From 5476ba3ad940ec4923243158cc3024bfa0dbeec8 Mon Sep 17 00:00:00 2001
From: Richard Thier <magosit@outlook.hu>
Date: Tue, 1 Oct 2024 17:49:48 +0200
Subject: [PATCH] finalized implementation, but probably buggy

---
 simap.h | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 54 insertions(+), 2 deletions(-)

diff --git a/simap.h b/simap.h
index 47aa2fe..d56ed0e 100644
--- a/simap.h
+++ b/simap.h
@@ -48,6 +48,7 @@ typedef union simap_ptr64 simap_ptr64;
 struct simap_instance {
 	arena a;
 	uint32_t end;
+	uint32_t prev_usage_end; /* previous usage_end or -1 if no previous exists... in bytes!!! */
 	uint32_t usage_end; /* in bytes!!! */
 	uint32_t next_previndex; /* in bytes!!! */
 	/** see doc comment for layout and why uint64_t* is the type */
@@ -59,6 +60,7 @@ static inline simap_instance simap_create() {
 	simap_instance ret;
 	ret.a = newarena((ptrdiff_t)1 << 33);
 	ret.end = 0;
+	ret.prev_usage_end = (uint32_t) -1;
 	ret.usage_end = 0;
 	ret.next_previndex = 0;
 	ret.base = ((uint64_t*) alloc(&(ret.a), sizeof(uint64_t), sizeof(uint64_t), 1)) /* addr divisible by 8 */
@@ -99,13 +101,18 @@ static inline simap_ptr64 *simap_search_internal(simap_instance *map, const char
 				}
 			}
 
+			simap_ptr64 *ptr = (simap_ptr64 *)((uint8_t *) (tipp - 2));
+
 			/* Check back & forth (jump validation) */
 			uint32_t previ = *((uint32_t *)(tipp - 1));
+			if(previ == (uin32_t) -1) {
+				/* Expect it be good if it was first insert ever? Statistically rare to be not like it */
+				return ptr;
+			}
 			uint32_t prevnexi = *(uint32_t *)(((uint8_t *)base) + previ
 					+ sizeof(simap_ptr64)
 					+ sizeof(uint32_t));
 
-			simap_ptr64 *ptr = (simap_ptr64 *)((uint8_t *)base + prevnexi);
 			uint64_t *retipp = (uint64_t *)(((uint8_t *)base + prevnexi)
 				+ sizeof(simap_ptr64) + sizeof(uint32_t) +
 				+ sizeof(uint32_t));
@@ -157,7 +164,52 @@ static inline void *simap_force_add_internal(simap_instance *map, const char *ke
 	}
 
 	/* Already have the storage */
-	/* TODO: Implement - beware that I NEED to store the first 8 characters as a simap_c64! */
+
+	/* Create first 8 char encoding (this ensures endianness and all such stuff) */
+	simap_c64 first8 {0};
+	uint32_t keylen = strlen(key);
+	strncpy(first8.str8, key, (keylen < 8) ? keylen : 8);
+
+	uint32_t usi = map->usage_end;
+	uint32_t previ = map->prev_usage_end;
+
+	/* Save data ptr */
+	simap_ptr64 *data = (simap_ptr_64 *)((uint8_t *)(map->base) + usi);
+	data->ptr = ptr;
+
+	/* Save link to previous */
+	uint32_t *usprev = (uint32_t *)((uint8_t *)(map->base) +
+		sizeof(simap_ptr64) +
+		sizeof(uint32_t));
+	*usprev = previ;
+	/* and nex */
+	*(usprev + 1) = (uint32_t) -1;
+
+	/* First 8 bytes */
+	simap_c64 *start_str = (uint8_t *)(usprev + 2);
+	*start_str = first8;
+
+	/* Remainin bytes */
+	if(keylen > 8) {
+		uint32_t key_remains = keylen - 8;
+		char *rem_str = (char *)(start_str + 1);
+		strcpy(rem_str, key + 8);
+	}
+
+	/* Update previous with linkage */
+	if(previ != (uint32_t)-1) {
+		uint32_t *prevnex = (uint8_t *)(map->base) + previ +
+			sizeof(simap_ptr64) +
+			sizeof(uint32_t);
+		*prevnex = usi;
+	}
+
+	/* Update prev usage end */
+	map->prev_usage_end = usi;
+
+	/* Administer usage_end offset */
+	map->usage_end += storage_needed;
+
 	return NULL;
 }