[caching] hint support

2013-09-24 12:00:09 +01:00
parent 2e58332e49
commit 17f7c982f2
6 changed files with 192 additions and 6 deletions
--- a/caching/hint_array.cc
+++ b/caching/hint_array.cc
@ -0,0 +1,147 @@
+#include "caching/hint_array.h"
+
+using namespace boost;
+using namespace caching;
+using namespace persistent_data;
+
+//----------------------------------------------------------------
+
+namespace {
+	using namespace caching::hint_array_detail;
+
+	// We've got into a bit of a mess here.  Templates are compile
+	// time, and we don't know the hint width until run time.  We're
+	// going to have to provide specialisation for all legal widths and
+	// use the appropriate one.
+
+#define all_widths \
+	xx(4); xx(8); xx(12); xx(16); xx(20); xx(24); xx(28); xx(32);\
+	xx(36); xx(40); xx(44); xx(48); xx(52); xx(56); xx(60); xx(64); \
+	xx(68); xx(72); xx(76); xx(80); xx(84); xx(88); xx(92); xx(96); \
+	xx(100); xx(104); xx(108); xx(112); xx(116); xx(120); xx(124); xx(128);
+
+	template <uint32_t WIDTH>
+	shared_ptr<array_base> mk_array(transaction_manager::ptr tm) {
+		typedef hint_traits<WIDTH> traits;
+		typedef array<traits> ha;
+
+		shared_ptr<array_base> r = typename ha::ptr(new ha(tm, typename traits::ref_counter()));
+
+		return r;
+	}
+
+	shared_ptr<array_base> mk_array(transaction_manager::ptr tm, uint32_t width) {
+		switch (width) {
+#define xx(n)	case n:	return mk_array<n>(tm)
+
+			all_widths
+#undef xx
+		}
+
+		// never get here
+		return shared_ptr<array_base>();
+	}
+
+	//--------------------------------
+
+	template <uint32_t WIDTH>
+	shared_ptr<array_base> mk_array(transaction_manager::ptr tm, block_address root, unsigned nr_entries) {
+		typedef hint_traits<WIDTH> traits;
+		typedef array<traits> ha;
+
+		shared_ptr<array_base> r = typename ha::ptr(new ha(tm, typename traits::ref_counter(), root, nr_entries));
+
+		return r;
+	}
+
+	shared_ptr<array_base> mk_array(transaction_manager::ptr tm, uint32_t width, block_address root, unsigned nr_entries) {
+		switch (width) {
+#define xx(n)	case n:	return mk_array<n>(tm, root, nr_entries)
+			all_widths
+#undef xx
+		}
+
+		// never get here
+		return shared_ptr<array_base>();
+	}
+
+	//--------------------------------
+
+	template <uint32_t WIDTH>
+	void get_hint(shared_ptr<array_base> base, unsigned index, vector<unsigned char> &data) {
+		typedef hint_traits<WIDTH> traits;
+		typedef array<traits> ha;
+
+		shared_ptr<ha> a = dynamic_pointer_cast<ha>(base);
+		if (!a)
+			throw runtime_error("internal error: couldn't cast hint array");
+
+		data = a->get(index);
+	}
+
+	void get_hint_(uint32_t width, shared_ptr<array_base> base, unsigned index, vector<unsigned char> &data) {
+		switch (width) {
+#define xx(n) case n: return get_hint<n>(base, index, data)
+			all_widths
+#undef xx
+		}
+	}
+
+	//--------------------------------
+
+	template <uint32_t WIDTH>
+	void set_hint(shared_ptr<array_base> base, unsigned index, vector<unsigned char> const &data) {
+		typedef hint_traits<WIDTH> traits;
+		typedef array<traits> ha;
+
+		shared_ptr<ha> a = dynamic_pointer_cast<ha>(base);
+		if (!a)
+			throw runtime_error("internal error: couldn't cast hint array");
+
+		a->set(index, data);
+	}
+
+        void set_hint_(uint32_t width, shared_ptr<array_base> base,
+		      unsigned index, vector<unsigned char> const &data) {
+		switch (width) {
+#define xx(n) case n: return set_hint<n>(base, index, data)
+		all_widths
+#undef xx
+		}
+	}
+}
+
+//----------------------------------------------------------------
+
+hint_array::hint_array(tm_ptr tm, unsigned width)
+	: width_(width),
+	  impl_(mk_array(tm, width))
+{
+}
+
+hint_array::hint_array(typename hint_array::tm_ptr tm, unsigned width,
+		       block_address root, unsigned nr_entries)
+	: width_(width),
+	  impl_(mk_array(tm, width, root, nr_entries))
+{
+}
+
+block_address
+hint_array::get_root() const
+{
+	return impl_->get_root();
+}
+
+void
+hint_array::get_hint(unsigned index, vector<unsigned char> &data) const
+{
+	get_hint_(width_, impl_, index, data);
+}
+
+void
+hint_array::set_hint(unsigned index, vector<unsigned char> const &data)
+{
+	set_hint_(width_, impl_, index, data);
+}
+
+//----------------------------------------------------------------