Added: implementation for conflict resolution

docs/CHANGELOG

@@ -1,7 +0,0 @@
-12-04-2024  René Huiberts  <rhuibertsjr@gmail.com>
-
-	Updated: references & documentation
-
-12-04-2024  René Huiberts  <rhuibertsjr@gmail.com>
-
-	Added: project layout

src/arena.c

@@ -1,40 +1,93 @@
+
 internal Arena *
-arena_initialize(u64 size)
+arena_initialize(u64 size, b8 growable)
 {
   Arena *result = 0;
-
-  void *backing_buffer = malloc(size);
+  void *backing_buffer = platform_memory_reserve(size);
 
   if (backing_buffer != NULL)
   {
-    result = (Arena*) backing_buffer;
+    platform_memory_commit(backing_buffer, ARENA_INITIAL_COMMIT_SIZE);
 
-    result->buffer = backing_buffer;
-    result->offset = sizeof(Arena); 
-    result->size   = sizeof(Arena) + size;
+    result = (Arena*) backing_buffer;
+    result->backing_buffer = (u64*) backing_buffer;
+    result->current = result;
+    result->prev = 0;
+
+    // rhjr: immutable arena header
+    result->base_pos =
+      memory_align(sizeof(Arena), ARENA_DEFAULT_ALIGNMENT);
+    result->offset = result->base_pos;
+
+    result->growable = growable;
+    result->size = size;
   }
 
+  // rhjr: arenas should be instantiated early on in the programs lifetime, that
+  //       is why this assertion will also be used in production.
+  ASSERT(result != 0);
+  return result;
+}
+
+internal Arena *
+arena_initialize_default()
+{
+  Arena *result = arena_initialize(ARENA_DEFAULT_RESERVE_SIZE, 1);
   return result;
 }
 
 internal void *
 arena_allocate(Arena *arena, u64 size)
 {
-  void *result = 0;
+  Arena *current = arena->current;
+  u64 pos_cur = current->base_pos + current->offset;
+  u64 pos_mem = memory_align(pos_cur, ARENA_DEFAULT_ALIGNMENT);
+  u64 pos_new = pos_mem + size;
 
-  if (arena->offset + size <= arena->size)
+  if (current->size < pos_new && current->growable)
   {
-    result = (void*)((u64) arena->buffer + (u64) arena->offset);
-    arena->offset += size;
+    Arena *new_memory_bock;
+
+    if (size > ARENA_DEFAULT_RESERVE_SIZE)
+    {
+      // rhjr: TODO add support for allocations larger then a single page, in a
+      //       single allocation call.
+      ASSERT(0);
+    }
+    else
+    {
+      new_memory_bock = arena_initialize_default();
+
+      if (new_memory_bock)
+      {
+        stack_push(arena->current, new_memory_bock, prev);
+
+        current = new_memory_bock;
+
+        pos_mem =
+          memory_align(current->offset, ARENA_DEFAULT_ALIGNMENT);
+        pos_new = current->offset + size;
+      }
+
+    }
 
-    memset(result, 0, size);
   }
 
-  return result;
+  void *memory = (void*)((u64) current->backing_buffer + pos_mem);
+  arena->offset = pos_new;
+
+  platform_memory_commit(memory, size);
+  memset(memory, 0, size);
+
+  return memory;
 }
 
 internal void
 arena_release(Arena *arena)
 {
-  arena->offset = 0;
+  for (Arena *node = arena->current, *prev = 0; node != 0; node = prev)
+  {
+    prev = node->prev;
+    platform_memory_release(node, node->size);
+  }
 }

src/arena.h

@@ -1,19 +1,30 @@
 #ifndef ARENA_H
 #define ARENA_H
 
+#define ARENA_INITIAL_COMMIT_SIZE sizeof(struct Arena)
+#define ARENA_DEFAULT_ALIGNMENT   0
+
+#ifndef ARENA_DEFAULT_RESERVE_SIZE
+#  define ARENA_DEFAULT_RESERVE_SIZE KB(4)
+#endif // ARENA_DEFAULT_RESERVE_SIZE
+
 typedef struct Arena Arena;
 struct Arena {
-  u64 *buffer;
+  struct Arena *current;
+  struct Arena *prev;
+  u64 *backing_buffer;
+  u64 base_pos;
   u64 offset;
   u64 size;
+  b8 growable;
 };
 
-internal Arena * arena_initialize(u64 size);
+//= rhjr: arenas
 
-internal void * arena_allocate(Arena *arena, u64 size);
-internal void   arena_release(Arena *arena);
+internal Arena * arena_initialize(u64 size, b8 growable);
+internal Arena * arena_initialize_default();
 
-//= rhjr: arena helpers
+internal void *  arena_allocate(Arena *arena, u64 size);
 
 #define arena_push_array(arena, type, count) \
   (type*) arena_allocate((arena), sizeof(type) * (count))
@@ -21,8 +32,12 @@ internal void   arena_release(Arena *arena);
 #define arena_push(arena, type) \
   (type*) arena_allocate((arena), sizeof(type))
 
+internal void arena_release(Arena *arena);
+
 //= rhjr: memory helpers
 
+#define memory_align(x, b) ((b != 0) ? (((x) + (b) - 1) & (~(b - 1))) : (x))
+
 #define memory_zero(s,z)       memset((s), 0, (z))
 #define memory_zero_struct(s)  memory_zero((s), sizeof(*(s)))
 

src/base.h

@@ -18,12 +18,30 @@ typedef int16_t i16;
 typedef int32_t i32;
 typedef int64_t i64;
 
+typedef uint8_t  b8;
+typedef uint16_t b16;
+typedef uint32_t b32;
+typedef uint64_t b64;
+
 #define KB(b) ((b) << 10)
 #define MB(b) ((b) << 20)
 
 #define STATEMENT(S) do{ S } while(0)
 #define ASSERT(c) STATEMENT( if (!(c)){ (*(volatile int*)0 = 0); } )
+#define STATIC_ASSERT(c,l) typedef u8 Glue(l,__LINE__) [(c)?1:-1]
 
 #define MIN(A,B) (((A)<(B))?(A):(B))
 
+//= rhjr: linked-list
+
+#define check_null(p) ((p)==0)
+#define set_null(p) ((p)=0)
+
+#define queue_push_nz(f,l,n,next,zchk,zset) (zchk(f)?\
+(((f)=(l)=(n)), zset((n)->next)):\
+((l)->next=(n),(l)=(n),zset((n)->next)))
+
+#define queue_push(f,l,n)    queue_push_nz(f,l,n,next,check_null,set_null)
+#define stack_push(f,n,next) ((n)->next=(f), (f)=(n))
+
 #endif // BASE_H

src/hash-store.c

@@ -1,58 +0,0 @@
-
-internal Table
-hash_store_initialize(void)
-{
-  Table result = {0};
-
-  result.ptr_arena = arena_initialize(KB(1));
-  result.str8_arena = arena_initialize(KB(1));
-
-  result.str8_ptr = arena_push(result.ptr_arena, String8);
-  result.str8_count = 1;
-  result.str8_ptr[0] = str8_lit("");
-
-  return result;
-}
-
-internal Key
-hash_store_string8_to_key(Table *table, String8 value)
-{
-  Key result = 0;
-  u32 count = table->str8_count;
-  result = count;
-
-  String8 *str8_ptr = table->str8_ptr;
-  for (u32 index = 0; index < count; index += 1, str8_ptr += 1)
-  {
-    if (string8_match(*str8_ptr, value))
-    {
-      result = index;
-      break;
-    }
-  }
-
-  if (result == count)
-  {
-    String8 *new_str8 = arena_push(table->ptr_arena, String8);
-    new_str8->content =
-      arena_push_array(table->str8_arena, u8, value.length);
-
-    memory_copy(new_str8->content, value.content, value.length);
-    table->str8_count += 1;
-  }
-
-  return result;
-}
-
-internal String8
-hash_store_string8_from_key(Table *table, Key index)
-{
-  String8 result = {0};
-
-  if (index < table->str8_count)
-    {
-      result = table->str8_ptr[index];
-    }
-
-  return result;
-}

src/hash-store.h

@@ -1,21 +0,0 @@
-#ifndef HASH_TABLE_H
-#define HASH_TABLE_H
-
-typedef u32 Key; 
-
-typedef struct Table Table;
-struct Table
-{
-  Arena *ptr_arena;
-  Arena *str8_arena;
-
-  String8 *str8_ptr;
-  u32 str8_count;
-};
-
-internal Table   hash_store_initialize(void);
-
-internal String8 hash_store_string8_from_key(Table *table, Key index);
-internal Key     hash_store_string8_to_key(Table *table, String8 value);
-
-#endif

src/hash_store.c

@@ -0,0 +1,69 @@
+
+internal Key
+hash_store_hash(String8 data)
+{
+  Key result = {0};
+
+  u64 hash = 5381;
+  for(u64 i = 0; i < data.length; i += 1)
+  {
+    hash = ((hash << 5) + hash) + data.content[i];
+  }
+
+  memory_copy(&result, &hash, sizeof(u64));
+  return result;
+}
+
+internal Table *
+hash_store_initialize(void)
+{
+  Arena *arena = arena_initialize_default();
+  Arena *str8_arena = arena_initialize_default();
+
+  Table *table = arena_push(arena, Table);
+  table->arena = arena;
+  table->str8_arena = str8_arena;
+  table->slots_count = 200;
+
+  table->slots = arena_push_array(arena, TableSlot, table->slots_count);
+
+  return table;
+}
+
+internal Key
+hash_store_string8_to_key(Table *table, String8 data)
+{
+  Key result = hash_store_hash(data);
+  u64 slot_idx = result.U32[0]%table->slots_count;
+
+  TableNode *node = arena_push(table->arena, TableNode);
+  node->data.content = arena_push_array(table->str8_arena, char, data.length);
+  node->data.length = data.length;
+  node->key = result;
+
+  memory_copy(&node->data.content, &data.content, data.length);
+
+  TableSlot *slot = &table->slots[slot_idx];
+  queue_push(slot->first, slot->last, node);
+
+  return result;
+}
+
+internal String8
+hash_store_string8_from_key(Table *table, Key key)
+{
+  String8 result = {0};
+  u64 slot_idx = key.U32[0]%table->slots_count;
+  TableSlot *slot = &table->slots[slot_idx];
+
+  for (TableNode *n = slot->first; n != 0; n = n->next)
+  {
+    if (key.U32[1] == n->key.U32[1])
+    {
+      result = n->data;
+      break;
+    }
+  }
+
+  return result;
+}

src/hash_store.h

@@ -0,0 +1,39 @@
+#ifndef HASH_TABLE_H
+#define HASH_TABLE_H
+
+typedef struct Key Key;
+struct Key
+{
+  u32 U32[2];
+};
+
+typedef struct TableNode TableNode;
+struct TableNode
+{
+  TableNode *next;
+  String8 data;
+  Key key;
+};
+
+typedef struct TableSlot TableSlot;
+struct TableSlot
+{
+  TableNode *first;
+  TableNode *last;
+};
+
+typedef struct Table Table;
+struct Table
+{
+  Arena *arena;
+  Arena *str8_arena;
+
+  TableSlot *slots;
+  u64 slots_count;
+};
+
+internal Table * hash_store_initialize(void);
+
+internal Key hash_store_string8_to_key(Table *table, String8 data);
+
+#endif

src/main.c

@@ -1,32 +1,28 @@
 #include "base.h"
-
+#include "win32_platform.h"
 #include "arena.h"
 #include "string.h"
-#include "hash-store.h"
+#include "hash_store.h"
 
+#include "win32_platform.c"
 #include "arena.c"
 #include "string.c"
-#include "hash-store.c"
+#include "hash_store.c"
 
 int
 main(void)
 {
-  Table store = hash_store_initialize();
-  Key a = hash_store_string8_to_key(&store, str8_lit("Hello"));
-  Key b = hash_store_string8_to_key(&store, str8_lit("Beautiful"));
-  Key c = hash_store_string8_to_key(&store, str8_lit("World"));
+  Table *table = hash_store_initialize();
 
-  String8 str_a = hash_store_string8_from_key(&store, a);
-  String8 str_b = hash_store_string8_from_key(&store, b);
-  String8 str_c = hash_store_string8_from_key(&store, c);
+  String8 str8_1 = str8_lit("Hello world");
+  String8 str8_2 = str8_lit("ayenooo");
 
-  ASSERT(hash_store_string8_to_key(&store, str8_lit("Hello")) == a);
-  ASSERT(hash_store_string8_to_key(&store, str8_lit("Beautiful")) == b);
-  ASSERT(hash_store_string8_to_key(&store, str8_lit("World")) == c);
+  Key key1 = hash_store_string8_to_key(table, str8_1);
+  Key key2 = hash_store_string8_to_key(table, str8_2);
+  Key key3 = hash_store_string8_to_key(table, str8_1);
 
-  ASSERT(string8_match(hash_store_string8_from_key(&store, a), str8_lit("Hello")));
-  ASSERT(string8_match(hash_store_string8_from_key(&store, b), str8_lit("Beautiful")));
-  ASSERT(string8_match(hash_store_string8_from_key(&store, c), str8_lit("World")));
+  String8 string = hash_store_string8_from_key(table, key2);
+  printf("%.*s\n", (i32) string.length, string.content);
 
   return 0;
 };

src/string.h

@@ -11,6 +11,7 @@ struct String8
 internal String8 str8_init(u8 *cstring, u64 length);
 #define str8_lit(cstring)                                                       \
     str8_init((u8*)(cstring), sizeof(cstring) - 1)
+#define str8_lit_comp(cstring) {(u8*)(cstring), sizeof(cstring) - 1}
 
 internal u8 string8_match(String8 a, String8 b);
 

src/win32_platform.c

@@ -0,0 +1,34 @@
+
+internal void *
+platform_memory_reserve(u64 size)
+{
+  void *result = VirtualAlloc(0, size, MEM_RESERVE, PAGE_READWRITE);
+  return result;
+}
+
+internal b8
+platform_memory_commit(void *ptr, u64 size)
+{
+  b32 result = (VirtualAlloc(ptr, size, MEM_COMMIT, PAGE_READWRITE) != 0);
+  return result;
+}
+
+internal void
+platform_memory_decommit(void *ptr, u64 size)
+{
+  VirtualFree(ptr, size, MEM_DECOMMIT);
+};
+
+internal void
+platform_memory_release(void *ptr, u64 size)
+{
+  VirtualFree(ptr, 0, MEM_RELEASE);
+}
+
+internal u64
+platform_get_page_size(void)
+{
+  SYSTEM_INFO sysinfo = {0};
+  GetSystemInfo(&sysinfo);
+  return sysinfo.dwPageSize;
+}

src/win32_platform.h

@@ -0,0 +1,17 @@
+#ifndef WIN32_PLATFORM_H
+#define WIN32_PLATFORM_H
+
+#undef internal
+#include <Windows.h>
+#define internal static
+
+//= rhjr: platform memory management
+
+internal void * platform_memory_reserve(u64 size);
+internal b8     platform_memory_commit(void *ptr, u64 size);
+internal void   platform_memory_decommit(void *ptr, u64 size);
+internal void   platform_memory_release(void *ptr, u64 size);
+
+internal u64    platform_get_page_size(void);
+
+#endif // WIN32_PLATFORM_H