zcash_proofs: Remove obsolete examples.

Since we now use the bundled prover everywhere, we no longer need
utilities to download Zcash parameters, which was the only purpose that
these examples were serving.

zcash_proofs/Cargo.toml

@@ -53,17 +53,5 @@ multicore = ["bellman/multicore", "zcash_primitives/multicore"]
 [lib]
 bench = false
 
-[[example]]
-name = "get-params-path"
-required-features = ["directories"]
-
-[[example]]
-name = "download-params"
-required-features = ["download-params"]
-
-[[example]]
-name = "download-sprout-and-sapling-params"
-required-features = ["download-params"]
-
 [badges]
 maintenance = { status = "actively-developed" }

zcash_proofs/examples/download-params.rs

@@ -1,4 +0,0 @@
-fn main() -> Result<(), minreq::Error> {
-    #[allow(deprecated)]
-    zcash_proofs::download_parameters()
-}

zcash_proofs/examples/download-sprout-and-sapling-params.rs

@@ -1,26 +0,0 @@
-fn main() -> Result<(), minreq::Error> {
-    const DOWNLOAD_TIMEOUT_SECONDS: u64 = 3600;
-
-    #[allow(unused_mut, unused_assignments)]
-    let mut params_folder =
-        zcash_proofs::default_params_folder().expect("unexpected missing HOME env var");
-
-    // Always do a download to /tmp, if compiled with `RUSTFLAGS="--cfg always_download"`
-    #[cfg(always_download)]
-    {
-        std::env::set_var("HOME", "/tmp");
-        params_folder =
-            zcash_proofs::default_params_folder().expect("unexpected missing HOME env var");
-
-        println!("removing temporary parameters folder: {:?}", params_folder);
-        let _ = std::fs::remove_dir_all(&params_folder);
-    }
-
-    println!("downloading sapling parameters to: {:?}", params_folder);
-    zcash_proofs::download_sapling_parameters(Some(DOWNLOAD_TIMEOUT_SECONDS))?;
-
-    println!("downloading sprout parameters to: {:?}", params_folder);
-    zcash_proofs::download_sprout_parameters(Some(DOWNLOAD_TIMEOUT_SECONDS))?;
-
-    Ok(())
-}

zcash_proofs/examples/get-params-path.rs

@@ -1,7 +0,0 @@
-fn main() {
-    if let Some(path) = zcash_proofs::default_params_folder() {
-        if let Some(path) = path.to_str() {
-            println!("{}", path);
-        }
-    }
-}