Add ability to disable some functionality via features (#23)

Features:
- TLS - since sometimes you may not have proper libssl/libcrypt
- flameshow - required for brew package Add chdig to brew #13

And also add new build to CI to ensure that this configuration will not be broken.

* features:
  ci: switch openssl.org (not available right now) to www.openssl.org
  ci: add build configuration without any features (just a sanity check)
  Add ability to disable TLS support
  Add ability to disable flameshow (for brew)

.github/workflows/build.yml

@@ -56,7 +56,7 @@ jobs:
         run: |
           mkdir build-openssl
           cd build-openssl
-          curl -L https://openssl.org/source/openssl-1.1.1w.tar.gz | tar --strip-components=1 -xzf -
+          curl -L https://www.openssl.org/source/openssl-1.1.1w.tar.gz | tar --strip-components=1 -xzf -
           ./Configure --prefix=$OPENSSL_DIR --libdir=lib linux-x86_64 -fPIC -g no-shared
           make -j
           make install_sw
@@ -83,6 +83,32 @@ jobs:
             *.rpm
             *.tar.*
 
+  build-linux-no-features:
+    name: Build Linux (no features)
+    runs-on: ubuntu-22.04
+
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          # To fetch tags, but can this be improved using blobless checkout?
+          # [1]. But anyway right it is not important, and unlikely will be,
+          # since the repository is small.
+          #
+          #   [1]: https://github.blog/2020-12-21-get-up-to-speed-with-partial-clone-and-shallow-clone/
+          fetch-depth: 0
+
+      - uses: Swatinem/rust-cache@v2
+        with:
+          cache-on-failure: true
+
+      - name: Build
+        run: |
+          cargo build --no-default-features # should be the same as 'make'
+
+      - name: Check package
+        run: |
+          cargo run --no-default-features -- --help
+
   build-macos-x86_64:
     name: Build MacOS (x86_64)
     # This is x86-64, M1 not for free

Cargo.toml

@@ -9,6 +9,11 @@ license = "MIT"
 version = "0.6.0"
 edition = "2021"
 
+[features]
+default = ["flameshow", "tls"]
+flameshow = ["dep:flameshow"]
+tls = ["clickhouse-rs/tls"]
+
 # TODO: convert this into feature set, but I'm not sure that it is easy right now (see [1]).
 #  [1]: https://github.com/rust-lang/cargo/issues/1197
 [target.'cfg(not(target_family = "windows"))'.dependencies]
@@ -56,11 +61,12 @@ syntect = "*"
 #
 # Drivers
 #
-clickhouse-rs = { git = "https://github.com/suharev7/clickhouse-rs", branch = "async-await", features = ["tls"] }
+clickhouse-rs = { git = "https://github.com/suharev7/clickhouse-rs", branch = "async-await" }
 tokio = { version = "*", features = ["full"] }
 
 [dependencies.flameshow]
 path = "contrib/flameshow"
+optional = true
 
 [profile.release]
 lto = true

src/interpreter/flamegraph.rs

@@ -1,13 +1,16 @@
 use crate::interpreter::clickhouse::Columns;
 use anyhow::{Error, Result};
-use flameshow::flameshow;
 use futures::channel::mpsc;
 use std::process::{Command, Stdio};
 use tokio::time::{sleep, Duration};
 use urlencoding::encode;
 use warp::http::header::{HeaderMap, HeaderValue};
 use warp::Filter;
 
+#[cfg(feature = "flameshow")]
+use flameshow::flameshow;
+
+#[cfg(feature = "flameshow")]
 pub fn show(block: Columns) -> Result<()> {
     let data = block
         .rows()
@@ -24,6 +27,11 @@ pub fn show(block: Columns) -> Result<()> {
     return flameshow(&data, "ClickHouse");
 }
 
+#[cfg(not(feature = "flameshow"))]
+pub fn show(_block: Columns) -> Result<()> {
+    return Err(Error::msg("chdig compiled without flameshow support"));
+}
+
 pub async fn open_in_speedscope(block: Columns) -> Result<()> {
     let data = block
         .rows()