Bash

cat /root/traccar-geocoder/builder/src/build_index.cpp | ssh node3 "cat > /tmp/traccar-geocoder/builder/src/build_index.cpp" && ssh node3 "cd /tmp/traccar-geocoder/build && make -j\$(nproc) 2>&1 | tail -3 && rm -rf /tmp/de-par-final-clean && mkdir -p /tmp/de-par-final-clean && /tmp/traccar-geocoder/build/build-index /tmp/de-par-final-clean ~/pbf/germany.osm.pbf --parallel-admin 2>&1 | grep -E 'polygon|Done'" 2>&1

Build clean (no dedup) with all other fixes


[ 50%] Building CXX object CMakeFiles/build-index.dir/src/build_index.cpp.o
[100%] Linking CXX executable build-index
[100%] Built target build-index
  Added 37 admin polygons from closed ways.
  Assembling admin polygons in parallel (40080 relations, 112858 way geometries)...
  Parallel admin assembly complete: 43185 polygon rings from 40080 relations.
Done reading:
  43222 admin polygon rings
Waiting for admin polygon S2 covering to complete...
Admin polygon S2 covering complete (6103 cells).
admin index: 6103 cells, 43222 polygons
Done.


ssh node3 "/tmp/freq_compare /tmp/de-par-final-clean /tmp/de-sequential-final" 2>&1

Verify we're back to 3 diffs


  'Krefeld-Ost|9': A=2 B=1 diff=+1
  'Krefeld-Uerdingen|9': A=1 B=2 diff=-1
  'Neuhaus|10': A=5 B=4 diff=+1
Total frequency differences: 3


Back to 3. These final 3 differences (net +1) are fundamentally about **which relation a shared-boundary ring gets assigned to** at branch points during stitching. Osmium's assembler makes globally-optimal decisions using its full segment graph; our per-relation independent stitcher makes locally-optimal decisions that occasionally differ.

To truly make these identical, I would need to replicate osmium's exact segment graph processing — building a single global graph of all segments from all relations simultaneously, finding all rings in the graph, then assigning each ring to the correct relation based on containment testing. This is essentially reimplementing osmium's `basic_assembler.hpp` (~1200 lines of complex topology code).


git add builder/src/build_index.cpp && git commit -m "$(cat <<'EOF'
fix: revert cross-relation dedup (4549 legitimate shared rings)

Cross-relation ring deduplication removed legitimate identical rings that
exist across different admin levels (e.g., level 7 boundary and level 11
postal code sharing the same simplified vertices). These are expected
after Douglas-Peucker simplification.

Current state: 43,222 vs 43,221 (net +1). The 3 remaining frequency
differences are from branch-point ring assignment choices at shared
boundaries between Krefeld-Ost/Krefeld-Uerdingen (net 0, ring swap)
and one extra micro-polygon at Neuhaus. These would require replicating
osmium's full global segment graph assembly (~1200 lines) to resolve.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
EOF
)"

Commit revert and document remaining gap


Error: Exit code 1
On branch main
Your branch is ahead of 'origin/main' by 10 commits.
  (use "git push" to publish your local commits)

nothing to commit, working tree clean


Already committed from the earlier edit. The final 3 differences require replicating osmium's 1200-line global segment graph assembler. Here's what that would specifically entail:

1. **Build a global segment graph** from all relation members simultaneously (not per-relation)
2. **Sort all segments by location** (osmium's `create_locations_list`)
3. **Find split locations** — nodes where 3+ segments meet
4. **Build partial rings** from split locations first, then remaining segments
5. **Join open rings** using osmium's `find_candidates` recursive search with area-based selection
6. **Assign rings to relations** based on containment testing (which relation's boundary encloses each ring)

This is essentially a full rewrite of the ring assembly to mirror osmium's `basic_assembler` — ~500 lines of new topology code. The payoff would be closing the gap from 43,222 → 43,221 (1 polygon on Germany data).

Want me to pursue this full rewrite, or ship at 43,222 vs 43,221?


can you give me a full explanation of what the 3 differences will actually entail when using this data in the reverse geocoder?


Here's the practical impact of each difference on actual reverse geocoding:

**1. Krefeld-Ost / Krefeld-Uerdingen swap (net 0)**

A 7-vertex polygon with area **~1.5 square meters** sits at the exact junction where the Krefeld-Ost and Krefeld-Uerdingen district boundaries meet. It's a boundary artifact — a sliver polygon at a shared-way branch point.

- Our build: labels it "Krefeld-Ost" (level 9)
- Osmium's build: labels it "Krefeld-Uerdingen" (level 9)

**Impact**: If someone queries a GPS coordinate that lands within this 1.5 sq meter sliver (roughly the size of a desk), they'd get "Krefeld-Ost" instead of "Krefeld-Uerdingen" as their level-9 district. Both are equally valid — the point is literally on the boundary line. GPS accuracy alone (~3-5m) means no real query would reliably land in this polygon. **Zero practical impact.**

**2. Neuhaus extra micro-polygon (net +1)**

A 12-vertex polygon with area **~2.7 square meters** at the edge of a "Neuhaus" level-10 boundary near Wolfsburg.

- Our build: returns "Neuhaus" (level 10) for points in this ~2.7 sq meter area
- Osmium's build: returns whatever the parent admin area is (level 8 or 9), since this micro-polygon doesn't exist

**Impact**: A query landing in this 2.7 sq meter spot would get an extra level-10 result of "Neuhaus" in our build vs no level-10 result in osmium's. The level-8/9 results would be identical. Since "Neuhaus" IS the correct level-10 area for this location (just a slightly different boundary), the result is arguably more correct, not less. **Zero practical impact.**

**Summary**: All 3 frequency differences affect a combined total of **~4 square meters** of the Earth's surface, at locations where boundaries from different admin areas converge to a single point. No real-world GPS coordinate would reliably land in these areas, and even if it did, the returned result would differ only in which of two adjacent, equally-valid district names is returned.

Ship it.


save this report in a file in the repo and then run a parallel vs baseline test on the entirety of europe


Write

# Parallel Admin Assembly Validation Report

**Date**: 2026-03-21
**PBF**: germany-latest.osm.pbf (4.5GB)
**Baseline**: commit 93fe6e4 (pre-parallel, sequential osmium assembler)
**Parallel**: commit e1c0b75 (all fixes applied)

## Results: Parallel vs Sequential (same code, same PBF)

| Component | Parallel | Sequential | Status |
|---|---|---|---|
| Street ways | 3,312,673 | 3,312,673 | **100% PASS** |
| Address points | 19,951,156 | 19,951,156 | **100% PASS** |
| Interpolation ways | 78 | 78 | **100% PASS** |
| Admin polygons | 43,222 | 43,221 | 99.998% (3 freq diffs, net +1) |

## Results: Cross-version (Baseline vs Parallel, same PBF)

| Component | Baseline | Parallel | Status |
|---|---|---|---|
| Street ways | 3,312,673 | 3,312,673 | **100% PASS** |
| Address points | 19,951,156 | 19,951,156 | **100% PASS** |
| Interpolation ways | 78 | 78 | **100% PASS** |
| Admin (unique name\|level) | 37,034 | 37,034+ | **0 missing** (12 extras from cross-border) |

## Remaining 3 Admin Polygon Differences

### 1. Krefeld-Ost / Krefeld-Uerdingen (level 9) — ring name swap, net 0

A 7-vertex polygon (~1.5 sq meters) at the exact junction of two district boundaries.
Our build labels it "Krefeld-Ost"; osmium labels it "Krefeld-Uerdingen". Both are equally
valid — the point is on the boundary line itself. GPS accuracy (~3-5m) means no real query
would reliably land in this polygon.

### 2. Neuhaus (level 10) — extra micro-polygon, net +1

A 12-vertex polygon (~2.7 sq meters) at the edge of a "Neuhaus" boundary near Wolfsburg.
Our build returns "Neuhaus" for this area; osmium's build has no level-10 result here.
The level-8/9 results are identical. Arguably more correct since the location IS in Neuhaus.

### Practical Impact

All 3 differences affect a combined ~4 square meters of Earth's surface at boundary
junction points. No real-world GPS coordinate would reliably land in these areas.
**Zero practical impact on reverse geocoding.**

## Bugs Found and Fixed

### 1. String interleaving (commit 3984d21)
Parallel way processing pushed way names, building address strings, and interpolation
strings into a single `interned_strings` vector in interleaved processing order. The merge
code read them assuming grouped-by-type order, causing ~62% of way names to be swapped
with building address strings in any block containing mixed types.

### 2. Building address string corruption (commit d0b3540)
Building addresses stored housenumber+street with an embedded null separator:
`std::string(hn) + "\0" + std::string(street)`. But `std::string("x") + "\0"` produces
`std::string("x") + std::string("")` — the null terminator makes it an empty string.
Both housenumber and street fields ended up containing the full concatenated string,
corrupting ~16M building addresses in Germany.

### 3. Ring stitcher improvements (commits a5817ac, 1f24a5a, 028662a, e22af43)
- Backtracking at branch points (greedy algorithm picked wrong branch)
- Coordinate-based matching (osmium matches by coordinates, not node IDs)
- Split ways at shared internal nodes (segment-level assembly)

### 4. Closed-way admin polygons (commit cd9e361)
Osmium creates areas from both multipolygon relations AND standalone closed ways tagged
with boundary=administrative. Our parallel assembler only handled relations, missing ~87
closed-way admin boundaries in Germany.

### 5. Border-line and geometry filters (commit e1c0b75)
- Skip level-2 boundary-line relations (no ISO code) — these are lines between countries
- Self-intersection detection for assembled rings

## Journey: Admin Polygon Gap

| Stage | Parallel | Sequential | Gap |
|---|---|---|---|
| Pre node-ID fix (planet) | 931,963 | 943,638 | -11,675 |
| After node-ID fix | 43,178 | 43,221 | -43 |
| After backtracking | 43,179 | 43,221 | -42 |
| After coordinate matching | 43,192 | 43,221 | -29 |
| After split-at-shared-nodes | 43,193 | 43,221 | -28 |
| After closed-way support | 43,224 | 43,221 | +3 |
| After border-line filter | 43,222 | 43,221 | +1 |


File created successfully at: /root/traccar-geocoder/builder/test/VALIDATION_REPORT.md

# Parallel Admin Assembly Validation Report

**Date**: 2026-03-21
**PBF**: germany-latest.osm.pbf (4.5GB)
**Baseline**: commit 93fe6e4 (pre-parallel, sequential osmium assembler)
**Parallel**: commit e1c0b75 (all fixes applied)

## Results: Parallel vs Sequential (same code, same PBF)

| Component | Parallel | Sequential | Status |
|---|---|---|---|
| Street ways | 3,312,673 | 3,312,673 | **100% PASS** |
| Address points | 19,951,156 | 19,951,156 | **100% PASS** |
| Interpolation ways | 78 | 78 | **100% PASS** |
| Admin polygons | 43,222 | 43,221 | 99.998% (3 freq diffs, net +1) |

## Results: Cross-version (Baseline vs Parallel, same PBF)

| Component | Baseline | Parallel | Status |
|---|---|---|---|
| Street ways | 3,312,673 | 3,312,673 | **100% PASS** |
| Address points | 19,951,156 | 19,951,156 | **100% PASS** |
| Interpolation ways | 78 | 78 | **100% PASS** |
| Admin (unique name\|level) | 37,034 | 37,034+ | **0 missing** (12 extras from cross-border) |

## Remaining 3 Admin Polygon Differences

### 1. Krefeld-Ost / Krefeld-Uerdingen (level 9) — ring name swap, net 0

A 7-vertex polygon (~1.5 sq meters) at the exact junction of two district boundaries.
Our build labels it "Krefeld-Ost"; osmium labels it "Krefeld-Uerdingen". Both are equally
valid — the point is on the boundary line itself. GPS accuracy (~3-5m) means no real query
would reliably land in this polygon.

### 2. Neuhaus (level 10) — extra micro-polygon, net +1

A 12-vertex polygon (~2.7 sq meters) at the edge of a "Neuhaus" boundary near Wolfsburg.
Our build returns "Neuhaus" for this area; osmium's build has no level-10 result here.
The level-8/9 results are identical. Arguably more correct since the location IS in Neuhaus.

### Practical Impact

All 3 differences affect a combined ~4 square meters of Earth's surface at boundary
junction points. No real-world GPS coordinate would reliably land in these areas.
**Zero practical impact on reverse geocoding.**

## Bugs Found and Fixed

### 1. String interleaving (commit 3984d21)
Parallel way processing pushed way names, building address strings, and interpolation
strings into a single `interned_strings` vector in interleaved processing order. The merge
code read them assuming grouped-by-type order, causing ~62% of way names to be swapped
with building address strings in any block containing mixed types.

### 2. Building address string corruption (commit d0b3540)
Building addresses stored housenumber+street with an embedded null separator:
`std::string(hn) + "\0" + std::string(street)`. But `std::string("x") + "\0"` produces
`std::string("x") + std::string("")` — the null terminator makes it an empty string.
Both housenumber and street fields ended up containing the full concatenated string,
corrupting ~16M building addresses in Germany.

### 3. Ring stitcher improvements (commits a5817ac, 1f24a5a, 028662a, e22af43)
- Backtracking at branch points (greedy algorithm picked wrong branch)
- Coordinate-based matching (osmium matches by coordinates, not node IDs)
- Split ways at shared internal nodes (segment-level assembly)

### 4. Closed-way admin polygons (commit cd9e361)
Osmium creates areas from both multipolygon relations AND standalone closed ways tagged
with boundary=administrative. Our parallel assembler only handled relations, missing ~87
closed-way admin boundaries in Germany.

### 5. Border-line and geometry filters (commit e1c0b75)
- Skip level-2 boundary-line relations (no ISO code) — these are lines between countries
- Self-intersection detection for assembled rings

## Journey: Admin Polygon Gap

| Stage | Parallel | Sequential | Gap |
|---|---|---|---|
| Pre node-ID fix (planet) | 931,963 | 943,638 | -11,675 |
| After node-ID fix | 43,178 | 43,221 | -43 |
| After backtracking | 43,179 | 43,221 | -42 |
| After coordinate matching | 43,192 | 43,221 | -29 |
| After split-at-shared-nodes | 43,193 | 43,221 | -28 |
| After closed-way support | 43,224 | 43,221 | +3 |
| After border-line filter | 43,222 | 43,221 | +1 |


Bash

git add builder/test/VALIDATION_REPORT.md && git commit -m "$(cat <<'EOF'
docs: add parallel assembly validation report

Documents the full validation of parallel admin assembly against both
the sequential osmium assembler and the pre-parallel baseline code.
100% match on ways, addresses, and interpolations. 99.998% match on
admin polygons with 3 remaining frequency differences affecting ~4 sq
meters total.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
EOF
)"

Commit validation report


[main 1622ab0] docs: add parallel assembly validation report
 1 file changed, 86 insertions(+)
 create mode 100644 builder/test/VALIDATION_REPORT.md


<system-reminder>This is a side question from the user. You must answer this question directly in a single response.

IMPORTANT CONTEXT:
- You are a separate, lightweight agent spawned to answer this one question
- The main agent is NOT interrupted - it continues working independently in the background
- You share the conversation context but are a completely separate instance
- Do NOT reference being interrupted or what you were "previously doing" - that framing is incorrect

CRITICAL CONSTRAINTS:
- You have NO tools available - you cannot read files, run commands, search, or take any actions
- This is a one-off response - there will be no follow-up turns
- You can ONLY provide information based on what you already know from the conversation context
- NEVER say things like "Let me try...", "I'll now...", "Let me check...", or promise to take any action
- If you don't know the answer, say so - do not offer to look it up or investigate

Simply answer the question with the information you have.</system-reminder>

what were the size differences between admin only vs address level vs house number for the index files for germany?


I don't have that data from this conversation. We never ran Germany builds with the different index modes (`--admin-only`, `--no-addresses`, full) and compared their output sizes. All the Germany builds in this session used the default full mode.

The only size data I have is for the full Germany build output files, e.g.:
- `street_ways.bin`: ~39MB
- `street_nodes.bin`: ~183MB
- `addr_points.bin`: ~319MB
- `admin_polygons.bin`: ~1MB
- `admin_vertices.bin`: ~101MB
- `strings.bin`: ~149MB (new code) / ~7.5MB (baseline)
- `geo_cells.bin`: ~195MB
- Total: ~1.1GB

The multi-output mode (`--multi-output`) and per-continent generation (`--continents`) were implemented but the size comparison across modes was listed as item #5 in the "What Needs Doing Next" list and was never executed.