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⚡ Bolt: Pre-compile Regex instances in spellchecker hot-path #636

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Merged
LeanBitLab merged 1 commit into from
Oct 9, 2026
Merged

⚡ Bolt: Pre-compile Regex instances in spellchecker hot-path #636

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3 changes: 3 additions & 0 deletions .jules/bolt.md
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Original file line number Diff line number Diff line change
Expand Up @@ -12,3 +12,6 @@
## 2024-05-18 - Pre-compile Regex in model importers
**Learning:** `TranslationModelImporter` and `HandwritingModelImporter` create `Regex` instances inside `detectLanguageCode` and `detectLanguageTag` methods, sometimes inside a loop parsing zip entries. This causes unnecessary overhead on every detection call.
**Action:** Extract frequently used `Regex` instances into `companion object`s as `private val`s to ensure they are compiled only once, reducing execution time and object allocation.
## 2024-05-18 - Pre-compile Regex in SpellCheckerSession
**Learning:** `AndroidWordLevelSpellCheckerSession` previously instantiated new `Regex` objects for every quote matching and punctuation splitting operation during `onGetSuggestionsInternal`, which is a highly invoked method on the spellchecker hot-path.
**Action:** Always extract frequently instantiated `Regex` objects from hot paths (like text replacement or splitting) into `companion object` private constants (e.g. `periodRegex`, `quotesStartRegex`) to reduce allocation and regex compilation overhead per keystroke.
15 changes: 9 additions & 6 deletions app/src/main/java/helium314/keyboard/latin/spellcheck/AndroidWordLevelSpellCheckerSession.kt
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Expand Up @@ -127,12 +127,12 @@ abstract class AndroidWordLevelSpellCheckerSession(
val locale = mLocale ?: return AndroidSpellCheckerService.getNotInDictEmptySuggestions(false)
var text = textInfo.text
.replace(AndroidSpellCheckerService.APOSTROPHE, AndroidSpellCheckerService.SINGLE_QUOTE)
.replace(Regex("^$quotesRegexp"), "")
.replace(Regex("$quotesRegexp$"), "")
.replace(quotesStartRegex, "")
.replace(quotesEndRegex, "")

val localeRegex = scriptToPunctuationRegexMap[locale.script()]
if (localeRegex != null) {
text = text.replace(Regex(localeRegex), "")
text = text.replace(localeRegex, "")
}

val cachedSuggestionsParams = mSuggestionsCache.getSuggestionsFromCache(text)
Expand All @@ -148,7 +148,7 @@ abstract class AndroidWordLevelSpellCheckerSession(
if (CHECKABILITY_CHECKABLE != checkability) {
val periodOnlyAtLastIndex = text.indexOf(Constants.CODE_PERIOD.toChar()) == (text.length - 1)
if (CHECKABILITY_CONTAINS_PERIOD == checkability) {
val splitText = text.split(Regex(Constants.REGEXP_PERIOD))
val splitText = text.split(periodRegex)
var allWordsAreValid = true
for (word in splitText) {
if (word.isNotEmpty() && !mService.isValidWord(locale, word) && !mService.isValidWord(locale, word.lowercase(locale))) {
Expand Down Expand Up @@ -218,8 +218,11 @@ abstract class AndroidWordLevelSpellCheckerSession(
val EMPTY_STRING_ARRAY = emptyArray<String>()

private const val quotesRegexp = "([\u0022\u0027\u0060\u00B4\u2018\u2019\u201C\u201D])"
private val scriptToPunctuationRegexMap = TreeMap<String, String>().apply {
put(ScriptUtils.SCRIPT_ARMENIAN, "(\u0028|\u0029|\u0027|\u2026|\u055E|\u055C|\u055B|\u055D|\u058A|\u2015|\u00AB|\u00BB|\u002C|\u0589|\u2024)")
private val quotesStartRegex = Regex("^$quotesRegexp")
private val quotesEndRegex = Regex("$quotesRegexp$")
private val periodRegex = Regex(Constants.REGEXP_PERIOD)
private val scriptToPunctuationRegexMap = TreeMap<String, Regex>().apply {
put(ScriptUtils.SCRIPT_ARMENIAN, Regex("(\u0028|\u0029|\u0027|\u2026|\u055E|\u055C|\u055B|\u055D|\u058A|\u2015|\u00AB|\u00BB|\u002C|\u0589|\u2024)"))
}

private const val CHECKABILITY_CHECKABLE = 0
Expand Down
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