GSoC 2025 Bandwidth Algorithm - pgRouting/pgrouting GitHub Wiki

Proposal

Brief Description

This project aims to add Bandwidth Boost Graph Library Algorithm for pgRouting.

State of the Project Before GSoC

Bandwidth algorithm has not been implemented in pgRouting. However, from the graph metrics of the Boost Graph Library, only brandes_betweenness_centrality has been implemented in pgRouting so far.

Deliverables

Implementation of pgr_bandwidth() function.
Code with detailed comments.
User's documentation.
A wiki page for each week's progress and product created.
Basic pgTap tests for the mentioned functions.
Integration examples with existing pgRouting algorithms.

Detailed Proposal

Detailed Proposal link

Participants

Title	GitHub Handle	Name
1st Mentor	@robe2	Regina Obe
2nd Mentor	@cvvergara	Vicky Vergara
3rd Mentor	@sanak	Ko Nagase
4th Mentor	@iosefa	Iosefa Percival
Student Developer	@Saloni-2005	Saloni Kumari

Timeline

Community Bonding Period

Introduce myself to the community, interact with my mentors, and learn more about pgRouting.
Understand the coding style, generating documentation, and the interaction of pgRouting with other applications.
Set up a wiki page to keep track of my progress.
Make a branch in the GSoC_pgRouting repository where I will push my weekly code.
Review pgRouting C++ coding style from Google C++ coding style guide.
Participate in community discussions, meetings, or forums to engage with the project
Community Bonding Period Report
- Created OSGeo profile and linked it to the GSoC 2025 Accepted Students wiki page.
- Set up project wiki page with project summary, and placeholders for weekly reports and deliverables.
- Initialized basic folder structure for the Bandwidth algorithm implementation in pgRouting.
- Explored pgRouting and Boost Graph Library to understand integration and function design.
- Interacted with mentors and participated in community discussions for onboarding and project clarity.
- Ready for coding phase with a clear understanding of next steps: C++ implementation, SQL wrapping, and testing setup.

First Coding Period

Week 1 (June 2nd - June 8th)

Original Plan
- Review BGL’s Bandwidth algorithm.
- Design data structures for pgr_bandwidth().
Revised Plan:
- Focused on setting up file structure to support later development.
Work Done:
- Created foundational files for pgr_bandwidth() implementation:
  - SQL: bandwidth.sql, _bandwidth.sql
  - Include: bandwidth_driver.h, bandwidth.hpp, bandwidth_process.h
  - Src: bandwidth_driver.cpp, bandwidth_process.cpp, bandwidth.c
Plan for Next Week:
- No major progress expected due to final exams (June 9–15).
- Will resume implementation and testing in Week 3.
Blockers:
- Final exams during Week 2 (non-technical).
PR links : #441 , #443

Week 2

Original Plan:
- Create initial SQL function interface
- Develop C++ bandwidth calculation algorithm
Revised Plan:
- Focus shifted to resolving structural and naming issues across files
- Postpone logic implementation until after final exams
- Prioritize clean, consistent codebase setup for upcoming development
Work Done:
- Fixed naming issues and removed duplicate/unnecessary files
- Renamed files for consistency and clarity
- Updated license headers across all implementation files
- Modified CMakeLists.txt accordingly
- Attended project meetings (June 8 & 9)
- Implemented mentor feedback
- Updated wiki documentation
PR link : #445
Plan for Week 3:
- Resolve compilation errors
- Resume full development
- Catch up on pending work
Blockers:
- None

Week 3

Original Plan:
- Implement basic driver to connect SQL and C++
- Create data pipeline from SQL input to graph representation
Revised Plan:
- Focus shifted to resolving compilation errors.
- Focused on resolving conflicts.
Work Done:
- Fixed parameters and data types based on my algorithm
- Resolved the merge conflicts
- Resolved compilation errors to reach a stable compilation point
- Attended project meetings (June 16 & 20)
- Implemented mentor feedback
- Updated wiki documentation
PR link : #454 , #453 , #450
Plan for Week 4:
- Start testing processes.
- Develop PostgreSQL integration methods
Blockers:
- None

Week 4

Original Plan:
- Incorporate core bandwidth calculation logic
- Develop error handling and edge cases
Revised Plan:
- Focus shifted to resolving compilation errors
- Focused on resolving parameter mismatches and type issues in C++ binding
Work Done:
- Fixed parameters and data types based on Boost algorithm implementation
- Resolved all compilation errors to achieve a stable build
- Resolved previous merge conflicts
- Added types_check.pg test file to begin testing the input types
- Attended project meetings (June 23)
- Collaborated with mentors for review and feedback
- Updated the wiki documentation
PR link: #456
Plan for Week 5 (June 30 – July 6):
- Start the doc-queries testing process
- Begin work on PostgreSQL integration methods for testing
Blockers:
- None

Week 5

Original plan
- Write comprehensive documentation
- Add performance optimizations
- Prepare for midterm evaluation
Revised plan
- Focus shifted to resolving compilation errors
- Started testing process
Work done
- Fixed parameters and data types based on my algorithm
- Resolved the merge conflicts
- Resolved compilation errors to reach a stable compilation point
- Implemented mentor feedback
- Updated wiki documentation
PR link: #463
Plan for Week 6 (July 7 – July 14)
- Develop PostgreSQL integration methods
Blockers:
- None

Week 6

TBD

Second Coding Period

Week 7

TBD

Week 8

TBD

Week 9

TBD

Week 10

TBD

Week 11

TBD

Week 12

TBD

Log of Pull Requests

Link to pull requests made in GSoC-pgRouting repository

Pull Request	Description	Date	Status
#441	Week 1	June 3	Closed
#443	Week 1	June 7	Merged
#445	Week 2	June 9	Merged
#454	Week 3	June 20	Merged
#456	Week 4	June 23	Merged
#463	Week 5	July 1	Merged

Final Report

TBD

Potential Future Work :

TBD

Links:

Pull Requests:
- Final Pull Request: TBD
- Intermediate pull requests: TBD