From 9bd18b0499d5096bc91b09a2d26e700ca1560de4 Mon Sep 17 00:00:00 2001
From: bd <bdunahu@operationnull.com>
Date: Sun, 9 Mar 2025 20:15:45 -0400
Subject: Untested implementation for loading absent data into cache

---
 src/storage/cache.cc | 38 ++++++++++++++++++++++++++++++++------
 1 file changed, 32 insertions(+), 6 deletions(-)

(limited to 'src/storage/cache.cc')

diff --git a/src/storage/cache.cc b/src/storage/cache.cc
index e0eaf58..ec14ce6 100644
--- a/src/storage/cache.cc
+++ b/src/storage/cache.cc
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "definitions.h"
 #include "response.h"
+#include "utils.h"
 #include <bits/stdc++.h>
 
 Cache::Cache(int lines, Storage *lower, int delay)
@@ -9,8 +10,7 @@ Cache::Cache(int lines, Storage *lower, int delay)
 	this->data->resize(L1_CACHE_SIZE);
 	this->lower = lower;
 	this->delay = delay;
-	for (int i = 0; i < L1_CACHE_SIZE; ++i)
-		this->stat[i] = 0b01;
+	this->meta.fill({-1});
 }
 
 Cache::~Cache() { delete this->data; }
@@ -25,8 +25,9 @@ Response Cache::write(Accessor accessor, signed int data, int address)
 
 	if (this->requester == accessor) {
 		fetch_resource(address);
-		if (this->wait_time == 0) {
-			// this->do_write(data, address);
+		if (this->is_waiting == true)
+			r = BLOCKED;
+		else if (this->wait_time == 0) {
 			r = OK;
 		}
 	}
@@ -34,8 +35,33 @@ Response Cache::write(Accessor accessor, signed int data, int address)
 	return r;
 }
 
-Response Cache::read(Accessor accessor, int address, std::array<signed int, LINE_SIZE>& data) { return WAIT; }
+Response Cache::read(
+	Accessor accessor, int address, std::array<signed int, LINE_SIZE> &data)
+{
+	return WAIT;
+}
+
+void Cache::fetch_resource(int expected)
+{
+	Response r = OK;
+	int etag, index, atag;
+	std::array<signed int, LINE_SIZE> actual;
+	std::array<int, 2> meta;
 
-void Cache::fetch_resource(int address) {
+	get_bit_fields(expected, &etag, &index, nullptr);
+	meta = this->meta.at(index);
+
+	if (atag != etag) {
+		// address not in cache
+		if (this->meta[index][0]) {
+			// occupant is dirty
+			// TODO
+			r = WAIT;
+		} else {
+			actual = this->data->at(index);
+			r = this->lower->read(L1CACHE, expected, actual);
+		}
+	}
 
+	this->is_waiting = (r == OK) ? false : true;
 }
-- 
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