1 files changed, 104 insertions, 0 deletions
diff --git a/src/hashmap.c b/src/hashmap.c
new file mode 100644
index 0000000..4a59e15
--- /dev/null
+++ b/src/hashmap.c
@@ -0,0 +1,104 @@
+#include "hashmap.h"
+
+#include <Windows.h>
+
+#include "utils.h"
+
+static const u32 initial_size = 4096U * 100U;
+static const u32 empty_psl = (u32)-1;
+static const float max_load_factor = 0.75f;
+
+void resize(struct hashmap* map) {
+    void* alloc = VirtualAlloc((void*)(map->arr + 1U), map->capacity * sizeof(struct element), MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
+
+    if (alloc == NULL) {
+        alloc = VirtualAlloc(NULL, map->capacity * 2U * sizeof(struct element), MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
+        map->capacity *= 2U;
+        // copy elements + rehashing
+    } else {
+        map->capacity *= 2U;
+        // rehashing
+    }
+}
+
+struct hashmap create_unordered_flat() {
+    struct hashmap map = {
+        .capacity = initial_size / sizeof(struct element),
+        .size = 0U,
+        .arr = (struct element*)VirtualAlloc(NULL, initial_size * sizeof(struct element), MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE),
+    };
+
+    for (u32 index = 0U; index <  map.capacity; index++) {
+        map.arr[index].name = 0ULL;
+        map.arr[index].start = 0U;
+        map.arr[index].end = 0U;
+        map.arr[index].psl = 0U;
+    }
+    return map;
+}
+
+struct element* insert_elem(struct hashmap* map, u32 start, u32 end, u64 name) {
+    if (map->size >= map->capacity) {
+        return NULL;
+    }
+    float load = map->size / (float)map->capacity;
+    if (load >= max_load_factor) {
+        resize(map);
+    }
+
+    u32 index = start % map->capacity;
+    u32 psl = 0U;
+
+    while(map->arr[index + psl].name != 0ULL || (map->arr[index + psl].psl >= psl && map->arr[index + psl].psl != 0U)) {
+        psl++;
+    }
+
+    map->arr[index + psl].name = name;
+    map->arr[index + psl].start = start;
+    map->arr[index + psl].end = end;
+    map->arr[index + psl].psl = psl;
+    map->size++;
+
+    return &map->arr[index + psl];
+}
+
+void remove_elem(struct hashmap* map, u32 start) {
+    u32 index = start % map->capacity;
+
+    while (map->arr[index].start != start) {
+        index++;
+    }
+
+    while (map->arr[index].name != 0U && map->arr[index].psl != empty_psl && index < map->capacity) {
+        map->arr[index - 1U].psl = map->arr[index].psl - 1U;
+        map->arr[index - 1U].start = map->arr[index].start;
+        map->arr[index - 1U].end = map->arr[index].end;
+        map->arr[index - 1U].name = map->arr[index].name;
+        index++;
+    }
+
+    map->arr[index].psl = empty_psl;
+}
+
+struct element* find_elem(struct hashmap* map, u32 start) {
+    u32 index = start % map->capacity;
+
+    while (index < map->capacity) {
+        if (map->arr[index].start == start) {
+            return &map->arr[index];
+        }
+        index++;
+    }
+
+    return NULL;
+}
+
+void iterate(struct hashmap* map) {
+    u32 counter = 0U;
+    for (u32 index = 0U; index < map->capacity && counter < map->size; index++) {
+        if (map->arr[index].name) {
+            print("%s\n", map->arr[index].name);
+            counter++;
+        }
+    }
+}