📦 Package Management Essential

Dependency Hell là vấn đề lớn nhất của C++ ecosystem. Conan và Vcpkg là giải pháp.

Tại sao cần Package Manager?

Cách "cổ điển" quản lý dependencies

# "Solutions" phổ biến nhưng SAI
project/
├── external/
│   ├── boost-1.74/             # Copy thủ công 50MB source
│   ├── fmt/                    # git clone
│   └── openssl/                # ???
└── CMakeLists.txt

❌ ANTI-PATTERNS

Cách làm	Vấn đề
Copy source vào repo	Bloated repo, không update được
`git submodule`	Conflict hell, recursive init
Download .zip thủ công	Không versioning, "works on my machine"
System package manager	Khác versions giữa Ubuntu/macOS/Windows

Cách đúng: Centralized Package Manager

┌─────────────────────────────────────────────────────────────────────────┐
│                   PACKAGE MANAGER WORKFLOW                               │
├─────────────────────────────────────────────────────────────────────────┤
│                                                                         │
│   1. DECLARE                                                            │
│   ────────────                                                          │
│   conanfile.txt / vcpkg.json                                            │
│   ├── fmt/9.1.0                                                         │
│   ├── spdlog/1.11.0                                                     │
│   └── boost/1.81.0                                                      │
│                                                                         │
│   2. INSTALL                                                            │
│   ────────────                                                          │
│   conan install . / vcpkg install                                       │
│   → Download prebuilt binaries (hoặc build from source)                 │
│   → Cache globally (~/.conan2 / vcpkg root)                             │
│                                                                         │
│   3. INTEGRATE                                                          │
│   ────────────                                                          │
│   find_package(fmt REQUIRED)                                            │
│   target_link_libraries(app PRIVATE fmt::fmt)                           │
│                                                                         │
│   ✅ Version locked                                                      │
│   ✅ Cross-platform                                                      │
│   ✅ Reproducible builds                                                 │
│                                                                         │
└─────────────────────────────────────────────────────────────────────────┘

Conan vs Vcpkg — So sánh

Aspect	Conan	Vcpkg
Creator	JFrog	Microsoft
Philosophy	Decentralized (như npm)	Centralized (1 registry)
Configuration	Python (`conanfile.py`) hoặc Text	JSON (`vcpkg.json`)
Binary Caching	Built-in, powerful	Có, khó setup hơn
CMake Integration	CMakeToolchain, CMakeDeps	Toolchain file
Learning Curve	Medium	Easy
Best For	Large projects, custom builds	Quick start, Microsoft stack

🎯 PENALGO Recommendation

Beginners/Microsoft stack: Vcpkg
Advanced/Cross-platform: Conan

Cả hai đều production-ready. Chọn 1 và stick with it.

Conan — The Pythonic Way

Installation

powershell

# Via pip (recommended)
pip install conan

# Verify
conan --version  # Conan version 2.x

Project Setup với Conan

project/
├── CMakeLists.txt
├── conanfile.txt        # Dependency declaration
└── src/
    └── main.cpp

conanfile.txt

ini

[requires]
fmt/10.1.1
spdlog/1.12.0
nlohmann_json/3.11.2

[generators]
CMakeDeps
CMakeToolchain

[layout]
cmake_layout

CMakeLists.txt (với Conan)

cmake

cmake_minimum_required(VERSION 3.20)
project(MyApp LANGUAGES CXX)

# find_package hoạt động nhờ CMakeDeps generator
find_package(fmt REQUIRED)
find_package(spdlog REQUIRED)
find_package(nlohmann_json REQUIRED)

add_executable(app src/main.cpp)

target_link_libraries(app PRIVATE 
    fmt::fmt
    spdlog::spdlog
    nlohmann_json::nlohmann_json
)

target_compile_features(app PRIVATE cxx_std_20)

Build Workflow

powershell

# 1. Install dependencies
conan install . --output-folder=build --build=missing

# 2. Configure CMake (sử dụng toolchain từ Conan)
cmake -B build -DCMAKE_TOOLCHAIN_FILE=build/conan_toolchain.cmake

# 3. Build
cmake --build build

Giải thích Workflow

┌─────────────────────────────────────────────────────────────────────────┐
│                    CONAN WORKFLOW BREAKDOWN                              │
├─────────────────────────────────────────────────────────────────────────┤
│                                                                         │
│   conan install . --output-folder=build --build=missing                 │
│   ─────────────────────────────────────────────────────                 │
│                                                                         │
│   1. Đọc conanfile.txt                                                  │
│   2. Resolve dependency graph (fmt depends on nothing,                  │
│      spdlog depends on fmt, etc.)                                       │
│   3. Download prebuilt binaries từ Conan Center                         │
│      (hoặc build from source nếu --build=missing)                       │
│   4. Generate:                                                          │
│      - conan_toolchain.cmake (compiler settings)                        │
│      - fmt-config.cmake, spdlog-config.cmake, ...                       │
│                                                                         │
│   cmake --preset conan-default                                          │
│   ─────────────────────────────                                         │
│                                                                         │
│   CMake tìm packages qua generated *-config.cmake files                 │
│   find_package(fmt) → loads build/fmt-config.cmake                      │
│                                                                         │
└─────────────────────────────────────────────────────────────────────────┘

Vcpkg — The Microsoft Way

Installation

powershell

# Clone vcpkg
git clone https://github.com/microsoft/vcpkg.git
cd vcpkg

# Bootstrap (Windows)
.\bootstrap-vcpkg.bat

# Bootstrap (Linux/macOS)
./bootstrap-vcpkg.sh

# Add to PATH
$env:PATH += ";$PWD"

Project Setup với Vcpkg (Manifest Mode)

project/
├── CMakeLists.txt
├── vcpkg.json           # Manifest file
├── vcpkg-configuration.json  # (optional) registry config
└── src/
    └── main.cpp

vcpkg.json

json

{
  "name": "my-app",
  "version": "1.0.0",
  "dependencies": [
    "fmt",
    "spdlog",
    "nlohmann-json"
  ],
  "builtin-baseline": "2024.01.12"
}

CMakeLists.txt (với Vcpkg)

cmake

cmake_minimum_required(VERSION 3.20)
project(MyApp LANGUAGES CXX)

find_package(fmt CONFIG REQUIRED)
find_package(spdlog CONFIG REQUIRED)
find_package(nlohmann_json CONFIG REQUIRED)

add_executable(app src/main.cpp)

target_link_libraries(app PRIVATE 
    fmt::fmt
    spdlog::spdlog
    nlohmann_json::nlohmann_json
)

target_compile_features(app PRIVATE cxx_std_20)

Build Workflow

powershell

# Configure với vcpkg toolchain
cmake -B build -DCMAKE_TOOLCHAIN_FILE=[vcpkg-root]/scripts/buildsystems/vcpkg.cmake

# Build
cmake --build build

💡 VCPKG_ROOT Environment Variable

powershell

# Set permanently
[Environment]::SetEnvironmentVariable("VCPKG_ROOT", "C:\vcpkg", "User")

# Then use
cmake -B build -DCMAKE_TOOLCHAIN_FILE=$env:VCPKG_ROOT/scripts/buildsystems/vcpkg.cmake

Practical Lab: fmt Library

Goal

Setup project sử dụng fmt library qua package manager.

main.cpp

cpp

// src/main.cpp
#include <fmt/core.h>
#include <fmt/color.h>
#include <vector>

int main() {
    // Basic formatting
    fmt::print("Hello, {}!\n", "World");
    
    // Number formatting
    fmt::print("Pi = {:.4f}\n", 3.14159265);
    
    // Colored output
    fmt::print(fg(fmt::color::green), "Success: {}\n", "Build completed");
    
    // Container formatting (fmt 10+)
    std::vector<int> nums = {1, 2, 3, 4, 5};
    fmt::print("Numbers: {}\n", nums);
    
    return 0;
}

Using Conan

ini

# conanfile.txt
[requires]
fmt/10.1.1

[generators]
CMakeDeps
CMakeToolchain

powershell

conan install . --output-folder=build --build=missing
cmake -B build -DCMAKE_TOOLCHAIN_FILE=build/conan_toolchain.cmake
cmake --build build
./build/app

Using Vcpkg

json

// vcpkg.json
{
  "name": "fmt-demo",
  "dependencies": ["fmt"]
}

powershell

cmake -B build -DCMAKE_TOOLCHAIN_FILE=$env:VCPKG_ROOT/scripts/buildsystems/vcpkg.cmake
cmake --build build
./build/app.exe

Conan Profile — Cross-Platform Builds

ini

# ~/.conan2/profiles/linux-gcc12
[settings]
os=Linux
compiler=gcc
compiler.version=12
compiler.libcxx=libstdc++11
build_type=Release
arch=x86_64

[conf]
tools.cmake.cmaketoolchain:generator=Ninja

ini

# ~/.conan2/profiles/windows-msvc
[settings]
os=Windows
compiler=msvc
compiler.version=193  # VS 2022
build_type=Release
arch=x86_64

powershell

# Build for specific profile
conan install . -pr:b=default -pr:h=linux-gcc12

Version Constraints

Conan

ini

# conanfile.txt
[requires]
fmt/[>=10.0 <11.0]          # SemVer range
spdlog/1.12.0               # Exact version
boost/[~1.80]               # ~= allows patch updates (1.80.x)

Vcpkg

json

{
  "dependencies": [
    {
      "name": "fmt",
      "version>=": "10.0.0"
    }
  ],
  "overrides": [
    {
      "name": "fmt",
      "version": "10.1.1"
    }
  ]
}

Private/Enterprise Registry

Conan

powershell

# Add private remote
conan remote add mycompany https://conan.mycompany.com
conan remote login mycompany username

# Priority order
conan remote list

Vcpkg

json

// vcpkg-configuration.json
{
  "registries": [
    {
      "kind": "git",
      "repository": "https://github.com/mycompany/vcpkg-registry",
      "baseline": "abc123...",
      "packages": ["internal-lib-*"]
    }
  ]
}

Best Practices

┌─────────────────────────────────────────────────────────────────────────┐
│              PACKAGE MANAGEMENT BEST PRACTICES                           │
├─────────────────────────────────────────────────────────────────────────┤
│                                                                         │
│   ✅ DO                                                                  │
│   ─────                                                                 │
│   • Lock versions trong manifest (reproducibility)                      │
│   • Use manifest mode, không classic mode                               │
│   • Cache binaries trong CI (conan cache, vcpkg binary caching)         │
│   • Test với multiple compiler versions                                 │
│   • Document required dependencies trong README                         │
│                                                                         │
│   ❌ DON'T                                                               │
│   ───────                                                               │
│   • Mix package managers (Conan + Vcpkg = disaster)                     │
│   • Commit build artifacts hoặc installed packages                      │
│   • Use system packages cho portability-critical deps                   │
│   • Ignore transitive dependency conflicts                              │
│   • Hardcode paths trong CMakeLists.txt                                 │
│                                                                         │
└─────────────────────────────────────────────────────────────────────────┘

Library Compatibility Guarantee

Library	Versioning	Compatibility
fmt	SemVer	Breaking changes in major versions
spdlog	SemVer	API stable across minor versions
Boost	Own scheme	Mostly backwards compatible
nlohmann_json	SemVer	Very stable API

⚠️ BOOST WARNING

Boost là dependency nặng (~500MB). Chỉ thêm khi thực sự cần. Prefer standalone alternatives:

boost::optional → std::optional (C++17)
boost::filesystem → std::filesystem (C++17)
boost::asio → vẫn cần, chưa có std alternative

Bước tiếp theo

Đã có dependency management, giờ tối ưu tốc độ build:

⚡ Ninja & CCache → — HPN Tunnel: Giảm build time từ phút xuống giây

📦 Package Management Essential ​

Tại sao cần Package Manager? ​

Cách "cổ điển" quản lý dependencies ​

Cách đúng: Centralized Package Manager ​

Conan vs Vcpkg — So sánh ​

Conan — The Pythonic Way ​

Installation ​

Project Setup với Conan ​

conanfile.txt ​

CMakeLists.txt (với Conan) ​

Build Workflow ​

Giải thích Workflow ​

Vcpkg — The Microsoft Way ​

Installation ​

Project Setup với Vcpkg (Manifest Mode) ​

vcpkg.json ​

CMakeLists.txt (với Vcpkg) ​

Build Workflow ​

Practical Lab: fmt Library ​

Goal ​

main.cpp ​

Using Conan ​

Using Vcpkg ​

Conan Profile — Cross-Platform Builds ​

Version Constraints ​

Conan ​

Vcpkg ​

Private/Enterprise Registry ​

Conan ​

Vcpkg ​

Best Practices ​

Library Compatibility Guarantee ​

Bước tiếp theo ​

📦 Package Management Essential

Tại sao cần Package Manager?

Cách "cổ điển" quản lý dependencies

Cách đúng: Centralized Package Manager

Conan vs Vcpkg — So sánh

Conan — The Pythonic Way

Installation

Project Setup với Conan

conanfile.txt

CMakeLists.txt (với Conan)

Build Workflow

Giải thích Workflow

Vcpkg — The Microsoft Way

Installation

Project Setup với Vcpkg (Manifest Mode)

vcpkg.json

CMakeLists.txt (với Vcpkg)

Build Workflow

Practical Lab: fmt Library

Goal

main.cpp

Using Conan

Using Vcpkg

Conan Profile — Cross-Platform Builds

Version Constraints

Conan

Vcpkg

Private/Enterprise Registry

Conan

Vcpkg

Best Practices

Library Compatibility Guarantee

Bước tiếp theo