Grow RawVec to fill the allocator bins tighter [please bench it]

flake.nix

@@ -0,0 +1,243 @@
+{
+  description = "Cryptographically verifiable Code REviews";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-22.05";
+    crane.url = "github:ipetkov/crane";
+    crane.inputs.nixpkgs.follows = "nixpkgs";
+    flake-utils.url = "github:numtide/flake-utils";
+    fenix = {
+      url = "github:nix-community/fenix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    flake-compat = {
+      url = "github:edolstra/flake-compat";
+      flake = false;
+    };
+  };
+
+  outputs = { self, nixpkgs, flake-utils, flake-compat, fenix, crane }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+        };
+        lib = pkgs.lib;
+
+        fenix-channel = fenix.packages.${system}.complete;
+
+        fenix-toolchain = (fenix-channel.withComponents [
+          "rustc"
+          "cargo"
+          "clippy"
+          "rust-analysis"
+          "rust-src"
+          "rustfmt"
+          "llvm-tools-preview"
+        ]);
+
+        craneLib = crane.lib.${system}.overrideToolchain fenix-toolchain;
+
+        # filter source code at path `src` to include only the list of `modules`
+        filterModules = modules: src:
+          let
+            basePath = toString src + "/";
+          in
+          lib.cleanSourceWith {
+            filter = (path: type:
+              let
+                relPath = lib.removePrefix basePath (toString path);
+                includePath =
+                  (type == "directory" && builtins.match "^[^/]+$" relPath != null) ||
+                  lib.any
+                    (re: builtins.match re relPath != null)
+                    ([ "Cargo.lock" "Cargo.toml" ".*/Cargo.toml" ] ++ builtins.concatLists (map (name: [ name "${name}/.*" ]) modules));
+              in
+              # uncomment to debug:
+                # builtins.trace "${relPath}: ${lib.boolToString includePath}"
+              includePath
+            );
+            inherit src;
+          };
+
+        # Filter only files needed to build project dependencies
+        #
+        # To get good build times it's vitally important to not have to
+        # rebuild derivation needlessly. The way Nix caches things
+        # is very simple: if any input file changed, derivation needs to
+        # be rebuild.
+        #
+        # For this reason this filter function strips the `src` from
+        # any files that are not relevant to the build.
+        #
+        # Lile `filterWorkspaceFiles` but doesn't even need *.rs files
+        # (because they are not used for building dependencies)
+        filterWorkspaceDepsBuildFiles = src: filterSrcWithRegexes [ "Cargo.lock" "Cargo.toml" ".*/Cargo.toml" ] src;
+
+        # Filter only files relevant to building the workspace
+        filterWorkspaceFiles = src: filterSrcWithRegexes [ "Cargo.lock" "Cargo.toml" ".*/Cargo.toml" ".*\.rs" ".*/rc/doc/.*\.md" ".*\.txt" ] src;
+
+        filterSrcWithRegexes = regexes: src:
+          let
+            basePath = toString src + "/";
+          in
+          lib.cleanSourceWith {
+            filter = (path: type:
+              let
+                relPath = lib.removePrefix basePath (toString path);
+                includePath =
+                  (type == "directory") ||
+                  lib.any
+                    (re: builtins.match re relPath != null)
+                    regexes;
+              in
+              # uncomment to debug:
+                # builtins.trace "${relPath}: ${lib.boolToString includePath}"
+              includePath
+            );
+            inherit src;
+          };
+
+        commonArgs = {
+          src = filterWorkspaceFiles ./.;
+
+          buildInputs = with pkgs; [
+            openssl
+            fenix-channel.rustc
+            fenix-channel.clippy
+          ];
+
+          nativeBuildInputs = with pkgs; [
+            pkg-config
+            perl
+          ];
+
+          LIBCLANG_PATH = "${pkgs.libclang.lib}/lib/";
+          CI = "true";
+          HOME = "/tmp";
+        };
+
+        workspaceDeps = craneLib.buildDepsOnly (commonArgs // {
+          src = filterWorkspaceDepsBuildFiles ./.;
+          pname = "workspace-deps";
+          buildPhaseCargoCommand = "cargo doc && cargo check --profile release --all-targets && cargo build --profile release --all-targets";
+          doCheck = false;
+        });
+
+        # a function to define cargo&nix package, listing
+        # all the dependencies (as dir) to help limit the
+        # amount of things that need to rebuild when some
+        # file change
+        pkg = { name ? null, dir, port ? 8000, extraDirs ? [ ] }: rec {
+          package = craneLib.buildPackage (commonArgs // {
+            cargoArtifacts = workspaceDeps;
+
+            src = filterModules ([ dir ] ++ extraDirs) ./.;
+
+            # if needed we will check the whole workspace at once with `workspaceBuild`
+            doCheck = false;
+          } // lib.optionalAttrs (name != null) {
+            pname = name;
+            cargoExtraArgs = "--bin ${name}";
+          });
+
+          container = pkgs.dockerTools.buildLayeredImage {
+            name = name;
+            contents = [ package ];
+            config = {
+              Cmd = [
+                "${package}/bin/${name}"
+              ];
+              ExposedPorts = {
+                "${builtins.toString port}/tcp" = { };
+              };
+            };
+          };
+        };
+
+        workspaceBuild = craneLib.cargoBuild (commonArgs // {
+          pname = "workspace-build";
+          cargoArtifacts = workspaceDeps;
+          doCheck = false;
+        });
+
+        workspaceTest = craneLib.cargoBuild (commonArgs // {
+          pname = "workspace-test";
+          cargoArtifacts = workspaceBuild;
+          doCheck = true;
+        });
+
+        # Note: can't use `cargoClippy` because it implies `--all-targets`, while
+        # we can't build benches on stable
+        # See: https://github.com/ipetkov/crane/issues/64
+        workspaceClippy = craneLib.cargoBuild (commonArgs // {
+          pname = "workspace-clippy";
+          cargoArtifacts = workspaceBuild;
+
+          cargoBuildCommand = "cargo clippy --profile release --no-deps --lib --bins --tests --examples --workspace -- --deny warnings";
+          doInstallCargoArtifacts = false;
+          doCheck = false;
+        });
+
+        workspaceDoc = craneLib.cargoBuild (commonArgs // {
+          pname = "workspace-doc";
+          cargoArtifacts = workspaceBuild;
+          cargoBuildCommand = "env RUSTDOCFLAGS='-D rustdoc::broken_intra_doc_links' cargo doc --no-deps --document-private-items && cp -a target/doc $out";
+          doCheck = false;
+        });
+
+        };
+      in
+      {
+        packages = {
+
+          deps = workspaceDeps;
+          workspaceBuild = workspaceBuild;
+          workspaceClippy = workspaceClippy;
+          workspaceTest = workspaceTest;
+          workspaceDoc = workspaceDoc;
+
+        };
+
+        # `nix develop`
+        devShells = {
+          default = pkgs.mkShell {
+            buildInputs = commonArgs.buildInputs;
+            nativeBuildInputs = commonArgs.nativeBuildInputs ++ (with pkgs;
+              [
+                fenix-toolchain
+                fenix.packages.${system}.rust-analyzer
+
+                pkgs.nixpkgs-fmt
+                pkgs.shellcheck
+                pkgs.rnix-lsp
+                pkgs.nodePackages.bash-language-server
+              ]);
+            RUST_SRC_PATH = "${fenix-channel.rust-src}/lib/rustlib/src/rust/library";
+            shellHook = ''
+              # auto-install git hooks
+              for hook in misc/git-hooks/* ; do ln -sf "../../$hook" "./.git/hooks/" ; done
+              ${pkgs.git}/bin/git config commit.template misc/git-hooks/commit-template.txt
+
+              # workaround https://github.com/rust-lang/cargo/issues/11020
+              cargo_cmd_bins=( $(ls $HOME/.cargo/bin/cargo-{clippy,udeps,llvm-cov} 2>/dev/null) )
+              if (( ''${#cargo_cmd_bins[@]} != 0 )); then
+                echo "Warning: Detected binaries that might conflict with reproducible environment: ''${cargo_cmd_bins[@]}" 1>&2
+                echo "Warning: Considering deleting them. See https://github.com/rust-lang/cargo/issues/11020 for details" 1>&2
+              fi
+            '';
+          };
+
+          # this shell is used only in CI, so it should contain minimum amount
+          # of stuff to avoid building and caching things we don't need
+          lint = pkgs.mkShell {
+            nativeBuildInputs = [
+              pkgs.rustfmt
+              pkgs.nixpkgs-fmt
+              pkgs.shellcheck
+              pkgs.git
+            ];
+          };
+        };
+      });
+}