38   Status Read(uint64_t offset, size_t n, Slice* result,  in Read()  argument
42       return file_->Read(offset, n, result, scratch);  in Read()
52     if (TryReadFromCache(offset, n, &cached_len, scratch) &&  in Read()
58     size_t advanced_offset = static_cast<size_t>(offset + cached_len);  in Read()
74   Status Prefetch(uint64_t offset, size_t n) override {  in Prefetch()  argument
83     size_t offset_ = static_cast<size_t>(offset);  in Prefetch()
98   Status InvalidateCache(size_t offset, size_t length) override {  in InvalidateCache()  argument
101     return file_->InvalidateCache(offset, length);  in InvalidateCache()
111   bool TryReadFromCache(uint64_t offset, size_t n, size_t* cached_len,  in TryReadFromCache()  argument
113     if (offset < buffer_offset_ ||  in TryReadFromCache()
114         offset >= buffer_offset_ + buffer_.CurrentSize()) {  in TryReadFromCache()
118     uint64_t offset_in_buffer = offset - buffer_offset_;  in TryReadFromCache()
128   Status ReadIntoBuffer(uint64_t offset, size_t n) const {  in ReadIntoBuffer()  argument
132     assert(IsFileSectorAligned(offset, alignment_));  in ReadIntoBuffer()
135     Status s = file_->Read(offset, n, &result, buffer_.BufferStart());  in ReadIntoBuffer()
137       buffer_offset_ = offset;  in ReadIntoBuffer()