According cpu cores to decide how many coins in one thread

Signed-off-by: Dengjianping <[email protected]>

pallets/manta-sbt/Cargo.toml

@@ -85,6 +85,7 @@ precompute-coins = [
   "manta-pay/bip32",
   "manta-pay/arkworks",
   "manta-util/std",
+  "num_cpus",
   "rand_chacha",
   "tempfile",
 ]
@@ -95,6 +96,7 @@ anyhow = { version = "1.0.55", optional = true, default-features = false }
 base64 = { version = "0.20", default-features = false, features = ["alloc"] }
 indoc = { version = "2.0.1", optional = true, default-features = false }
 libsecp256k1 = { version = "0.7", default-features = false, features = ["hmac", "static-context"], optional = true }
+num_cpus = { version = "1.16.0", optional = true }
 rand_chacha = { version = "0.3.1", optional = true, default-features = false }
 sha3 = { version = "0.10.6", default-features = false }
 tempfile = { version = "3.3.0", optional = true, default-features = false }

pallets/manta-sbt/src/bin/precompute_coins.rs

@@ -81,6 +81,74 @@ macro_rules! write_const_array {
 /// Builds sample transactions for testing.
 #[inline]
 fn main() -> Result<()> {
+    let target_file = env::args()
+        .nth(1)
+        .map(PathBuf::from)
+        .unwrap_or(env::current_dir()?.join("precomputed_coins.rs"));
+    assert!(
+        !target_file.exists(),
+        "Specify a file to place the generated files: {target_file:?}.",
+    );
+    fs::create_dir_all(
+        target_file
+            .parent()
+            .expect("This file should have a parent."),
+    )?;
+
+    let directory = tempfile::tempdir().expect("Unable to generate temporary test directory.");
+    println!("[INFO] Temporary Directory: {directory:?}");
+
+    let mut rng = ChaCha20Rng::from_seed([0; 32]);
+    let (proving_context, _, parameters, utxo_accumulator_model) =
+        load_parameters(directory.path()).expect("Unable to load parameters.");
+    let mut utxo_accumulator = UtxoAccumulator::new(utxo_accumulator_model);
+    let asset_id = 1.into();
+
+    let to_private = to_private_example(
+        &proving_context.to_private,
+        &parameters,
+        &mut utxo_accumulator,
+        asset_id,
+        1,
+        &mut rng,
+    );
+
+    let mut target_file = OpenOptions::new()
+        .create_new(true)
+        .write(true)
+        .open(target_file)?;
+
+    writeln!(
+        target_file,
+        indoc! {r"
+            // Copyright 2020-2023 Manta Network.
+            // This file is part of Manta.
+            //
+            // Manta is free software: you can redistribute it and/or modify
+            // it under the terms of the GNU General Public License as published by
+            // the Free Software Foundation, either version 3 of the License, or
+            // (at your option) any later version.
+            //
+            // Manta is distributed in the hope that it will be useful,
+            // but WITHOUT ANY WARRANTY; without even the implied warranty of
+            // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+            // GNU General Public License for more details.
+            //
+            // You should have received a copy of the GNU General Public License
+            // along with Manta.  If not, see <http://www.gnu.org/licenses/>.
+
+            //! Precomputed Coins
+            //!
+            //! THIS FILE IS AUTOMATICALLY GENERATED by `src/bin/precompute_coins.rs`. DO NOT EDIT.
+        "}
+    )?;
+
+    write_const_array!(target_file, TO_PRIVATE, to_private)?;
+    Ok(directory.close()?)
+}
+
+#[allow(dead_code)]
+fn generate_coins_by_multithreading() -> Result<()> {
     use std::time::Instant;
     let now = Instant::now();
 
@@ -101,15 +169,17 @@ fn main() -> Result<()> {
     let directory = tempfile::tempdir().expect("Unable to generate temporary test directory.");
     println!("[INFO] Temporary Directory: {directory:?}");
 
-    let mut rng = Arc::new(ChaCha20Rng::from_seed([0; 32]));
+    let rng = Arc::new(ChaCha20Rng::from_seed([0; 32]));
     let (proving_context, _, parameters, utxo_accumulator_model) =
         load_parameters(directory.path()).expect("Unable to load parameters.");
 
-    let step = 20;
+    let cpu_num = num_cpus::get() as u128;
+    let total_coins_to_be_minted = 1024;
+    let batch = total_coins_to_be_minted / cpu_num; // how many coins in one thread
     let mut threads = vec![];
-    for i in 0..4 {
-        let start = i * step;
-        let end = step + start;
+    for i in 0..cpu_num {
+        let start = i * batch;
+        let end = batch + start;
         let utxo = utxo_accumulator_model.clone();
         let mut utxo_accumulator = Arc::new(UtxoAccumulator::new(utxo));
         let mut r = rng.clone();
@@ -132,22 +202,19 @@ fn main() -> Result<()> {
                 mints.push(to_private.clone());
                 println!("to_private size: {:?}", to_private.encode().len());
             }
-            let path = format!(
-                "/home/jamie/my-repo/Manta/pallets/manta-sbt/precomputed_mints-{}-to_{}",
-                start, end
-            );
+            let path = format!("precomputed_mints-{}-to_{}", start, end);
             let mut file = File::create(path).unwrap();
             file.write_all(&<[TransferPost]>::encode(&mints)).unwrap();
         });
         threads.push(thread_join_handle);
     }
 
     for t in threads {
-        t.join();
+        let _ = t.join();
     }
 
     let elapsed = now.elapsed();
     println!("Elapsed: {:.2?}", elapsed);
 
-    Ok(directory.close()?)
+    Ok(())
 }