From 6b6f2290a74475bbdb7fb9a1d8fd4c04023596aa Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@redhat.com>
Date: Fri, 11 Oct 2013 10:03:51 +0100
Subject: [PATCH] [cache_dump/restore] add discards to the xml format

---
 caching/emitter.h          |  6 ++++++
 caching/restore_emitter.cc | 15 +++++++++++++++
 caching/xml_format.cc      | 37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 58 insertions(+)

diff --git a/caching/emitter.h b/caching/emitter.h
index 1563cdc..8a01d6c 100644
--- a/caching/emitter.h
+++ b/caching/emitter.h
@@ -37,6 +37,12 @@ namespace caching {
 
 		virtual void hint(pd::block_address cblock,
 				  std::vector<unsigned char> const &data) = 0;
+
+		virtual void begin_discards() = 0;
+		virtual void end_discards() = 0;
+
+		virtual void discard(pd::block_address dblock_begin,
+				     pd::block_address dblock_end) = 0;
 	};
 }
 
diff --git a/caching/restore_emitter.cc b/caching/restore_emitter.cc
index 787163c..6c862bf 100644
--- a/caching/restore_emitter.cc
+++ b/caching/restore_emitter.cc
@@ -78,7 +78,22 @@ namespace {
 
 		virtual void hint(pd::block_address cblock,
 				  vector<unsigned char> const &data) {
+			md_->hints_->set_hint(cblock, data);
+		}
 
+		virtual void begin_discards() {
+			// noop
+		}
+
+		virtual void end_discards() {
+			// noop
+		}
+
+		virtual void discard(block_address dblock, block_address dblock_e) {
+			while (dblock != dblock_e) {
+				md_->discard_bits_->set(dblock, true);
+				dblock++;
+			}
 		}
 
 	private:
diff --git a/caching/xml_format.cc b/caching/xml_format.cc
index 71b7823..b03e997 100644
--- a/caching/xml_format.cc
+++ b/caching/xml_format.cc
@@ -88,6 +88,24 @@ namespace {
 			     << "/>" << endl;
 		}
 
+		virtual void begin_discards() {
+			indent();
+			out_ << "<discards>" << endl;
+			inc();
+		}
+
+		virtual void end_discards() {
+			dec();
+			indent();
+			out_ << "</discards>" << endl;
+		}
+
+		virtual void discard(block_address dblock_b, block_address dblock_e) {
+			indent();
+			out_ << "<discard dbegin=\"" << dblock_b << "\""
+			     << " dend=\"" << dblock_e << "\"/>" << endl;
+		}
+
 	private:
 		string as_truth(bool v) const {
 			return v ? "true" : "false";
@@ -196,6 +214,12 @@ namespace {
 		e->hint(cblock, get<vector<unsigned char> >(doe));
 	}
 
+	// FIXME: why passing e by ptr?
+	void parse_discard(emitter *e, attributes const &attr) {
+		e->discard(get_attr<uint64_t>(attr, "dbegin"),
+			   get_attr<uint64_t>(attr, "dend"));
+	}
+
 	void start_tag(void *data, char const *el, char const **attr) {
 		emitter *e = static_cast<emitter *>(data);
 		attributes a;
@@ -217,6 +241,12 @@ namespace {
 		else if (!strcmp(el, "hint"))
 			parse_hint(e, a);
 
+		else if (!strcmp(el, "discards"))
+			e->begin_discards();
+
+		else if (!strcmp(el, "discard"))
+			parse_discard(e, a);
+
 		else
 			throw runtime_error("unknown tag type");
 	}
@@ -241,6 +271,13 @@ namespace {
 			// do nothing
 			;
 
+		else if (!strcmp(el, "discards"))
+			e->end_discards();
+
+		else if (!strcmp(el, "discard"))
+			// do nothing
+			;
+
 		else
 			throw runtime_error("unknown tag close");
 	}