first pass memory buckets

1 files changed, 92 insertions, 0 deletions

diff --git a/src/memory.cpp b/src/memory.cpp
new file mode 100644
index 0000000..83f8483
--- /dev/null
+++ b/src/memory.cpp
@@ -0,0 +1,92 @@
+
+#include "memory.hpp"
+
+struct pke::MemBucket {
+	int64_t size;
+	int64_t head;
+	int64_t free;
+	int64_t allocs;
+	char * ptr;
+};
+
+pke::MemBucket buckets[128]; // 32 gigs
+int64_t bucketHead = 0;
+
+int64_t InitNewBucket(int64_t sz) {
+	buckets[bucketHead].size = sz;
+	buckets[bucketHead].ptr = reinterpret_cast<char *>(std::malloc(sz));
+	buckets[bucketHead].free = 0;
+	buckets[bucketHead].head = 0;
+	buckets[bucketHead].allocs = 0;
+	return bucketHead++;
+}
+
+void *pke::PkeNew(std::size_t sz) {
+	MemBucket *bkt = nullptr;
+	for (long i = 0; i < bucketHead; ++i) {
+		if (buckets[i].size - buckets[i].head > sz) {
+			bkt = &buckets[i];
+		}
+	}
+	if (bkt == nullptr) {
+		bkt = &buckets[InitNewBucket(DEFAULT_BUCKET_SIZE)];
+	}
+	void *ptr = bkt->ptr + bkt->head;
+	bkt->head += sz;
+	bkt->allocs++;
+	return ptr;
+}
+
+void *pke::PkeNew(std::size_t sz, pke::MemBucket *bkt) {
+	void *ptr = bkt->ptr + bkt->head;
+	bkt->head += sz;
+	bkt->allocs++;
+	return ptr;
+}
+
+void pke::PkeDelete(void *ptr) {
+	pke::MemBucket *bkt = nullptr;
+	for (long i = 0; i < bucketHead; ++i) {
+		bkt = &buckets[i];
+		if (ptr > bkt->ptr && ptr < bkt->ptr + bkt->size) break;
+	}
+	if (bkt == nullptr) {
+		std::printf("bad pointer %llu", reinterpret_cast<unsigned long long>(ptr));
+		throw "bad pointer";
+	}
+	bkt->allocs--;
+	if (bkt->allocs == 0) {
+		bkt->head = 0;
+		bkt->free = 0;
+	}
+}
+
+void pke::PkeDelete(void *ptr, pke::MemBucket *bkt) {
+	bkt->allocs--;
+	if (bkt->allocs == 0) {
+		bkt->head = 0;
+		bkt->free = 0;
+	}
+}
+
+pke::MemBucket *pke::BeginTransientBucket(int64_t sz) {
+	return &buckets[InitNewBucket(sz)];
+}
+
+void pke::EndTransientBucket(pke::MemBucket *bkt) {
+	int64_t foundIndex = -1;
+	for (int64_t i = 0; i < bucketHead; ++i) {
+		if (&buckets[i] == bkt) {
+			foundIndex = i;
+			std::free(bkt->ptr);
+			bkt->size = 0;
+			bkt->head = 0;
+			bkt->free = 0;
+			bkt->ptr = reinterpret_cast<char *>(0xCAFEBABE);
+			break;
+		}
+	}
+	if (foundIndex == bucketHead) {
+		bucketHead--;
+	}
+}