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() { }) } }