Initial commit

table.c

@@ -0,0 +1,173 @@
+#include <stdlib.h>
+#include <string.h>
+
+#include "memory.h"
+#include "object.h"
+#include "table.h"
+#include "value.h"
+
+#define TABLE_MAX_LOAD 0.75
+
+void initTable(Table* table)
+{
+    table->count = 0;
+    table->capacity = 0;
+    table->entries = nullptr;
+}
+
+void freeTable(Table* table)
+{
+    FREE_ARRAY(Entry, table->entries, table->capacity);
+    initTable(table);
+}
+
+static Entry* findEntry(Entry* entries, int capacity, ObjString* key)
+{
+    auto index = key->hash & (capacity - 1);
+    Entry* tombstone = nullptr;
+
+    for (;;) {
+        Entry* entry = &entries[index];
+        if (entry->key == nullptr) {
+            if (IS_NIL(entry->value)) {
+                return tombstone != nullptr ? tombstone : entry;
+            } else {
+                if (tombstone == nullptr) {
+                    tombstone = entry;
+                }
+            }
+        } else if (entry->key == key) {
+            return entry;
+        }
+
+        index = (index + 1) & (capacity - 1);
+    }
+}
+
+bool tableGet(Table* table, ObjString* key, Value* value)
+{
+    if (table->count == 0) {
+        return false;
+    }
+
+    Entry* entry = findEntry(table->entries, table->capacity, key);
+    if (entry->key == nullptr) {
+        return false;
+    }
+
+    *value = entry->value;
+    return true;
+}
+
+static void adjustCapacity(Table* table, int capacity)
+{
+    Entry* entries = ALLOCATE(Entry, capacity);
+    for (auto i = 0; i < capacity; i++) {
+        entries[i].key = nullptr;
+        entries[i].value = NIL_VAL;
+    }
+
+    table->count = 0;
+    for (auto i = 0; i < table->capacity; i++) {
+        Entry* entry = &table->entries[i];
+        if (entry->key == nullptr) {
+            continue;
+        }
+
+        Entry* dest = findEntry(entries, capacity, entry->key);
+        dest->key = entry->key;
+        dest->value = entry->value;
+        table->count++;
+    }
+
+    FREE_ARRAY(Entry, table->entries, table->capacity);
+
+    table->entries = entries;
+    table->capacity = capacity;
+}
+
+bool tableSet(Table* table, ObjString* key, Value value)
+{
+    if (table->count + 1 > table->capacity * TABLE_MAX_LOAD) {
+        auto capacity = GROW_CAPACITY(table->capacity);
+        adjustCapacity(table, capacity);
+    }
+
+    Entry* entry = findEntry(table->entries, table->capacity, key);
+    auto isNewKey = entry->key == nullptr;
+    if (isNewKey && IS_NIL(entry->value)) {
+        table->count++;
+    }
+
+    entry->key = key;
+    entry->value = value;
+
+    return isNewKey;
+}
+
+bool tableDelete(Table* table, ObjString* key)
+{
+    if (table->count == 0) {
+        return false;
+    }
+
+    Entry* entry = findEntry(table->entries, table->capacity, key);
+    if (entry->key == nullptr) {
+        return false;
+    }
+
+    entry->key = nullptr;
+    entry->value = BOOL_VAL(true);
+    return true;
+}
+
+void tableAddAll(Table* from, Table* to)
+{
+    for (auto i = 0; i < from->capacity; i++) {
+        Entry* entry = &from->entries[i];
+        if (entry->key != nullptr) {
+            tableSet(to, entry->key, entry->value);
+        }
+    }
+}
+
+ObjString* tableFindString(Table* table, const char* chars, int length, uint32_t hash)
+{
+    if (table->count == 0) {
+        return nullptr;
+    }
+
+    auto index = hash & (table->capacity - 1);
+    for (;;) {
+        Entry* entry = &table->entries[index];
+        if (entry->key == nullptr) {
+            if (IS_NIL(entry->value)) {
+                return nullptr;
+            }
+        } else if (entry->key->length == length && entry->key->hash == hash && memcmp(entry->key->chars, chars, length) == 0) {
+            return entry->key;
+        }
+
+        index = (index + 1) & (table->capacity - 1);
+    }
+}
+
+void tableRemoveWhite(Table* table)
+{
+    for (auto i = 0; i < table->capacity; i++) {
+        Entry* entry = &table->entries[i];
+        if (entry->key != nullptr && !entry->key->obj.isMarked) {
+            tableDelete(table, entry->key);
+        }
+    }
+}
+
+void markTable(Table* table)
+{
+    for (auto i = 0; i < table->capacity; i++) {
+        Entry* entry = &table->entries[i];
+        markObject((Obj*)entry->key);
+        markValue(entry->value);
+    }
+}
+