Files
thptqg/docs/system-architecture.md
T
tiennm99 219c7c6a69 fix(parser): read the two 2016 layouts that were column-shifted
Four of the 119 files in data/2016 publish one score column per subject
instead of a DIEM_THI sentence, and none of them was being read correctly.

The ĐH Công nghiệp Thực phẩm file puts a three-row ministry title block
above its header, so no header was recognised and the positional fallback
shifted every column by one: the serial number became so_bao_danh, the
exam number became ho_ten, the name became ngay_sinh, and the national ID
became the score cell. All 7,833 rows were unusable. The three ĐH Cần Thơ
files name an SBD column but no DIEM_THI, so they fell to the same
fallback: surname into ngay_sinh, given name into ten_cum_thi, birth date
into the score cell, and 12,152 candidates with no scores at all.

Both are now read by FormatSubjectColumns, which resolves identity and one
column per subject from the header. The header is searched for in the
first five rows, so a title block no longer hides it.

The Cần Thơ score columns are numbered rather than named. They follow the
order the exam was sat — each morning an essay paper, each afternoon a
multiple-choice one — which is what identifies them: columns 1/3/5/7
quantise to 0.25 and 2/4/6/8 do not, and each column's mean lands within
0.5 of the same subject's mean across the rest of the dataset. The
foreign language is filed under the subject its N1..N6 code names.

Gender now accepts the 0/1 encoding those files use: of the rows marked
1, 53% carry "Thị" in the name against 1% of those marked 0. Birth dates
in the compact ddmmyy form are expanded so the column holds one format.

A score of 0 is stored rather than dropped, recovering 302 real scores
that a JavaScript falsy check had been turning into NULL.

Row count falls by one, to 877,460: the removed row is the title line
"ĐƠN VỊ: / TRƯỜNG ĐẠI HỌC CÔNG NGHIỆP THỰC PHẨM TP. HỒ CHÍ MINH", which
had been stored as a student. The dataset has no duplicate exam numbers;
the three rows previously described as collapsing were that same file's
title and header lines being counted and then rejected.

Also drops behaviour that existed only to match the parser this one
replaced: the inert "SINH " header token, the untrimmed diem_thi cell, an
unreachable blank-row branch, and a cross-check test against a database
that can no longer exist. None of them changes output.

Verified by rebuilding both datasets: 877,460 and 861,068 rows, both
artifacts through the assembler's row and size guards, and the reader
fidelity suite unchanged across all 182 files.
2026-08-14 10:38:59 +07:00

7.7 KiB
Raw Blame History

System Architecture

Static site, no backend. The browser downloads a compressed SQLite file at boot and every query runs locally via sql.js (SQLite compiled to WebAssembly).

One frontend, one parser, one schema, two datasets.

Data flow

Each stage is a directory; data/ and _site/ are the stores they hand work through. assembler/ sequences everything from the parser onwards.

        ▲  crawler/   (Go — manual refresh only, never part of the build)
data/<id>/*.xls(x)
        │
        ▼  parser/    (Go, one binary, one config per dataset)
   .build/public/db/<id>.db
        │
        ▼  assembler/ — row count must match datasets.json, then gzip
   .build/public/db/<id>.db.gz      (the raw .db does not survive)
        │
        ▼  assembler/ → vite build   (root = web/, publicDir = .build/public)
   web/dist/
        │
        ▼  assembler/ — one index.html per dataset; every database must be present
   _site/   →  GitHub Pages
        │
        ▼  browser
   sql.js (WASM) opens the .db → queries run client-side

The dataset id

One identifier ties the whole pipeline together:

data/2017/  →  parser/configs/2017.yml  →  db/2017.db.gz  →  /thptqg/2017/

datasets.json at the repository root declares the ids once, with the row count and artifact size the assembler enforces. It is JSON rather than a module because the assembler is a Go program and the Vite app is not, and JSON is the only format both parse without a dependency.

Presentation — titles, labels, search examples, SQL presets — stays in web/src/datasets.js, keyed by id. That file cross-checks the two: a registry entry with no content, or content for a dataset that was never built, throws at module load rather than rendering a page with no title or a link to a database that does not exist.

id Exam Rows Source
2016 2016 877,460 dtnt.bacninh.edu.vn
2017 2017 861,068 baotintuc.vn

Full source URLs are in data-pipeline; the web footer links to them per dataset.

Canonical schema

Defined once in parser/internal/schema/schema.go — DDL, INSERT, column order and the 16 subject regexes. The two YAML configs carry no SQL at all, only per-dataset parse rules. Config parsing sets KnownFields(true), so a leftover schema: block fails loudly instead of looking effective while schema.go drives the build.

CREATE TABLE student (
  so_bao_danh   TEXT PRIMARY KEY,   -- 2017: 8 digits; 2016: 9 digits or a
                                    -- 2-4 letter cluster code then digits
  ho_ten        TEXT NOT NULL,
  ho_ten_ascii  TEXT NOT NULL,      -- NFD-stripped lowercase, for accent-insensitive search
  ngay_sinh     TEXT,               -- dd/mm/yyyy
  ten_cum_thi   TEXT,               -- 2016 only
  gioi_tinh     TEXT,               -- 2016 only
  toan, ngu_van, vat_ly, hoa_hoc, sinh_hoc, khtn,
  lich_su, dia_ly, gdcd, khxh,
  tieng_anh, tieng_phap, tieng_nga, tieng_duc, tieng_nhat, tieng_trung   REAL
);
CREATE INDEX idx_ho_ten       ON student(ho_ten);
CREATE INDEX idx_ho_ten_ascii ON student(ho_ten_ascii);
CREATE INDEX idx_ten_cum_thi  ON student(ten_cum_thi) WHERE ten_cum_thi IS NOT NULL;

Every dataset gets all 22 columns; ones it has no data for are NULL, costing about a byte per row. khtn, khxh and gdcd are empty on 2016; ten_cum_thi and gioi_tinh are empty on 2017.

idx_ten_cum_thi is partial, so it holds zero entries where the column is always NULL.

Routing

URLs are flat, one segment per dataset, and the segment is the id:

/thptqg/            hub
/thptqg/2016/
/thptqg/2017/

web/src/router.js is an exact match on that segment. The nested form used before (/thptqg/2017/old/) would have needed longest-prefix matching, since it also starts with /thptqg/2017/. Both of those URLs addressed the two removed 2017 archives, so the rewrite that kept them working has gone with them; they fall through to the hub like any other unknown path.

A single Vite build emits one index.html. Because base is absolute (/thptqg/), that file references /thptqg/assets/... regardless of the directory it is served from, so the assemble step copies it to every route and each URL is a real static file. No SPA 404-fallback redirect is used — the usual hack rewrites URLs and would interfere with the deep links.

Serving both exam years without branching

No component contains a per-dataset conditional. Two mechanisms do the work:

  • All-NULL columns are hidden. score-table.jsx drops any column where every row in the result set is NULL, so 2016 rows surface Cụm thi / GT / Đức / Nhật and 2017 rows surface KHTN / KHXH / GDCD / Nga.
  • Incomplete admission blocks are skipped. computeBlocks() only returns a block when the student has all three subjects, so one block list covers both years: GDCD blocks self-exclude on 2016, German and Japanese blocks self-exclude wherever those languages were not sat.

Anything genuinely per-dataset — title, source, database size, search examples, SQL presets — lives in web/src/datasets.js.

Exam ID formats

web/src/lib/query-mode.js decides whether a query is an exam ID or a name, and is shared by App.jsx and search-form.jsx (they previously held separate copies and had drifted apart on exactly this rule).

Form Example Where
8 digits 49008235 2017 — first two digits are the province
9 digits with leading zero 017006021 2016
2-4 letters then digits BAL000001 2016 — exam cluster code

The letter-prefixed form is the majority case for 2016: 624,424 of 877,460 candidates (71.2%); the remaining 253,036 are all 9-digit. Letter prefixes are upper-cased before lookup, so bal000001 resolves.

Score tiers

Six-level ladder in scoreTier() (web/src/lib/admission-blocks.js), paired with a symbol so meaning is never colour-only.

Tier Range Vietnamese
common ≤ 1 Điểm liệt
uncommon < 5 Chưa đạt
rare 5–6.5 Trung bình
epic 6.5–8 Khá
legendary 8–9 Giỏi
prismatic 9–10 Xuất sắc

Admission blocks

Vietnamese universities admit on three-subject combinations (khối thi). web/src/lib/admission-blocks.js lists the blocks computable from this schema (A00–A11, B00–B08, C00–C20, D01–D15, plus D05/D06 for German and Japanese). computeBlocks(student) returns those where all three scores exist, sorted by total descending.

Design decisions

Concern Choice Rationale
Storage Static SQLite file No backend; the datasets are frozen
Compression gzip in CI, DecompressionStream in the browser Native API, no extra library
WASM hosting sql.js.org CDN Smaller self-hosted artifact
Diacritics search Pre-computed ho_ten_ascii LOWER(REPLACE(...)) at query time defeats the index
SQL safety Leading-keyword allowlist sql.js is in-memory so writes cannot persist; the allowlist prevents confusion
Row caps 100 (lookup), 1000 (SQL) Keeps DOM render sizes reasonable
Routing Hand-rolled, ~15 lines Three static routes do not justify a router dependency

Risks and limitations

  • Database size. 44–48 MB gzipped per dataset; slow links wait, mitigated by a progress bar.
  • Browser memory. The full database lives in RAM; older mobile devices may run out.
  • sql.js.org dependency. If that CDN is unreachable, the WASM fails to load. Self-hosting sql-wasm.wasm and updating SQL_WASM_URL in web/src/hooks/use-sqlite.js is the fix.
  • Excel format drift. A new source file with an unseen header layout needs a new branch in parser/internal/ingest/detect2016.go or a new config.