Initial import

vendor/spinoza/src/config.rs

@@ -0,0 +1,81 @@
+//! Configuration options for running spinoza
+use clap::Parser;
+
+use crate::core::CONFIG;
+
+/// Config for simulations that are run using the CLI
+#[derive(Clone, Copy, Debug)]
+pub struct Config {
+    /// The number of threads to distribute the workload.
+    /// `u32` is used to represent number of threads since 4,294,967,295 is a
+    /// reasonable upperbound. If you have access to a matrioshka brain, and you
+    /// need a larger data type, please reach out.
+    pub threads: u32,
+    /// Whether or not to print the State represented as a table.
+    pub print: bool,
+    /// The number of qubits that will make up the State.  State vector size is 2^{n}, where n is
+    /// the # of qubits. Assuming single precision complex numbers, the upper bound with u8 is
+    /// 2^255 * 64 bit ≈ 4.632 * 10^{65} TB (terabytes). Thus, using u8 suffices.
+    pub qubits: u8,
+}
+
+impl Config {
+    /// Get or init the global Config. The default
+    pub fn global() -> &'static Config {
+        CONFIG.get_or_init(Config::test)
+    }
+
+    /// Convert the provided CLI args and turn it into a Config
+    pub const fn from_cli(args: QSArgs) -> Config {
+        assert!(args.threads > 0 && args.qubits > 0);
+        Config {
+            threads: args.threads,
+            qubits: args.qubits,
+            print: args.print,
+        }
+    }
+
+    fn test() -> Config {
+        Config {
+            threads: std::thread::available_parallelism()
+                .unwrap()
+                .get()
+                .try_into()
+                .expect("Too much power"),
+            // no input for tests, so this quantity should not matter
+            qubits: 0,
+            print: false,
+        }
+    }
+}
+
+/// Representation of the CLI args
+#[derive(Parser)]
+#[command(author, version, about)]
+pub struct QSArgs {
+    /// Number of threads to use
+    #[clap(short, long)]
+    threads: u32,
+    /// Whether or not to print the state in tabular format
+    #[clap(short, long)]
+    print: bool,
+    /// The number of qubits to use in the system
+    #[clap(short, long)]
+    qubits: u8,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn no_args() {
+        let config = Config::global();
+        assert_eq!(
+            config.threads,
+            u32::try_from(std::thread::available_parallelism().unwrap().get()).unwrap()
+        );
+        assert_eq!(config.qubits, 0);
+        assert!(!config.print);
+    }
+}