From 5dbaf8371ca8216cb223df6424af95e671f27ed6 Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@redhat.com>
Date: Thu, 10 Oct 2013 13:08:04 +0100
Subject: [PATCH] [caching] start wiring up the discard bitset

---
 Makefile.in         |  1 +
 caching/metadata.cc | 13 +++++++++++++
 caching/metadata.h  |  3 +++
 3 files changed, 17 insertions(+)

diff --git a/Makefile.in b/Makefile.in
index e8117a0..e0ce06f 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -239,6 +239,7 @@ CACHE_CHECK_SOURCE=\
 	persistent-data/hex_dump.cc \
 	persistent-data/lock_tracker.cc \
 	persistent-data/data-structures/btree.cc \
+	persistent-data/data-structures/bitset.cc \
 	persistent-data/space_map.cc \
 	persistent-data/space-maps/disk.cc \
 	persistent-data/space-maps/recursive.cc \
diff --git a/caching/metadata.cc b/caching/metadata.cc
index 49e7a4d..0f9b82f 100644
--- a/caching/metadata.cc
+++ b/caching/metadata.cc
@@ -52,6 +52,7 @@ metadata::commit()
 	commit_space_map();
 	commit_mappings();
 	commit_hints();
+	commit_discard_bits();
 	commit_superblock();
 }
 
@@ -94,6 +95,8 @@ metadata::create_metadata(block_manager<>::ptr bm)
 
 	// We can't instantiate the hint array yet, since we don't know the
 	// hint width.
+
+	discard_bits_ = bitset::ptr(new bitset(tm_));
 }
 
 void
@@ -112,6 +115,10 @@ metadata::open_metadata(block_manager<>::ptr bm)
 		hints_ = hint_array::ptr(
 			new hint_array(tm_, sb_.policy_hint_size,
 				       sb_.hint_root, sb_.cache_blocks));
+
+	if (sb_.discard_root)
+		discard_bits_ = bitset::ptr(
+			new bitset(tm_, sb_.discard_root, sb_.cache_blocks));
 }
 
 void
@@ -133,6 +140,12 @@ metadata::commit_hints()
 	sb_.hint_root = hints_->get_root();
 }
 
+void
+metadata::commit_discard_bits()
+{
+	// FIXME: finish
+}
+
 void
 metadata::commit_superblock()
 {
diff --git a/caching/metadata.h b/caching/metadata.h
index 418d0e6..611b424 100644
--- a/caching/metadata.h
+++ b/caching/metadata.h
@@ -3,6 +3,7 @@
 
 #include "persistent-data/block.h"
 #include "persistent-data/data-structures/array.h"
+#include "persistent-data/data-structures/bitset.h"
 #include "persistent-data/endian_utils.h"
 #include "persistent-data/space-maps/disk.h"
 #include "persistent-data/transaction_manager.h"
@@ -37,6 +38,7 @@ namespace caching {
 		checked_space_map::ptr metadata_sm_;
 		mapping_array::ptr mappings_;
 		hint_array::ptr hints_;
+		bitset::ptr discard_bits_;
 
 	private:
 		void init_superblock();
@@ -47,6 +49,7 @@ namespace caching {
 		void commit_space_map();
 		void commit_mappings();
 		void commit_hints();
+		void commit_discard_bits();
 		void commit_superblock();
 	};
 };