'a>, first_id: u64, free_id: u64) -> Option<Vec<Variable<'a>>> {
let var_ids = conn.variable_ids()?.safe_slice();
let vars = (first_id..free_id)
.filter(|id|
!var_ids.contains(id)
).map(|id|
Variable {
id,
value: &[],
}
).collect();
Some(vars)
}
impl<'a> IntoIterator for &'a Messages {
type Item = Root<'a>;
type IntoIter = MessageIterator<'a>;
fn into_iter(self) -> MessageIterator<'a> {
MessageIterator {
bufs: &self.messages,
offset: 0,
}
}
}
pub struct MessageIterator<'a> {
bufs: &'a [Vec<u8>],
offset: usize,
}
impl<'a> Iterator for MessageIterator<'a> {
type Item = Root<'a>;
fn next(&mut self) -> Option<Self::Item> {
loop {
if self.bufs.len() == 0 { return None; }
let buf = &self.bufs[0][self.offset..];
let size = {
let size = read_size_prefix(buf);
if size <= buf.len() {
size
} else {
buf.len()
}
};
if size == 0 {
self.bufs = &self.bufs[1..];
self.offset = 0;
continue;
}
self.offset += size;
let root = get_size_prefixed_root_as_root(&buf[..size]);
return Some(root);
}
}
}
impl Messages {
pub fn iter_constraints(&self) -> R1CSIterator {
R1CSIterator {
messages_iter: self.into_iter(),
constraints_count: 0,
next_constraint: 0,
constraints: None,
}
}
}
pub type Term<'a> = Variable<'a>;
#[derive(Debug)]
pub struct Constraint<'a> {
pub a: Vec<Term<'a>>,
pub b: Vec<Term<'a>>,
pub c: Vec<Term<'a>>,
}
pub struct R1CSIterator<'a> {
messages_iter: MessageIterator<'a>,
constraints_count: usize,
next_constraint: usize,
constraints: Option<flatbuffers::Vector<'a, flatbuffers::ForwardsUOffset<BilinearConstraint<'a>>>>,
}
impl<'a> Iterator for R1CSIterator<'a> {
type Item = Constraint<'a>;
fn next(&mut self) -> Option<Self::Item> {
while self.next_constraint >= self.constraints_count {
let message = self.messages_iter.next()?;
let constraints = match message.message_as_r1csconstraints() {
Some(message) => message.constraints().unwrap(),
None => continue,
};
self.constraints_count = constraints.len();
self.next_constraint = 0;
self.constraints = Some(constraints);
}
let constraint = self.constraints.as_ref().unwrap().get(self.next_constraint);
self.next_constraint += 1;
fn to_vec<'a>(lc: Variables<'a>) -> Vec<Term<'a>> {
let mut terms = vec![];
let var_ids: &[u64] = lc.variable_ids().unwrap().safe_slice();
let values: &[u8] = lc.values().unwrap();
let stride = values.len() / var_ids.len();
for i in 0..var_ids.len() {
terms.push(Term {
id: var_ids[i],
value: &values[stride * i..stride * (i + 1)],
});
}
terms
}
Some(Constraint {
a: to_vec(constraint.linear_combination_a().unwrap()),
b: to_vec(constraint.linear_combination_b().unwrap()),
c: to_vec(constraint.linear_combination_c().unwrap()),
})
}
}
impl Messages {
pub fn iter_assignment(&self) -> WitnessIterator {
WitnessIterator {
messages_iter: self.into_iter(),
var_ids: &[],
values: &[],
next_element: 0,
}
}
}
pub struct Variable<'a> {
pub id: u64,
pub value: &'a [u8],
}
impl<'a> Variable<'a> {
pub fn has_value(&self) -> bool {
self.value.len() > 0
}
}
impl<'a> fmt::Debug for Variable<'a> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "var{}={:?}", self.id, self.value)
}
}
pub struct WitnessIterator<'a> {
messages_iter: MessageIterator<'a>,
var_ids: &'a [u64],
values: &'a [u8],
next_element: usize,
}
impl<'a> Iterator for WitnessIterator<'a> {
type Item = Variable<'a>;
fn next(&mut self) -> Option<Self::Item> {
while self.next_element >= self.var_ids.len() {
let message = self.messages_iter.next()?;
let witness = match message.message_as_witness() {
Some(message) => message.assigned_variables().unwrap(),
None => continue,
};
self.var_ids = witness.variable_ids().unwrap().safe_slice();
self.values = witness.values().unwrap();
self.next_element = 0;
}
let stride = self.values.len() / self.var_ids.len();
let i = self.next_element;
self.next_element += 1;
Some(Variable {
id: self.var_ids[i],
value: &self.values[stride * i..stride * (i + 1)],
})
}
}