Feat/countries example (#322)

# Rationale for this change
Add an additional countries example to help improve documentation.

# What changes are included in this PR?
Adding an example with a table of launch vehicles.

# Are these changes tested?

.github/workflows/lint-and-test.yml

@@ -130,6 +130,8 @@ jobs:
         run: cargo run --example plastics
       - name: Run sushi example
         run: cargo run --example sushi
+      - name: Run countries example
+        run: cargo run --example countries
       - name: Run posql_db example (With Blitzar)
         run: bash crates/proof-of-sql/examples/posql_db/run_example.sh
       - name: Run posql_db example (Without Blitzar)

crates/proof-of-sql/Cargo.toml

@@ -127,6 +127,10 @@ required-features = [ "arrow" ]
 name = "sushi"
 required-features = [ "arrow" ]
 
+[[example]]
+name = "countries"
+required-features = [ "arrow" ]
+
 [[bench]]
 name = "posql_benches"
 harness = false

crates/proof-of-sql/examples/countries/countries_gdp.csv

@@ -0,0 +1,35 @@
+Country,Continent,GDP,GDPP
+UnitedStates,NorthAmerica,21137,63543
+China,Asia,14342,10261
+Japan,Asia,5081,40293
+Germany,Europe,3846,46329
+India,Asia,2875,2099
+UnitedKingdom,Europe,2825,42330
+France,Europe,2716,41463
+Italy,Europe,2001,33279
+Brazil,SouthAmerica,1839,8718
+Canada,NorthAmerica,1643,43119
+Russia,EuropeAsia,1637,11229
+SouthKorea,Asia,1622,31489
+Australia,Oceania,1382,53799
+Spain,Europe,1316,28152
+Mexico,NorthAmerica,1265,9958
+Indonesia,Asia,1119,4152
+Netherlands,Europe,902,52477
+SaudiArabia,Asia,793,23206
+Turkey,EuropeAsia,761,9005
+Switzerland,Europe,703,81392
+Argentina,SouthAmerica,449,9921
+Sweden,Europe,528,52073
+Nigeria,Africa,448,2190
+Poland,Europe,594,15673
+Thailand,Asia,509,7306
+SouthAfrica,Africa,350,5883
+Philippines,Asia,402,3685
+Colombia,SouthAmerica,323,6458
+Egypt,Africa,302,3012
+Pakistan,Asia,278,1450
+Bangladesh,Asia,302,1855
+Vietnam,Asia,283,2900
+Chile,SouthAmerica,252,13120
+Finland,Europe,268,48888

crates/proof-of-sql/examples/countries/main.rs

@@ -0,0 +1,132 @@
+//! This is a non-interactive example of using Proof of SQL with a countries dataset.
+//! To run this, use `cargo run --release --example countries`.
+//!
+//! NOTE: If this doesn't work because you do not have the appropriate GPU drivers installed,
+//! you can run `cargo run --release --example countries --no-default-features --features="arrow cpu-perf"` instead. It will be slower for proof generation.
+
+use arrow::datatypes::SchemaRef;
+use arrow_csv::{infer_schema_from_files, ReaderBuilder};
+use proof_of_sql::{
+    base::database::{
+        arrow_schema_utility::get_posql_compatible_schema, OwnedTable, OwnedTableTestAccessor,
+        TestAccessor,
+    },
+    proof_primitive::dory::{
+        DynamicDoryCommitment, DynamicDoryEvaluationProof, ProverSetup, PublicParameters,
+        VerifierSetup,
+    },
+    sql::{parse::QueryExpr, postprocessing::apply_postprocessing_steps, proof::QueryProof},
+};
+use rand::{rngs::StdRng, SeedableRng};
+use std::{fs::File, time::Instant};
+
+// We generate the public parameters and the setups used by the prover and verifier for the Dory PCS.
+// The `max_nu` should be set such that the maximum table size is less than `2^(2*max_nu-1)`.
+const DORY_SETUP_MAX_NU: usize = 8;
+// This should be a "nothing-up-my-sleeve" phrase or number.
+const DORY_SEED: [u8; 32] = *b"7a1b3c8d2e4f9g6h5i0j7k2l8m3n9o1p";
+
+/// # Panics
+/// Will panic if the query does not parse or the proof fails to verify.
+fn prove_and_verify_query(
+    sql: &str,
+    accessor: &OwnedTableTestAccessor<DynamicDoryEvaluationProof>,
+    prover_setup: &ProverSetup,
+    verifier_setup: &VerifierSetup,
+) {
+    // Parse the query:
+    println!("Parsing the query: {sql}...");
+    let now = Instant::now();
+    let query_plan = QueryExpr::<DynamicDoryCommitment>::try_new(
+        sql.parse().unwrap(),
+        "countries".parse().unwrap(),
+        accessor,
+    )
+    .unwrap();
+    println!("Done in {} ms.", now.elapsed().as_secs_f64() * 1000.);
+
+    // Generate the proof and result:
+    print!("Generating proof...");
+    let now = Instant::now();
+    let (proof, provable_result) = QueryProof::<DynamicDoryEvaluationProof>::new(
+        query_plan.proof_expr(),
+        accessor,
+        &prover_setup,
+    );
+    println!("Done in {} ms.", now.elapsed().as_secs_f64() * 1000.);
+
+    // Verify the result with the proof:
+    print!("Verifying proof...");
+    let now = Instant::now();
+    let result = proof
+        .verify(
+            query_plan.proof_expr(),
+            accessor,
+            &provable_result,
+            &verifier_setup,
+        )
+        .unwrap();
+    let result = apply_postprocessing_steps(result.table, query_plan.postprocessing());
+    println!("Verified in {} ms.", now.elapsed().as_secs_f64() * 1000.);
+
+    // Display the result
+    println!("Query Result:");
+    println!("{result:?}");
+}
+
+fn main() {
+    let mut rng = StdRng::from_seed(DORY_SEED);
+    let public_parameters = PublicParameters::rand(DORY_SETUP_MAX_NU, &mut rng);
+    let prover_setup = ProverSetup::from(&public_parameters);
+    let verifier_setup = VerifierSetup::from(&public_parameters);
+
+    let filename = "./crates/proof-of-sql/examples/countries/countries_gdp.csv";
+    let inferred_schema =
+        SchemaRef::new(infer_schema_from_files(&[filename.to_string()], b',', None, true).unwrap());
+    let posql_compatible_schema = get_posql_compatible_schema(&inferred_schema);
+
+    let countries_batch = ReaderBuilder::new(posql_compatible_schema)
+        .with_header(true)
+        .build(File::open(filename).unwrap())
+        .unwrap()
+        .next()
+        .unwrap()
+        .unwrap();
+
+    // Load the table into an "Accessor" so that the prover and verifier can access the data/commitments.
+    let mut accessor =
+        OwnedTableTestAccessor::<DynamicDoryEvaluationProof>::new_empty_with_setup(&prover_setup);
+    accessor.add_table(
+        "countries.countries".parse().unwrap(),
+        OwnedTable::try_from(countries_batch).unwrap(),
+        0,
+    );
+
+    prove_and_verify_query(
+        "SELECT COUNT(*) AS total_countries FROM countries",
+        &accessor,
+        &prover_setup,
+        &verifier_setup,
+    );
+
+    prove_and_verify_query(
+        "SELECT country FROM countries WHERE continent = 'Asia'",
+        &accessor,
+        &prover_setup,
+        &verifier_setup,
+    );
+
+    prove_and_verify_query(
+        "SELECT country FROM countries WHERE gdp > 500 AND gdp < 1500",
+        &accessor,
+        &prover_setup,
+        &verifier_setup,
+    );
+
+    prove_and_verify_query(
+        "SELECT SUM(gdp) AS total_market_cap FROM countries WHERE country = 'China' OR country = 'India'",
+        &accessor,
+        &prover_setup,
+        &verifier_setup,
+    );
+}