Three reversals had landed without the documentation following them, so the
docs described a pipeline that compresses its output, a schema with three
secondary indexes, and a browser that re-downloads the file on every visit.
None of those are true any more.
- Compression: the assembler stopped producing .gz when the databases began
shipping as .sqlite3. The deployment guide's "why no uncompressed database
can ship" section explained a guard that now exists for the opposite reason
— to keep .db, .gz and journals out, so .sqlite3 stays the only name.
- Indexes: the architecture printed a DDL with three CREATE INDEX statements
and a paragraph on the partial one. schema.go carries none.
- Persistence: "the download is repeated every visit ... has not been done"
was listed as an open risk after db-cache.js closed it. Replaced with the
ETag flow, the offline fallback, and the risks that did replace it.
Measured both transfers rather than scaling one from the other, which would
have been wrong: 2016 is 142 MB stored and 31 MB delivered, 2017 is 119 MB and
36 MB. The smaller database is the larger download, so neither figure follows
from the stored size.
Also corrects a CHUNK_BYTES reference to a module that no longer exists, the
238-289 MB per-dataset figure, two paths to web/src/lib/datasets.js, and the
CI step list, which omitted npm test and the post-deploy header check.
The two code comments that said the same outdated things go with them.
Reading the file where it lay never worked well enough. Two costs were
structural rather than bugs: reads are serial, because the worker uses
synchronous XHR, so a name search touching 390 pages waited 17 seconds
to move 608 KB — roughly one request per result row, which no page size
removes — and the first visitor after each deploy waited ~26 seconds for
the CDN to fill its cache with a 288 MB object.
The browser now downloads the whole database once and queries it in
memory with sql.js. A dataset page is gated behind that: the gate states
what it will cost, in transfer and in memory, and offers only the
download, because there is nothing to show without it.
Dropping the structures that existed to make range-request queries
index-driven halved the file. name_word carried one row per word of
every name, about 3.5 million of them, and with the partial score
indexes it was more than half of what every visitor would now download.
Measured on rebuilt databases: 2016 went 288.6 -> 142.5 MB (31 MB
gzipped on the wire), 2017 237.7 -> 119.3 MB, both with row counts and
audits unchanged. Queries on the result: an exam number is immediate, a
name scans all 877,460 rows in about 240 ms.
Alternatives were measured before choosing this. sqlite-wasm-http sizes
files from a HEAD Content-Length with no override, so on a host that
gzips it silently uses the compressed size. DuckDB-WASM ships 32-37 MB
of WebAssembly before its Parquet extension, more than this whole
download. Static pre-generated shards are the most robust option but
cannot answer arbitrary SQL, and cannot stop early the way LIMIT does.
The published name loses its chunk index, the byte budgets and the SQL
consent modal go with the range reads that made them necessary, and the
docs no longer describe a design the site does not use.
The 1 KiB page size optimised for the fewest bytes per seeked row. The
first real measurement says that is the wrong quantity: a name search
made 390 requests for 608 KB and took 16.9 seconds. The worker reads
with synchronous XHR (lazyFile.ts opens every GET with async=false), so
requests are strictly serial at roughly 40 ms each, and 390 x 40 ms is
the whole of that time. The bytes were never the problem.
Four times the page size means a quarter of the pages for the same
scan, and a shallower b-tree for each of the 100 result rows the search
seeks individually. It also costs about 5% less file.
Every .ts becomes .js, every lang="ts" becomes lang-less, and the type
declarations go with them: types.ts held nothing but types, so it is
deleted outright.
Tooling follows. typescript, svelte-check, typescript-eslint and
@types/sql.js are uninstalled; tsconfig.json becomes jsconfig.json, which
still extends the generated SvelteKit config so $lib and $app resolve in
an editor; `npm run lint` is now ESLint alone, and CI's comment about it
covering the type check goes too.
What this gives up, stated plainly: a mistyped column name like
row.nguvan used to fail the build and now renders blank, and the
datasets.json-to-CONTENT cross-check is back to throwing at module load
rather than at compile time. The runtime guard for the latter is still
there and still throws loudly.
Two mechanical notes. The svelte/no-navigation-without-resolve rule
started flagging the footer's source link, which points at an off-site
article — without type information the rule can no longer tell an
external URL from a route, so that one line carries a disable comment.
And Vitest's include pattern had to follow the tests to .js.
Lint, 25 tests and the build all pass.
The browser fetches this file one page per HTTP request, so the page size
is the granularity of every read. At SQLite's 4 KiB default a row reached
by an index seek dragged 4 KB across the network; at 1 KiB it drags 1 KB.
A name search returns up to 100 scattered rows, so its row fetches fall
from about 400 KB to about 100 KB.
Measured on the rebuilt 2016 file: 6.3 rows share a page where 27 did.
The index walks are sequential and unaffected in bytes — the library's
read-ahead already collapses those into few requests.
Cost is 4% file size: 2016 288.6 -> 302.4 MB, 2017 237.7 -> 247.3 MB,
the site 528 -> 552 MB against the 1 GB GitHub Pages limit. Both
sql.js-httpvfs and sqlite-wasm-http recommend this page size.
The PRAGMA has to run before the DDL, since a page size is fixed once a
table exists, and requestChunkSize on the client has to match or every
page read spans two requests.
Row counts unchanged and through the assembler guards; query plans
re-checked and still index-driven on the rebuilt files.
The browser downloaded 45 MB of gzipped SQLite before it could answer
anything. Now sql.js-httpvfs asks for the pages a query touches and the
databases ship uncompressed as <id>.sqlite3 — a byte range of a gzip
stream is not a byte range of a database.
That only works if every query the site issues is index-driven, and
measured against the real 2016 file, most were not:
so_bao_danh = ? SEARCH via PK ~20 KB
ho_ten_ascii LIKE '%x%' SCAN 127 MB
ho_ten_ascii LIKE 'x%' SCAN 127 MB
COUNT(*) covering index scan 20 MB
ORDER BY toan DESC LIMIT 10 SCAN + temp b-tree 127 MB
Prefix LIKE scans because SQLite's LIKE optimisation needs a NOCASE
index; a range comparison does use the index. So the schema changed to
suit the access pattern rather than the search changing to suit the
schema.
name_word holds one row per word of each name, WITHOUT ROWID so the
table is the index, carrying ho_ten_ascii so a multi-word query is
resolved inside a single b-tree. name_word_freq says which word of a
query is rarest — the vocabulary is 4,397 words across 2.87M entries, so
"buu loc" seeks on 287 entries rather than walking the 300,000 that
"thi" would. Searching by any word of a name survives, at a few hundred
KB a query.
idx_ho_ten and idx_ho_ten_ascii are gone: no plan could use either.
Partial indexes on toan, khtn and khxh cost 12 MB and keep the SQL
presets off a full scan. The footer's candidate count now comes from
datasets.json instead of COUNT(*).
2016 grows 223.5 MB to 288.6 MB, 2017 162.7 MB to 237.7 MB, and the site
is 528 MB against the 1 GB GitHub Pages limit. Row counts are unchanged.
The SQL tab is the one place a user can still write a query that reads
the whole table, so it asks before it opens, runs under a byte budget
that stops a runaway query, and shows what each query actually fetched.
Verified: row counts through the assembler guards, every app query
index-driven under EXPLAIN QUERY PLAN, and GitHub Pages returning 206
with a correct Content-Range. Not verified in a browser — this machine
has none — and the library refuses to open a file the host compresses,
so the deployed response headers need a look.
The app was a single-entry React SPA: one index.html that the assembler
copied to every dataset path, with a hand-rolled router resolving the
dataset from window.location and the title patched in at runtime because
one file had to serve every route.
SvelteKit prerenders a real page per route instead. The entry generator
in routes/[dataset]/+page.ts reads the same datasets.json the assembler
does, so the set of pages and the set of databases cannot drift apart,
and each dataset page ships its own <title> and description.
Everything framework-free moved across unchanged in behaviour and became
typed: the admission blocks, subject list, query classifier and SQL
presets. `Student` now mirrors the 22-column table, so a mistyped column
name fails the build rather than rendering blank.
Tailwind replaces the stylesheet. Theme tokens are CSS variables, which
keeps dark mode a single block of overrides rather than a `dark:` variant
on every class. The score tiers stay hand-written CSS: the class is
chosen at runtime from a score, and no utility generator can see that.
Adds the tests the frontend never had, over the three modules where a
silent wrong answer is possible — most importantly that toAscii here
folds exactly as ToAscii does in the parser, which is what makes
accent-insensitive search find anything.
The assembler stops copying index.html per dataset and checks that the
build prerendered each one instead. The database presence, raw-artifact
and idempotence guards are untouched.
Verified: 25 tests, ESLint and svelte-check clean, and a full
`assemble site` producing /thptqg/, /thptqg/2016/, /thptqg/2017/ and
404.html with absolute asset URLs. Not verified in a browser — this
machine has none.
govulncheck fails the pipeline on GO-2026-6088: encoding/xml decodes
without a recursion depth guard, reachable from excelize's OpenFile,
GetRows and GetSheetList and from buildCRFixups directly. The parser is
fed spreadsheets downloaded over the network by the crawler, so the path
is real.
Raising the go directive to 1.26.6 in all three modules puts the fix
below every build rather than leaving it to whichever patch release the
runner happens to install.
govulncheck is clean on all three modules, and every suite passes on the
new toolchain — including the reader fidelity sweep, which matters here
because buildCRFixups depends on how encoding/xml normalises line endings.
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.
Comments across the tree justified the code by pointing at a Rust
implementation that is no longer in the repository, citing files and line
numbers (config.rs:132, schema.rs:26-54, reader.rs:42) that cannot be
opened, plus crates and datasets that are equally gone. A reader could not
check any of it.
Every invariant those comments carried is kept and restated so it stands on
its own: the bytewise sort that decides which row survives a duplicate exam
number, the literal U+0300..U+036F range that must match the site's toAscii,
the trailing space in "SINH ", the BIFF and shared-string corrections, the
VACUUM-after-COMMIT rule, the deploy-from-main guard.
The reader's contract is now anchored to the frozen oracle in
parser/testdata, which still exists and is still checked, rather than to the
tool that originally produced it.
TestDDLMatchesRust becomes TestDDLIsFrozen: it compares against a copy of
the DDL inside the test and never read schema.rs, so both the name and the
failure message were misleading.
ToAscii no longer claims the d-replacement must precede lowercasing. Both
cases map to 'd' and ToLower runs last, so the order has no effect.
The pipeline is now Go outside web/. differential-parity.mjs becomes
assembler/internal/verify, reachable as `assemble verify A B`. The port fixed a
real weakness: the JavaScript hashed each row's fields joined bare, so a value
shifted across a column boundary produced the same digest. A test now pins that.
The hub still rendered "Phiên bản cũ của trang 2017" above a permanently empty
list — it split datasets on id.includes("old"), and both such datasets are gone.
The heading and the filter are removed. index.html titled every page "THPT QG
2017", including 2016 and the hub, because one file is copied to every route;
the static title is now neutral and the app sets the dataset's own.
Dead code removed: the isOld2/containsOld branches in the stats block, which
only 2017-old2 could ever reach; SUBJECT_LABELS, DATASET_IDS and the unread
`short` subject field; an unused vite.svg and a favicon link to a file that
never existed; two unused CSS rules and --shadow-sm; site.Paths.Root.
Corrected comments that were confidently wrong rather than merely stale: the
reader claimed to be row-streaming when both implementations decode the whole
workbook into memory first, and the fidelity oracle still spoke of 299 input
files when it covers 182. Candidate counts in the hub now derive from
datasets.json instead of being written a second time as prose.
plans/ is emptied. The parity report it held was cited by docs/data-pipeline.md,
so the evidence that the recovered foreign-language scores are real — not the
citation, the four arguments themselves — is now inline there.
Verified: 2017 rebuilt after the writer change hashes identically to the build
before it.
The repository now reads as the pipeline it is: crawler fetches, parser
converts, assembler verifies and publishes, with data/ and web/ as the stores
they hand work through. go-parser is renamed parser now that there is no other.
The assembler replaces build-db.js and assemble-site.js. It compiles the
parser, builds and verifies each database, compresses it, runs the Vite build
and assembles _site — one command, and the only place that knows the order.
It also closes a real hole: nothing previously asserted that a database reached
the site. An empty staging directory assembled happily, so every page rendered,
every query 404d and CI stayed green. The row-count and size guards could not
catch that, since they only run when a database was built at all.
Removing Node from the root forced the dataset list out of web/src/datasets.js,
which the assembler cannot import. datasets.json is now the registry both sides
read — JSON because Go and the browser both parse it without a dependency —
while presentation stays in the web app, keyed by id and cross-checked against
the registry so a half-added dataset fails instead of half-working.
Guards verified by making each one fail: a missing database, and an expected
row count one higher than the truth.
The Go parser has matched the Rust one field-by-field across all four datasets,
so the Rust crate is retired and CI builds the Go binary instead.
crawl-baotintuc.js moves to go-parser/scripts/ — it is the only mechanism for
refreshing data/2017 and has a documented runbook. check-duplicates.js and
diff-datasets.js are dropped: both had been broken since before the repo was
unified, and neither had a caller. db-stats.js and verify-parity.js are dropped
as superseded by differential-parity.mjs, which compares more and cannot
silently skip a dataset.
The reader-fidelity oracle is kept and marked frozen. It was produced by the
Rust reader so it can no longer be regenerated, but it still fails if any single
cell of any of the 299 input files reads differently.
Source comments cite the original Rust by file and line; those paths resolve at
tag pre-go-parser-removal, recorded in go-parser/README.md.
Adds go-parser/, a Go reimplementation of the xlsxread parser, verified
byte-for-byte against the Rust original before any cutover.
Reader fidelity is exact across all 299 input files: the canonical cell dump
of every sheet matches calamine's, locked in as a test against a committed
hash oracle. Reaching that required replacing extrame/xls, which corrupted
69% of cells and dropped a further 28% on the BIFF corpus, with pbnjay/grate;
correcting excelize's number-format application and trailing-cell trimming;
restoring carriage returns that XML line-ending normalisation strips from
2,233 ten_cum_thi values; and gating numeric re-rendering on cell type so
shared strings that merely look numeric keep their leading zeros.
The differential gate compares both parsers over all four datasets:
3,265,641 rows with identical full-table SHA-256, identical per-column
non-NULL counts, identical schema metadata and identical stdout.
Config moves from TOML to YAML for both parsers, so they keep reading the
same files and the gate stays meaningful. Verified by rebuilding 2016 and
2017-old2 with Rust under the new configs and matching the recorded counts.
build-db.js now refuses to publish a database whose row count does not match
the known figure, closing a path where an under-producing parser could ship a
truncated public dataset with green CI. The deploy workflow gains a
pull_request trigger and guards deploy to main, so branch verification can no
longer publish to production.
The docs still described two standalone projects with separate frontends,
separate parsers and three Vite variants. Rewritten around what the repo now
is, merging both projects' copies rather than keeping one and discarding the
other — deployment-guide.md and system-architecture.md existed in both and
documented different pipelines.
project-overview.md goal, scope, constraints, the four datasets, history
system-architecture.md data flow, canonical schema, routing, how one
frontend serves both exam years without branching
data-pipeline.md per-dataset Excel formats, the three 2016 layouts,
overflow-sheet gotcha, expected row counts
deployment-guide.md the single-build workflow, adding a dataset,
why no uncompressed database can ship
Records the release gate in plans/reports/parser-parity-result.md: row counts,
all 18 pre-existing per-column non-NULL counts and the deterministic student
samples are identical across all four datasets, against databases decompressed
from the exact bytes the pipeline publishes. The 1,691 recovered
foreign-language scores are documented with the evidence they are real.
Also drops a machine-specific absolute path from a comment in
format_detect_2016.rs. The build-database.js citations there are kept: that
file no longer exists in this repo, but the references explain why several
parsing rules look arbitrary.
The repo held two near-duplicate projects. 2016/ and 2017/ each carried their
own React frontend, their own copy of the same Rust crate, and their own
package manager setup. 2016/tools/sync-from-thptqg2017.sh existed purely to
copy the parser source between them.
New layout:
index.html + src/ the 2017 frontend, now the only one
data/<id>/ 2016, 2017, 2017-old, 2017-old2
parser/ the single Rust crate, configs renamed to <id>.toml
docs/ both projects' docs, 2016 copies suffixed -2016-legacy
pending the merge pass
<id> is now one identifier end to end: data/<id>/ feeds parser/configs/<id>.toml
and produces db/<id>.db.gz.
pnpm gives way to npm. pnpm-workspace.yaml existed only to whitelist
better-sqlite3's native build, which npm permits by default, so it has no
equivalent and is simply gone. Lockfiles cannot be converted; package-lock.json
is generated fresh. The migration direction is safe — pnpm's strict layout
forbids phantom dependencies, so anything that resolved under pnpm resolves
under npm's flat tree.
Adds parser/scripts/build-db.js and src/datasets.js: the four dataset IDs are
declared once and read by both the build tooling and (from the next phase) the
frontend.
Follow-on fixes the move made necessary:
- eslint's Node-globals override pointed at scripts/, now parser/scripts/
- crawl-baotintuc.js wrote to <root>/data, now data/2017
- golden tests loaded configs by their old thptqg*-data.toml names
Drops the #[ignore]d Rust-vs-Node golden test. It shelled out to pnpm to run
scripts/build-database.js, a file removed when the parser was ported to Rust,
so it could never pass. check-duplicates.js and diff-datasets.js were already
broken before this change and are annotated as such rather than half-fixed.
63 Rust tests pass and clippy is clean from the new location.
tiennm99