[thin_show_dups] Support fractions of a pool block size

Makefile.in

@@ -75,6 +75,7 @@ SOURCE=\
 	thin-provisioning/cache_stream.cc \
 	thin-provisioning/chunk_stream.cc \
 	thin-provisioning/device_tree.cc \
+	thin-provisioning/fixed_chunk_stream.cc \
 	thin-provisioning/human_readable_format.cc \
 	thin-provisioning/mapping_tree.cc \
 	thin-provisioning/metadata.cc \

thin-provisioning/fixed_chunk_stream.cc

@@ -0,0 +1,113 @@
+#include "thin-provisioning/fixed_chunk_stream.h"
+
+using namespace thin_provisioning;
+
+//----------------------------------------------------------------
+
+fixed_chunk_stream::fixed_chunk_stream(chunk_stream &stream, unsigned chunk_size)
+	: index_(0),
+	  stream_(stream),
+	  chunk_size_(chunk_size),
+	  big_chunk_(0) {
+	next_big_chunk();
+}
+
+fixed_chunk_stream::~fixed_chunk_stream()
+{
+	put_big_chunk();
+}
+
+bcache::block_address
+fixed_chunk_stream::size() const
+{
+	return stream_.size();
+}
+
+void
+fixed_chunk_stream::rewind()
+{
+	// FIXME: not complete
+	index_ = 0;
+	stream_.rewind();
+}
+
+bool
+fixed_chunk_stream::next(bcache::block_address count)
+{
+	while (count--) {
+		index_++;
+		advance_one();
+	}
+
+	return !eof();
+}
+
+bool
+fixed_chunk_stream::eof() const
+{
+	return stream_.eof();
+}
+
+chunk const &
+fixed_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_.begin = little_b_;
+	little_chunk_.mem_.end = little_e_;
+
+	return little_chunk_;
+}
+
+void
+fixed_chunk_stream::put(chunk const &c)
+{
+	// noop
+}
+
+bool
+fixed_chunk_stream::next_big_chunk()
+{
+	put_big_chunk();
+
+	if (!stream_.next())
+		return false;
+
+	big_chunk_ = &stream_.get();
+	little_b_ = little_e_ = last_hashed_ = big_chunk_->mem_.begin;
+
+	return true;
+}
+
+bool
+fixed_chunk_stream::advance_one()
+{
+	uint8_t *big_e;
+
+	big_e = big_chunk_->mem_.end;
+	little_b_ = little_e_;
+
+	if (little_b_ >= big_e) {
+		if (next_big_chunk())
+			big_e = big_chunk_->mem_.end;
+		else
+			return false;
+	}
+
+	little_e_ += chunk_size_;
+	return true;
+}
+
+void
+fixed_chunk_stream::put_big_chunk()
+{
+	if (big_chunk_)
+		stream_.put(*big_chunk_);
+
+	big_chunk_ = 0;
+}
+
+//----------------------------------------------------------------

thin-provisioning/fixed_chunk_stream.h

@@ -0,0 +1,39 @@
+#ifndef THIN_PROVISIONING_FIXED_CHUNK_STREAM_H
+#define THIN_PROVISIONING_FIXED_CHUNK_STREAM_H
+
+#include "thin-provisioning/chunk_stream.h"
+
+//----------------------------------------------------------------
+
+namespace thin_provisioning {
+	class fixed_chunk_stream : public chunk_stream {
+	public:
+		fixed_chunk_stream(chunk_stream &stream, unsigned chunk_size);
+		~fixed_chunk_stream();
+
+		virtual bcache::block_address size() const;
+		virtual void rewind();
+		virtual bool next(bcache::block_address count = 1ull);
+		virtual bool eof() const;
+		virtual chunk const &get();
+		virtual void put(chunk const &c);
+
+	private:
+		bool next_big_chunk();
+		bool advance_one();
+		void put_big_chunk();
+
+		bcache::block_address index_;
+
+		chunk_stream &stream_;
+		unsigned chunk_size_;
+		chunk const *big_chunk_;
+
+		uint8_t *little_b_, *little_e_, *last_hashed_;
+		chunk little_chunk_;
+	};
+}
+
+//----------------------------------------------------------------
+
+#endif

thin-provisioning/thin_show_duplicates.cc

@@ -30,6 +30,7 @@
 #include "persistent-data/space-maps/core.h"
 #include "persistent-data/space-maps/disk.h"
 #include "thin-provisioning/cache_stream.h"
+#include "thin-provisioning/fixed_chunk_stream.h"
 #include "thin-provisioning/pool_stream.h"
 #include "thin-provisioning/commands.h"
 #include "thin-provisioning/device_tree.h"
@@ -54,7 +55,6 @@ using namespace thin_provisioning;
 
 namespace {
 	bool factor_of(block_address f, block_address n) {
-		cerr << n << " % " << f << "\n";
 		return (n % f) == 0;
 	}
 
@@ -145,6 +145,21 @@ namespace {
 
 	class duplicate_detector {
 	public:
+		void scan_with_variable_sized_chunks(chunk_stream &stream) {
+			variable_chunk_stream vstream(stream, 4096);
+			scan(vstream);
+		}
+
+		void scan_with_fixed_sized_chunks(chunk_stream &stream, block_address chunk_size) {
+			fixed_chunk_stream fstream(stream, chunk_size);
+			scan(fstream);
+		}
+
+		duplicate_counter const &get_results() const {
+			return results_;
+		}
+
+	private:
 		void scan(chunk_stream &stream) {
 			block_address total_seen(0);
 			auto_ptr<progress_monitor> pbar = create_progress_bar("Examining data");
@@ -164,17 +179,6 @@ namespace {
 			results_.display_results(stream);
 		}
 
-
-		void scan_with_variable_sized_chunks(chunk_stream &stream) {
-			variable_chunk_stream vstream(stream, 4096);
-			scan(vstream);
-		}
-
-		duplicate_counter const &get_results() const {
-			return results_;
-		}
-
-	private:
 		void examine(chunk const &c) {
 			if (all_zeroes(c))
 				results_.add_zero_duplicate(c.len_);
@@ -230,8 +234,16 @@ namespace {
 
 		if (fs.content_based_chunks)
 			detector.scan_with_variable_sized_chunks(pstream);
-		else
-			detector.scan(pstream);
+		else {
+			if (*fs.block_size) {
+				if (factor_of(*fs.block_size, block_size))
+					block_size = *fs.block_size;
+				else
+					throw runtime_error("specified block size is not a factor of the pool chunk size\n");
+			}
+
+			detector.scan_with_fixed_sized_chunks(pstream, block_size);
+		}
 
 		return 0;
 	}
@@ -254,7 +266,7 @@ namespace {
 		if (fs.content_based_chunks)
 			dd.scan_with_variable_sized_chunks(stream);
 		else
-			dd.scan(stream);
+			dd.scan_with_fixed_sized_chunks(stream, block_size);
 
 		return 0;
 	}