From 2dc9d118efb64de6ea54a5a9eb4474f8e5ef3145 Mon Sep 17 00:00:00 2001
From: Paul Oliver <contact@pauloliver.dev>
Date: Thu, 29 Feb 2024 01:50:44 +0100
Subject: Initial commit

---
 src/memory.c | 227 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 227 insertions(+)
 create mode 100644 src/memory.c

(limited to 'src/memory.c')

diff --git a/src/memory.c b/src/memory.c
new file mode 100644
index 0000000..4befd4f
--- /dev/null
+++ b/src/memory.c
@@ -0,0 +1,227 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "types.h"
+#include "instset.h"
+#include "memory.h"
+
+#define MEM_BLOCK_START_FLAG (0x80)
+#define ALLOCATED_FLAG       (0x40)
+#define INSTRUCTION_MASK     (0x3f)
+
+static sbool  g_isInit;
+static sword  g_order;
+static sword  g_size;
+static sword  g_memBlockCount;
+static sword  g_allocated;
+static sword  g_cap;
+static sbyte *g_data;
+
+void
+sm_init(sword order)
+{
+	assert(!g_isInit);
+	assert(INSTRUCTION_MASK == SINST_COUNT - 1);
+	g_isInit = STRUE;
+	g_order  = order;
+	g_size   = 1 << g_order;
+	g_cap    = g_size / 2;
+	g_data   = calloc(g_size, sizeof(sbyte));
+	assert(g_data);
+}
+
+void
+sm_quit(void)
+{
+	assert(g_isInit);
+	free(g_data);
+	g_isInit        = SFALSE;
+	g_order         = 0;
+	g_size          = 0;
+	g_memBlockCount = 0;
+	g_allocated     = 0;
+	g_cap           = 0;
+	g_data          = NULL;
+}
+
+void
+sm_load(FILE *file)
+{
+	assert(!g_isInit);
+	assert(file);
+	fread(&g_isInit,        sizeof(sbool), 1, file);
+	fread(&g_order,         sizeof(sword), 1, file);
+	fread(&g_size,          sizeof(sword), 1, file);
+	fread(&g_memBlockCount, sizeof(sword), 1, file);
+	fread(&g_allocated,     sizeof(sword), 1, file);
+	fread(&g_cap,           sizeof(sword), 1, file);
+	g_data = calloc(g_size, sizeof(sbyte));
+	assert(g_data);
+	fread(g_data, sizeof(sbyte), g_size, file);
+}
+
+void
+sm_save(FILE *file)
+{
+	assert(g_isInit);
+	assert(file);
+	fwrite(&g_isInit,        sizeof(sbool), 1,      file);
+	fwrite(&g_order,         sizeof(sword), 1,      file);
+	fwrite(&g_size,          sizeof(sword), 1,      file);
+	fwrite(&g_memBlockCount, sizeof(sword), 1,      file);
+	fwrite(&g_allocated,     sizeof(sword), 1,      file);
+	fwrite(&g_cap,           sizeof(sword), 1,      file);
+	fwrite(g_data,           sizeof(sbyte), g_size, file);
+}
+
+sbool
+sm_isInit(void)
+{
+	return g_isInit;
+}
+
+sword
+sm_getOrder(void)
+{
+	return g_order;
+}
+
+sword
+sm_getSize(void)
+{
+	return g_size;
+}
+
+sword
+sm_getMemBlockCount(void)
+{
+	return g_memBlockCount;
+}
+
+sword
+sm_getAllocated(void)
+{
+	return g_allocated;
+}
+
+sword
+sm_getCap(void)
+{
+	return g_cap;
+}
+
+sbool
+sm_isOverCap(void)
+{
+	assert(g_isInit);
+	return g_allocated > g_cap;
+}
+
+sbool
+sm_isValidAt(sword addr)
+{
+	assert(g_isInit);
+	return addr < g_size;
+}
+
+sbool
+sm_isMemBlockStartAt(sword addr)
+{
+	assert(g_isInit);
+	assert(sm_isValidAt(addr));
+	return !!(g_data[addr] & MEM_BLOCK_START_FLAG);
+}
+
+sbool
+sm_isAllocatedAt(sword addr)
+{
+	assert(g_isInit);
+	assert(sm_isValidAt(addr));
+	return !!(g_data[addr] & ALLOCATED_FLAG);
+}
+
+void
+sm_setMemBlockStartAt(sword addr)
+{
+	assert(g_isInit);
+	assert(sm_isValidAt(addr));
+	assert(!sm_isMemBlockStartAt(addr));
+	g_data[addr] ^= MEM_BLOCK_START_FLAG;
+	g_memBlockCount++;
+	assert(sm_isMemBlockStartAt(addr));
+	assert(g_memBlockCount);
+	assert(g_memBlockCount <= g_size);
+}
+
+void
+sm_unsetMemBlockStartAt(sword addr)
+{
+	assert(g_isInit);
+	assert(g_memBlockCount);
+	assert(sm_isValidAt(addr));
+	assert(sm_isMemBlockStartAt(addr));
+	g_data[addr] ^= MEM_BLOCK_START_FLAG;
+	g_memBlockCount--;
+	assert(!sm_isMemBlockStartAt(addr));
+	assert(g_memBlockCount <= g_size);
+}
+
+void
+sm_allocateAt(sword addr)
+{
+	assert(g_isInit);
+	assert(sm_isValidAt(addr));
+	assert(!sm_isAllocatedAt(addr));
+	g_data[addr] ^= ALLOCATED_FLAG;
+	g_allocated++;
+	assert(sm_isAllocatedAt(addr));
+	assert(g_allocated);
+	assert(g_allocated <= g_size);
+}
+
+void
+sm_freeAt(sword addr)
+{
+	assert(g_isInit);
+	assert(g_allocated);
+	assert(sm_isValidAt(addr));
+	assert(sm_isAllocatedAt(addr));
+	g_data[addr] ^= ALLOCATED_FLAG;
+	g_allocated--;
+	assert(!sm_isAllocatedAt(addr));
+	assert(g_allocated <= g_size);
+}
+
+sbyte
+sm_getInstAt(sword addr)
+{
+	assert(g_isInit);
+	assert(sm_isValidAt(addr));
+	return g_data[addr] & INSTRUCTION_MASK;
+}
+
+void
+sm_setInstAt(sword addr, sbyte inst)
+{
+	assert(g_isInit);
+	assert(sm_isValidAt(addr));
+	assert(si_isInst(inst));
+	g_data[addr] &= (MEM_BLOCK_START_FLAG | ALLOCATED_FLAG);
+	g_data[addr] |= inst;
+}
+
+sbyte
+sm_getByteAt(sword addr)
+{
+	assert(g_isInit);
+	assert(sm_isValidAt(addr));
+	return g_data[addr];
+}
+
+void
+sm_setByteAt(sword addr, sbyte byte)
+{
+	assert(g_isInit);
+	assert(sm_isValidAt(addr));
+	g_data[addr] = byte;
+}
-- 
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