[thin_show_dups] variable_chunk_stream

thin-provisioning/variable_chunk_stream.cc

@@ -0,0 +1,152 @@
+#include "thin-provisioning/variable_chunk_stream.h"
+
+using namespace boost;
+using namespace std;
+using namespace thin_provisioning;
+
+//----------------------------------------------------------------
+
+variable_chunk_stream::variable_chunk_stream(chunk_stream &stream, unsigned window_size)
+	: index_(0),
+	  h_(window_size),
+	  stream_(stream),
+	  big_chunk_(0) {
+	next_big_chunk();
+}
+
+variable_chunk_stream::~variable_chunk_stream()
+{
+	put_big_chunk();
+}
+
+void
+variable_chunk_stream::rewind()
+{
+	// FIXME: not complete
+	index_ = 0;
+	stream_.rewind();
+	h_.reset();
+}
+
+bool
+variable_chunk_stream::next(bcache::block_address count)
+{
+	while (count--) {
+		index_++;
+		advance_one();
+	}
+
+	return !eof();
+}
+
+bool
+variable_chunk_stream::eof() const
+{
+	return stream_.eof();
+}
+
+bcache::block_address
+variable_chunk_stream::index() const
+{
+	return index_;
+}
+
+chunk const &
+variable_chunk_stream::get()
+{
+	assert(big_chunk_);
+
+	little_chunk_.len_ = little_e_ - little_b_;
+	little_chunk_.offset_ = big_chunk_->offset_ + little_chunk_.len_;
+
+	little_chunk_.mem_.clear();
+	little_chunk_.mem_.push_back(mem(little_b_, little_e_));
+
+	return little_chunk_;
+}
+
+void
+variable_chunk_stream::put(chunk const &c)
+{
+	// noop
+}
+
+bool
+variable_chunk_stream::next_big_chunk()
+{
+	put_big_chunk();
+
+	if (!stream_.next())
+		return false;
+
+	big_chunk_ = &stream_.get();
+	little_b_ = little_e_ = big_chunk_->mem_.front().begin;
+	h_.reset();
+
+	return true;
+}
+
+bool
+variable_chunk_stream::advance_one()
+{
+	uint8_t *big_e;
+
+	assert(big_chunk_);
+
+	big_e = big_chunk_->mem_.front().end;
+	little_b_ = little_e_;
+
+	if (little_b_ == big_e) {
+		if (next_big_chunk())
+			big_e = big_chunk_->mem_.front().end;
+		else
+			return false;
+	}
+
+	assert(little_e_ >= big_chunk_->mem_.front().begin);
+	assert(little_b_ >= big_chunk_->mem_.front().begin);
+#if 1
+	if (little_e_ > big_e) {
+		cerr << "before -- little_e_: " << (void *) little_e_ << ", big_e: " << (void *) big_e << "\n";
+	}
+#endif
+	assert(little_e_ <= big_e);
+	assert(little_b_ <= big_e);
+
+
+	while (little_e_ != big_e) {
+		optional<unsigned> maybe_break = h_.step(*little_e_);
+
+		if (maybe_break) {
+			// The break is not neccessarily at the current
+			// byte.
+			little_e_ = little_b_ + *maybe_break;
+			break;
+		}
+
+		little_e_++;
+	}
+
+	assert(little_e_ >= big_chunk_->mem_.front().begin);
+	assert(little_b_ >= big_chunk_->mem_.front().begin);
+#if 1
+	if (little_e_ > big_e) {
+		cerr << "after -- little_e_: " << (void *) little_e_ << ", big_e: " << (void *) big_e << "\n";
+	}
+#endif
+	assert(little_e_ <= big_e);
+	assert(little_b_ <= big_e);
+
+	return true;
+}
+
+void
+variable_chunk_stream::put_big_chunk()
+{
+	if (big_chunk_)
+		stream_.put(*big_chunk_);
+
+	big_chunk_ = 0;
+}
+
+//----------------------------------------------------------------