Hashmap

.gitignore

@@ -68,3 +68,4 @@ _deps
 vgcore.*
 src/main.c
 .clangd
+acl

CMakeLists.txt

@@ -1,11 +1,19 @@
 project(advanced_C_standard_library C)
-set_property(GLOBAL PROPERTY C_STANDARD)
+cmake_minimum_required(VERSION 3.17)
-cmake_minimum_required(VERSION 3.9)
 include_directories(include)
-file(GLOB SOURCES "src/*.c")
+file(GLOB ACLSOURCES "src/*.c")
-add_executable(test.out ${SOURCES})
+add_executable(acl ${ACLSOURCES})
 find_program(CCACHE_PROGRAM ccache)
 if(CCACHE_PROGRAM)
     set(CMAKE_C_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
 endif()
 set( CMAKE_EXPORT_COMPILE_COMMANDS ON )
+set_property(TARGET acl PROPERTY C_STANDARD 99)
+INCLUDE(TestBigEndian)
+TEST_BIG_ENDIAN(IS_BIG_ENDIAN)
+if(IS_BIG_ENDIAN)
+	add_compile_definitions(ACL_BIG_ENDIAN)
+else()
+	add_compile_definitions(ACL_LITTLE_ENDIAN)
+endif()
+target_link_libraries(acl PRIVATE m)

build_and_run.sh

@@ -2,4 +2,4 @@
 rm -rf build
 cmake .
 make
-./build/test.out
+./acl

include/acl/array.h

@@ -6,4 +6,5 @@ void acl_arraylist_free(void *arraylist);
 void* acl_arraylist_remove(void *arraylist_void, size_t index);
 void* acl_arraylist_create(size_t array_size, size_t sizeof_one_element);
 void* acl_arraylist_append(void *arraylist_void, void *element_void);
+void* acl_arraylist_append_ptr(void *arraylist_void, void **append_element);
 #endif

include/acl/hashmap.h

@@ -1,4 +1,14 @@
 #ifndef _acl_hashmap_h
 #define _acl_hashmap_h
-unsigned hash(unsigned K);
+#include <stddef.h>
+union acl_hashmap_meta {
+        void *dummy_ptr;
+        struct {
+        	size_t bucketCount;
+        	size_t sizeOneElement;
+		size_t keyBits;
+        };
+};
+union acl_hashmap_meta* acl_hashmap_create(size_t bucketCount, size_t sizeOneElement, size_t keySize);
+void acl_hashmap_put(union acl_hashmap_meta *hashmap_meta, void *key, void *element);
 #endif

src/array.c

@@ -2,6 +2,7 @@
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
+#include <acl/array.h>
 
 union arraylist_meta {
 	double dummy_double;
@@ -25,17 +26,24 @@ void* acl_arraylist_create(size_t array_size, size_t sizeof_one_element) {
 }
 
 void* acl_arraylist_append(void *arraylist_void, void *element) {
+	void *append_pointer;
+	void **element_append = &append_pointer;
+	union arraylist_meta *arraylist = (union arraylist_meta*)acl_arraylist_append_ptr(arraylist_void, element_append) - 1;
+	memcpy(*element_append, element, arraylist->sizeof_one_element);
+	return arraylist + 1;
+}
+void* acl_arraylist_append_ptr(void *arraylist_void, void **append_element) {
 	union arraylist_meta *arraylist = arraylist_void;
 	--arraylist;
 	if(arraylist->len == arraylist->cap) {
 		if(arraylist->len > 10) arraylist->cap = arraylist->len + 10;
-		else arraylist->cap = arraylist->len * 2;
+		else arraylist->cap = arraylist->len * 2 + 1;
 		arraylist = realloc(arraylist, arraylist->cap * arraylist->sizeof_one_element + sizeof *arraylist);
 		if(!arraylist) return NULL;
 	}
-	memcpy((char*)(arraylist + 1) + arraylist->sizeof_one_element * arraylist->len, element, arraylist->sizeof_one_element);
+	*append_element = (char*)(arraylist + 1) + arraylist->sizeof_one_element * arraylist->len;
 	++arraylist->len;
-	return arraylist+1;
+	return arraylist + 1;
 }
 
 void acl_arraylist_free(void *arraylist) {

src/hashmap.c

@@ -1,6 +1,79 @@
+#ifdef ACL_LITTLE_ENDIAN
+#define LEFT_OR_RIGHT_SHIFT >>
+#else
+#ifdef ACL_BIG_ENDIAN
+#define LEFT_OR_RIGHT_SHIFT <<
+#else
+#error "endianiss not specified. make sure to properly add the cmake subdirectory."
+#endif
+#endif 
 #include <math.h>
-const unsigned acl_w = sizeof (unsigned) * 8;
+#include <stddef.h>
-const unsigned acl_m = 9;
+#include <stdlib.h>
-unsigned hash(unsigned K) {
+#include <acl/hashmap.h>
-	return (149695736*K) >> (acl_w-acl_m);
+#include <acl/array.h>
+#include <stdint.h>
+#include <string.h>
+
+size_t acl_hash(void *data, size_t dataSize, size_t bucketBits) {
+	switch(dataSize) {
+		case 1:
+			return (uint8_t)(101u * *(uint8_t*)data >> (8 - bucketBits));
+		case 2: {
+				uint16_t cache;
+				memcpy(&cache, data, 2);
+				return (uint16_t)(15227u * cache >> (16 - bucketBits));
+			}
+		case 3:
+		case 4: {
+				uint32_t cache = 0;
+				memcpy(&cache, data, dataSize);
+				return (uint32_t)(4000846301u * cache >> (32 - bucketBits));
+			}
+		default:
+			if(dataSize <= 8) {
+				 uint64_t cache = 0;
+				 memcpy(&cache, data, dataSize);
+				 return (uint64_t)(10223372036854775833u * cache >> (64 - bucketBits));
+			 }
+			uint8_t rest = (uintptr_t)data % sizeof(uint64_t);
+			size_t data_len = dataSize / sizeof(uint64_t);
+			uint8_t restEnd = dataSize % sizeof(uint64_t);
+			if(restEnd) ++data_len;
+			uint64_t *cache;
+			if(rest) {
+				cache = malloc(data_len * sizeof *cache);
+				memcpy(cache, data, dataSize);
+				cache[data_len - 1] = 0;
+			}
+			else cache = data;
+			uint64_t hash = 0;
+			for(size_t i = 0; i < data_len - 1; ++i) { 
+				hash ^= (uint64_t)(10223372036854775833u * cache[i]);
+			}
+				hash ^= (uint64_t)(10223372036854775833u * cache[data_len - 1] & (18446744073709551615u LEFT_OR_RIGHT_SHIFT (sizeof *cache - restEnd)));
+				free(cache);
+				return hash >> (64 - bucketBits);
+	}
+}
+union acl_hashmap_meta* acl_hashmap_create(size_t bucketCount, size_t sizeOneElement, size_t keySize) {
+	union acl_hashmap_meta *hashmap_meta = malloc(sizeof *hashmap_meta + bucketCount * sizeof(void*));
+	hashmap_meta->bucketCount = bucketCount;
+	hashmap_meta->sizeOneElement = sizeOneElement;
+	hashmap_meta->keyBits = log2(keySize);
+	void **hashmap_buckets = (void**)(hashmap_meta + 1);
+	for(size_t i; i < bucketCount; ++i) {
+		hashmap_buckets[i] = acl_arraylist_create(0, sizeOneElement);
+	}
+	return hashmap_meta;
+}
+
+void acl_hashmap_put(union acl_hashmap_meta *hashmap_meta, void *key, void *element) {
+	void **hashmap_buckets = (void**)(hashmap_meta + 1);
+
+}
+#include <stdio.h>
+int main() {
+	int baum[3] = {89, 120, 36};
+	printf("Hash: %lu\n", acl_hash(baum, 3 * sizeof *baum , 5));
 }