feat: implement saving ENR/s to file and loading ENR/s from file

.github/workflows/ci.yml

@@ -0,0 +1,54 @@
+name: Enr CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
+
+env:
+  ZIG_VERSION: 0.14.1
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4  
+
+      - name: Cache Zig
+        id: cache-zig  
+        uses: actions/cache@v4  
+        with:
+          path: ~/zig
+          key: ${{ runner.os }}-zig-${{ env.ZIG_VERSION }}
+
+      - name: Install Zig
+        if: steps.cache-zig.outputs.cache-hit != 'true'
+        run: |
+          wget https://ziglang.org/download/${{ env.ZIG_VERSION }}/zig-x86_64-linux-${{ env.ZIG_VERSION }}.tar.xz
+          tar -xf zig-x86_64-linux-${{ env.ZIG_VERSION }}.tar.xz
+          mv zig-x86_64-linux-${{ env.ZIG_VERSION }} ~/zig
+
+      - name: Add Zig to PATH
+        run: echo "${HOME}/zig" >> $GITHUB_PATH
+
+      - name: Cache Zig build artifacts
+        uses: actions/cache@v4  # Updated to v4
+        with:
+          path: |
+            zig-cache
+            ~/.cache/zig
+          key: ${{ runner.os }}-zig-build-${{ hashFiles('**/*.zig') }}
+          restore-keys: |
+            ${{ runner.os }}-zig-build-
+
+      - name: Formatting
+        run: zig fmt --check --color on .
+
+      - name: Unit testing
+        run: zig build test --summary all
+
+      - name: Building
+        run: zig build -Doptimize=ReleaseSafe

README.md

@@ -1,2 +1,49 @@
 # enr
-About Ethereum Node Records (ENR)
+Ethereum Node Records (ENR) utility in Zig.
+
+## Prerequisites
+
+- Zig 0.14.1
+
+## Building
+
+To build the project, run the following command in the root directory of the project:
+
+```bash
+zig build -Doptimize=ReleaseSafe
+```
+
+## Running Tests
+
+To run the tests, run the following command in the root directory of the project:
+
+```bash
+zig build test --summary all
+```
+
+## Docs
+
+To generate documentation for the project, run the following command in the root directory of the project:
+
+```bash
+zig build docs
+```
+
+# Usage
+
+Update `build.zig.zon`:
+
+```sh
+zig fetch --save git+https://github.com/blockblaz/enr
+```
+
+In your `build.zig`:
+
+```zig
+const enr_dep = b.dependency("zig_enr", .{
+    .target = target,
+    .optimize = optimize,
+});
+const enr_module = enr_dep.module("zig-enr");
+root_module.addImport("zig-enr", enr_module);
+```

build.zig

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+const std = @import("std");
+
+// Although this function looks imperative, note that its job is to
+// declaratively construct a build graph that will be executed by an external
+// runner.
+pub fn build(b: *std.Build) void {
+    // Standard target options allows the person running `zig build` to choose
+    // what target to build for. Here we do not override the defaults, which
+    // means any target is allowed, and the default is native. Other options
+    // for restricting supported target set are available.
+    const target = b.standardTargetOptions(.{});
+
+    // Standard optimization options allow the person running `zig build` to select
+    // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall. Here we do not
+    // set a preferred release mode, allowing the user to decide how to optimize.
+    const optimize = b.standardOptimizeOption(.{});
+
+    const discv5 = b.dependency("discv5", .{});
+
+    const enr_mod = discv5.module("enr");
+
+    // This creates a "module", which represents a collection of source files alongside
+    // some compilation options, such as optimization mode and linked system libraries.
+    // Every executable or library we compile will be based on one or more modules.
+    const lib_mod = b.createModule(.{
+        // `root_source_file` is the Zig "entry point" of the module. If a module
+        // only contains e.g. external object files, you can make this `null`.
+        // In this case the main source file is merely a path, however, in more
+        // complicated build scripts, this could be a generated file.
+        .root_source_file = b.path("src/root.zig"),
+        .target = target,
+        .optimize = optimize,
+    });
+
+    lib_mod.addImport("enr", enr_mod);
+
+    b.modules.put(b.dupe("zig-enr"), lib_mod) catch @panic("OOM");
+    // Now, we will create a static library based on the module we created above.
+    // This creates a `std.Build.Step.Compile`, which is the build step responsible
+    // for actually invoking the compiler.
+    const lib = b.addLibrary(.{
+        .linkage = .static,
+        .name = "enr",
+        .root_module = lib_mod,
+    });
+
+    // This declares intent for the library to be installed into the standard
+    // location when the user invokes the "install" step (the default step when
+    // running `zig build`).
+    b.installArtifact(lib);
+
+    // Creates a step for unit testing. This only builds the test executable
+    // but does not run it.
+    const lib_unit_tests = b.addTest(.{
+        .root_module = lib_mod,
+    });
+
+    const run_lib_unit_tests = b.addRunArtifact(lib_unit_tests);
+
+    // Similar to creating the run step earlier, this exposes a `test` step to
+    // the `zig build --help` menu, providing a way for the user to request
+    // running the unit tests.
+    const test_step = b.step("test", "Run unit tests");
+    test_step.dependOn(&run_lib_unit_tests.step);
+
+    const install_docs = b.addInstallDirectory(.{
+        .source_dir = lib.getEmittedDocs(),
+        .install_dir = .prefix,
+        .install_subdir = "docs",
+    });
+    const docs_step = b.step("docs", "Generate documentation");
+    docs_step.dependOn(&install_docs.step);
+}

build.zig.zon

@@ -0,0 +1,52 @@
+.{
+    // This is the default name used by packages depending on this one. For
+    // example, when a user runs `zig fetch --save <url>`, this field is used
+    // as the key in the `dependencies` table. Although the user can choose a
+    // different name, most users will stick with this provided value.
+    //
+    // It is redundant to include "zig" in this name because it is already
+    // within the Zig package namespace.
+    .name = .zig_enr,
+
+    // This is a [Semantic Version](https://semver.org/).
+    // In a future version of Zig it will be used for package deduplication.
+    .version = "0.0.0",
+
+    // Together with name, this represents a globally unique package
+    // identifier. This field is generated by the Zig toolchain when the
+    // package is first created, and then *never changes*. This allows
+    // unambiguous detection of one package being an updated version of
+    // another.
+    //
+    // When forking a Zig project, this id should be regenerated (delete the
+    // field and run `zig build`) if the upstream project is still maintained.
+    // Otherwise, the fork is *hostile*, attempting to take control over the
+    // original project's identity. Thus it is recommended to leave the comment
+    // on the following line intact, so that it shows up in code reviews that
+    // modify the field.
+    .fingerprint = 0x499ae5d25c594f6a, // Changing this has security and trust implications.
+
+    // Tracks the earliest Zig version that the package considers to be a
+    // supported use case.
+    .minimum_zig_version = "0.14.1",
+
+    // This field is optional.
+    // Each dependency must either provide a `url` and `hash`, or a `path`.
+    // `zig build --fetch` can be used to fetch all dependencies of a package, recursively.
+    // Once all dependencies are fetched, `zig build` no longer requires
+    // internet connectivity.
+    .dependencies = .{
+        .discv5 = .{
+            .url = "git+https://github.com/blockblaz/zig-discv5#bc96ea8e6a8c3ddc5880256a11e19df3afe37870",
+            .hash = "discv5-0.1.0-fkJduBNjAQCUYP7JVBtZ6A5Y79UYpyC8JHz5kzGnB-K5",
+        },
+    },
+    .paths = .{
+        "build.zig",
+        "build.zig.zon",
+        "src",
+        // For example...
+        //"LICENSE",
+        //"README.md",
+    },
+}