Distributed Caching Layer for System Packages - High-Performance Package-Aware Transparent Proxy
Current Version: v0.1.0 | Release Notes
pacPrism aims to be a distributed caching layer for system packages that enhances existing package managers through transparent proxy mode.
- Transparent Proxy - Modify
sources.listto intercept APT/Pacman requests - Semantic Sharding - Group related packages for locality and dependency completeness
- Hybrid Distribution - Central gateway + decentralized P2P data layer
- Smart Routing - Query DHT to find optimal nodes for content retrieval
This is early-stage prototype code. Most features above are design goals, not working implementations.
HTTP Transparent Proxy System:
- Real transparent HTTP proxy (NOT redirects) - Fetches files from upstream and returns them directly
- FileCache with upstream fetching, local disk caching, SHA256 verification
- Range request support (HTTP 206 Partial Content) - Critical for APT resume
- Conditional request support (If-Modified-Since, If-None-Match → HTTP 304)
- Error handling with retries (3 attempts, exponential backoff: 1s, 2s, 4s)
- Configurable timeouts (connect: 10s, read: 30s)
DHT Core Operations:
- 9-dimensional index system fully implemented
- Node verification, storage with conflict resolution, shard-based queries
- Automatic expiry cleanup
- O(1) core operations with multi-dimensional indexing
HTTP Router with Triple Dependency Injection:
- Validator integration for request type classification (PlainClient vs Node vs Invalid)
- Complete DHT HTTP API (5 JSON endpoints: verify, store, query, clean/expiry, clean/liveness)
- File proxy with Range/conditional request support via FileCache
- Production-ready, not placeholders
Validator with SHA256:
- Request type validation based on custom headers
- Cross-platform SHA256 calculation (Windows: bcrypt, Linux: OpenSSL)
- SHA256 verification for file integrity
Debian Package Parser:
- Binary package parsing:
name_version_arch.extension - Source package parsing:
.orig.tar.gz/xz,.dsc,.tar.gz/xz - Component extraction (main/contrib/non-free)
Build System:
- CMake Presets (debug/release) with cross-platform support
- Automated vcpkg dependency management
- Successfully tested on Windows MSYS2 (GCC 15.2.0)
ClientTrans::start_connecting()- Empty stub (client connection logic)DHT_operation::clean_by_liveness()- Empty stub (health-based node pruning)Validator::verify_node_identity()- Demo mode, always returns true (Ed25519 TODO)
- P2P Protocol - Node-to-node communication protocol
- Real Distributed DHT - Network communication between nodes
- Semantic Sharding Algorithm - Intelligent package grouping strategy
- Node Authentication - Ed25519 signature verification (currently demo mode)
- Core System: C++23 - High performance, low latency network processing
- Network Library: Boost.Beast (from Debian packages) - HTTP/1.1 asynchronous server
- Build System: CMake 3.14+ - Modular build system
- Dependencies: System packages via apt (Boost, OpenSSL, nlohmann-json)
- Platform: Linux (Debian/Ubuntu)
- C++23 compatible compiler (GCC 13+, Clang 14+)
- CMake 3.14+
- Debian/Ubuntu system packages:
libboost-dev(Boost.Beast HTTP library)libssl-dev(OpenSSL for SHA256)nlohmann-json3-dev(JSON library)
Debian/Ubuntu:
sudo apt update
sudo apt install -y \
build-essential \
cmake \
g++ \
libboost-dev \
libssl-dev \
nlohmann-json3-dev \
libcxxopts-devOr use:
make depsUsing Makefile (Recommended):
# Clone repository
git clone https://github.com/tzbkk/pacPrism.git
cd pacPrism
# Build (Release mode)
make release
# Or build (Debug mode)
make debug
# Run the application
./build/bin/pacprismUsing CMake directly:
mkdir build && cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
make -j$(nproc)
./bin/pacprism- 🗺️ Development Roadmap - Three-phase evolution strategy: from campus to public P2P
- 📋 Current Development Status - Detailed implementation progress and feature verification
- 🏗️ Project Architecture - Complete architecture design documentation
- 📝 Development Log - Daily development records
GPLv3