Update completion list logic

Author: fwcd

server/src/main/kotlin/org/javacs/kt/completion/Completions.kt

@@ -59,22 +59,22 @@ fun completions(file: CompiledFile, cursor: Int, index: SymbolIndex, config: Com
     val partial = findPartialIdentifier(file, cursor)
     LOG.debug("Looking for completions that match '{}'", partial)
 
-    var isIncomplete = false
     // TODO: Filter non-imported (i.e. the elementCompletions already found) and auto-import these when selected by the user
-    val items = (elementCompletionItems(file, cursor, config, partial) + indexCompletionItems(index, partial))
-            .ifEmpty { keywordCompletionItems(partial).also { isIncomplete = true } }
+    val elementItems = elementCompletionItems(file, cursor, config, partial)
+    val elementItemList = elementItems.take(MAX_COMPLETION_ITEMS).toList()
+    val items = (elementItemList.asSequence() + indexCompletionItems(index, partial)).ifEmpty { keywordCompletionItems(partial) }
     val itemList = items
         .take(MAX_COMPLETION_ITEMS)
         .toList()
         .onEachIndexed { i, item -> item.sortText = i.toString().padStart(2, '0') }
-    isIncomplete = isIncomplete || (itemList.size == MAX_COMPLETION_ITEMS)
+    val isIncomplete = itemList.size >= MAX_COMPLETION_ITEMS || elementItemList.isEmpty()
 
     return CompletionList(isIncomplete, itemList)
 }
 
 /** Finds completions in the symbol index. */
 private fun indexCompletionItems(index: SymbolIndex, partial: String): Sequence<CompletionItem> = index
-    .query(partial)
+    .query(partial, limit = MAX_COMPLETION_ITEMS)
     .map { CompletionItem().apply {
         label = it.fqName.shortName().toString()
         kind = when (it.kind) {

server/src/main/kotlin/org/javacs/kt/index/SymbolIndex.kt

@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
 import org.jetbrains.kotlin.name.FqName
 import org.javacs.kt.LOG
 import org.jetbrains.exposed.sql.Database
+import org.jetbrains.exposed.sql.SqlExpressionBuilder.like
 import org.jetbrains.exposed.sql.insert
 
 private object Symbols : Table() {
@@ -23,6 +24,7 @@ private object Symbols : Table() {
  */
 class SymbolIndex {
     private val db = Database.connect("jdbc:h2:mem:symbolindex;DB_CLOSE_DELAY=-1", "org.h2.Driver")
+    private var initialized = false
 
     init {
         transaction(db) {
@@ -31,6 +33,10 @@ class SymbolIndex {
     }
 
     fun update(module: ModuleDescriptor) {
+        // TODO: Remove this once a proper debounce mechanism (and ideally incremental updates) are in place.
+        if (initialized) return
+        initialized = true
+
         val started = System.currentTimeMillis()
         LOG.info("Updating symbol index...")
 
@@ -70,7 +76,7 @@ class SymbolIndex {
 
     fun query(prefix: String, limit: Int = 20): List<Symbol> = transaction(db) {
         Symbols
-            .selectAll()
+            .select { Symbols.shortName.like("$prefix%") }
             .limit(limit)
             .map { Symbol(FqName(it[Symbols.fqName]), Symbol.Kind.fromRaw(it[Symbols.kind])) }
     }