Files
SubMiner/src/core/services/frequency-dictionary.ts

310 lines
8.6 KiB
TypeScript

import * as fs from 'node:fs/promises';
import * as path from 'node:path';
export interface FrequencyDictionaryLookupOptions {
searchPaths: string[];
log: (message: string) => void;
}
type FrequencyDictionaryMode = 'occurrence-based' | 'rank-based';
interface FrequencyDictionaryEntry {
rank: number;
term: string;
}
const FREQUENCY_BANK_FILE_GLOB = /^term_meta_bank_.*\.json$/;
const NOOP_LOOKUP = (): null => null;
const ENTRY_YIELD_INTERVAL = 5000;
function isErrorCode(error: unknown, code: string): boolean {
return Boolean(error && typeof error === 'object' && (error as { code?: unknown }).code === code);
}
async function yieldToEventLoop(): Promise<void> {
await new Promise<void>((resolve) => {
setImmediate(resolve);
});
}
function normalizeFrequencyTerm(value: string): string {
return value.trim().toLowerCase();
}
async function readDictionaryMetadata(
dictionaryPath: string,
log: (message: string) => void,
): Promise<{ title: string | null; frequencyMode: FrequencyDictionaryMode | null }> {
const indexPath = path.join(dictionaryPath, 'index.json');
let rawText: string;
try {
rawText = await fs.readFile(indexPath, 'utf-8');
} catch (error) {
if (isErrorCode(error, 'ENOENT')) {
return { title: null, frequencyMode: null };
}
log(`Failed to read frequency dictionary index ${indexPath}: ${String(error)}`);
return { title: null, frequencyMode: null };
}
let rawIndex: unknown;
try {
rawIndex = JSON.parse(rawText) as unknown;
} catch {
log(`Failed to parse frequency dictionary index as JSON: ${indexPath}`);
return { title: null, frequencyMode: null };
}
if (!rawIndex || typeof rawIndex !== 'object') {
return { title: null, frequencyMode: null };
}
const titleRaw = (rawIndex as { title?: unknown }).title;
const frequencyModeRaw = (rawIndex as { frequencyMode?: unknown }).frequencyMode;
return {
title: typeof titleRaw === 'string' && titleRaw.trim().length > 0 ? titleRaw.trim() : null,
frequencyMode:
frequencyModeRaw === 'occurrence-based' || frequencyModeRaw === 'rank-based'
? frequencyModeRaw
: null,
};
}
function parsePositiveFrequencyString(value: string): number | null {
const trimmed = value.trim();
if (!trimmed) {
return null;
}
const numericMatch = trimmed.match(/[+-]?(\d+(\.\d*)?|\.\d+)([eE][+-]?\d+)?/)?.[0];
if (!numericMatch) {
return null;
}
const parsed = Number.parseFloat(numericMatch);
if (!Number.isFinite(parsed) || parsed <= 0) {
return null;
}
const normalized = Math.floor(parsed);
if (!Number.isFinite(normalized) || normalized <= 0) {
return null;
}
return normalized;
}
function parsePositiveFrequencyNumber(value: unknown): number | null {
if (typeof value === 'number') {
if (!Number.isFinite(value) || value <= 0) return null;
return Math.floor(value);
}
if (typeof value === 'string') {
return parsePositiveFrequencyString(value);
}
return null;
}
function parseDisplayFrequencyNumber(value: unknown): number | null {
if (typeof value === 'string') {
const leadingDigits = value.trim().match(/^\d+/)?.[0];
if (!leadingDigits) {
return null;
}
const parsed = Number.parseInt(leadingDigits, 10);
return Number.isFinite(parsed) && parsed > 0 ? parsed : null;
}
return parsePositiveFrequencyNumber(value);
}
function extractFrequencyDisplayValue(meta: unknown): number | null {
if (!meta || typeof meta !== 'object') return null;
const frequency = (meta as { frequency?: unknown }).frequency;
if (!frequency || typeof frequency !== 'object') return null;
const rawValue = (frequency as { value?: unknown }).value;
const parsedRawValue = parsePositiveFrequencyNumber(rawValue);
const displayValue = (frequency as { displayValue?: unknown }).displayValue;
const parsedDisplayValue = parseDisplayFrequencyNumber(displayValue);
if (parsedDisplayValue !== null) {
return parsedDisplayValue;
}
return parsedRawValue;
}
function asFrequencyDictionaryEntry(entry: unknown): FrequencyDictionaryEntry | null {
if (!Array.isArray(entry) || entry.length < 3) {
return null;
}
const [term, _id, meta] = entry as [unknown, unknown, unknown];
if (typeof term !== 'string') {
return null;
}
const frequency = extractFrequencyDisplayValue(meta);
if (frequency === null) return null;
const normalizedTerm = normalizeFrequencyTerm(term);
if (!normalizedTerm) return null;
return {
term: normalizedTerm,
rank: frequency,
};
}
async function addEntriesToMap(
rawEntries: unknown,
terms: Map<string, number>,
): Promise<{ duplicateCount: number }> {
if (!Array.isArray(rawEntries)) {
return { duplicateCount: 0 };
}
let duplicateCount = 0;
let processedCount = 0;
for (const rawEntry of rawEntries) {
processedCount += 1;
if (processedCount % ENTRY_YIELD_INTERVAL === 0) {
await yieldToEventLoop();
}
const entry = asFrequencyDictionaryEntry(rawEntry);
if (!entry) {
continue;
}
const currentRank = terms.get(entry.term);
if (currentRank === undefined || entry.rank < currentRank) {
terms.set(entry.term, entry.rank);
continue;
}
duplicateCount += 1;
}
return { duplicateCount };
}
async function collectDictionaryFromPath(
dictionaryPath: string,
log: (message: string) => void,
): Promise<Map<string, number>> {
const terms = new Map<string, number>();
const metadata = await readDictionaryMetadata(dictionaryPath, log);
if (metadata.frequencyMode === 'occurrence-based') {
log(
`Skipping occurrence-based frequency dictionary ${
metadata.title ?? dictionaryPath
}; SubMiner frequency tags require rank-based values.`,
);
return terms;
}
let fileNames: string[];
try {
fileNames = await fs.readdir(dictionaryPath);
} catch (error) {
log(`Failed to read frequency dictionary directory ${dictionaryPath}: ${String(error)}`);
return terms;
}
const bankFiles = fileNames.filter((name) => FREQUENCY_BANK_FILE_GLOB.test(name)).sort();
if (bankFiles.length === 0) {
return terms;
}
for (const bankFile of bankFiles) {
const bankPath = path.join(dictionaryPath, bankFile);
let rawText: string;
try {
rawText = await fs.readFile(bankPath, 'utf-8');
} catch {
log(`Failed to read frequency dictionary file ${bankPath}`);
continue;
}
let rawEntries: unknown;
try {
await yieldToEventLoop();
rawEntries = JSON.parse(rawText) as unknown;
} catch {
log(`Failed to parse frequency dictionary file as JSON: ${bankPath}`);
continue;
}
const beforeSize = terms.size;
const { duplicateCount } = await addEntriesToMap(rawEntries, terms);
if (duplicateCount > 0) {
log(
`Frequency dictionary ignored ${duplicateCount} duplicate term entr${
duplicateCount === 1 ? 'y' : 'ies'
} in ${bankPath} (kept strongest rank per term).`,
);
}
if (terms.size === beforeSize) {
log(`Frequency dictionary file contained no extractable entries: ${bankPath}`);
}
}
return terms;
}
export async function createFrequencyDictionaryLookup(
options: FrequencyDictionaryLookupOptions,
): Promise<(term: string) => number | null> {
const attemptedPaths: string[] = [];
let foundDictionaryPathCount = 0;
for (const dictionaryPath of options.searchPaths) {
attemptedPaths.push(dictionaryPath);
let isDirectory = false;
try {
isDirectory = (await fs.stat(dictionaryPath)).isDirectory();
} catch (error) {
if (isErrorCode(error, 'ENOENT')) {
continue;
}
options.log(
`Failed to inspect frequency dictionary path ${dictionaryPath}: ${String(error)}`,
);
continue;
}
if (!isDirectory) {
continue;
}
foundDictionaryPathCount += 1;
const terms = await collectDictionaryFromPath(dictionaryPath, options.log);
if (terms.size > 0) {
options.log(`Frequency dictionary loaded from ${dictionaryPath} (${terms.size} entries)`);
return (term: string): number | null => {
const normalized = normalizeFrequencyTerm(term);
if (!normalized) return null;
return terms.get(normalized) ?? null;
};
}
options.log(
`Frequency dictionary directory exists but contains no readable term_meta_bank_*.json files: ${dictionaryPath}`,
);
}
options.log(
`Frequency dictionary not found. Searched ${attemptedPaths.length} candidate path(s): ${attemptedPaths.join(', ')}`,
);
if (foundDictionaryPathCount > 0) {
options.log(
'Frequency dictionary directories found, but no usable term_meta_bank_*.json files were loaded.',
);
}
return NOOP_LOOKUP;
}