// writes block/offset locations for all events
// associated with the given index to the file
// in timestamp descending order.
// Marks the event with which block it's located in,
// as well as the offset within the block.
func writeIndexBlocks(i *index, out io.Writer) {
sort.Stable(sort.Reverse(i.evs))
writer := blocks.NewWriter(out, 4096)
for _, event := range i.evs {
// Each entry in the index is
// the block the event is located in,
// and the offset within the block.
binary.WriteInt64(writer, event.block)
binary.WriteInt16(writer, event.offset)
}
// Mark the end of the grouping's events with an empty event.
writer.Write([]byte{0})
writer.Flush()
i.length += int64(writer.Written)
}
// writes all events associated with the given
// grouping to the file in timestamp descending order.
// Marks the event with which block it's located in,
// as well as the offset within the block.
func writeEventBlocks(i *index, out io.Writer) {
sort.Stable(sort.Reverse(i.evs))
writer := blocks.NewWriter(out, 4096)
for _, event := range i.evs {
// mark event with the current location in the file.
event.block = i.offset + int64(writer.Written)
event.offset = writer.Buffered()
// push the encoded event onto the buffer.
event.push(writer)
}
// Mark the end of the grouping's events with an empty event.
writer.Write([]byte{0})
writer.Flush()
i.length += int64(writer.Written)
}