tiennm99
dbf13d0094
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.
parser
Reads the .xls/.xlsx source spreadsheets in data/ and writes one SQLite
database per dataset.
go -C parser build -o bin/xlsxread ./cmd/xlsxread # compile
go -C parser test ./... # unit tests + the reader-fidelity suite
xlsxread build --schema parser/configs/<id>.yml --input data/<id> --output <db>
xlsxread audit --schema parser/configs/<id>.yml --input data/<id> --db <db>
This stage only produces a database. Verifying it against the expected row
count, compressing it and publishing it belong to assembler/, which compiles
this binary and drives it per dataset:
go -C assembler run ./cmd/assemble db
Layout
| path | role |
|---|---|
internal/reader |
spreadsheet reading; the only place that knows about file formats |
internal/ingest |
dataset policy — sheet selection, header skipping, blank rows, the build loop, and the 2016 per-sheet layout detection |
internal/transform |
ToAscii, score-regex parsing, row validation |
internal/schema |
the canonical 22-column table: DDL, INSERT, subject regexes |
internal/config |
per-dataset YAML parse rules |
internal/writer |
SQLite lifecycle and the stats block |
internal/audit |
source-vs-database SBD comparison |
The reader deliberately knows nothing about datasets: it reports every sheet and
every row verbatim. All policy lives in ingest. That split is what made the
reader independently verifiable against a hash oracle.
Behaviour worth knowing
ToAsciistrips combining marks in the literal range U+0300–U+036F rather than by Unicode category. That covers every Vietnamese diacritic and must stay identical totoAsciiinweb/src/lib/to-ascii.ts, or accent-insensitive search misses rows.- Gender is normalised to
Nam/Nữ; the Cần Thơ files write0/1instead and are translated. Anything else becomes NULL. - A score of
0is a real score — the candidate sat the paper and scored nothing — and is stored, not dropped. - Birth dates are stored as
dd/mm/yyyy. The Cần Thơ files' compactddmmyyis expanded; the century is always 19xx, since a 2016 candidate born later would have sat the exam under age.
This code began as a port of a Rust crate that occupied the same path, and was
gated on a field-by-field comparison against it. That comparison is over:
correctness against the source spreadsheets decides behaviour now, not
agreement with the old implementation. assemble verify is the comparator
that gated it, and still compares any two sets of built databases.
Verification
testdata/reader-fidelity-hashes.tsv holds a SHA-256 per input file over a
canonical dump of every cell of every sheet. It is frozen: the tool that
produced it no longer exists, so it cannot be regenerated. It still fails if
any single cell of any input file reads differently, which is what makes it
useful — cell rendering and sheet geometry are settled, and a change there is
a regression until proven otherwise. Dataset policy lives in ingest, so
fixing a layout never touches it.
A mismatch names the file but not the cell. cmd/dumpcells prints the stream
the hash is taken over, so two runs can be diffed:
go -C parser run ./cmd/dumpcells ../data/2017/an-giang.xls out.tsv
The assembler refuses to publish a database whose row count does not match the known figure, or whose artifact is under 90% of its usual size.