feat: Waku v2 bridge

Issue #12610

vendor/github.com/VictoriaMetrics/fastcache/malloc_mmap.go

@@ -0,0 +1,53 @@
+// +build !appengine,!windows
+
+package fastcache
+
+import (
+	"fmt"
+	"sync"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+const chunksPerAlloc = 1024
+
+var (
+	freeChunks     []*[chunkSize]byte
+	freeChunksLock sync.Mutex
+)
+
+func getChunk() []byte {
+	freeChunksLock.Lock()
+	if len(freeChunks) == 0 {
+		// Allocate offheap memory, so GOGC won't take into account cache size.
+		// This should reduce free memory waste.
+		data, err := unix.Mmap(-1, 0, chunkSize*chunksPerAlloc, unix.PROT_READ|unix.PROT_WRITE, unix.MAP_ANON|unix.MAP_PRIVATE)
+		if err != nil {
+			panic(fmt.Errorf("cannot allocate %d bytes via mmap: %s", chunkSize*chunksPerAlloc, err))
+		}
+		for len(data) > 0 {
+			p := (*[chunkSize]byte)(unsafe.Pointer(&data[0]))
+			freeChunks = append(freeChunks, p)
+			data = data[chunkSize:]
+		}
+	}
+	n := len(freeChunks) - 1
+	p := freeChunks[n]
+	freeChunks[n] = nil
+	freeChunks = freeChunks[:n]
+	freeChunksLock.Unlock()
+	return p[:]
+}
+
+func putChunk(chunk []byte) {
+	if chunk == nil {
+		return
+	}
+	chunk = chunk[:chunkSize]
+	p := (*[chunkSize]byte)(unsafe.Pointer(&chunk[0]))
+
+	freeChunksLock.Lock()
+	freeChunks = append(freeChunks, p)
+	freeChunksLock.Unlock()
+}