Simple text chat Rust implementation

.clippy.toml

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+# High-performance Rust clippy configuration
+cognitive-complexity-threshold = 25
+type-complexity-threshold = 600
+too-many-arguments-threshold = 10

.editorconfig

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+# EditorConfig is awesome: https://editorconfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending every file
+[*]
+end_of_line = lf
+insert_final_newline = true
+indent_style = space
+indent_size = 4

.github/workflows/chat-test.yml

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+name: chat ci
+
+on:
+  push:
+    branches: [ main, master ]
+  pull_request:
+    branches: [ main, master ]
+
+env:
+  CARGO_TERM_COLOR: always
+  RUST_VERSION: 1.91.1
+
+jobs:
+  test-chat:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Install Rust
+      uses: dtolnay/rust-toolchain@master
+      with:
+        toolchain: ${{ env.RUST_VERSION }}
+        components: rustfmt, clippy
+
+    - name: Cache cargo registry
+      uses: actions/cache@v4
+      with:
+        path: |
+          ~/.cargo/registry
+          ~/.cargo/git
+          target
+        key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+        restore-keys: |
+          ${{ runner.os }}-cargo-
+
+    - name: Check formatting
+      run: |
+        cargo fmt --all -- --check
+
+    - name: Check for clippy
+      run: |
+        cargo clippy --workspace --all-targets --all-features -- -D warnings
+
+    - name: Run all tests
+      run: |
+        cargo test --all
+
+    - name: Build the project
+      run: |
+        cargo build --workspace
+
+    - name: Verify binaries can be executed
+      run: |
+        ./target/debug/chat-server --help
+        ./target/debug/chat-client --help
+
+    - name: Start chat server
+      run: |
+        nohup cargo run --bin chat-server -- --host 127.0.0.1 --port 8080 --max-connections 100 > server.log 2>&1 &
+        SERVER_PID=$!
+
+        # save the server PID for cleanup in later phase
+        echo "SERVER_PID=$SERVER_PID" >> $GITHUB_ENV
+
+        # Wait a moment for the server to start (technically not required as it's rust 😉)
+        sleep 3
+
+        # Check if server is running and listening on the port
+        if kill -0 $SERVER_PID 2>/dev/null; then
+          echo "Server started successfully with PID $SERVER_PID"
+          if lsof -i :8080 >/dev/null 2>&1; then
+            echo "Server is listening on port 8080"
+          else
+            echo "Server is not listening on port 8080"
+            cat server.log
+            exit 1
+          fi
+        else
+          echo "Server failed to start"
+          cat server.log
+          exit 1
+        fi
+
+    - name: Test client connection and message sending
+      run: |
+        echo "Testing first client connection..."
+        {
+          echo "send Hello from test client"
+          echo "leave"
+        } | cargo run --bin chat-client -- --host 127.0.0.1 --port 8080 --username testuser1
+
+        echo "Testing second client connection..."
+        {
+          echo "send Hello from second client"
+          echo "leave"
+        } | cargo run --bin chat-client -- --host 127.0.0.1 --port 8080 --username testuser2
+
+        # Test 3: Test username collision detection
+        echo "Testing username collision..."
+        {
+          echo "send Message from duplicate user"
+          echo "leave"
+        } | cargo run --bin chat-client -- --host 127.0.0.1 --port 8080 --username testuser1 &
+
+        sleep 1
+        wait
+
+        echo "Everything is fine"
+
+    - name: Stop chat server
+      run: |
+        if [ ! -z "$SERVER_PID" ]; then
+          kill $SERVER_PID
+          wait $SERVER_PID 2>/dev/null || true
+          echo "server stopped"
+
+          echo "=== Server Logs ==="
+          cat server.log
+          echo "=== End Server Logs ==="
+        fi
+
+    - name: Verify no processes left running
+      run: |
+        if command -v lsof >/dev/null 2>&1; then
+          if lsof -i :8080 >/dev/null 2>&1; then
+            echo "Warning: Port 8080 still in use after server shutdown"
+            lsof -i :8080
+            exit 1
+          else
+            echo "Port 8080 is free"
+          fi
+        else
+          echo "lsof not available, skipping port check"
+        fi

.rustfmt.toml

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+# High-performance Rust formatting configuration
+tab_spaces = 2
+hard_tabs = false
+
+# Code organization
+reorder_imports = true
+reorder_modules = true
+
+# Performance-oriented settings
+force_explicit_abi = false
+
+# Readability
+use_field_init_shorthand = true
+use_try_shorthand = true

.vscode/settings.json

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+{
+    "editor.tabSize": 2
+}

Cargo.toml

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+[workspace]
+resolver = "3"
+members = ["chat-client", "chat-core", "chat-server"]
+default-members = ["chat-client", "chat-core", "chat-server"]
+exclude = ["developer-tools"]
+
+[workspace.package]
+version = "0.1.0"
+edition = "2024"
+rust-version = "1.91.1"
+
+[workspace.dependencies]
+tokio = { version = "1", features = ["full"] }
+bincode = "2"
+uuid = { version = "1", features = ["v4"] }
+serde = { version = "1" }
+dashmap = "6"
+anyhow = "1"
+thiserror = "2"
+tracing = "0.1"
+clap = "4"
+tracing-subscriber = "0.3"
+bytes = "1"
+
+# Testing and benchmarking
+criterion = "0.7"
+tokio-test = "0.4"

README.md

@@ -1,4 +1,19 @@
 # Simple Chat
+## 🎥 Demo Video
+[Watch Demo (vimeo)](https://vimeo.com/1141420619?fl=pl&fe=sh)
+
+## 🪶 Features
+- **Protocol**: Custom binary protocol over TCP for effciency and throghput avoided json over websockets
+- **Least Cloning**: efficient broadcasting,  optimized for least message cloning regardless of scale
+- **Least Serialization effort**: O(1) effort for message serialization regardless of amount of receivers with smart caching
+- **Resource efficient**: Easy on memory and cpu
+- **Graceful shutdowns**: graceful shutdowns for server and client
+
+## 🫣 Out of Scope
+
+- Encryption in transit
+- State machines implemented at protocol levels
+
 
 ## Summary
 

chat-client/Cargo.toml

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+[package]
+name = "chat-client"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+
+[dependencies]
+chat-core = { path = "../chat-core" }
+clap = { workspace = true, features = ["derive"] }
+anyhow = { workspace = true }
+tokio = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true }