Architecture¶

Core Design Principles¶

Performance First: Maximize processing throughput and resource utilization
Modern C++: Full adoption of C++23 standard features
High Cohesion, Low Coupling: Clear module boundaries and interface design

Technology Stack¶

Area	Technology	Rationale
Language	C++23	Modern features, excellent performance
Build	CMake	C++ project standard
Dependencies	Conan	Automated third-party library management
Concurrency	Intel TBB	High-performance parallel computing
CLI	cxxopts	Lightweight command-line parsing
Logging	spdlog	High-performance logging library
Testing	GoogleTest	Powerful testing framework

Architecture Layers¶

User / Caller
    ↓
CLI Layer (src/cli/)
    ↓
Application Command Layer (src/cli/commands/)
    ↓
Core Library Layer (include/fqtools/)
    ↓
Implementation Layer (src/pipeline/, src/modules/)

1. CLI Layer¶

Entry point: src/cli/main.cpp
Responsibilities: Argument parsing, command dispatch, logging initialization
Uses: cxxopts + spdlog

2. Application Command Layer¶

Interface: CommandInterface (command_interface.h)
Implementations: StatCommand, FilterCommand
Responsibilities: Argument validation, business logic invocation

3. Core Library Layer¶

Public API: include/fqtools/
Key interfaces:
processing_pipeline.h: ProcessingPipelineInterface
statistic_calculator.h: StatisticCalculatorInterface
fq.h: Aggregate header file

4. Implementation Layer¶

Pipeline & processing: src/processing/
Statistics: src/statistics/
IO: src/io/

Concurrency Model¶

Uses tbb::parallel_pipeline for high-performance parallel processing:

source: Serial FASTQ record reading
processing: Parallel filtering and transformation
sink: Serial result writing

Built-in backpressure mechanism automatically balances I/O and computation speed.

Build System¶

Modern CMake target decomposition:

# Base modules
fq_common
fq_error
fq_config
fq_core
fq_modern_io

# Core functionality
fq_pipeline

# Application layer
fq_cli

Dependencies flow bottom-up, ensuring modular design.