1 files changed, 69 insertions, 0 deletions
diff --git a/weed/mount/page_writer/page_chunk_mem.go b/weed/mount/page_writer/page_chunk_mem.go
new file mode 100644
index 000000000..dfd54c19e
--- /dev/null
+++ b/weed/mount/page_writer/page_chunk_mem.go
@@ -0,0 +1,69 @@
+package page_writer
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/util"
+	"github.com/chrislusf/seaweedfs/weed/util/mem"
+)
+
+var (
+	_ = PageChunk(&MemChunk{})
+)
+
+type MemChunk struct {
+	buf             []byte
+	usage           *ChunkWrittenIntervalList
+	chunkSize       int64
+	logicChunkIndex LogicChunkIndex
+}
+
+func NewMemChunk(logicChunkIndex LogicChunkIndex, chunkSize int64) *MemChunk {
+	return &MemChunk{
+		logicChunkIndex: logicChunkIndex,
+		chunkSize:       chunkSize,
+		buf:             mem.Allocate(int(chunkSize)),
+		usage:           newChunkWrittenIntervalList(),
+	}
+}
+
+func (mc *MemChunk) FreeResource() {
+	mem.Free(mc.buf)
+}
+
+func (mc *MemChunk) WriteDataAt(src []byte, offset int64) (n int) {
+	innerOffset := offset % mc.chunkSize
+	n = copy(mc.buf[innerOffset:], src)
+	mc.usage.MarkWritten(innerOffset, innerOffset+int64(n))
+	return
+}
+
+func (mc *MemChunk) ReadDataAt(p []byte, off int64) (maxStop int64) {
+	memChunkBaseOffset := int64(mc.logicChunkIndex) * mc.chunkSize
+	for t := mc.usage.head.next; t != mc.usage.tail; t = t.next {
+		logicStart := max(off, int64(mc.logicChunkIndex)*mc.chunkSize+t.StartOffset)
+		logicStop := min(off+int64(len(p)), memChunkBaseOffset+t.stopOffset)
+		if logicStart < logicStop {
+			copy(p[logicStart-off:logicStop-off], mc.buf[logicStart-memChunkBaseOffset:logicStop-memChunkBaseOffset])
+			maxStop = max(maxStop, logicStop)
+		}
+	}
+	return
+}
+
+func (mc *MemChunk) IsComplete() bool {
+	return mc.usage.IsComplete(mc.chunkSize)
+}
+
+func (mc *MemChunk) WrittenSize() int64 {
+	return mc.usage.WrittenSize()
+}
+
+func (mc *MemChunk) SaveContent(saveFn SaveToStorageFunc) {
+	if saveFn == nil {
+		return
+	}
+	for t := mc.usage.head.next; t != mc.usage.tail; t = t.next {
+		reader := util.NewBytesReader(mc.buf[t.StartOffset:t.stopOffset])
+		saveFn(reader, int64(mc.logicChunkIndex)*mc.chunkSize+t.StartOffset, t.Size(), func() {
+		})
+	}
+}